Research Note 86-37

TRANSFER OF MOVEMENT CONTROL IN MOTOR SKILL LEARNING

Richard A. Schmidt and Douglas E. Young

* I Motor Control Laboratory

Department of Kinesiology

University of California, Los Angeles

Contracting Officer's Representative

Judith Orasanu

DTIOc

SELECT

BASIC RESEARCH0

Milton S. Katz, Director

geeac Institute for the Behavioral and Social Sciences

April 1986

Approved for public release; distribution unlimited.

S6 5 3 of--
/ Unclassified A

READ INSTRUCTIONS

REPORT DOCUMENTATION PAGE BEFORE COMPLETING FORM

is REPORT NUMBER 12. GOVT ACCESSION NO. 3. RECIPIENT'S CATALOG NUMBER

ARI Research Note 86-37

4. TITLE (and Stabillo) S. TYPE OF REPORT & PERIOD COVERED

Transfer of Movement Control in Motor Skill Jan 86 Apr 86

Learning FINAL

6. PERFORMING ORG. REqORT NUMBER

7. AUTHOR(*) S. CONTRACT OR GRANT NUMBER(e)

Richard A. Schmidt and Douglas E. Young MDA 903-85..K-0225

PERFORMING F ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT. TASK

AREA & WORK UNIT NUMBERS

Motor Control Laboratory

Department of Kinesiology 2Q161102B74F

UCIA,Los Angeles, CA 90024

It. CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT OAT

Army Research Institute for the Social and April 1986

Behavioral Sciences 1s. NUMBER OF PAGES

5001 Eisenhower Ave., Alexandria, VA 22333-5600 60 14. MONITORING AGENCY N AME A ADDRESSif different frm Controlling Office) IS. SECURITY CLASS. (Of this r• e.po porl) 

Unclassified

IS. DECLASSIFICATION/DOWNGRADING

SCHEDULE

I. DISTRIBUTION STATEMENT (of chiE Report)

Approved for public release; Distribution unlimited.

17. DISTRIBUTION STATEMENT (ot th. abstract efnered In block 20, It differntf from Report)

IS. SUPPLEMENTARY NOTES

Schmidt, R.A., & Young, D.E. (1986). Transfer of movement control in motor

skill training. In Cormier, S.M., & Hagman, J.D. (Eds.), Transfer of

Learning. Orlando: Academic Press.

COR: J. Orasanu

It. KEY WORDS (Continu. on reverse ad necesary and Identify by bloc& number)

Movement control feedback bilateral transfer

transfer of learning motor program part-whole transfer

motor behavior movement specificity negative transfer

deafferation practice interference

20. A TACT (ra_.4mu s m to"- .44 Of n* .m ad Idntimft by block ntixb.)r

This chapter is concerned with transfer of learning in situations

involving the kinds of responses that are defined primarily as motor behaviors.

