AM 67-6 

ADAPTATION TO VESTIBULAR DISORIENTATION 

V. Eye-Movement and Subjective Turning Responses to 

Two Durations of Angular Acceleration 

Approved by 

~~ J. RoBERT DILLE, M.D. 

CHIEF, CIVIL AEROMEDICAL 

INSTITUTE 

William E. Collins, Ph.D. 

Fred E. Guedry, Jr., Ph.D. 

May 1967 

Released by 

P. v. SIEGEL, M.D. 

FEDERAL Am SuRGEON 

FEDERAL AVIATION ADMINISTRATION 

Office of Aviation Medicine 
ACKNOWLEDGMENTS 

Dr. Collins is Chief, Psychology Laboratory, Civil Aeromedical Institute; Dr. Guedry is Chief of Experimental Psychology, Research Department, 

USN Aerospace Medical Institute, Pensacola, Florida. 

This study was conducted at the Civil Aeromedical Institute in Oklahoma City with the technical assistance of Billy P. Updegraff, Ruth Ann 

Mertens, and Kathryn Quattlebaum. 

Qualified requestors may obtain Aviation Medical Reports from Defense Documentation 

Center. The general public may purchase from Clearinghouse for Federal Scientific and 

Technical Information, U.S. Dept. of Commerce, Springfield, Va. 22151 
ADAPTATION TO VESTIBULAR DISORIENTATION 

V. Eye-Movement and Subjective Turning Responses to 

Two Durations of Angular Acceleration 

I. Introduction. 

During prolonged angular acceleration, inertial 

torque deflects the cupula but the deflection is 

eventually balanced, primarily by the cupula's 

elastic restorative force. Assuming that cupula 

displacement from its position of static equilibrium controls the magnitude of vestihuJ.ar reactions, a prolonged angular acceleration should, 

according to the "Torsion-Pendulum" theory11, 

yield an increasing response for about 20-30 sec ; 

this response level should be maintained without 

decline .as long as the angular ·acceleration continues. Several authors 9•

10•

13•

18•19 have reported 

that the subjective velocity rises and declines 

during prolonged angular acceleration, contrary 

to theoretical expectations. Guedry & Ceran13 

showed that the temporal period required for the 

subjective reaction to peak (and then decline) 

was about constant ( 27 sec) for angular accelerations ranging in magnitude from 0.5 to 2° j8ec2 • 

Subsequent experiments (Guedry & Cunat, unpublished) showed this to be true for stimuli 

up to 4° jsec2 • 

The present experiments seek to compare cat 

and man in regard to several characteristics of 

the nystagmic response elicited by two durations 

of a 4° jsec2 angular acceleration. 

II. Methodology. 

A. Cats 

Apparatus. The Huffman Rotation Device6 

located in a light-proof room, was used to produce acceleration programs. Animals were tested 

on the rotator in pairs with their heads at the 

center o£ rotation. One cat box was secured to 

runners on the turntable and the second box was 

secured to a framed tier arrangement above the 

first box.7 

Restraint. Cats were restrained by the method 

of Henriksson, Fernandez, and Kohut. 16 Three 

or more days prior to testing, the animals were 

1 

anesthetized and holes were drilled transversely 

through their canine teeth. At the same time, 

fur around the ocular orbits was shaved off and 

a guideline for positioning the head was drawn 

with washable ink from the canthus to the tragus 

on each side. For testing, each animal was 

wrapped in a towel and placed in a cat box. A 

strand of piano wire was inserted through the 

holes in the canine teeth. The wire was held 

securely and the head of the animal was positioned by means of an adjustable device on the 

front of the box. 

Recording. For recording horizontal components of eye movements, needle electrodes were 

inserted by the outer canthi. Vertical components were obtained by means o£ surface electrodes taped above and below the left eye. The 

recorder was an Offner TypeR Dynograph with 

3-sec time constants used in amplification. Prior 

to testing, animals were placed in an optokinetic 

stimulator; a drum speed of 24° /sec was used 

to obtain data for calibration purposes. 

B. Human Subjects 

Apparatus. A Stille-Werner RS-3 rotating 

chair, situated in a light-proof room, provided 

the acceleratory stimuli for the human subjects. 

