ICP2016

Yumiko Fujii, Hiromi Morita, University of Tsukuba, Japan.
Exp 2

Dorsal pathway

Spatial attributes

In the human visual system, diﬀerent attributes are processed separately.
Then attributes of an object are integrated to elicit a response.
According to the paired-attribute model (Morita et al., 2010), these
attributes are written to the object ﬁle in the form of multiple feature-pairrepresentations.
The results of stimulus-response mapping experiments (Ishizaki et al.,2015) showed that a pair of features is directly associated with a response incontrast to a triplet of features represented by multiple feature-pairs which
are associated with a response together. In these experiments visual
identiﬁcation attributes such as shape, color, and texture of objects deﬁned
the responses.

SExp 1, 2

are processed

SResponse
Response

Ventral pathway

Ishizaki et al.(2015)

V

Visual identiﬁcation
attributes are processed

V*S=Spa/al a9ribute*V=Visual iden/ﬁca/on a9ribute

PurposeSV

Response(1) Are the spatial attributes such as location and motion also associatedwith a response by forming feature-pairs?
(2) Are there any diﬀerences between spatial attributes andvisual identiﬁcation attributes in the manner of associating feature-pairs
to responses?

Mapping between stimuli and responses

Exp 1: Color, Shape and Location
2-attribute sets : Two attributes are relevant to the response.

Participants learn the mapping of eight stimulus items tofour response keys.

CS(color-shape) set

Stimulus

Response keys

Key C

3-attribute set： All attributes are relevant to the response.

Designpress a response key
A 400 Hz buzzer sounds ifthe response is incorrect.

Key D

14 learning blocks with time limit
2 test blocks without time limit■1 block comprises 80 trials

We presented the results of Exp 1 at APCV2015.

Exp 2: Color, Location and Motion
2-attribute sets : Two attributes are relevant to the response.

If participants cannot respond to the target within the time limit,
a 900 Hz buzzer sounds and the next trial start.

Participants

CM(color–motion) set

CL(color-location) set

Key A

Key B

28 students aged 18-28 (Exp 1) and 29 students aged 18-24 (Exp 2)
with normal or corrected vision.

Key DRT︎ ( Test blocks )

Exp 1

Exp 2

Exp 1

100%100%20%$44$

4-$-

$44$-

Percent correct

40%60%40%20%CMCLML

CML

0%0%

Response time [ms]1200

80%60%Key C

CML(color-motion–location) set

Percent correct versus block number

80%

ML(motion-location) set

3-attribute set： All attributes are relevant to the response.

Exp 2***:p<.001, **:p<.01, +:p<.10, ns:p>.10

1000

nsns

ns

800
600
400

CSSLCSLCL

2000**+***

1200

Response time [ms]ProcedurePercent correct

Key B

CSL(color-shape–location) set

Four keys arranged in vertical on the numeric keypad＋SL(shape-location) set

Key A

Eight types of items, made by combining one of two values of three attributes.

1.0 s

CL(color-location) setns

1000**:p<.01, *:p<.05, ns:p>.10ns
ns

800
600400CMCLCML

ML

2000*****・No signiﬁcant diﬀerence in the RT among the 2-attribute sets.
middle phase***:p<.001, +:p<.10100%
80%
60%
40%CSSLCLCSL

20%0%initialmiddlelater

・CL and SL sets are more diﬃcult
to learn than CS set （p<0.05 in each case）.

initial phase

middle phase100%

later phase***:p<.001, **:p<.01, *:p<.05

・Responses to the three attributes sets take longer time than that to thetwo attributes sets.

80%

***
**
*

***
+ ******

Percent correct

later phase

Percent correct

initial phase

60%
40%

CMCL
ML
CML

20%
0%

initialmiddlelater

・No signiﬁcant diﬀerence
among CM, CL, and ML sets.

→ It is diﬃcult for an attribute-pair including a spatial attributeto be associated with a response.
・Two-attribute items are easier than the three-attribute items to map to theresponses when spatial attributes are included.
→ The association of CM, CL, or ML attribute-pair with the response is stored
as the connection between a single feature-pair and a response.
The mapping between CML attribute-triplet and the response is stored
as the connection between two or more feature-pairs with a response.

Spatial attributes are also associated with a response by forming
feature-pairs.
However, it is diﬃcult to form an association when spatial attributes
are included.
The processing pathways of the cerebral cortex is considered toaﬀect the forming of the association.
Why?
We pay little attention to spatial attributes when we memorize
and remember the appropriate reaction to an object.
Representation of spatial attributes in memory does not haveenough discriminability to associate diﬀerent locations or motions
with diﬀerent responses.