Blood oxygen level-dependent activation of the primary visual cortex predicts size adaptation illusion

Arezoo Pooresmaeili, Roberto Arrighi, Laura Biagi, Maria Concetta Morrone

Research output: Contribution to journalArticle

Abstract

In natural scenes, objects rarely occur in isolation but appear within a spatiotemporal context. Here, we show that the perceived size of a stimulus is significantly affected by the context of the scene: brief previous presentation of larger or smaller adapting stimuli at the same region of space changes the perceived size of a test stimulus, with larger adapting stimuli causing the test to appear smaller than veridical and vice versa. In ahumanfMRI study, we measured the blood oxygen level-dependent activation (BOLD) responses of the primary visual cortex (V1) to the contours of large-diameter stimuli and found that activation closely matched the perceptual rather than the retinal stimulus size: the activated area of V1 increased or decreased, depending on the size of the preceding stimulus. A model based on local inhibitory V1 mechanisms simulated the inward or outward shifts of the stimulus contours and hence the perceptual effects. Our findings suggest that area V1 is actively involved in reshaping our perception to match the short-term statistics of the visual scene.

Original languageEnglish
Pages (from-to)15999-16008
Number of pages10
JournalJournal of Neuroscience
Volume33
Issue number40
DOIs
Publication statusPublished - 2013

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ASJC Scopus subject areas

  • Neuroscience(all)

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