The authors focus on situations where movement control is learned and

transferred to some other situation. Complimentary treatments of the motor

and cognitive bases of transfer are offerred. Definitional and experimental

design questions surrounding transfer are discussed as are a number of

important principles of motor behavior and motor control which habe emerged

in the past few decades. Principles of movement control are also discussed

D O PIJ 1473 EDITION OF I NOV 6% IS OBSOLETE nr1i4fo

SECURITY CLASSIFICATION OF TNIS PAGE (Wlr-. Deco Enteed)

- ~~~~~~~~~~~~~............................ ....-...... _.. ... ..-.....................-.... ,.. ... .....-. ,". .- . ..-. ... .. . . ,.
-61 ---.....

Unclassified

SECURITY CLASSIVICATIOW OF T041S PAGE(Wn Doe MAlove4)

A1RI Research Note 8'6-37 -in terms of understanding some of the phenomena seen in transfer of learning situations.

S. U I

',.cesjon For

U!:annoc

..................................

Dial, ito!1 ... ~~. ...... . . . . . . . . . .

....

Unclassified - . IF . ~SECURITY CLASS gI CATION Of -4Sl~ p G~ 7. Dome Em o .
-ulrL&"%R F -. AF .Mf% lp rp -I TV n LrVV' ' rX ' wVUmm d vxw ww W -v -1 -.- - RX -U w,', PainN

DISCLAIMER NOTICE

THIS DOCUMENT IS BEST QUALITY

PRACTICABLE. THE COPY FURNISHED

TO DTIC CONTAINED A SIGNIFICANT

NUMBER OF PAGES WHICH DO NOT

REPRODUCE LEGIBLY.

,.4

-.--

I-. "

* °.

.'.°%

'V.-.....................-.. . . . . . . .....
VVWT IN

U. S. ARMY RESEARCH INSTITUTE

FOR THE BEHAVIORAL AND SOCIAL SCIENCES

A field Operating Agency under the Jurisdiction of the

* Deputy Chief of Staff for Personnel

WM. DARRYL HENDERSON

*EDGAR M. JOHNSON COL, IN

Technical Director Cmadn

Research accomplished under contract

for the Department of the Army

Motor Control Laboratory

* Department of Kinesiology

* University of California, Los Angeles

* Technical Review by

Steve Kronheim%

This report. as submitted by the contractor, has been cleared tot release to Defense Technical Inf ofmation Center

(DTIC) to comply with regulatory requirements. It has been given no primary distribution othet than to DTIC

and will be available only through DTIC of other reference services such as the National Technical Information

Service (NTIS). The vicws. opinitno. and/or findings contained in this report are those of the author (si and

should not be constru.4 as an officiao (Depaitment of the Army position. policy. or decision. unless so designated

by other official documentation.

-2.
11,01 - wF-L- -.- ... .-. % .. "-. .. . 4.. --...--.-. .r.. . . .

I Transfer of Motor Control 1

Certainly one important concern for any examination of the phenomenon

of human learning--and of the aspects of learning concerned with transfer

discussed in this volume--is the area of skilled motor behavior and its

acquisition. It is, of course, extremely difficult to provide a simple

distinction between those aspects of human functioning that we would

w ,sr t-' term "motor" and "non-motor," and yet on a more superficial level

these divisions of numan responding are generally understood oy most

stJorr of human learning. The diffcultv is that every "motor" resoonse

'evce oerhaps for the most simple of laboratory reflexes) nas components

..,, are oerceptual-cognitive in nature, with some degree of

aecision-making invariably being required. On the other side, even the most

"coonitive" of tasks necessarily involves a movement of some sort in order

hat the subject convey a response to tne experimenter (a button press, or

verbal report).

Nevertheless, it still makes sense to consider a motor/non-motor

dlichotomy, if by it we can agree to mean that "motor" tasks are those for

which the primary problem for the responder is to determine how to

produce a givt action which is clearly specified by instructions and/or

stimulus materials, rather than to determine which of a number of

*Pev': e''ly learned ,actions is to be produced when a particular stimulus

situation is encountered. This focus on "motor" behavior emphasizes how %

the Derformer controls his/her limbs in particular ways that we term

sK'leo (piano playing, pole vaulting, etc.), where the precise patterning of

rnscie forces and their timing are the primary determinants of success, "

in-a wrhere decision making and the choice among patterns of activity are

minimized. Thus, motor behavior involves situations in which the learner's

problem is "how to do it" rather than "what to do" (Schmidt, 1982).

This chapter is concerned with transfer of learning in situations
Transfer of Motor Control 2

involving the kinds of responses that we nave defined here as primarily

motor behaviors. Specifically, we have focused on situations where

movement control is learned and transferred to some other situation,

where such evidence often gives insight into the nature of the

representations that were learned and transferred. We have deliberately

deemohaszed literature and ideas that are concerned with the transfer of

pe...e t"', cognitive, or information-processing capabilities, as these are

emphasized beautifully by Cormier (this volume). Our two chapters here

can be :een as providing complimentary treatments of the motor and

coanitive Dases of transfer (see also Lintern, 1985).

After a treatment of some important efinitional and experimental

design questions surrounding transfer, we turn to a discussion of a number

of important principles of motor behavior and motor control which have

emerged in the past few decades, and which have been generated in

experimental settings where transfer of learning has not been the primary

focus. In later sections of the chapter, we discuss how some of these

principles of movement control can perhaps help us to understand some of

the phenomena seen in transfer of learning situations. Earlier analyses of

transfer in motor situations has not had the benefit of these newer

insights into movement control, and adding them here appears to contribute

consi-eraclv (although tentatively) to our understanding of transfer.

Transfer. Some Delinitlonal Issues

Transfer of learning is usually defined as the gain (or loss) in the

caoability for responding in one task (termed the criterion task) as a

function of practice or experience on some other task(s) (the transfer

tasks) As such, transfer becomes involved when we want to understand

how tasks contribute to, or interact with, each othier in training situations,

and it forms the basis of understanding such situations as those involving

the use of simulators for learning some complex and expensive criterion
Transfer of Motor Control 3

task (e g., piloting a 747), the use of various training strategies (e.g.,

lead-up activities), and the intelligent design of effective environments

for maximizing learning. Here, the focus is on how learning one task

affects the performance capability of another task.

Problems in Defining a "Task"

But the field of transfer has a definitional problem, as can be readily

-en when one tries to define precisely what is meant by saying that a

given task is different from some other task. Consider pairs of activities

such as (a) throwing a ball 20 m versus 25 m, or (b) skiing in bright

.u..iiht versus in dark clouds. Do these pairs represent different tasks, or

rerely variations of the "same" task? We can (and often do) arbitrarily

aefine two "tasks" by altering relatively minor goal requirements (distance -.-..

thrown) or the conditions under which the tasks are performed (lighting

conditions). But, it should also be clear that one can progressively change

these conditions along various continua so that, beyond some point, we

would all readily agree that there nave indeed been two "tasks" formed by

such alterations (e.g., throwing 2 m versus throwing 100 m).

We can carry this extension somewhat further. If it can be argued that

minor variations in an activity (e.g., distance thrown) produce two

different tasks, then the same can be said for variations in behavior which

occur "naturally" in the course of learning to throw an object, say, exactly

30 in. Because of our inevitable variability in such actions, some of the

throws will be too long, others too short, and we must according to this

argument consider each of these throws as examples ot "different" tasks.

And, it is well known that the structure of the underlying abilities shifts

somewhat with practice (e.g., Fleishman & Hempel, 1955; Schmidt, 1982),

which makes it possible to say that the task is "different" (in terms of its

factorial structure) in early practice than it is in late practice. If so, then

a Performance of a given Trial n of some motor task is dependent on the
Transfer of Motor Control 4

transfer from Trial n- I and all previous trials.

Implications for Understanding Learning

This realization, for us at least, carries with it important implications

for the study of learning and transfer. If this analysis is correct, then

many earlier approaches in which the transfer of learning was considered

as a particular category of learning, with its own laws, experimental

designs, and spaces alloted in textbooks, is not particularly aefensiDle.

Rather, our view implies that transfer and learning are, in the final P.

analysis, essentially indistinguishable, and that we should be careful about

sear:hing for the principles of transfer as if they were in some way

distinct from those of learning. Later, we will present a number of

examples which should make this issue more clear.

The Learning-Performance Distinction

These ideas about the similarity of learning and transfer have strong

implications for how transfer (and hence learning) is studied. First, recall

that transfer was defined as the gain (or loss) in the capability for

responding in the criterion task as a result of practice or experience on

iome other task(s). The emphasis here on the capability for responding is

exactly parallel to the emphasis in the study of learning, in which the old

distinction (e.g., Hull, 1943, Guthrie, 1952) between learning and

performance figures heavily (see also Schmidt, 1982) Here, the notion is

that many variables influnece performance only temporarily (e.g., fatigue,

druas, "moods," and so on), the effects disaDpearinq as soon as the variable

is removed, these influences should probably not be thought of as learning.

As a result, often elaborate designs are employed, in which subjects who

performed under different levels of an indepenaent variable in the

acquisition phase are switched after a rest to the same "task," but with a

common level of the independent variable. On such a test, the temporary

performance effects should disappear, leaving behind the relatively .- '
Transfer of Motor Control 5

permanent effects that we wish to attribute to learning.

The same concern can be applied to studies of transfer. Many

variations of transfer tasks can influence the performance on a criterion

task, some of which are temporary and others "relatively permanent." As a

result, many of the same concerns for the learning versus performance

effects of independent variables are also present in traditional transfer

situations, and the same cautions should be raised about the

interpretations of the results, especially when one wants to understand the

transfer of the underlyinq capabilities for performance. This issue further

hichlights tre difficulties in distinguishing transfer from learning,

Some Fundamental Principles of Motor Behavior and Control

Consistent with the idea that the goal of transfer research is to

understand the nature of what is learned and transferred, we have found it

useful to try to bring some of the recent findings and thinking in the area

of movement control and learning--which recently has focused on the

underlying representations for actions--to bear on the problems of

movement transfer. In the next few sections, we turn to a discussion of

some of these ideas and principles which have emerged from the literature

on movement control. Following this, we turn to a discussion of how these

concepts might help us to understand some of the common transfer findings

for movement situations.

Motor Programs

One of the most important ideas in motor control for the past 70 years

or so has been the idea that (at leabt some) movements are controlled

primarily open-loop, with a centrally "stored" structure (a motor progrm)

responsible for the grading, timing, and coordination of the muscular

activities needed to produce skilled movement behavior The

motor-program idea has had many forms, each with its own share of

critics, and it is difficult to characterize in a simple way all of the various ...
Transfer of Motor Control 6

notions that come under this banner But there are a few features which

serve to define these kinds of ideas reasonably well. Three lines of

evidence comDel us to take the notion of motor programs seriously

First, very old (Lashley, 1917) ana more recent (Taub & Berman, 1968)

evidence on deafferentation has h.wn that movements are certainly

ossible without sensory informat'on from the responding limn. Some

movements, such as climbing, SW-r) , and groorn.g Dehavr_ ln .. monkeys

tend to be controlled rather well w'thout this feedback, whereas others Wk

uch as fine finqer movements . -n 3 ather serious aisru-tions But the

--Ocr point :s not how muh ',. .;re disrupted, rather, the important

fn'n,,g is that some movement can: occcr at all. If so, then a larae class of

moaets emphasizing chaining of reccnses to feedback proauced from a

Dror ,part of the chain (e.g., James, 1890), or strictly closed-loop models

based on error-nuiling (Adams, 1971), are weakened considerably. At the

same time, these findings support the notion that some central

e -resentation, not atslutely dependent on resoonse-produced feedback, is

reSpor, sible for the action.

A second line of evidence is that sensory information processing has

.. en considered to be too slow to be an effective basis for controlling the

moment-to-moment phenomena seen in at least rapid movement control.

ystems which use reonnn-Dr'c feedback are very sensitive to

fee.ccck delays, and will oscillate uncontrollably if the feedback delays J,

are toD lonq (particilariy if the 2in cf rie feedback loop is large) As such,

wrile response-produced sensory mnf:rration undoubtedly plays a role in

Slo;er, ongoing movements (e g st e erq a car), is is unlikely that quick

responses can be controlled in this way onsideracle evidence shows that,

when the subject is suddenly and unexpe:tedly asked to change a movement

