呂1絲氏 4

1 信果程博士(英文))Date of submission (month day, year)

Janual},6,2023

Depar[ment ofComputer science

StudentlD Number

D141302and Engineering
PP11Canfs nameShi牙ekiNakauchi
SupeYvisors

YumaTaniyama

Testuto Minami

Abstract (Doctor)
Title oflhesis

Visual preference for c010r and object composition

Approx.80o words
The most important criterion for aesthetic jud牙ment of a paintin晉 is considered to be aharmonious composition. Then, what is a harmonious composition? The "ori牙inal paintin牙C010r composition preference," in which the c010r composition of the 仇,i号inal paintin牙 before
hue chan牙es is most preferred, and the "ri牙ht'facing preference " in which the modelis often
Painted facing to the ri牙ht, and the facin牙 ri又ht is pref飢'red over le丘, can be considered biases

that arise when the painter's preference is reaected in the paintin曾. since high aesthetic
Preference is known to be caused by the hi牙h processing auency of the object, the hi牙hProcessin曾 auency of the c010r composition in the paintin牙S and the ri牙ht・facin牙 faces may
Cause this bias.1n order to clarify the factoTs that conh'ibute to preference for c010r

Composition and object composition, we investi牙ated the mechanisms of "original paintin牙C010r composition preference (EXP.1 & 2)" and "rightward preference bias (EXP.3 & 4)" fromthe perspective of processin晉 auency. Experiment l aimed to test the hypothesis that thenaturalness、based preference drives pupil dilation, based on previous research, that art
Paintin牙S with image features similar to those of natural scenes are prefa,Nd. As a result,the extent of pupil dilation had a significant positive correlation with the perceptions ofnaturalness for the paintin牙, wheTeas there was no significant Cの1モ1ation between pupildilation and preference. This was observed not only in representational paintin曾S but also inabstract paintin宮S, SU牙gesting that the c010r compoS北ion of a paintin宮北Self, Tather thanmemory c010rs‑the standard, known hues of objects‑or other inauences, is an importantfactor of perceived naturalness that produces pupil dilation.1n Experiment 2, we test thehypothesis obtained in EXP田'iment l that the reason for the ori牙inal paintin牙 Preference isdue to the hi牙h familiaTity with the c010r composition of the ori部nal paintin牙 Using the P3
asymmetry index to visualize familiarity. As a result, P3 asymmetry was found between theOr1宮inal and 180 de晉rees of hue、Totated paintings in both abstract and aower paintings
These findin曾S SU曾曾est a difference in familiarity and perceptual auency between the original
and the 180"degree hue、rotated paintin曾S, which is evidence that the original paintin晉S havea familiar c010r composition. Experiment 3 focused on whether a face・specific effect caused

the left、ri牙ht diffeTence in preference and investi套ated the left・ri曾ht difference in preference
for face'1ike and non'face"1ike objects. The ri号ht hemisphere is specialized for facerecognition, and facial parts of a ri曾ht'facing face are located on the left side; hence thehi曾her the face"1ikeness of objects, the more preferred it is facin号 to the ri宮ht. As a Tesult, wefound that the 晉reater the de曾ree of face'1ikeness, the greater the preference for right、facin牙Objects, which is consistent with our hypothesis. This sug曾ests that the reason why theri牙ht'facing was preferred only for face、1ike objects is that the ri今ht hemisphere is more
activated when the parts correspondin牙 to the eyes and mouth of a face'1ike object areConcentrated in the left visual field, and thiS 曾reater activation of the brain activity may be

responsible for the highet evaluation of attractiveness、 Experiment 4 investi牙ated therelationship between the left"right difference in pTeference and processin今 auency byComparing P3 asymmetry, W'hich reaects the perceptual auency of stimuli, and N170 latency

and amplitude between face・1ike and face・unlike objects under the assumption that one ofthe
factors causin牙 the left'ri曾ht difference in preference is the high processin牙 fluency ofri牙ht・facin曾 faces. As a result, P3 asymmetry, which mi曾ht be reflects processin牙 auency,

Occurs regardless of the face・1ikeness (1ar宮er P3 amplitudes in left'facin牙 objects), indicatin曾that the improvement in processing auency for ri曾ht、facin号 objects occurs re曾ardless of
face・1ikeness.1n addition, Hemispheric differences in N170 latency and amplitude occurreddependin牙 on the face・1ikeness of the object and its orientation.1t is possible that the P3
asymmetry was caused by the concentration of parts important for object identification in
front of the object in the left visual field when the object was facin牙 the right, increasing
Processin曾 auency. The present result that N170 latency is faster in the ri曾ht hemisphere for
face・1ike objects only sug牙ests that processin曾 is more auent when faces are oriented to theri牙ht hemisphere, where face recognition is predominant. Experiments about the right、facin曾Preference (EXP.3 & 4) SU牙曾est that the P3 asymmetry, independent of face、1ikeness, resultsfrom acqulred processin曾 fluency due to previous experience. on the other hand, the hi晉herright・facing processin号 auency shown from latency N170 was only observed for face、1ikeObjects. This may reaect an innate increase in processin晉 fluency due to an anatomical
feature that the brain re牙ions involved in face rec0曾nition are formed in the human brain

Experiments about the ori部nal paintin牙 C010r composition preference (EXP.1 & 2) showedthat the c010r processin曾 auency of the ori宮inal paintin牙 is hi曾h, re曾ardless of the painting
Cate曾ory. This P3 asymmetTy observed here is considered an acquired auency enhancement
due to previous experience. However, we cannot rule out the possibility of an innate factor inthe c010r composition preference, just as an innate factor may manipulate object m'ientation
Preference based on anatomicalfeatures