Abstract
People tend to respond faster to self-relevant stimuli relative to stimuli associated with other people. There is well-established evidence on the self-bias effect on high level memory and attentional processes, but little evidence for effects on perception. In this study, we test whether the self-bias effect can modulate perception, by focusing on the effect of self-bias on the earliest cortical component C1 which links to activity in the primary visual cortex (V1). Using high-density event-related potential measures, we recorded participants’ brain activity when they performed a matching task to personally relevant stimuli. Participants were randomly assigned three sets of geometric shapes (triangle, circle, and square) to three personal labels (self, mother, and stranger). After the associative instruction, they carried out a shape-label matching task. The size of the stimuli was manipulated (large vs. small). The results showed that there were faster responses to the shape associated with the self compared to others, showing the self-bias effect. The effect was modulated by the size of stimuli – participants made faster responses to the large than to the small stimuli in the self association, whereas there were no differences between the large and small stimuli for other associations (mother and stranger associations). The size effect in self-bias was linked to the activity in the C1 component. The amplitude of C1 increased for the large relative to small shapes associated with the self, but the size of stimuli did not affect the amplitude between the large and small stimuli in other associations. The results indicated that self-bias can affect perception by modulating the earliest C1 component generated in the primary visual cortex. The data suggest that the self-bias may automatically facilitate the perceptual encoding of visual stimuli early on just following stimuli onset.
Meeting abstract presented at VSS 2015