in proqress (Henry & Harrison, 1 95 ), or to abort it completely (Logan,

1932, Slater-Hammel, 1 960), ap rcvr,, ,-tely 200 ms can elapse before any

. . . . .- ................. ..........-...- '. --
Transfer of Motor Control 7

changes can be seen in the movement. Presumably, the movement is being

controlled by some motor program in the mean time.

Such a concept is further strengthened by the findings of Wadman, -

Denier van der Gon, Geuze, and Mol (1979; Shapiro & Walter, 1 982) with

quick limb movements. In Fiqure I are EMG records from one of their

experiments in which the sub,,ect made a quick elbow-shoulder extension

movement to a new position sore 13 cm away Thje trace laeeeJ Normal

snows the patterning of EMGs during the normal conauct of tis action,

revealing a distinct temDorai -:ructure in which the aaonist is 3-clve for

about 100 ms, followed by the anticonist activity, with the aconst acting

-again near the end of the movement. A feedback-based view of control of

such actions argues that this atterning is determined by the sensory

mnformation from the responding limb switching the muscles off and on1.

Sut Wadman et al. also used a condition in which the limb was unexcectedly .

mechanically blocked, so that no movement could occur, and the EMGs for

* ese trials are shown as the trace labeled Blocked. Here, we see that the

E1G Datterns are essentially identical for the first 100 ms or so, and then

begin to be modified (presumably reflexively) during the later portion of

.ne action. The important point here, in our view, is that the antaqonist

muscle is switched on at the prooer time, even though the feedback from

the 'responding" limb must have been massivelv disrupted. This suggests

that the patterning of the EMs was stuctured before the action, and was;

carried out open-loop, at least for a while until the reflexive activities

could begin to have an influence.

-!Ir I about here

A third lire of evluen.lCe * b from a reaction-time (RT) analysls of id

7 movements begun by Henry and Pocers (i 960). Here, the RT for a movement

*.-erends on the cotlexity of tre response that ,s to be made 5ince the

PT measurement begins when the stimulus appears, and ends when the
... •.-., 1.. .. T .r. . . . . . . . . . .

Transfer of Motor Control a .,

movement begins, it was difficult to understand how RT (which occurs

before the movement) could be affected by something that occurred later

(i.e,, movement complexity). This result is generally understood by

assuming that the motor system is organized (during a response

proqramming substage of RT) to proauce the movement, and that more

co pIex movements require more time for such processes to occur.

'e ,.ibcK involvement. Original statements of the program view (e.g.,

Lasnley, 19 17), and even more recent ones (e.g., Keele, 1968), have been too

* rn in insisting that the movement control be strictly open-loop, with

essenta!ly no involvement from peripheral feedback. Evidence has always

f 'ed _ feedback control in slower movements, and more recent evidence

su, ests considerable feedback involvement in movement control even in

qU,.r.er actions. For example, there is now strong evidence of spindle

contriLutions to the fine details of an ongoing response, and that these

acti-vities may be responsible for such important features as

•,... ations for unexpected loads (Dewhurst, 1967) or the maintenance

of important mechanical (spring-like) properties of muscle (Crago, Houk, &

Hasan, 1976). Recent work also suggests that vision can operate far more

quickly than we had believed earlier (Zelaznik, Hawkins, & Kisselburgh,

1983) And, Forssberg, Grillner, and Rossignol (1975) found that a given

stimulus presented during locomotion (e.g., a tap on the top of a cat's foot) -V

leaas to a completely different response depending on the phase of the step

cYcle in which the stimulus is delivered. Analogous findings have been

found recently in speech motor control by Abbs (1984) and Kelso, Tuller,

Vatdkoitis-Bateson, and Fowler (1984) These so-called "reflex reversals"

can ,e interpreted to mean that the program, in addition to controlling

commands to musculature, is also involved in the "choice" of various reflex

pathways. Presumably, this ensures that particular subgoals of the action

during that phase are carried out faithfully if the limb is perturbed.

*: , . ..-. . . .. . . .. .
a- --. -- - - - - - - - ----

Transfer of Motor Control 9

But it should also be pointed out that these results do not detract in

any important way from the idea that some central representation of the

action is the basis for action, and that feedback can interact with this

central structure in a variety of ways. Under consistent movement

situations, where the peripheral influences are presumably predictable or

absent, the central representation could assume a particularly dominant - -

ro e in movement producftion. Understanding the relationsip between these

central and peripheral influences in movement control has become one of

the most irnoortant -"2t'c ,of motor control work recently.

Summarv. Overall, the dominant idea is that at least quick movements

are orgainized in advance, with some central representation defining the

muscular activities that are to occur, and then this action is initiated and

carried out aided by slight involvement from response-produced feedback.

Current thinking is that some oscillator-like neural network (motor

proqram, coordinative structure, central pattern generator, etc.) is

activated, and that the ryhthmic properties of this structure are

responsible for the timing of the various phases of the movement, with this

control lasting for perhaps 1 s, or longer (Shapiro, 1978).

Generalized Motor Programs

Recent concerns about movement control focused on the fact that the

motor program idea seemed to require that each movement that is to be

made have a separate motor program to control it. This loads to logical

problems concerning where so many programs could be stored, and how

individuals could ever produce a novel movement (Schmidt, 1975, 1976,

1982) Various attempts to save the attractive features of movement

programs discussed above, while addressing these storage and novelty

problems, resulted in various ways of considering programs as generalized

across a particular class of movements.

Rate parameters. For many of us, the first suggestion of this idea came

A-. . * * * -. - .. . : ..- ~-* - ,*.-*. * *. ° ,*
_U -it iJ17rT.1V.F V. _vJJV'. 1n W'WIFL W ~-~ mc AMTruL fly v 

Transfer of Motor Control 10

from Armstrong's (1970) experiment in which the subject learned a

complex pattern of arm movement defined in both space and time, as most

- movements are. In Figure 2, the goal pattern is shown as the solid line, and

* a movement that happened to end too early is shown as the dotted trace.

Armstrong's observation was that, when this movement occurred too

quickly, the whole movement tended to be sped up as a unit. Notice that the

dotted trace leads the solid one by only 90 ms at the first peak, by 230 ms

at the trough (downward "peak"), and by 620 ms at the third peak. This was

" consistent with the idea that the entire movement was sped u: essentially

proportionally. More importantly, it suggested that the movement might be

represented as some abstract temporal structure, but that it could be

produced on any particular trial by selecting a rate parameter to define the

particular movement time, the temporal structure remaining invariant.

Figure 2 gbout here.

Relative timing. Important to this idea was the identification of some

invariant feature of the action--a feature which remained essentially

constant while other features (e.g., overall movement time) were changing

markedly (Schmidt, 1985a). One such feature has been termed relative

timing, which is a measure of the overall temporal structure of the action.

Invariant relative timing means that the proportion of the movement time

devoted to some segment of the movement (e.g., the time from the first

peak until the second) remains constant while th: ;,ovement time changes.

To a rough approximation, this invariance seem to be present, as this value

is (2.94-.75)/3.59,.61 for the solid trace, and (2.28-.66)/2.90=.56 for the

* dotted trace. The invariance is not perfect in this example, but it suggests

that some underlying timing structure miqht be operating here, prompting

additional searches for these or similar invariants.

Initially, these and )ater findings in rapid limb movements (Shapiro,

1978, Summers, 1977), typing (Terzuolo & Viviani, 1979), and locomotion

" "" " "" ........ " " " " "' " '-....-...-...-.....'....".."...,...",,.",-..,.....".......'- . -...--"-- .* 

- ...... - ...

" ' "-'" " "' " ' "" "' ' " "" "" " '"' " ' .
Transfer of Motor Control '-

(Shapiro, Zernicke, Gregor, & Diestal, 1981) generalized the idea of an

essentially constant relative timing to a variety of tasks. This work

generated a great deal of interest, as it seemed to provide one kind of

solution to the storage and novelty problems of the earlier motor program

ideas. Further, it suggested that this abstract structure might be one of

the products of motor learning, and that each motor program might have a

particular relative timing "signature," allowing us to recognize when one

program (versus some other one) was being produced (e.g., Schmidt, 1982,

!985b). In terms of our present interests in motor transfer, these

signatures" could provice evidence of what was transferred by seeing that

a particular timing structure learned in the transfer task is also evidenced

in the criterion task after transfer. We return to this idea in a later

section examining specific transfer phenomena.

Other movement parameters. This work has also revealed other ways

that movements can be varied, while retaining their original timing

structure. One common example is the parameter of movement size'

revealed particularly well in handwriting. Consider one's signature,

written on a check versus on a blackboard some 10 times larger. The two

patterns, reduced photographically to the same size, show nearly identical

features (Merton, 1972), suggesting that the same pattern was produced in

both instances, but with a variable amplitude parameter This example is

interesting from another perspective %,o,, one realizes that the muscles

and joints involved in the two actions are different. Check-sized writing

involves mainly the fingers, with the "heel" of the hand fixed on the writing

surface; blackboard writing involves essentially fixing the fingers, and

moving the elbow and shoulder joints. The fact that the patterns are the

"same" implies that the movement representation was certainly more

abstract than the leve; of specific muscles and joints. In addition, various

other parameters, such as movement direction (Shapiro & Schmidt, 1983), =77

• . .a -a ..'-'-- .- " ...: ,. : - . ." --- "- ' " "." '-.-. '.'- -- ----"":- '.':. :"."." :, . : '. :" ":. " '- . ,
Transfer of Motor Control 12

movement loading (Denier van der Gon & Thuring, 1965; Sherwood, Schmidt,

& Walter, 1986), and the slant in writing (Hollerbach, 1981), have been

suggested. This work is relevant for transfer because it suggests that

movements learned in one condition can be easily transferred to certain

other conditions (only) if the underlying temporal structure is the same.

Current status of the generalized motor program concept. Looking back

on this body of research conducted over the past dec.de, some general

conclusions seem to emerge quite clearly. First, there is clear evidence

that the patterns of activity in such actions "exEDnd" -rd "contract" w'th

changes in movement time, with the various segm1nts in t1he action being

nearly proportional to movement time. But a mcre careful analysis of this

problem by Gentner (1 985) recently reveals that a proportional expansion

model is too simple to account for the data. And various nonlinear

expansions have been shown in both limb movement studies (Schmidt,

Sherwood, Zelaznik, & Leikind, 1985; Zelaznik, Schmidt, & Gielen, 1986) and

in speech motor control (Kelso et al., 1984, Ostry & Cooke, in press). While

this realization detracts considerably from the idea of - simple, abstract

temporally organized movement program, it does not deny the possibility

that some abstract structure is involved. And, it does not detract very

much from the idea that these abstract structures--however they be

defined exactly--will be the major basis for the learning and transfer of

movement control.

Movement Specificity

We turn now to a completely different set of findinQs--using entirely

separate methodology, tasks, and analyses emerging from the work on

individual differences in skills--which appear to have considerable

relevance to motor transfer. Many different investigations, produced

mainly in the 1950s and 1960s, show consistently that movement skills

- are quite specific. That is, even skills that appear to be quite similar to

at 1° -- • ~ ~ ~ . . ~ . ~ . .~ .. ~ . ~ .. ~ ... .~ 7 . e . . e .-, .. . . .- ,. ..-'
Transfer of Motor Control 13

each other show very little correlation with each other. Not generally

recognized by scientists dealing with learning and transfer, this

phenomenon is evidenced by two different but related lines of research.

Intercorrelations. The formation of the specificity concept for motor

behavior appeared against a backdrop of thinking about the generallity of

motor (and cognitive) abilities that had emerged from the factor analytic

work of the 1930s, in which a "general motor ability" was thought to

underlie much of human motor responding. Although it was never precisely

spelled out, the overall idea was that motor behavior was based on a

relatively small number of movement capabilities, such as "balance,"

eye-hand coordination," "agility," and the like. It was not until the 1960s

that the underlying structure of movement skills began to be studied in

earnest, with Fleishman's (e.g., 1965) work leading the way.,

But ,n the 1 950s and I 960s, Henry (e.g., 19358/ 1968), in his studies of a

wide number of laboratory movement skills, noticed that the correlations

among skills was never very large. Indeed, even skills which seemed to be

substantiall the same, and thus would seem to be based on essentially the

same ability structures, were found to correlate very poorly. One example

from this series is Bachman's (1 960) study of two balancing tasks--the