Recording. A pair of surface electrodes, taped 

by the outer canthi of the eyes, detected horizontal eye movements, while a second pair was 

positioned above and below the left eye for the 

rtJcording of vertical eye movement. An Offner 

Type T polygraph with a 3-sec time constant 

was used in amplifying ·and recording the eye 

movement signals. Eye calibrations were obtained prior to each test by means o£ a calibration chart located on one wall o£ the rotation 

room. 

III. Procedure. 

Each of eight cats and eight human subjects 

received '2 angular accelerations (for 8.4 and 36 

sec) stimulating the lateral semicircular canals. 
The same durations were used for the vertical 

canals. Stimuli were 4° jsec2 accelerations and 

decelerations separated by 54 sec of constant 

velocity for cats and by 120 sec of constant velocity for humans. In cats, vertical canal stimulation was accomplished by placing each animal 

on its right side to locate its sagittal plane at 

the center and in the plane of rotation; human 

subjects leaned forward with the head turned to 

place the sagittal plane of the skull in the plane 

(and at the center) of rotation. A biteboard 

and head rest assisted in this positioning. Stimuli were presented in a counter-balanced order 

as indicated in Table 1. 

Neither the cats nor the human subjects had 

been used in previous vestibular experiments. 

For the humans, this necessitated instruction regarding the signalling of subjective events without actual practice in making such judgments; 

they reported onset and cessation of apparent 

rotation by means of a signal key. 

TABLE 1. Order of stimulus presentation. All trials comprised stimuli of 4 ° /sec2• Duration 

of the stimulus was either 8.4 or 36 seeonds. L and V refer, respectively, to lateral and 

vertical canal stimulation. 

Human Rotation 

SubJects Cats Direction 

Or& Wa 100 & 101 cw 

Nu & Jo 102 & 103 ccw 

Pe& Me 104 & 105 cw 

Fr& Ma 106 & 107 ccw 

IV. Results and Discussion. 

The 8 animals received only 4 trials (2 lateral 

and 2 vertical canal stimulations) on the first 

day. Some examples of recorded nystagmus 

appear in Figure 1. The critical portion of the 

response for several purposes of this study began 

at the end of each stimulus. Thus, time measurements were made from the end of each stimulus 

Trials 

1 2 3 4 

8.4 L 36.0 L 8.4 v 36.0 v 

36.0 L 8.4 L 36.0 v 8.4 v 

8.4 v 36.0 v 8.4 L 36.0 L 

36.0 v 8.4 v 36.0 L 8.4 L 

(a) to the end of the primary response and (b) 

to the start of the secondary nystagmus. The 

number of beats of primary nystagmus which 

followed stimulus termination was also tabulated. 

These data appear in Table 2. In 47 of the 48 

comparisons, the primary post-stimulus responses 

to the 8.4 sec stimulus exceeded those of the 36 

sec stimulus. 

TABLE 2. Measures of primary nystagmus following the termination of each rotatory stimulus for cats. Each response 

value is a mean of responses to an acceleration and a decleration stimulus. Stimuli were 4° ;sec2 for either 8.4 or 36 

seconds. 

Time From End of Stimulus to Time From End of Stimulus to Beats of Primary Nystagmus 

End of Primary Nystagmus (Sec) Start of Secondary Nystagmus (Sec) After End of Stimulus 

Lateral Vertical Lateral Vertical Lateral Ve:tical 

Cat 8.4 36 8.4 36 8.4 36 8.4 36 8.4 36 8.4 36 

100 9.2 2.5 6.5 0.5 12.9 5.7 11.1 3.4 8.8 2.8 9.0 1.0 

101 11.4 7.0 7.9 7.0 14.4 8.7 9.1 9.4 14.8 10.0 11.5 7.8 

102 3.2 0.5 25.7 5.7 6.0 0.9 28.3 9.1 3.3 0.5 18.5 4.0 

103 4.9 4.4 8.8 4.2 8.1 6.3 18.1 6.2 3.5 1.5 7.5 3.5 

104 10. 7 5.4 8.2 3.1 12.0 6.6 10.9 3,9 8.8 2.0 7.0 2.5 

105 13.8 6.9 13.6 3.0 15.8 10.4 14.6 4.3 14.5 8.0 10.0 2.8 

106 11.5 5.7 6.0 4.8 14.7 7.0 7.7 7.2 10.0 4.5 5.5 4.5 

107 10.9 8.2 6.0 -1.5* 14.6 11.0 17.5 3.7 7.5 6.0 6.5 1.0 

M= 9.5 5.1 10.3 3.4 12.3 7.1 14.7 5.9 8.9 4.4 9.4 3.4 

* Nystagmus ended during stimulus. 

