Amodal completion instead of predictive coding can explain activity suppression of early visual cortex during...

Area of Science:

• Neuroscience
• Visual Perception
• Cognitive Science

Background:

• Neuroimaging studies show early visual cortex activity changes with illusory shapes like the Kanizsa illusion.
• Previous research linked these modulations to predictive coding, where neural activity aligns with prediction accuracy.

Purpose of the Study:

• To investigate whether neural adaptation to stable input, rather than prediction error, explains activity suppression in the early visual cortex during Kanizsa illusions.
• To test Moors' (2015) hypothesis on neural adaptation as an alternative to predictive coding.

Main Methods:

• Manipulated the perceptual stability of the Pac-Man inducers used in the Kanizsa illusion.
• Compared neural activity patterns in the early visual cortex under conditions of stable versus unstable inducers.

Main Results:

• Replicated previous findings of enhanced activity for illusory shapes and suppressed activity for inducers when inducers were perceived as stable.
• Observed enhanced activity for illusory shapes but absent suppression for inducers when their perceptual stability was disrupted.

Conclusions:

• The findings support the neural adaptation hypothesis, suggesting that activity suppression for inducers in the Kanizsa illusion is due to adaptation to perceptually stable input.
• Challenges the interpretation of these modulations solely through the lens of reduced prediction error within the predictive coding framework.