stabilometer balance platform, and the Bachman ladder-climb task; here,

the correlation between the two tasks, for subjects of different ages and

sexes, ranged from 25 to - 15, with the average correlation being

essentially zero. This was surprising to many who expected an important

"balancing ability" to account for much more of the variance between these

two tasks. Lotter (1960) studied striking tasks, where a forward stroke of

the right or left hand or the right or left foot was required. The hand-foot

correlations were quite low (ranging from 18 to .36), which was unsettling

* to the ideas about some general "speed" or "quickness" factor However, the

correlations between the two hands (.58) and the two feet (.64) were
Transfer of Motor Control 14

somewhat higher, suggesting that the "same" skills done bilaterally are

somewhat more strongly related, which is relevant to work on bilateral

transfer as we will see later on.

In general, an impressive volume of carefully done work on various

motor skills tends to show that the correlations among tasks are generally

very low It is informative to peruse some of the intercorrelation matrices

from the large abilitles-oriented proarams of movement skills done in this

period. For example, Parker and Fleishman ( 1960) studied 50 widely varied

tasks, 2rd evaluated the intercorrelations among them as a basis for later

'actor analvsis. Of the 1,22:5 separate correlations, most correlated 40 or

e.aid only rarely was there a correlation of greater than 50. The

"!nest correlation was 85. A fair generalization is that motor skills tend

!o ne very poorly correlated unless they are very minor variants of each

30ner, making them essentially identical.

The usual interpretation of these findings is that the underlying

:,itles for movernert skills tend to be very specific to the task. Henry's

?i58/ 1968) and Fleishman's (e g., 1957) views are that the number of

abilities underlying all motor behavior are very large, perhaps 100 or so.

Each Skll has underlying it a large number of these abilities, but "selected"

ifferently aepenaina on the exact nature of the skill to be produced. Even

a slight modification in the task requirements, such as slight shifts in the

control-display rel- inships, the overall force requirements, or the role of

sensory information, would be expected to call in a substantial number of

different abilities for the two "tasks." Since these various abilities are

cresumably independer.t , these models, subtle shifts in task requirements

tend to make the correlations drop sharply Even though we would agree

Subjectively that the two tasks were really the same, and would happily

assign them the same name (e g., a test of "anticipation"), they might not

correlate to any appreciable degree. 7
V, 9. . ...

Transfer of Motor Control 15

Shifting ability structure with practice. Another important principle

from the motor skills work, also with important implications for

understanding transfer, is that the pattern of abilities underlying a skill

appears to shift with practice, a clear demonstration of which is provided

by Fleishman and Rich (1963). Subjects learned a two-hand coordination

task, in which movements of two handwheels had to be coordinated to

cause a pointer to follow a target. Separately, subjpcts were tested on

two other tasks--a kinesthetic-sensitivity tasK involving judging the

differences amonc lifted weiahts, and a soatia--reL.tions test. Subjects

were then div,ded into two groups according to the performances on these

latter tests, and the group performances on the ty.-,-nand coordination test

were plotted separately, although the groups were treated identically.

Figure 3 about here

In the top graph in Figure 3, the two-band coordination test scores are

shown for subjects grouped as high and low on the kinesthmetic sensitivity

measure. Subjects classified as high performed, no differently from

subjects classified as low in early practice, but a difference between

groups emerges as practice continued, we can say that the kinesthetic

sensitivity test (and whatever ability or abilities it measures) became

increasingly important in this task with practice. The bottom graph shows

the two-hard coordination performances for the groups classified as high

and low on the spatial-relations test. Here, sutjects classed as high

performed more effectively than subjects classified as low in early

practice, but this difference disappeared with continued practic."-

Gerer-iy, the irterpretation of this work has been that the pattern of

abilities ur1erly,1r a giver skill shifts with ora:tice, with some abilities

(eg., kinesthetic sensitivity) becomming more important with practice, and

others becommna less important (spatial relations) One Is tempted to say

that various cognitive abililties seem to drop out. while other more motor

. • . "
Transfer of Motor Control 16

abilities come in:tc :lay; but this generalization is probably too simple to

be useful for more tnan the most global analysis of skilled behavior.

Finally, in a.dition to movement skills being very specific (i.e.,

uncorrelated ,vitn each other), evidence suggests that they become

increasingly so witn continued practice. This is usually seen in various

factor analytic stunies of skills, such as the well known analysis by

Fleishman and Hem,el (1955). Here, various staces of practice of a given

task (discriminati n, RT) are examined in the same factor analysis with a

number of refererc. tests. In addition to the expected reference factors,

ne .uth-ors a "specific" factor, which is thought of as containing

a.ilities specf : the task and not related to tne other reference

aDlities. Ths D ecfic factor grows in importance with practice, so that

at the end of the orsctice session it accounts for more variance than any of

the other fac o"s Cne interpretation of this work is that the task becomes .

increasingly s-ecific with practice, so that it correlates systematically

lower with ooer tasi:s. Another view, which a~pears less certain, is that

oractice aener-tes a "learned ability," specific only to that task, and with

nearly notninc in common with other tasks. As we will see, this idea has a

number of interestl,,- implications for understanding transfer of learning.

Some Principles of Motor Transfer

In this sect,,r we consider some of the more common "kinds" of

transfer, or at le- situations or experimental designs in which transfer

is seen After describing some of the generalizations from the emprical

work in these situations, updated with the relatively few new findings in

this area from the .ast decade, we attempt an analysis in terms of the

principles of movement control discussed in the previous sections.

Measurement ,f >rt, Transfer

Fioure 4 about he, -

An importart :t3ting point will be the oescmrDtion of the "amount of
Transfer of Motor Control 17

transfer" found in motor-task situations, where a rough estimate of this

"amount" can be had through percentage transfer. Consider a simple

two-arcoup design, in which all groups transfer to the criterion Task B, but

where !,roup I practices some Task A beforehand and Group B does not..

Some rvPothetical results are shown in Figure 4 (left), where the fact that

Group I! performs more effectively than Group I on the first Task B trial(s)

is evicence for positive transfer from Task A to B. Considering trie

improvement on Task B by Group II (i.e., X-C in the figure) as a kind of total,

the iin in initial performance of Group i over Group I (i.e., X-Y) can be

exzressed as -aoercentage of this total [i.e., (X-Y)/'(X-C) x 100]. While these

nl s,,r-lar measures (Murdock, 1957) are (

i enerally useful, they raise many

rroC.!erS for subsequent interpretation Ceiling and floor effects in task

scor"'r, and pnenomena that alter the scores temporarily (e.g., fatugue),

make :r~erpretations in terms of some transferred capabilitv for

performance aifficult to draw (Schmidt, 1982). But even with these

:mitations, some insights into the magnitude of motor transfer can be

Drcved by sucn measures.

r-an-fer Amon.o Different Motor Tasks

When such measures are applied to experiments on motor transfer, the

outcomes are relatively consistent: Motor transfer is generally very small.

Cc-,ider a case in which the various "tasks" were formed by varying the

speees of pursuit rotor rotation (e.g., Lordanl & Archer, 1958; Namikras &

Archer, 1960), with groups practicing at either 40 or 80 RPM before being

r:.fer-ed to the 60-RPM criterion task From our computations of

DerertaCe transfer to the 60-RPM task, transfer never exceeded 67, and

the average percentage transfer computed across these various

experments was only 37%. See also Arimons, Ammons, and Morgan ( 56),

Baker wylie, and Gagne (1950), Jensen 1976), Lincoln and Smith (1951),

and Sieiel and Davis (1980) for other examples showing essentially the

,, ~~~~~~~~~~~~. ,................ . ... . ........ .... ,.-....... ,,- ,.,-., . .... - ., .
7 71 7 V V. V, PTransfer of Motor Control 18

same thing. This low transfer is quite remarkable, in view of the fact that "

the tasks were essentially the same, and varied only in speed.

When the pursuit rotor is varied by cnanging the radius of rotation on

the rotor), transfer in the Lordahl-Arcner (1958) study was somewhat

higher (,4o by our computations) than for changes in speed, which lends

some s':.Dort to the idea that changina the temporal structure is more

detrimrnTal to transfer than changes in size. Fumoto (!981) found tnat

changina the shape of the track produced no transfer in some situations,

and 1iw transfer in others. Overal Ihe transfer among these t s"

vari at:1cr appears to be very small.

These findinqs of low transfer can Le explained by, or at least nre mi

general agreement with, some of the principles from the motor control

literature discussed earlier. First, wnen the task requirements are shifted

slightly ,e.g., among different speeds for tre pursuit rotor) to produce two I

"different" tasks, the literature on specificity suggests that the two,,

variations would nQt correlate well witri each other, implying considera -tdifferences in the underlying ability structures of the tasks. If so, then it

is understandable how even slight snifts in the response requirements,

which subjectively only alter the task in a minor way, may actually prcviae

massive changes in the individual differences and in the underlying motor

control requirements of the task. Trus an important point from tniliterature, as viewed from a motor-control perspective, is how "fracle"

the structure of tasks is to variations in response requirements.

These results on low transfer amon skills seem surprising in view of

the work on generalized motor programs One of the ideas was that a given

program could be used at different speed s, maintaining the relative timing ., -

structure, simply by using a different seed parameter. Thus, one can ask

whv the variations in the pursuit rotor soeed did not show large pos~tive

trans f

e, as each variant would presumably be controlled by the same

......................... .- v .....
fI 1 .2 -.-.-. 

Transfer of Motor Control 19

structure, but with a different overall rate parameter. we nave no

particularly satisfying answers But one possibility is that the "span" of

variations over which a given generalized motor program can operate is

much narrower than the motor-control literature has led us to believe.

Thus, the variations in rotor speed might not have resulted in simply %

parametric changes, but could nave produced a shift from one proqram to a

completely different one If so, because there is good reasor tc suspect

that these programs are distinct and generally nonoverlapping, tnere should

be little reason to expect much positive transfer amc-r speeds

Determining the 'span" of movement programs is a dffvult ermpirical

question because of problems in distinguisring (a) two different variations

of a given program from (b) two different programs (3chmict, -35), and

good answers are not available at present.

But another Possibility is that shifting the speed requirements of these

tasks disrupts not only tne motor control requirements, but also the

information processing and/or strategic patterns of the learner. For

example, a shift in speed could change the perceived subgoals of the task

(e g., being quick versus being accurate), it could change the attentional

focus of the subject (attending to what has happened versus what will

happen), or it could change the strategies (Fumoto, 1981) that tne learner

Crings to bear on the situation. This is possibile in tasks like the pursuit

rotor, where ample time is involved in a 30-s trial to process sensory

information, modify strategies, and the like, as not all the performance is

Oetermined by the effectiveness of some _iotoc program as it would be in a

more rapid movement. If so, then these changes in the f_,-.rnental

information processsing activities wh,,en the rnoverment requirerr, ents are

changed even slightly may explain the relatwvely small transfer fzund.

In one way, these observations could be relpful in tr,nmng and/or

simulation settings by encouraainq a more careful considerat!on of what WII

--....--..--.-- ,-. ....- .......- :.... .. ....;........................................................................ .;..: :.-..:-.. i.-.;-.
- -17-~ V. - T.1 7, T- 7 N7 .. 7 -

Trarsfer of Motor Control 20

motor-control and information-processing activities might be changed by

rather arbitrary alterations in the training or simulation conditions But in

another way, these views are disappointing because they only tell us what

kinds of situations lead to a lack of transfer, and are inadequate in telling

us about what is transferred. Part of the proDlem is that systemnatic work

on the fundamental bases of motor transfer, in which hypotheses about the

s,milarities and differences amona tasks winch do and do not trnsfer to

each other are evaluated, have simoly not been cone.

-'lateral Transfer

Bilateral transfer ,s one of the oldest subdivisions of the transfer

nr.-.lem (e.g., Davis, 1898), and was studied extensively early n this

ntury using tasKs liKe handwriting, drawing and figure production, maze

1 earning, and the like (Cook, 193-4; Weig, 1932; see Ammons, 1958, for a

review). While all of this work involved manual responding, from the-.

perspective of movement control the "motorness" of these tasks was not

particularly hignh In most of the cases, the understanding of the transfer