2 
Plots o:f the complete nystagmic responses to 

the 8.4 and the 36 sec stimuli appear in Figure 2. 

Slow-phase output was scored by summing the 

vertical displacements o:f beats :from peak to 

base-line :for successive 3-sec intervals. Greater 

output o:f primary nystagmus is evident :for the 

lateral canals, as compared with the vertical 

canals, :for both stimulus durations. For the 

8.4 sec stimuli, primary nystagmus increased 

throughout the stimulus. period :for both the 

"horizontal" and "vertical" curves. For the 36 

sec stimulus, there was a marked peaking i!l the 

response to stimulation o:f the vertical canals 

during the 15-18 sec interval, and a steady decline o:f that response throughout the remainder 

o:f the stimulus. For stimulation o:f the lateral 

canals during the 36 sec stimulus, peaking occurred in the 18-21 sec interval and was :followed by a lesser decline than that noted :for the 

vertical canals. 

Secondary nystagmus was also plotted in 

Figure 2. With only one exception (the 8.4 sec 

stimulus to the vertical canals :for cat No. 100), 

scorable secondary nystagmus was obtained :from 

each cat :for each stimulus condition. For both 

vertical and lateral canal responses, the 36 sec 

stimuli produced greater secondary responses 

than did the 8.4 sec stimuli. In addition, horizontal secondary nystagmus showed greater output than vertical secondary nystagmus by 

amounts proportional to differences in their respective primary reactions. Further, the mean 

peak o:f the secondary response occurred 21-24 

sec after the end o:f the 8.4 and 36 sec stimuli for 

horizontal nystagmus, and 15-31 sec after the 8.4 

and 36 sec stimuli for vertical nystagmus. 

To pursue :further the relationship o:f secondary 

to primary nystagmus and the effects o:f prolonged stimuli on those responses, six of the animals were given, one day later, a series o:f 15 

trials stimulating the lateral canals with the 

4° jsec2 stimulus for 36 sec duration. Tracings 

for trials 1, 5, 10, and 15 were scored and the 

data plotted in Figure 3. With repeated stimulation, a marked depression of both the primary 

and secondary response curves occurred, peaking 

of the response was :followed by a decline in 

nystagmic output during the remainder o:f the 

stimulus, and the peaks o:f both primary and 

secondary nystagmus shifted toward earlier occurrences. 5 

A. Human Subjects 

Eight human subjects ( 4 males and 4 females) 

were given stimulations identical to those administered to the cats. Nystagmus data were 

also scored similarly and appear in Table 3. 

Some examples o:f nystagmus tracings are presented in Figure 4. In addition, duration o:f the 

sensation o:f turning was calculated from the 

end of each stimu7JUs to the end point of the 

sensation (Table 4). 

In 20 of the 48 comparisons (Table 3), human 

responses to the 36 sec stimulus exceeded responses to the 8.4 sec stimulus (9 of these cases 

were :for the "number of beats" measure) and, 

TABLE 8. Measures of primary nystagmus following the termination of each rotatory stimulus for human subjects. Each 

response value is a mean of responses to an acceleration and a deceleration stimulus. Stimuli were 4 ° /sec~ for either 8.4 or 

36 seconds. 

