Abstract
Individual observers show reliable biases in perception across the visual field, which are stable across time (Afraz et al., 2010). Furthermore, biases for perceiving stimulus size correlate with individual spatial tuning properties in V1 (Moutsiana et al., 2016). Previous studies have shown that brain volume, cortical thickness, and surface area of the brain are highly heritable (e.g. Baaré et al., 2001). Here we explore the heritability of perceptual heterogeneity and functional cortical architecture in early visual cortex using behavioral and functional magnetic resonance imaging (fMRI) measures in a classical twin design. In particular, we compare correlations of size perception biases, higher-order ambiguous perception biases (Rubin's vase; Rubin, 1915), and population receptive field (pRF) parameters between monozygotic and dizygotic twins. Behavioral results showed a significantly greater between-subject correlation of size perception biases for monozygotic than dizygotic twins. However, there was no evidence of a heritable component for the distribution of size biases across the visual field. There was no compelling evidence for heritability effects in higher-order biases for perceptually ambiguous stimuli. Our fMRI results found no evidence for higher correlations between monozygotic compared to dizygotic twin pairs with regard to pRF sizes or cortical magnification factor. However, we do see evidence for higher correlations between monozygotic than dizygotic twin pairs for the surface area of early visual cortex regions, even after normalising to total surface area. These findings suggest that there may be some genetic component in size perception, but perceptual heterogeneity across the visual field for size perception is not strongly heritable. We find no clear evidence of a genetic component for high-level perceptual biases or fine-grained measures of functional architecture in early visual cortex.
Meeting abstract presented at VSS 2017