that was produced could be attributed largely to the subject's symbolic

learning of the structure of the maze, the figure, etc., and applying this

)argely verbal/coqnitive representation to the Droduction of the same

response with the other hand. Of course, many of the submovements (draw

line, m. turn left, etc) were learned pre-experimentally, and the basis of

transfer seems to be knowinq wnen, under what condi.tions, or in what

order to produce these already learned actions This older literature, and

similar recent additions to it (,g., Junnam, 1977, Puretz, 1983, Tsuji &

1,3,e, 1974), rere_.nt additional :upport and some limitations (e g, Hicks,

Frank, & Klnsbourne, !9%82) for L',lateral effects, but unfortunatelv do not

seem to provide much insight into the nature of motor transfer.

But some recent findings, using more motor" tasks, do provide

considerable insight into this Droblem One example comes from Shapiro

............. ~--*..'-.-A
Transfer of Motor Control 21

(1977), who had subiects learn a complex wrist rotation task similar to

that used by Armstrong (1970, see Figure ). The learner had to move to

each of seven target positions in the proper order and in the proper time,

the entire response occupying 1600 ms The subjects practiced this task

for five days with the right hand, receiving feedback of their space-time

patterns after each trial from a computer screen, and the average -

patterning of the movements on the fifth day are shown in Figure 5 (open

circles). These are expressed in terms of relative timing as discussed

earlier, where the proportion of the total movement time occupied by each

of the segments is piottea for eacn of tne seqments, the entlre plot

providing one kind of description of the temporal structure. As one might

e- cect, tnis patterning :nanqed considerably over the five days, and the

pattern shown here is the result of consideraDle experience.

Fiqure 5 about here.

On the firth day, 5haDiro unexpectedly asked her subjects to do the task

acain, but this time to do it with the lia hand. The filled circles in Figure

5 represent the proportions for these trials, and it is immediately obvious

that the patterning was nearly identical to that done with the right hand,

implying very high transfer from the right to left sides. This was true even

though the left- and right-hand movements were not anatomically opposite

to each other; the same directions of the handle were required for each

limb, thus requiring opposite movement directions and muscle groupings

(defined anatomically). Thus, something abstract was being transferred,

whwas r t e othe specific muscles and joints involved.

Th)es e resuts a3,,,, g,ce, 1, nt,,,,, ,,, be seen as involving motor

transfer, as The abstract basis for transfer here could be some cognitive

reresentatcn of -what to do." But evidence from the motor literature

. converaes to suggest a more "motor" interpretation. Other aspects of

- 5haplro s work (riht-handed performances only) show that when the

-7. -7-
Transfer of Motor Control 22

subjects are asked to speed up this pattern, they do so with only minor

shifts in the temporal paterning; and, when the subjects are asked to speed

up these patterns, and to ignore the timing they learned in previous

practice, they aqain maintain the relative timing. This evidence, plus other

work citea earlier here, suggests strongly that the representation for

action was 3 Knd of qeneralized motor program that was run off at various

seeis e . on the task instructions. Our interpretation of the

bilateral transfer effects, consistent with this programming view,

suggests a relativeiy abstract program structure that can employ various

!limb sYste,,,,,s .n ,.roducing the response.

Other orevious findings enrichen this picture considerably Bray (1928)

showed transfer of mirror-tracing performance from the hand to the foot.

Using somewhat less rigorous methods, Raibert (1977) recorded his own

writing with the dominant hand, with the dominant arm (hand fixed), with

. the nondominant hand, with the pen gripped in his teeth, and with the pen

taped to his foot, all of which produced similarities in the movement

patterning. The example cited earlier by Merton (1972), in which a

check-sized and blackboard-sized signature were structured similarly,

makes an additional point; the muscles and joints used in the two

movements are entirely different, involving primarily the fingers in small

writing and the elbow and shoulder in larger writing. In another example

(Schmidt, 1982), try writing your signature backward with your

nondominant hand; most people say it is nearly imposible. But now try it at

the same time yLJ are producing your normal signature with the dominant

hand; most people say that the nondominant-hand movements just "flow

out," simultaneously with the dominant-hand movements, although the

*i signature is not perfect. This is similar to the recent two-handed aiming

* experiments, where the timing of the two hands is remarkably similar

(Kelso, Southard, & Goodman, 1979), but can be slightly differen,, depending

%,: .., .. ..: ., ....: .....: ._. -:: .. : ....... , :::.. ... ., ...... :: ....,.,, . ,: ., .., ..:.: -:. ,
Transfer of Motor Control 23

on various task constraints (e.g., Marteniuk, MacKenzie, & Baba, 1984).

All of this work is consistent with the idea that movement control is

based on a centrally structured movement program, with rather rigid

temporal structure, perhaps defined in something like relative time. When

the same structure is used to produce the movement in another way,

perhaps at another speed, with another size, with another limb, or with two

limbs simultaneously, the motor system has relatively little difficulty in

doing so. This is not to say that all of the learning that occurs is muscle

independent, because that view would expect perfect bilateral transfer,

w.dhich is certainly not usually the case. But it does force the view that a

sizable part of what is learned, and what is then transferred in shifts to

siilar situations, is some motor progam representation such as described

nere. And, the work showing the similar kinematic patterning of the left-

*and right-hand movements adds considerable credence to this viewpoint. It

provides strong direction for future work, in which similar bases for motor

transfer from one task to another might be sought.

Dart-Whote Transfer

The literature on the effects of practicing a part of a task on its

subsequent whole-task performance--so-called "part-whole transfer"--is

not particularly large, but a number of results agree well with an

interpretation in terms of motor programming. Such effects are relevant

for skill training situations, where instructors are tempted to "break down"

a skill into its parts for individual practice before transfer to the whole

task agz 'n. As we shall see, the effectiveness of these procedures depends

strongly on the nature of the task examined....

If we define the "task" as a series of serially organized subactions,

with a relatively long task duration (e.g., >10 s), then there is clear

evidence that practicing tne subtasks in isolation can transfer

substantially to the total task (e.g., Seymour, 1954). This is not

°'.0 *- -,,' .-. - -. * " . ,'- . . - - *' .'- *%* '-,*- '.*' . .- " . ". '% . " .''- . - •. .. .. , -,• *" *.* "- "% ." '. ,"". ._"
X',, oY , V. .. *-L , -. . . -'.. '•

Transfer of Motor Control 24

particularly surprising, because with the long movement times, the

subtasks are treated as essentially independent activities, and there is

little difference in performing them alone versus in the "context" of tne

other subtasks. If the task is continuous, with segments that are less well

defined sequentially, then the effectiveness of part practice appears to

decrease markedly. Or, if the "parts" are defined as two simultaneous

dimensions (e.g., X and Y in trackir), the practice on these parts can

transfer to the whole task, with transfer increasing as the "complexity" of

the task increases (e.g., Naylor & Bricas, 1963; Stammers, 1980).

tut if the task is discrete, ,vith short movement times, tne

eff e:tiveness of part practice chances markedly. Lersten (1968) exarmned -'

a raD[id W s) sequentially organized discrete movement. Grasping a Knob

atzacned to a lever, the subject made a circular movement to contact a

stop, then released the knob and made a linear movement to a tarqet,

attempting to minimize movement time for the whole (circular plus linear)

response. Different groups practiced various parts of this task (circular,

linear, etc.) in isolation before being transferred to the whole task. Unlike

the situation with the slower sequential tasks, transfer was generally very

low (less than 7%) or zero from the parts to the whole task. Surprisingly,

for the group which practiced the linear component alone, the transfer to

the whole task was negative measured as -8%, but it is questionalbe as to

wnetrer this effect is reliably different from zero. In any case,

essentially no transfer from part practice to the whole task was shown

0 ie interpretation of this interaction between part-whole transfer nd

task type is based on the notions discussed earlier about movement

programming. In the long-duration sequential tasks, the parts can De

:ontrolled by movement programs organized sequentially, where the

learners task is to initiate each of the programs when its predecessor has

run its course. In the rapid movements, however, there is not sufficient

W .°. .,
Transfer of Motor Control 25

NN* .4

time during the whole task to initiate each of the subparts sequentially,

and here it is more reasonable to believe that the whole task was

orgainized as a separate unit. Even though, at one level, the part in

isolation and the part in the whole-task context are formally identical, on

closer examination there may be considerable differences between them.

In Lersten's case, for examDie, the linear part in isolation required the

subiect to accelerate from a stop located at the end of the crcular phase,

in contrast, this part in the context of the whole task already had the limb

at a high velocity when it eani Thus, there should be marKec differences

between these two linear c-nSes, especially when viewed 'n terms of the

movement kinematics or in .ne structure of the EMGs.

If the kinematic or neuromuscular (i.e., EMG) structure of the "same"

part is fundamentally different depending on whether it is performed alone

versus in the context of the whole movement sequence, then it is

reasonable to think of these otherwise identical parts as Deing different

movements, with different temporal structures, and different motor

programs. Thus, practicinq a part in this situation involves practicing a

motor program which is not involved in the whole task, resulting in

essentially no transfer betwe,,%,,n them, which is essentially the result

found. This interpretation nclds that the programs for the part and for the

whole are distinct, and that the part-program is not capable of being

merged" or transferred into tne whole-program

When can practice of zarts be beneficial for whole-task performance?

From the motor programmina perspective, the answer cou]l bCe based on an

analysis of the structure of the whole task. If the task is actuadly made up,-

of two separate motor proarams run sequentially, then practice on the first

part in isolation should transfer to that part in context. An example might

be a tennis serve, where (acoarently) the movement is mace up of a

ball-toss and backswinq as the first program, followed D, a second

-... .. p. .--.
Transfer of Motor Control 26

* program which produces the hit at the proper time and place. Between

programs, the performer analyzes the result of the first program (where

the toss sent the ball), and decides where and when to produce the hitting

motion. Presumably, effective decisions about whether or not to divide a

task into its some component parts for practice in isolation could be based

on estimations of the structure of the actions involved. According to this

view, parts should be formed only on natural boundaries, and ta--,; that are

r~rogrammed as a single unit should porobably not be divided at all.

Although such analyses of motor skills have not, to our knowledge,

. ctually been conouGuc_:.L, ae .tLe bases for separating tre ac:-ion into

: arts already exist. For example, the temporal structure witin e-h of the

:;ogrammed parts s"culd snow very little variability (ac-os- trials),

whereas the temporal structure between two different programmed parts

=hould show more variability. Thus, points at which variability increases

could be taken as boundaries between two movement programs. Such

analyses, of course, would require continuous records of the subject's

.,ehaviors during the action, and would not be simple to conduct. But such

procedures are technically possible with the newer recording methods

beinq used today, and could provide a strong link between movement control

:hinking and concepts of part-whole transfer.

Negative Transfer

In spite of its importance for understanding learning and transfer in

motor behavior, negative transfer has not been examined very much since

'e. systematc examination o

, .nese problems by Lewis and colleagues

',Lewis, McAllister, & Adams, i95; Lewis, Smith, & McAllister, 1952;

.. A..ister, 105I2, te e w, _SA 1951). Lewis et al. (19E used the

so-called "complex coordinatic ., ,ask,' in which the subjects had to move a

two-dimensional joystick and a foot control to match each of three

stimulus positions, where a "standard" version of the task had the display

o. • , - °o .o o , o~oo. . o~% • o •. -% . . - i. o........................"....................°" ° o" ° °o -. , ", • "° • °.'-.-°oo o ",.," . "................................,....I.........o.............................,-....,- ,---' --
-XVX-- . - . LO UN OW 

Transfer of Motor Control 27

respond in the same direction as the controls. They studied the effect of

practicing this task with a reversed control-display relationship on W

transfer to the standard task, varying the number of oriQinal (standard

task) trials and the number of reversed task trials. They showed

considerable negative transfer, which increased as the number of reversed

task trials increased, as seen in Figure 6. This evidence suggested that

negative transfer might be a serious :roblem in many practical settinas.

Figure 6 about here.