Time From End of Stimulus to Time From End of Stimulus to Beats of Primary Nystagmus 

End of Primary Nystagmus (Sec) Start of Secondary Nystagmus (Sec) After End of Stimulus 

Lateral Vertical Lateral Vertical Lateral Vertical 

Subject 8.4 36 8.4 36 8.4 36 8.4 36 8.4 36 8.4 36 

Nu 24.7 18.9 21. 1 7.6 32.9 26.5 55.2 13.4 18.5 14.5 15.0 9.0 

Or 29.8 34.7 16.1 26.5 32.0 36.6 9.8 9.0 92.0 61.5 25.5 23.0 

Me 32.0 25.4 16.0 14.6 38.6 32. 1 24.2 16.5 25.0 24.5 13.0 9.5 

Wa 42.4 33.0 8.5 10.5 48.1 38.6 13.6 14.9 23.0 32.5 5.0 10.5 

Pe 1S.2 23.2 6.2 11.2 21.6 24.5 9.S 19.2 9.5 21.0 2.5 9.5 

Fr 36.2 30.4 22.4 9.0 39.8 30.1 15.8 14.5 38.5 45.5 16.0 13.0 

Jo 37.1 36.1 15.8 4.9 36.6 32.6 8.0 36.0 47.5 6.5 7.0 

Ma 41.0 38.8 9.4 13.7 41.4 43.0 20.2 17. 1 54.5 77.5 7.5 10.5 

M= 32.7 30.1 14.4 12.3 36.4 33.0 21.2 14. 1 37.1 40.6 11.4 11.5 

3 
although the mean group data for "duration of 

primary nystagmus" and for "time from end of 

stimulus to start of secondary nystagmus" were 

longer for· the 8.4 sec stimulus, the differences 

were slight. Mean number of beats of primary 

nystagmus following stimulus termination actually favored the 36 sec over the 8.4 sec stimulus, 

but the differences were not significant. Thus, 

results obtained from the cats, in which the poststimulus nystagmic responses to the 8.4 sec stimulus consistently exceeded those of the 36 sec 

stimulus, were not borne out in the data from 

human subjects. 

TABLE 4. Time in seconds from end of each rotatory 

stimulus to end of subjective turning experience for uuman 

subjects. Each value is a mean for an acceleration and a 

deceleration stimulus. Stimuli were 4 ° /sec 2 for either 8.4 

or 36 seconds. 

Lateral Canals 

Subject 8. 4 

Nu 

Or 

~e 34.5 

VVa 27.8 

Pe 11.0 

Fr 23.1 

Jo 20.4 

~a 7.7 

36 

29.5 

12.4 

14.9 

6.7 

14.3 

12.4 

3.1 

Vertical Canals 

8.4 36 

12.5 9.3 

44.0 9.2 

10.4 23.7 

7.7 2.0 

11.5 28.6 

19.9 -1. 3* 

7.4 -15.1* -------------------------------

~ = 20.8 13.3 16.2 8. 1 

*Subjective turning experience ended during stimulus. 

Human subjective data (Table 4), in 11 of 13 

comparisons ( 3 comparisons were not obtained), 

showed that the 8.4 sec stimulus resulted in sensations of longer duration after termination of 

angular acceleration than did the 36 sec stimulus. 

For bvo subjects the sensation to vertical canal 

stimulation ended during the 36 sec stimulus. 

Time plots of the nystagmus recorded during 

the two stimulus conditions appear in Figure 5. 

Responses from the lateral canals ·were of greater 

magnitude than those from the vertical canals. 

No clear peaking or decline in output during the 

stimulus appeared for either set of canals. Secondary nystagmus was plotted in the same figure. 

How·ever, of the 8 subjects, 6 gave no scorable 

secondary responses to the 8.4 sec lateral canal 

stimulus, 5 gave none to the same stimulus applied to the vertical canals, 3 gave none to the 36 

4 

sec vertical canal stimulus, and one gave no scorable secondary nystagmus to the 36 sec lateral 

canal stimulus. Thus, in two general respects, 

human data differed from cat data: 1) humans 

did not show a rise and decline during prolonged 

(36 sec) stimulation whereas the cats did; 2) 

little or no secondary nystagmic reactions to the 

8.4 sec stimuli were demonstrated by humans 

whereas cats consistently gave such responses. 

