Past events

When faced with complex visual scene, observers inspect different parts of a scene sequentially, storing corresponding features in working memory for subsequent integration into a holistic perception. Yet models of perception rarely consider working memory explicitly. We probed processing hierarchy by comparing absolute judgements of single orientations and relative/ordinal judgements between two sequentially presented orientations. We found that lower-level, absolute judgements failed to account for higher-level, relative/ordinal judgements. However, when ordinal judgement was used to retrospectively decode memory representations of absolute orientations, striking aspects of absolute judgements, including their correlation and forward/backward aftereffects, were explained. We suggest that the brain prioritizes decoding of more useful, higher-level features, which are more invariant and categorical and thus easier to specify and maintain in noisy working memory, and that more-reliable higher-level decoding.

Understanding the Self has fascinated artists, writers, philosophers and psychologist for generation. In the past two decades cognitive and neurocognitive tools have been applied to the study of the Self. The talk will present research on the Self and the Friend. Not surprisingly, it is consistently found that our brain prioritize the Self. For example, deciding whether a face looks to the left or right is faster on one’s own face than on a face of a friend. This prioritization transcend time, showing similar prioritization to one’s face in the past as in the present. Lesions to the fusiform gyrus hinders Self facilitation, while lesions to lateral frontal cortices amplifies it. Associating a simple geometric shape to oneself is done much more efficiently than to a stranger an effect that is mediated via the left STS, medial and lateral frontal cortices. Participants are also better at judging a perspective of an avatar if it is tagged as them than as a stranger. But in all these studies the Friend is also prioritized relative to a stranger. Why is the friend prioritized, is it because it is relevant, or because it is liked? In a simple shape-identity matching task, we manipulated orthogonally the valence and relevance of familiar identities. We found that prioritization is given based on relevance and valence in Western culture, but primarily based on valance in Asian cultures. Using spatial maps to represent the social space, we observed consistent representation of social relations as physical distances. Physical distance between identities was affected by the valence and relevance factors, though this was modulated by the participants’ culture. Finally, presenting participants with incongruent spatial maps of their social relations, resulted in increase and decrease responses in a large network of regions including the Amygdala and superior temporal structure known to play a rule in social cognition. Taken together this body of work highlight neurocognitive mechanism by which our brain prioritize information based on social rules.