Although little new evidence on negative transfer has been provided

since the early 1950s, c. rrent speculation is that negative transfer wifil

niot be such a larqe pro:lem after all. First, most of the transfer

exPeriments examined in a previous section here showed essentially zero

or low-positive transfer, and never showed negative transfer, leaving the

Lewis et al. experiments as the only ones that provide c)ler evidence of

negative transfer in motor situations. 5econd, in order to achieve the

neoative transfer they did, Lewis et al. completely reversed the

control-display relationships--a drastic change that probably exceeded the

task-to-task interference found in most everyday learning situations. And

third, it is likely that the negative transfer was mediated in large part by

cognitive processes (confusions about "what to do"), rather than to any

neqative transfer of motor control.

These ideas are supported by one of the few recent studies directed at

negative transfer. Ross -% 974) examined a common idea tnat two tasks

naving many early features of the motor pattern in common, but with some

critical difference later or (e g, a tennis vs badminton stroke), provides a

sufflcijent condjition for n'iove transfer to oc.Cur In a laboratory analog

of this situation, where the force requirements of the final segment of an

otherwise identical three-segment limb-movement task was manipulated,

only minimal negative transfer between the versions was demonstrated

-7 -
Transfer of Motor Control 28

and what negative transfer did occur was eliminated with just 10 trials of

criterion task practice. Again, negative transfer did not seem to be a

serious problem in these movement situations. Rather, we seem to find

that, when the tasks are changed from being opposite to being merely

different, transfer quickly switches from negative to zero, or perhaps to

low-positive if simiiarities might outweigh the differences.

But various diverrent findings make us uneasy about our conclusions

concerning the general lack of negative transfer. Shapiro (1978) had

subiects learn a nine-segment movement with a particular spatial and

temooral pattern. Wner' subjects were asked to speed up the movement, and

to ignore the temporal pattern learned earlier,, surjects had great

difficulty in doing so. Rather, they sped up the same pattern that they had

been practicing previously, thus failing to produce a different pattern that

might have been faster. This effect can be regarded as negative transfer,

where doing the task at maximal speed was interferred with by prior

learninQ of the particular temporal structure experienced earlier. Such

effects appear to have important implications for practice situations in

which the learner attempts to modify only a part of an action, and suggests-.-

that such patterns could be particularly resistant to modification.

Another example involves second-ianguage learners. Speech production

(not grammar or vocabulary) can be thought of as another example of a

complex motor skill involving many muscles and articulators. We all know

that difficulties in producing particular speech sounds in, say, English is

critically related to tne speaker's first language, for example, the "same"

acoustic goal is produced systematically differently in speakers whose

first language is Frencn versus German. If negative transfer were not

occurring, we would not expect to have these pronunciation difficulties be

common for a particjlar group of first-language speakers, anJ we would

not expect to be able to recognize one with a French accent. As such,
- ~. * . -. 

Transfer of Motor Control 29

"foreign accents" might be our best evidence for negative transfer.

Specificity. Even with the two examples just given from limb

paternng and speech tasks, the evidence still points to a general lack of

negative transfer for skills. This conclusion fits well, however, with the

evidence discussed earlier about movement specificity. Changing a task . -

slightlv presumabiy alters the processes and abilities involved in its

execution, with only minor alterations being needed before the correlations

-among tasks aDroach zero. If so, then perhaps the reason we find so little

r-e 3ative transfep is that the task variations used in the literature are

-lated so ,)-v to each other that there is no common basis for negative

:r nsfer to occur In terms of the motor programming literature, we argued

earlier that changing a movement task slightly can De argued to involve the

same generalized motor program, but parameterized differently. However,

chIanging it more than slightly, perhaps beyond the narrow limits of the

Drogram's capabilities, demands that a completely different movement

Drogram be used, having essentially nothing in common with the previous

one. If the practice of one program does not alter the "strength" of other

ones, then neither negative nor positive transfer would be expected . -

between apparently similar tasks that use different movement programs.

Forgetting The evidence on lack of negative transfer also agrees well

with the common findings of nearly perfect long-term retention of at least

some movpmont skills. Bicycling is the common example, and continuous

tasks like pursuit tracking and stabilometer balancing provide the

empirical justification (Fleishman & Parker, 1962, Ryan, 1962) If, as the

'nterference theory suggests, forgetting is mainly caused by negative

transfer from other tasks learned either prior to or after the original

learning of some motor task, and negative transfer does not appear unless

the tasks are essentially opposite to each other, then long-term retention

might be so cornDlete because at least some motor tasks do iot have any . . . . . . . . . . . . . . .* .. . .. . ... . a . .. , .. . . ,.- . . . . , . . , :
Transfer of Motor Control 30

other motor tasks to interfere with them. This, of course, seems quite

different than in the verbal domain, and indicates at least one place where

forgetting of motor versus verbal skills might be explained differently.

Transfer Among Various Conditions of Practice

At this point, we change directions slightly to deal with a somewhat

different, but strongly related, area of transfer research--that dealing

with the transfer among different conditions under which a task is to be

performed. At first glance, this area does not seem to fall clearly within

the bounds of transfer research, which is concerned with transfer from one

variation of a task to another. However, remember tnat changing the

conditions under which a task is to be performed, such as eliminating

illumination, changing the mass of the control lever, or even performing

under massed vs. distributed conditions, can be thought of as altering the

task somewhat. And, it is nearly impossible to define now much we can

change task conditions before we are no longer willing to say that the task

s the "same" task as before. Such task variations may De continuous, and

decisions about where to "draw the line" are often arbitrary.

In the traditional learning experiment, the variations in the conditions

of practice are studied in an acquisition phase, and then the effects of

these variations on learning are evaluated in a "transfer test" (or a

"retention test"), where all groups are switched to identical levels of the

independent variable2 Such transfer designs allow the separation of

temporary effects of tne independent variable (e g, fatigue) from the

relatively permanent effects that we usually wish to ascribe to l'arning

(see Schmidt, 1982) For the present purposes, it is interesting to note

that the effects of practice (i e., learning) under various conditions is

". evaluated in terms of transfer to another condition. Thus if a change in

conditions real*y amounts to a change in task, as we argue here, then

* learning is evaluated by transfer to a different "task." Viewed in this way,

_V.-' . %. . ... .. ...- * ... 7
, -P

Transfer of Motor Control 31

transfer experiments and learning experiments share many similarities, %

and perhaps cannot be distinguished at all.

Using this approach, a number of lines of research have been conducted

which provide interesting insights into what might be learned (and, hence,

transferred) in practice situations. One of these involves variability in

practice, discussed next.

Variabiliy in Practice

The motivation for much of this work was Schmidt's (1975) schema

theory, which holds that practice generates abstract rules that govern

classes of responses, with each class being represented by a generalized

motor proqram. For example, throwing motions are presumably produced by

a generalized throwing program, and individual instances (e.g., throwing a Nparticular object a particular distance at a particular speed) are generated

by specifying parameters for the generalized motor program. Parameter

selection is based on rules (or schemas), formed on the basis of past

experience with the program, which define the relationship between the

environmental outcomes of the movements and the values of the

arameters that were chosen. Thus, when the performer wants to throw a

particular distance, the schema defines the parameter for the generalized

throwing program, and the program is run off with this parameter value. In

this way, each separate throwing movement does not have o be

represented, and the person can generate novel movements whi h he/she

has not produced previously (see Schmidt, 1975, 1982, for more deta'is) *.

One major prediction of this theory is that increaseC variability in

practice along the task dimensions relevant to the generalized motor

program should result in greater performance on a novel variant of that

task. Numerous recent experiments have examined this prediction in a

variety of tasks (e.g., Johnson & McCabe, 1982, Husak & Reeve, 1979, Kerr &

Booth, 1977, 1978, McCracken & Stelmach, 1977, Pease & RuDnow, 1983,
Transfer of Motor Control 32

Pigott & Shapiro, 1984; Siegel & Davis, 1980, Wrisuerg & Mead, 1981, see

Shapiro & Schmidt, 1982, for a review of the earlier work). One study

which shows these effects particularly strongly was reported by Catalano

and Kleiner (1984). Two groups performed a coincience anticipation task,

in which a series of lights "moved" toward the subject who responded with

a button press when they "arrived." A Constant group received practice at

the same speed of light travel on each -rial, wh h wvs e..he. 5, 5. 7, oir

MPH for each of four subgroups. The Variable group received practice at

each of these speeds in a variable order, the number of total trials being

constant across groups. Then, after a rest. eacn subject was tranferrea to

four novel light speeds, two which were slower than the previous

experience ( 1 and 2 MPH), and two which were faster ( 11 and 12 MPH).

Figure 7 about here.

Absolute errors on the transfer tests for these two groups are shown in

Figure 7. Errors increased as the speed of liaht travel deviated more from

.he sDeeds practiced Previously. and there was a clear advantage for the

variable practice groups on the novel transfer tests. Such findings are

reminiscent of generalization gradients, in which the errors are smaller as

.he test situation is made more similar to those involved in earlier

learning. If so, then one can say that variable practice made the

,-eneralizaton gradient flatter, providing improved c,,,bility to generalize

the earlier skill learning to novel situations. Such results are reasonably

well established (but are occasionally absent) for adults (see Shapiro &

Schmidt, 1932, for a review), and are very strong for children (but see

Wr1isberg,1 & Mead, 1951)

These varable-practice effects have been important, for theory In

various ways. Their major impact has Dean seen in terms of support for

schema theory, especially because the prediction of variable practice

!eading to improved performance on some novel variant of the task could

......................................................... "...."...,...........'.- "" _ "" 'F" Jr_ "' ':''' '" "''' '
Transfer of Motor Control 33

not be made by earlier viewpoints (e.",, Adams, 1971) Consequently, such

results have been interpreted to mean that variable practice produces

stronger" rules for parameter selection, a view strengthened by the

converging evidence from motor control on generalized motor programs.

'Althouqh there have been other lines of support, the fact that variable

practice produces more effective transfer to novel variants of tnie task nas

been 5een as the single strongest -re f evidence for troe concept 3

motor learning is based on schem-at*La. And, of course, this sun.:or'L

_crez sd our confidence that an 1,rm--'Dnt basis for motor Iearmrnc and

an~fr-r was tlhe aeeaie moty) orogrnm, w itp tne nart.1cur

vana~cesin relative timing dic-c=-? in an earlier Section hiere. Ti

,nCre.-ea conficence tempted us t Lelieve that we were -1ose to

* jncierstad ht wslandimotor -kill acquisition, and what might

bc- 1-1- casis for the transfer of motor coT--rrol.

* Cc~:e'tual terference Effects

.L~ some recent findings concernefd w,.th snc-cali-d "Corte>t effects"

nave cdetracted considerably from trins viewpoint. Shea and Morgan ( 1979)

* exnmined the acquisition of three simnilar motor tasks which invoived

knocking over a series of barriers in a Prescribed order, with minimum

movement time as the goal. Each of th"e tasks was defined by a separate

* pattern of barrier contacts, indicated bv i diagram available to the sub, 'ect

W*oDeOr each) trial. Subjects pract'iceia tlese tasks in two differe nt ways3

for :) otal of 54 trials. Blocked pract'c e involved doing 18 trials cf %$,-K

* A, tner 18 trials of Task B, and tnen 5 tr-,als of Task C, whereas Rar~xm

*practice involved a random oroerir- 7 A, B, and C arosa tne 5-4

* trials. Then, sub iects in were Lrru~at either Eiocked practice or,

Random practice in a transfer test, f'c7-7ina a 22design, these tase

*tes ts w ere Conductedl e ither 10m r or; 'ays 3fter acQuisition.

Ficiure an. ",, ere.
Transfe, of Motor Control 34 &

Figure 8 shows the results curing the acquisition and transfer phases.

Consider first the Blocked retention test (squares). Subiects who

practiced under the Random conditions in the acquisition onase (filled

squares) performed more effectively than those who practiced under the

51ocked condition in acquisition (open squares), suggesting that the Random

practice was more effective for iearning. For the Random retention test