Arousal. The importance of arousal on nystagmic responses was noted earlier and has been 

examined in considerable detail elsewhere. 3 To 

assure reliability of the present data with regard 

to this :factor, a second group of 10 cats was 

treated with d-amphetamine in accordance with 

procedures described by Crampton and Brown.8 

Each animal received 4 trials with each trial 

comprising an acceleration stimulus of 4° jsec2 

for 36 sec, 2 min of constant velocity, and a subthreshold deceleration ( 0.15° jsec2 ). The first 

two trials \Vere always stimulation of the lateral 

canals; the remaining two trials involved vertical canal stimulation. Trials were alternately 

CW and CCW. Half the animals began with 

CW rotation; the remaining 5 began with CCW 

rotation. Data from CW and CCW accelerations 

were similar for the horizontal and the vertical 

nystagmus curves and, therefore, were averaged. 

The mean response curves for the 10 animals 

appear in Figure 6 and demonstrate the same 

type of decline during stimulation and almost 

identical transition points from primary to secondary nystagmus as those presented by the undrugged cats. Vertical nystagmus again shows 

a more pronounced decline during stimulation 

than does horizontal nystagmus. Some supportive neural data for this decline of response 

during stimulation of the cat has been presented 

by CappeJ2 who showed plots of single neural 

unit activity during a ·prolonged angular acceleration and reported a rise and decline of 

firing during the stimulus period. 

A reliability check of the findings for humans 

was accomplished by exposing 4 males and 4 

females, all previously untested, to stimulus 

conditions ( 4° jsec2 for 36 sec) identical to those 

administered to the other human subjects. Hal£ 

of the males and females received CW stimulation, the remaining half received CC1V rotation. 

Four trials were administered, two each for the 

lateral and vertical canals. The first two trials 

always employed mental arithmetic (MA) as 
an arousal taskS, while in the last two trials, the 

Key Press (KP) technique of estimating subjective velocity was used to maintain alertness. 

With the KP technique, the subjects attempted 

to signal successive angular displacements of 90°. 

Table 5 contains an outline of the test procedures 

for this reliability check. Nystagmus data for 

acceleration and deceleration and for the two 

tasks showed no evidence of a fall-off in response 

during stimulation, and the primary-to-secondary 

nystagmus transition points were almost identical 

to those obtained under the first set of conditions. 

The data were thus combined and curves depicting horizontal and vertical nystagmus were 

plotted in Figure 7. As in the first group of 

human subjects, no clear evidence for a decline 

of response during the stimulus is evident. However, the vertical nystagmus time-plot does show 

considerable irregularity as compared with hori· 

zontal nystagmus data. Thus, the differences 

between man and cat that were obtained from 

the first groups of subjects were confirmed with 

different subjects and under conditions in which 

the arousal variable was manipulated. 

TABLE 5. Order of stimulus presentation for human subjects used in the reliability check. 

Arousal of subjects was controlled by Mental Arithmetic and Key Press tasks. All trials 

comprised accelerations and decelerations of 4 ° /sec2 for 36 sec separated by 2 min of constant 

velocity. 

Subjects Rotation Mental Arithmetic Key Press 

Male Female Direction Trialt Trial2 Trial 3 Trial4 

A w cw Lateral Vertical Vertical Lateral 

B X cow Lateral Vertical Vertical Lateral 

c y cw Vertical Lateral Lateral Vertical 

D z cow Vertical Lateral Lateral Vertical 

It has been reported that vestibular nystagmus 

rises and declines, like the subjective reaction, 

during constant angular acceleration. 1 •

17•

20•21 

However, Guedry & Lauver15 demonstrated that 

the nystagmic reaction in man did not decline 

during prolonged constant angular acceleration 

if the subjects were required to signal estimates 

of angular displacement. Occasionally, however, 

a subject would yield a rise and decline in the 

nystagmus response similar to the subjective responses in earlier experiments (see Figure 4 in 

Guedry & Lauver15 ). To check the possibility 

that arousal accounted for the variety of findings, Collins & Guedry4 required subjects, during 

prolonged angular accelerations, to perform 

mental tasks, which would maintain mental activity independent of the subjective perception 

of rotation. Subjects were required to make 

arithmetic computations throughout the vestibular stimulation and post-stimulation periods. 

Results showed again that nystagmus first increased and then remained constant during constant angular acceleration. Following the termination of stimulation, nystagmus decayed about 

as expected from the "torsion pendulum" theory11, 

although rates of decay were not calculated. 

