Object-centered shifts of receptive field positions in monkey primary visual cortex

Area of Science:

• Neuroscience
• Visual Perception
• Computational Neuroscience

Background:

• Stimuli with the same retinal visual angle can be perceived as different sizes based on perceived distance.
• Previous human studies using fMRI showed perceived size alters activity in the primary visual cortex (V1).
• Understanding the neuronal mechanisms requires an animal model for single-neuron examination.

Purpose of the Study:

• To establish an animal model for studying size perception at the single-neuron level.
• To test if neurons in V1 shift their receptive fields (RFs) based on monocular depth cues.
• To investigate the neural basis of the size-distance illusion.

Main Methods:

• Macaca mulatta monkeys were used to model human size-distance perception.
• Extracellular recordings were performed on V1 neurons.
• Ring-shaped stimuli were presented at varying perceived distances within a corridor scene.

Main Results:

• Macaque monkeys demonstrated a size-distance illusion similar to humans.
• V1 neurons exhibited RF shifts in response to perceived distance.
• RFs shifted inward for stimuli perceived at a distance and outward for stimuli perceived as near.

Conclusions:

• V1 receptive field shifts provide a potential neural mechanism for the perception of angular size.
• This study establishes an animal model for investigating the neural basis of visual perception.
• The findings offer new insights into how the brain integrates depth information to perceive object size.