subjects practicmg urer Random conditions in acruisition

,'unfilled circles) were again more effective than those who practiced under

Elocked conditions in acquisition (filled circles), but the differences here

were very much larger than ;n he Blocked retention test. ThuS, even

-_,uq, the Random practice .. , iocuced less effective performances during

:ne acquisition phase, they procuced more learning as measured on a

retention test, this was true reaardless of the nature of the retention test

Rancom vs Blocked) or the lenctr, of the retention intervai. Other studies

have shown much the same thing (e.g., Lee, in press; Lee & Magill, 1983;

e.e, agill, & Weeks, 1985, Snea . Zimny, 1983), although the effects do

not appear to be present in children (Wrisberg & Mead, 1983) or in

,nexperienced" subjects (Del Rey, Wughalter, & Whitehurst, 1982).

The leading explanations of these effects come in essentially two

forms. First, Shea and Morgan (1979, Shea & Zimny, 1983) have argued

convincinaly using verbal protocols that the interference produced by

Random practice results in 'deteper" processing of task-related A.

information, with more extra-experimental relationships being formed and ..-

increased distinctiveness amona tie various tasks to be learned. This

ceeper" processing then results in more effective performance at transfer.

Lee and Magill (1983, Lee, in press), on the other hand, argue that Random

practice causes forgetting of the solution to the movement prftlem, so

,,)at when the subject faces that problem again, a solutior "lust be

3enerated again, with this generation being an important -- ccess in

. ............. . .-. . .

. . . .. . . - _. - ,
'l"F

Transfer of Motor Control 35

learning. Subjects with Blocked practice can presumably use the solution

generated on the previous trial (perhaps with slight modification), leading

to fewer generations, and to less learning as seen on the transfer tests.

But whatever the explanation, these findings produce considerable

difficulty for tne schema theory. First, if random practice is viewed as a

kind of variable practice, tnen across the whole acquisition phase both the

rcom and Dloced con.....s receive exactly the same degree of

variability; the difference is merely in the ordering of trials. Thus, the

theory would expect ,schema t.at, with the amount of variaoility being

ecual etwee. groups, transr wculd be ecuivalent as well, which is of

courSe ontr.vy to the fincns. seen in Figure 8. Second, the versions of

tre tasKs studied in the context-effect experiments can not easily be

thought of as "parametric variations" of each other; there is no simple way

that one movement task can De transformed into another, and hence no way

that a single generalized motor program (at least as conceptualized by

schema theory) could control all of them with only a parameter change.

But most importantly, tne variability in practice experiments

supporting schema theory can be considered as studies of blocked and

random practice. Along w,th more variability in responses, variable

practice conditions also make the subject do something different on

successive trials, whereas 'Ue constant conditions allow the subject to

produce the same response on successive trials. Thus, there is a strong

liklihood that the basis of the variabile practice effects is mainly related

to the fact that subjects vere prevented from doing the same response

. e.quentialy, rather than to tre fact that they had more varied oractice per

se across tne ranae of movements. If so, then there remains little

compelling reason to continue to believe that variability in practice

effects--the most solid evicence for schema theory as we have just

indicated--indicate the learning of schemata and the use of generalized

L.
Transfer of Motor Control 36

motor programs. Also, variabile practice effects tend to be quite small and

difficult to demonstrate in adults, whereas blocked-random effects tend to

be very large, and easily demonstrated. Perhaps the variability in practice

experiments have not made the task versions suffiriently different to

generate the random effects seen in the context effect literature.

In terms of the major goal of this paper, a discussion of the evidence

about the nature of motor-control transfer, these contextual interference

effects detract considerably from the credibility of our earlier arguments.

Earlier, we argued that motor learning involved acquiring generalized motor

programs and schemata to parameterize them. And, we arcued that these

motor program representations were primary "ingredients" in transfer,

perhaps even to the point that what is or is not transferred could be

recognized by the kinematic structures produced. Such optimism was based

on the belief that the concepts of the generalized motor program and

schemata were secure and well protected by the compelling evidence about

variability in practice But now, with the plausible suggestion that

variability in practice effects may actually be nothing more than random

practice effects, much of the strength of the argument for schema learning

and generalized motor programs has been withdrawn.

But two kinds of findings make us wonder whether all of the effects of

variable practice are capable of being explained in terms of

blocked/random practice effects. First, for children, variable practice is

more effective than constant practice (Shapiro & Schmidt, 1982), and yet

random practice is ,ot more effective than blocked practice (e.g., Wrisberg

& Mead, 1983). Second, variable practice conditions in which practice on a

given variant of the task is presented in small blocks seems to be more

effective for learning than completely randomized practice in children

(Pigott & Shapiro, 1984, Wrisberg & Mead, 1983), not less effective as

might be expected if ranaom practice dominated. Also, there is the
Transfer of Motor Control 37

question of how novel behaviors are produced, whicn does not seem

predictable from the notions of how blocked and random practice operates.

But the issues are complex, and it is probably premature to reject the

concept of generalized motor programs and schemata, as a number of lines

of evidence do support them relatively well. But it gives us strong

motivation to consider other ways to explain data on learning and transfer.

Generalizations an1 Future Directn'n''

In the previous pages we have described a number of important ideas

from the literature on movement control, and have attemoted to show how

such concepts might be merged with various phenomena involved in

transfer of motor learning. The outcome provides mixed messages, with

some interesting suggestions about the basis of motor control transfer, but

at the same time with some serious shortcomings.

On the positive side, we appear to be close to identifying some

important invariant features that are a part of the representations of at

least programmed acts, the most important of which was the idea tnat

relative timing is reasonably well preserved across changes in a number of

surface" features such as movement time and movement amplitude. If so,

then an exciting possibility is that this relative timing structure can be

used as a kind of "fingerprint" to identify whether, or under what

conditions, a particular movement program has become a part of, or has

been transferred to, some other movement task. As we indicated, these

ideas have a number of weaknesses, and they do not account for the precise

details in ,ie data very well (e.g., Gentner, 1985). Pernaps future models

along similar lines will be able to account for the pnenomena more :.%,

effectively. If this ca'n oe done, then a number of irnport-ant hypotheses can

be evaluated with respect to what is learned, and what is transferred.

Even if these ioeae, about the nature of generalized motor programs do

not provide the kinds cf explanations we need, the fundamental data about

-. . . . . . . - . , . . . . , . . . . o,

o " '/ "o .' " / . * . . . * " " il % * . . * 5 ° * **"* " " 5-.° ' ' ' ' % ° . ° ' ' % " . ' ' ' ' " o . % ° " *
Transfer of Motor Control 38

the specificity of skills, the sensitivity of these correlations to apparently

small changes in task situations, and the underlying motor-program

structure of at least quick actions seem to help considerably in

understanding the important findings in transfer of motor learning. The

overall amount of transfer found is apparently low because of the lack of

commonality among even similar-appearing movement tasks. The lack of

negative transfer, and the nearly perfect long-term retention of mny

skills, may arise because there are almost no tasks which are similar

enough to interfere with a particular learned action. And, understanding

some of the fundamental ideas of motor proqrammr, may provide a way to

explain why part practice is effective for slow, seauertial actions, and is

essentially ineffective for quick movements. The answers are incomplete

about movement programming, and there are as a result many gaps in our

capability to apply these findings to transfer phenomena. But with the

additional emphasis on kinematic and kinetic analyses of movement skills,

progress in this area is occurring quickly, and these newer insiqhts should

nave relevance to problems of transfer of movement control in the ways we

nave suggested here.

But a final problem is that problems of movement transfer have not

Deen studied very extensively in the past few decades. In reviewing the

recent literature on transfer in preparation for writing tnis cnapter, we

were shocked to find so little interest in problems of transfer of movement

control capabilities represented in the literature. We find this curious, as

trai.3fer is certainly important in its own right, related as it is to

simulator design and many training methods We also see transfer as being

more fundamentally related to, and perhaps inseparable from, larger

.. problems of motor learning, which has also been relatively neglected

lately We do detect a renewed irterest in motor learning, fueled by the

* interesting new findings in contextual interference discussed briefly here,

............ . I
Transfer of Motor Control 39

as well as new insights into the ways that feedDack processes operate to

maximize learning (Salmoni, Schmidt, & Walter, 1984). This rekindled

interest in learning, together with the presently strong emphasis on

kinematic and kinetic analyses that inform us about motor programming

processes, should contribute strongly to the related area of motor transfer,

hopefully generating a more systematic approach to problems in transfer

that have been awaiting a solution for so long.

.1.

4 • .
4Transfer of Motor Control 40

Ref erences 1

Abbs, J.H., Gracco, V.L., & Cole, K.J. (1 984). Control of multimovement

coordination: Sensorimotor mechanisms in speech and motor

programming. Journal of Motor Behavior 16, 195-231.

Adams, .A. (1971 ). A closed-loop theory of motor learning. Journal of

Motor Behav ior, 3 1 1 1-IS.

.N.

Armmons, R.B. ( 1958) Le mouvement. in G, Seward & J Seward (Eds.),

Current psychological issues. Essays in honor of P. Wocaworth. New York:

Holt.

F~m-Y., ,Amm~:,~ ,& 1or an, P.L.. (S Tr-,F er ,F --ill 3nd

,%,e31ta factors alonq tne speed dimensions in rotary pursuit.

Z~orrc_2tuo 1 and Mo)tor Sk.j1-Is 6£ 43.

Armstrong, T.P. ( 1970). Training for the production of memorized movement

patterns. Technical Report No. 26, Human Performance Center, University

of Michigan.

Bachman, J.C. ( 1961 ). Specificity vs. generality in learning and performing

two large muscle motor tasks. Research Quarterly 32 3-11.

Baker, K.E., Wylie, P.C., & Gagne, P.M. ( 1950). Transfer of training to a motor.

skill as a function of variation in rate of response. Journal of

Experimental Psychology. 40 71-732.

Bray, C.W.(19'28). Transfer of learning. Journal of Experimental

Psyv-holcg, I11 443-467.

Catalano, j.F, & Kle iner, B.M. (19g84). Distant transfer and practice

variabi 1 itv Perceptual and Mjotor Sk~ i c 8 85 1-856.

i , 51 i (in press) An inform.3tion processing percpective on the

transfer of training problem. In S.M. Cormier & J.D. Hagman (Eds.), .

Qrlan-do, FL Academic Press.

Crao, P E., Houk, J C , & Hasan, Z. (1976) Regulatory actions of the human

stretcr) reflex. Journal of Neurophysiolog 39, 925-935.

Davis, W W ( 1898). Researches in cross education. Studies from the Yale

Psychological Laboratory 6., 6-50.

4 .- %
Transfer of Motor Control 41

Del Rey, P., Wughalter, E.H., & Whitehurst, i (1982) The effects of

contextual interference on females with varied experience in open sport

skills. Research Quarterly for Exercise and Sport, 3 108-1 15.

Denier, van der Gon., J.J., & Thuring, J.P.H. (1965). The guiding of human

writing movements. Kvbernetik. 2 145-148.

* Dewhurst, D.J. (1967). Neuromuscular control system. iEEE Transactions on

_iomecidcal Eralneering,. 14, 167-1 71.

Dunham, P. (1977) Effect of bilateral transfer on concidence/anticipation

performance. Research Quarterly 48, 5 1-55.

~~ A. . o riof nucle 'Erct -+i- ~

oequil!orium point of the muscle-load system Bicnhvsics I9. 544-548.

-'ishman, E.A. (1 957). A comparative stU.dy of aptitude patterns in

unsKIl led and sKilled psychomotor performances. Journal of Apptled

Osycnology 41. 253-272.

.I Fleisnman, E.A. (%55). The description and prediction of perceptual-motor

skills learning, in R. Glaser (Ed.), Training research and education. New

Fleishman, E.A., & r.empel, W.E. (1955). The relation between abilities and

improvement wrtn practice in a visual discrimination task. Journal of

ExDerimental Os'chology, 49, 301-312.

Fleisnman, E.A., & Parker, J.F. (1 962). Factors in the retention and

relearning of perceptual-motor skill. Journal of Experimental

Psychology .- 1 5-226.

: Fleishman, E.A,& Pich, S. (1 .Role of kinesthetic and spatial-visual

abllities in perceptual motor skill learning. Journal of Experimental

Forssberg, H., Gri!Iner, 5, & Rossignol, S (1975) Phase dependent reflex

r.?VerSal during wa!king in chronic spinal cats Brain Research 85.

103- 107.

Fumoto, N (1981) Asymetric transfer in a pursuit tracking task related to

a cnange of strategy. Journal of Motor Behavior 1 3 1 97-206.

Gentner, D.R. (1985, Skilied motor performance at variable rates- A
Transfer of Motor Control 42

composite view of motor control. Technical Report No. CHIP 124, Center

for Human information Processing, University of California, San Diego.

Guthrie, E.R (1 952). The psychology of learning (Rev. ed.). New York: Harper