5 

The same subjects, when allowed to relax, occasionally showed a rise and decline of nystagmus 

during constant stimulation, and a rapid decay 

of response on termination of the stimulus. The 

present experiments confirm the fact that nystagmus does not decline during prolonged angular 

acceleration in alert human subjects, although 

such declines appear to occur in cats. 

In cats, time to onset of secondary nystagmus 

was inversely related to duration of the stimulus. 

The earlier onset of the secondary reaction cannot be attributed to loss of arousal. This result 

strongly suggests that the decline in primary 

nystagmus during and after the longer stimuli 

resulted from a counteracting process which reduced the intensity and duration of the primary 

nystagmus and then became evident as an early 

secondary nystagmus. Data from humans have 

shown that as the duration of a constant angular 

acceleration is increased beyond certain time 

limits, the duration of the subjective after-. 

responses becomes shorter and shorter.12•

14 Nystagmic reactions in cats showed similar effects 

and, in tl).ese respects, more closely resembled 

the subjective reactions of man than they did the 

nystagmus of man. 
V. Summary. 

Recordings of ocular nystagmus were obtained 

from a group of cats and a group of human subjects to 4° jsec2 angular accelerations of 8.4 sec 

and of 36 sec duration. Lateral canals and vertical canals were stimulated on separate trials. 

Results showed that the output of both primary 

and secondary nystagmus was greater for lateral 

canals. In cats, both lateral- and vertical-canal 

responses to the 36 sec stimuli peaked after 15-21 

sec of angular acceleration and this was followed 

by a steady decline. Declines were not apparent 

in nystagmus of human subjects. A further test 

of these .findings was conducted by manipulating 

arousal variables; human subjects 'vere given 

special tasks and cats received d-amphetamine. 

6 

Essentially the same results were obtained as 

described above. Other differences between the 

two groups were noted. Cats consistently demonstrated secondary nystagmus whereas humans 

did not. After termination of acceleration, primary nystagmus from cats lasted longer and 

exhibited a greater number of eye movements 

following the 8.4 sec stimulus than following 

the 36 sec stimulus; this consistency was not evident in humans. However, for humans the sensation of motion following termination of acceleration was of longer duration for the 8.4 sec 

stimulus than for the 36 sec stimulus. In this 

regard, nystagmus from cats resembled the subjective reactions of man more than they did the 

nystagmus of man. 
-:( 

CAT NO. 100 (HORIZONTAL NYSTAGMUS} 

so·L I SEC 

~'--

~~~ 

36 SEC STIMULUS 

~ r-----~-------------~ 

8.4 SEC STIMULUS 

CAT NO. 105 (VERTICAL NYSTAGMUS) 

so-L I SEC 

______,______ 

36 SEC STIMULUS 

..... 

8.4 SEC STIMULUS 

FIGURE 1. Nystagmus recorded from two cats for two durations of a 4° /sec• angular acceler~tion. Responses to stimulation of the lateral canals (Cat 

No. 100) and the vertical canals (Cat No. 105) are presented. Vertical bars through the tracings demar~ate the stimulus periods; arrows indicate the 

start· of secondary nystagmus. Note the longer poststimulus primary nystagmus and the later onset of secondary nystagmus for the shorter duration of 

acceleration. 

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70 

60 

50 

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70 

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50 

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36 SEC STIMULUS 

AVERAGE FOR 8 CATS 

36 45 54 63 72 81 90 

8.4 SEC STIMULUS 

•--• HORIZONTAL NYSTAGMUS 

o----o VERTICAL NYSTAGMUS 

27 36 45 54 63 

TJME IN SECONDS 

72 81 90 

FIGURE 2. Time-course plots of slow-phase eye displacement in 3-sec intervals for 8 cats. Arrows indicate termination of acceleration. Points above the zero line represent primary nystagmus; points below the zeroline repreRent secondary nystagmus. In the upper graph, a cle<tr peaking and decline of nystagmus during the acceleration iR evident for responses to both lateral- and vertical-canal ;;timulation. In the lower graph (8.4 sec 

stimulus), 3-sec interval:;; were marked off from the end of the stimulus (thus the first "3-sec" interval represents response during only 2.4 sec of stimulus). Total output of both primary and secondary nystagmus is 

consistently greater for the lateral canals. 

8 
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PRIMARY NYSTAGMUS 

• 

6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 

SECONDARY NYSTAGMUS 

•--• TRIAL 

x--x TRIAL 5 

o--o TRIAL 10 

•--• TRIAL 15 

AVERAGE FOR 6 CATS 

27 30 33 36 39 42 45 48 51 

TIME IN SECONDS 

'IGURE 3. Time-course plots of slow-phase eye displacement for trials 1, 5, 10, and 15 of the habituation series. 

With repeated trials there occurs a depression of output with early peaking followed by rapid declines during 

the accelerations. Effects are similar for both primary and secondary nystagmus. 

9 

, 
...... 

0 

SUBJECT Ma (HORIZONTAL NYSTAGMUS) 

so•L 

I Sec 

