The Japanese journal of neuropsychology

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ArticleTitle	Behavioral and neural correlates of visual preference decision
Language	J
AuthorList	Shinsuke Shimojo
Affiliation	California Institute of Technology (Division of Biology/Computation and Neural Systems) JST. ERATO Shimojo Implicit Brain Function Project, Director
Publication	Japanese Journal of Neuropsychology: 25 (2), 92-98, 2009
Received
Accepted
Abstract	Even a newborn shows "preferential looking," referring to a tendency of selective orienting to a particular visual stimulus. We found that even in the normal adult, a gaze bias towards the to-be-chosen stimulus precedes the subject's conscious preference decision on faces. It indicates an intrinsic link between an implicit orienting mechanism and the explicit preference decision. In an fMRI study, we found dynamic activation starting from a subcortical area (NAC, nucleus accumbens) and shifting to a frontal area (OFC, orbito-frontal cortex). Also we found that the NAC is activated by the more-preferable face even when the subject is engaged in a non-preference, control task, indicating an implicit nature of the mechanism. In another set of study, we addressed the issue as to how memory can affect preference. We found that familiarity preference became more dominant in faces, whereas novelty preference became dominant in natural scenes, across repeated experiences. Our fMRI study suggests that these different types of preference decision are supported by entirely different neural circuits. For the human and the monkey, perceiving (eg. watching a movie) itself has its own intrinsic reward value, as we demonstrated with multiple electric recording in the OFC of the monkey. Such intrinsic reward of perception may be due to the positive feedback pathway; i.e. memory (reward map)→orienting→preference choice→updating of memory.
Keywords	preference, decision making, orienting, nucleus accumbens, orbitofrontal cortex