and Row

Henry, FM. ( 1958/1968). Specificity vs. generality in learning motor skill.

In R.C. ,rc'n & G.S. Kenyon (Eds.), Classical studies on physical activity.

Enqlewoo" Cliffs, NJ. Prentice-Hall. (Originally published, 1958).

Henry, F.M, & Harrison, J.S. (1961). Refractoriness of a fast movement.

Perceotu, and Motor Skills, 13, 351-354

-,qers, D.E. (1 950). ncrease1-,. re'-- --se latency for '

-omp..cazo movements and a "memory rurr," theory of neuromotor

reaction. :kesearch Quarterly 31, 448-458

Hicks, RE., Frank, J.M., & Kinsbourne, M. (19 82) The locus of bimanual skill

transfer .,e Journal of General Psychology, 107. 277-281.

.Holierbach, ,J r-. (1981). An oscillation theory of handwriting. Biological

Cybernet'c 3,. 139-156.

Hull, CL. _,) Principles of behavior. New York. Appleton Century Crofts.

Husak, W5 , & Reeve, T.G. (1979). Novel response production as a function of

variability and amount of practice. Research Quarterly 50. 215-221.

James, W ( 1590). The principles of psychology (Vol. 1). New York: Holt.

j en.se r, . ( 976). Pretask speed training and movement complexity.

Research Quarterly 47. 657-665.

jonnson, R.M cCabe, J. (1982). Schema theory A test of the hypothesis,

varlatior -,practice Perceptual and Moto- El 1s. 5 5,23 1 -234.

S.,eele, S.W ( 68). Movement control in skilled motor performance.

Psycnoino_ ,i Bulletin 70, 387-403.

kelso, J A.S.. Douthard, D.L., & Goodman, D. (1 9 On the nature of human

interlimu coordination Science 203 1029- 1031

Kelso, J.A S, Tuller, B., Vatikoitis-Bateson, E, & Fowler, CA (1984).

,-..Functionally specific articulatory cooperation following jaw
Transfer of Motor Control 43

perturbations during speechr Evidence for coordinative structures

* ~journal of Experimental Psychology Human Perception and Performance.,-

I Q. 812-832.

K~err, R., & Booth, B. ( 1977). Skill1 accuisition in elementary school children

-1na schema theory. In D.M. Larnoer3 & R.W. Christina (Eds.), Psycnology of

miotor behavior and sport (Vol. ).Ch ampaign, IL: Human Kinetics Press.

?-,er R., & Booth, B. (1978). Specif ic and varied practice of motor skil11

Derceptual and Motor, Skill s, 46, 305-40l1.

n.3ley, K.S. (1917). The accuracy of movement in the absence of excitation

from the moving organ. Amer 1,car i~ournalI of Physiology 43 1I94.

~ ,T.D. (in press). Testing for moctor learning. A focus on transfer

a-ppropriate practice. In 0. Mei ier, & K Roth (Eds.), CompleX moto~r

E'ehavior: Action and motor theo-'es Amsterdam: Elsevier. b

d~"

Lee, T.D., & Magill, R.A. ( 1983). The locus of contextual interference in

motor-skill acquisition. Journal of Experimental Psychology Learnn.

~emry.and Cognitiion. 9, 7-3O-746.

i-ee, T.D., Magil11, R.A., & Weeks, D~ (. 985). Influence of practice schedule

on testing schema theory pred.cictions in adlults. Journal of Motor

7-enavior j17, 283-299.

Le rsten, K.C. (1968). Transfer of movement components in a motor learning ts.Research Quarterly, 39, 575-58 1.

*Lewis, D., McAllister, D.E., & Adams, J.A. ( 1951) Facilitation and

Interference in performance on the modified Mashburn apparatus. 1. Tne

effects of varying the amount of original learning. Journal of

Experimental Psychology A. '147--260.

Lewis, D., Smith, P N., & McAlllster, D E. (1952). Retroactive faC1,1tia'ln arnd

interference in performance on the modified 2-hand coordination task.

Journal of Experimental Psychclogqy 44, 44-50.

Liircoin, L R.S., & Smith, K.U. (1951) Transfer of training in tracking

performance at different taroet -=Deeds. Journal of Applied Qsycnclc.1y,

35358-362.

Logan, G.D (1982). On the ability to inh ibit complex movements: A

stop-signal analysis of typewri t iri Journal of Experimental ycoly ...............................
a'..' ~ ~ ~ ~ -WW %1~U*WI 

Trans~e, .)f "otor Control 44

* Humlan Derception and Performrvc. L 778-793. ad

Lintern, G. ( 1985). A perceptual lecjrron model proposed to account for

5i11i transfer in manual control Ur:cubijshed manuscript. -

Lordani, D.S., & Archer, J.E. ( 1958) Transfer effects on a rotalry pursu,,t

task. as a function of first task dlffozulty. Journal of Expe7!rnmenta)

Psychology 56, 42 1-426.

Lc toter, W. 5. (1960). Interrelatiornsrp27 -nmona reaction times an- scp?ns

movement in different flm~ns. Ri?~Cr 0uar t erly 3 715

t Nurteniuk, R.G., MacKen.-ie, C.L., D ~1. M.: (984/\_ Bimanual moveirentl

= c*t o' PInformation r cs~ n~teantion e ft ~~

.'ourmal of Experimental Qsvcn,, c%m~ 53

Y L~hserD.E. ( 1952)Y Retroact-1ve c- to and intorfernce-IS

-,cton of level of learninc Jora f sc1n oa 

-32.

lc, 1,s ter, D.E., & Lew is, D_(~) .a~tto and interference ~

cperformance on the modi fed ns~r apoaratus:- 11. The effct of

va,:',,nc the amount of interpolateo etairning. Journal ofExeir'a

Dcvcr~oogy. 41 356-363.

M , Cr-G.-, ccken, H.D., & Stelmach, (1977). A test of the scriera trneor- of

discrete motor learning. Journa c- Moto BehviOr. j 1-20 1.

* -lertcr, P A. ( 1972). How we conto tne contraction of our muscles.

S.cientific American 226 303

* ~ 1u-1cc~-~,B1.B. (1957). Transfer an,%r.,,V formulas. Py~i~~

* ;]mllk 35 & Archer, J .(90 ~l ransfer -S a furnctio- o

intertisk. interval and ore-transre ta7s difficulty. joujrnal1 of

J vi o, JC, &B5r ig gs, 3E, 7i :t~ of task comrPle-t/ anc t:

-raization on tre elatlv-z :f -art and w0Cole tr ~inj

metod .JUrnal f Dert :C~lg 1 7-2214.

)stry, iD.J.. & CooKe, J.D (in press ,,rrntlc patterns in s~e~aro i mo

Movements. In E. Keller &I M " Eds.), Symposium or) mrotor* and

2....................................
Transfer of Motor Control 45

sensory languagae processes illsdale, NJ: Erlbaum.

Parker, J.F., & F Ieishm an, E.A. ( 1960). AbilIity factors and comoonent

performance measures as predictors of complex tracking behavior.

Psychological Monogjrapls 4(W'hole No. 503).

3ese, D.G., & Rupnow, A. A. ( 1985) LEf fec ts of vary ing f orce proauct, 1on i n

practice schedules of children learning a discrete motor task De%~eOtijal

mDd Motor Skill s 572 275-22

P, gott, R.E., & Shapiro, D.C (1&%4. Motor scnema. Tre structure 01, rie

variability session. Research --Ij.--,terlv for.Exerc-ise and Spcrt H,41-45. Pv

::4 retz, S.L. (1953). Bilateral t-lncfer: The effect-, of practice or,:~

ransfer of complex aance mie-vemnent patterns. Researcn Quar-: or

Exercise and, Sport 54, 48-:-:

31nert, M.H. ( 1977). Motor c t and learning by the saes~~~il

Technical Report No. AI-TRP-439, Artificial Intelligence Laboratory, MIT.

Ross, I.D. 1974). Interferen-eir, ciscrete motor tasks: A test of nteoy

Pr.D. dissertation, University of Michigan.

Pvan, E.D. (1 962). Retention of sta~bi lometer and pursuit rotor ski I s

Researcri Quartgriy. 33. 59-7-598.

Salmoni, A.W., Schmidt, R.A., &Walter, C.B. (1984). Know ledge of resqults

and motor learning: A review 3nd critical reappraisal. Psycrolcomc7J

Bulletin 95, 355-386.

Schmidt, R.A. (1975). A schema th'eory of discrete motor skill iayrng.

c~vc1clnogica1I Review. 22!:-2;_60.

Dcnmridt, R.A. ( 1976). Control Drce-sses in motor sKills Ex ~~~Snort.''

5ciences Reviews 4.29 %

Scnmnidt, R.A (1982) Motor cnr,rci1 an dleyrn A behavioral 

ChaMP3ign, IL Human Kinetic: Dress

zS:cnm idt, R.A. I1985a). The searcn, for invariance in skilledrovmt

behavior Research Quarte!rly, for, Exercise and S1port. 56, 1 85-20'r

Schm i dt, R.A. (1I 985b). I derit f v, units of motor behavior Th~5lea~ca

and Brain Sciences. 153-
* 'r--.-fer of Motor C:-146

Schmidt, R A. (in~ press) Crtongthe temcra~ stucu.

movements. The B ena\'Ior---, .-nd Brain Scier,ce-;

Sch~midt,P A, 7herwccid, LD. Zan i k, H N., 3 e~u .

Speed-accuracy trade' 0 ff' in motor oehavior Tncnesc' . us

varlabi'ltv H. Heue,. u r*- 1 mibec,&K- ci'a

behavicr ;-ooramrin m ri- :tro1. and cu1 rHeao~

Sprina-Verlao.

Seymurw.D 194) ... er ntson the acqul ictri of rutWskills.

'71 -7 fer of :- -r -srented -

1: An .A- r.u e:' Marc1,h, 197 7

7, n 1-' Of aeneravie 'ctc :-r D.

d1se:2lc nvers,,t.' -7 couthern C.A Ijf or-i~

Sh)P o. 9C0h':,~~ 2). The scrier a triecr- ,Kceievidence

and de1vneta1 m:'ctons. In J.A.S. Ke:!so & j. E, Yi~~ --s), The

Jeveloor.ner+ of moverne,- -- ntrol and cooc a'n. New Wiley.y*

~narc D& ~r'm~z, '983). The ron.ro; of direct ico raoid

aiminq mcvements. 3cit"for Neurosclenitce .osrc,__ 1031.

Shapiro, DC, & Wal ter. !Z.E. 19'34). The control of raoid Dositiornng rmovements wA.ith sp at tctmcoral constralnts. UnubIlished m3-uscript, UCLA.

* Shpiro Dr ~mir~, ~~-Qor, R.J., & 3D 1) 8-s:' E jidence f or

aene~'zi -motor procr.-r-m u:in gt-pattem" anaiysis*i'aloMtr

retentior> Jr'i trnsfer of a rnoo s, l Jon ri

Dc!c:'-ua vDr~~ Lear,~r 87

3 hea,, .P. ,Zrnnv, T r ontext effect: i n m emrry -r .?ngjF 

MoVernrt 'fr tc \Magill (Ea..,, t-er-Dry ana oc~ f action

Amster ,, -r, 'ioth--ic

Sherwood, ~L cmi dt A,_. Walter, C.B. ( p6).Ricmvetswh

reversals ,r oarectioT, Cc,trol Of MOVemner~t 1mDl1LtUaEf 3,1 'nertial
Transfer of Motor Cro 47

load. ranuscriot in preparation, UCLA.

del

Siegel, D., & Davis, C. ( 1980). Transfer effects of erigat specific

speeds on performance over a range of sneecc :',rcz Dtual and Motor

Slater-Hammn-e*U AT. (1960). Reliability, --Ir~ rer~oInS;C

transi rac T ior e)- earch Quarteri l y fatoies.c

.4 r- T. ar- t Part and whole :t -c-ck c o tas. E'f acts V"' tas a 3r. m U-1 O f prctcec;: :- Motor 5,1!s. 5

- , a sK i~. Journal1 f miotnr -ka 9.

SA.,-, (1 968). Movement i te n"> arsence of

sensr fee=7'cK in S.J. Freedman S Coo of~

Sotan rier,-ed behavior. Homewood, L. FLorz v Press.

Terzuolc, C.A., Ex& Viviani, P. (1979). The centr.-l! reE'-.sentation of learning

motor pr cramsr. In R.E. Talbot & D.R. Humpnrev, Ea.,Pocture and

mo veentn*. New YorK:. Raven Press.

Tsui I, K., C&x!Qe, Y 1I974). Development of batr' transfer skills in the

mirrorJ~ rancJanese Psychological Rosc. ,j 7118

* Wadmrar WJDener van der Gon, J.J., Geuze, P H .Mol, C.R. (1979).

Control of fast qoal directed arm movements. -;rurnal of Human

Mcve'~t 5=ces' 5, 3- 17.

We1;E:X El-a teral transfer in tne -mctor ;P7.r, ig of young chflaren)

ancd a7-cts r t-'-Pvaloprert 3. 247-2,57

Wrisce,r-o A., & ecBJ ( 1981). Ant ici Pat'c ln- -mncidence in chidrer.

A test o schema~ theory Perceptual and Mot, 5v us 52 599-606.

V*AI Ir SDe'r, CA -~ leau-, B.J. (1983). Deve lc-in coi;rc ient tim ing skill in 5

cil'eiAcm rln of trrinmng metnla iErr Quyterly for

:x~':'an-,, z: n- 54. 67-7-4

Zelaznik, N- H3awkins, B., & Kisselburr). L U 7P Rad visual feedb,3ck

procecsinq in inale-aiming movements Jc rrla orf Motor, Behavior. 5.

2 17 -25.
Transfer of Motor Control 48

Zelaznik, .N., Schmidt, R.A., & Gielen, CC.A.M (1986). Kinematic properties of rapid aimed hand movements. Manuscript submitted for publication,

Durdue University
Transfer of Miotor Control 49

Footnotes

I Other models, also using sensory information from the responding

musculature as a critical feature, are possible also. See Fel'dman (1974)

for one such example, and Schmidt (in press) for a critique of it. 7

2- he use of the term "transfer test" is in some ways unfortunate, as it

,mvies a shift to a different task. What is meant here, -iowever, is a

7ar'ferto Common conditions of a given task. But this 3oair n ict

the diffilcu'ties in deciding when a change in conditions is to be conisiulered

veeenough for it to be regarded as a change in "task."
Transfer of Motor Control 50

Figure Captions

1. Rectified EMG patterns from a rapid arm movement (Normal), and for

trials (Blocked) on which the movement was unexpectedly blocked

mechanically) many features of the EMG patterns occured even though the

limb was prevented from moving (after Wadman et al., 1979).

2. Position-time trace of a goal movement pattern (solid) and of a trial

which was Derformed too rapidly (dotted); the dotted trace appears to De

roughly "combressed" in time (after Armstrono, 1970).

3. Performance on the two-hand coordination test over trials. (Upper

graph, groups classified as high and low on kinesthetic sensitivity; lower -.

'-aoh. arouDs :lassified as high and low onalal .D'ta f' "

Pleishman & !ich, 1963).

4. Hyothetica* performance curves on Task B f.r Grouo (oric ,ra",' e

on Task A) and Group II (without prior practice on TaSK A), whether

transfer is positive (left) or negative (right), percentage transfer is

j(X-Y)/(X-C) x 100] (from 5chmidt, 1982).

5. Proportions of time for the seven segments in a wrist-twist task for

right-hand practice and after transfer to the left nand (after Shapiro,

1977) "'")

6. Mean decrement in number of correct matches on the Mashburn task as a

function of number of original learning trials and the numDer of

reversed-task interpolated trials; clear negative transfer is shown (after

Lewis et al., 1951).

7 Absolute error in coincidence-anticipation after transfer to four

stimulus velocities outside the range of previous experience; practice"-

under varied conditions in acquisition produced less error in transfer than

practice under constant conditions (from Catalano & Klener, 1984).

8. Movement time on u discrete arm-movement task as a function of the

practice conditions in acquisition, and the practice conditions in transfer;

oractice under random conditions in acquisition produced faster

performance in transfer than practice under blocked conditions (from Shea

& Morgan, 1979). .

%*° • -% ° * ... . . . - * *.- . - .. . . ,- , .-. a- .. .- . . . i J . . ,* * . .
-97": T .

St

-Norm~al

/ Agonist

DI

Tm secl

0.0 0.1 0.2 0.3

Antagonis
IL

N.

Lefy

20~

S 15

E 1-4

R~gt 660751.2 1952.8 2902.4 35I4.

ElpeNim sc

%.-

10U

15-U.

-AL

,-A -

-UX.
-~~~T 7 TV -~ 'V~

35

S25

20

-0 Group High on "KinlestlietC Sensitivity" Measure

< 0 0GroupLow on"Kinethetic Sensitry Measure

10 0 Gru Lo on Kinetei SIsy Mesr

1 2 3 4 5 6 7 a 9 10

35

30

S25

00

~15

*Group High on Spatial Measure

< 10 0 Group Low on Spatial Measure

1 2 3 4 6 a I a 9 10

Blocks of Four One-Min. Trials

% %A
\~. L VI~.~-.~~.*-v~ ~ WL. ~.v rv v~ -.~ %~ ~W~.q ~ ~i7 -m -- 

80 0

80 y

Positive Transfer 70 - I

6so 60 -x

Q 50 5

~40 40

~iit 0530 - -- -- -

20 -C 20 -

10 to

1 6

Trials on Task B Trials on Task B
.20i.

0 Right Hand

0 0 Left Hand

0.75

C

02

0

C.

0

AT

1 2 3 4 5 a 7

Segment Number in Sequence
18 -50 Trisis of Onaina! Learning d

16 inA

14 D -30Til

12 -1

r 10

2 6 M

-2-

0 10 20 30 40 50

Number of Reversed-Task Trials

%%,
% -.

CI

L&Jz

c,

FE\~

> I Lo.

N N NaNE

3L

00 0 Lo U) 0 U) Lo

co w Lo L

(oisu jj~jiiin-os/
j. ~a. ji7J

2.0.

C.4F*anmBoce

2 3 4 5 6 10Min. 10ODay

AcusinTilBoksRtninItra

Ongial 0 10 Lamin Trnsf'Test

Z&V zp.