~~~~~o/~ lA r1AM 

~~~vJ0~VvfVvv ~ ~v"/v'''VV-\~""' 

--L---~---------------------- ~ ~ 

36 SEC STIMULUS 

~~~~·~~~~~ 

~~~ ---- ~~ 

8.4 SEC STIMULUS 

SUBJECT Me (VERTICAL NYSTAGMUS) 

-~~- -~--~~~-4---~--~--~---~~~~--~--~~--~------~--~~--

36 SEC STIMULUS 

"' 

8.4 SEC STIMULUS 

FIGURE 4. Nystagmus recorded from two human subjects for two durations of a 4o /sec• angular acceleration. Responses to stimulation of the lateral canals. 

(Subject Ma) and of the vertical canals (Subject Me) are presented. Markings are the same as in Figure 1. The clearly longer responses of the lateral 

canals to the shorter stimulus duration which were obtained from cats are not so evident here (compare Subject Ma data with Figure 1). Subject Me 

(vertical nystagmus) was atypical of human subjects in demonstrating clear and consistent secondary nystagmus with tracings closely resembling those 

obtained from <'ll t,;_ 
!--' 

!--' 

120 36 SEC STIMULUS 

AVERAGE FOR 8 HUMAN SUBJECTS 

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8.4 SEC STIMULUS 

HORIZONTAL NYSTAGMUS 

VERTICAL NYSTAGMUS 

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0 9 18 27 36 45 54 63 72 81 90 99 108 117 126 135 144 153 162 171 180 189 

TIME IN SECONDS 

FIGURE 5. Time-course plots of slow-phase eye displacement in 3-sec intervals 

of both primary and secondary nystagmus is greater for the lateral canals. 

during the acceleration is evident, although a large dip appears in the data 

for 8 human subjects. Markings are the same as in Figure 2. Total output 

In the upper graph, no clear peaking and subsequent decline of nystagmus 

for the vertical canals (compare with Figure 7). 

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• 

I \ e 

e I \ ? \ I o 

I \ 

I \ 

I \ 

0 0 

\ 

\ 

\ 

\ 

\ 

36 SEC STIMULUS 

AVERAGE FOR 10 

D-AMPHETAMINE CATS 

e-e HORIZONTAL NYSTAGMUS 

0--0 VERTICAL NYSTAGMUS 

0~------------------;i-----------------=----------- ~ .o--o··o...o--o 

10 

20 

30 

9 18 27 

• d ~~ I' ~ • 

' ~~0 •" • o. .o-0 / e I '01 e ,, I .~•" 

o/p-J •../ 

., . ;··_/ ...... \ 

• 

36 45 54 63 72 

IN SECONDS 

81 90 

TIME 

99 108 

FIGURE 6. 'l'ime-course plots of primary and secondary nystagmus in 3-sec intervals for cats treated with d-amphetamine. Similar to results obtained from undrugged cats, a peaking and decline of the response during the 36 

sec stimulus ( 4° ;sec') is evident for both lateral- and vertical-canal stimulation (compare with Figure 2). 

12 
I-' 

<:>:> 

120 

110 

100 

(/) 90 

w 

w 

0:: 80 (!) 

w 

0 

70 

(/) 

::::> 60 ::?! 

(!) 

~ 50 

(/) 

>-

z 40 

w 

(/) 

<( 30 

I 

CL. 

I 20 3: 

0 

_J 

(/) 10 

0 

10 

......... . ,. \ 

r"j \ 

j \ I . • a. \ 0 I '() I ; ··o·.o, / I 

'o . I • I ·-o I \ 

!:

. p·.d \ 

I "\ \ 

I o I I ., 

•' I e I I I \ 0 

I \ 

I \ • 

r \ \ 

I ~ \ 

~ ' ~ .'. I \ \ 0 \ 

36 SEC STIMULUS 

AVERAGE FOR 7 HUMAN SUBJECTS 

e-e HORIZONTAL NYSTAGMUS 

o--o VERTICAL NYSTAGMUS 

. , 

"o '•o •• •, •.... Cf'-.0 .o·..o·o--u-..o·u·o·v·o"""'~-~ - -o·--::::~-:--=~::::;;.:e;:::-::;:r-<i=lr:::"-~--

O.o-o-o·O·o-· •... _, ·-· ... -·,., / .... ,. ...... , /.,.,._.,.-. ...... _ ............... ,. .... ..--._. ... •-.... -._ .... ... ........ . 

20 

9 18 27 36 45 54 63 72 81 90 99 108 117 126 135 144 153 162 171 180 189 198 207 

TIME IN SECONDS 

FIGuRE 7. Time-course plots of primary nystagmus in 3-sec intervals for a second group of humans who were given instructions influencing arousal during 

the tests. Stimuli were 4° ;sec' angular accelerations for 36 sec. Each point is an average of two task-trials (metal arithmetric and key pressing) for 

each of the 8 subjects. Similar to results obtained under other arousal conditions (compare with Figure 5), no peaking and subsequent decline of 

nystagmus during accelerations is evident. One female subject was excluded from the average curves due to the presence of a spontaneous nystagmus 

which particularly affected scoring of secondary responses. 

Nl 
REFERENCES 

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2. CAPPEL, K. L., 1966 : Determination of physical con- stants of the semicircular canals from measurement 

of single neural unit activity under constant angular 

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the Vestibular Organs in the Exploration of Space. 

NASA Report SP-115, 229-236. 

3. CoLLINs, W. E., 1962 : Effects of mental set upon 

vestibular nystagmus. J. exp. Psychol., 63, 191. 

4. CoLLINs, W. E., 1964: Primary, secondary, and 

caloric nystagmus of the cat following habituation 

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angular acceleration. Acta oto-laryng. ( Stockh.), 

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6. CoLLINs, W. E., and HuFFMAN, H. W., 1964: Design 

and performance characteristics of a mechanically 

driven vestibular stimulator. OAM Report No. 6.'f-15. 

Oklahoma City, Oklahoma. 

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the dog. Acta oto-laryng. ( Stockh.), 6:2, 19. 

8. CRAMPTON, G. H., and BROWN, J. H., 1964: Repeated 

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Psychol., 6, 1. 

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Acta oto-laryng., ( Stockh.), Suppl. 163, 59. 

14 

12. GuEDRY, F. E., and BEBERMAN, N., 1957: Apparent 

adaptation effects in vestibular reactions. U. S. 

Army Med. Res. Lab., Report No. 293, Fort Knox, 

Kentucky. 

13. GuEDRY, F. E., and CERAN, S. J., 1959: Derivation 

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in the vestibular system. U. S. Army Med. Res. 

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15. GUEDRY, F. E., and LAUVER, L. S., 1961: Vestibular 

nystagmus during constant angular acceleration. 

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(Stockh.), 53, 21. 

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Ewald's second law. Acta oto-laryng. ( Stockh.), 

Suppl. 159, 50. 

18. MITTERMAIER, R., and ROSSBERG, G., 1956: VestibU· 

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313. 

19. MONTANDON, A., and FUMEAUZ, J., 1957: Valeur 

Diagnostique comparative des nystagmus peret postrotatories a' l'epreuve girotoire liminaire. Prac. 

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20. MowRER, 0. H., 1935 : The nystagmic response of 

the pigeon to constant angular acceleration at liminal 

and supraliminal intensities. J. comp. Psychol., 19, 

177. 

21. WENDT, G. R., 1950: Some characteristics of vesti 

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