The dynamic contribution of the high-level visual cortex to imagery and perception

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neuroimaging

Background:

• Mental imagery and visual perception engage shared brain regions within the high-level visual cortex (HVC).
• The dynamic neural mechanisms governing these processes, particularly within the HVC and hippocampus (HC), remain incompletely understood.

Purpose of the Study:

• To investigate and differentiate the local and inter-regional dynamic mechanisms of mental imagery and visual perception.
• To explore the roles of the high-level visual cortex (HVC) and hippocampus (HC) in processing familiar visual content during imagery and perception.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was employed with 19 healthy participants.
• Participants either viewed or imagined familiar scenes (landmarks) and faces.
• Analysis focused on neural coding, regional adaptation effects, and inter-regional functional connectivity.

Main Results:

• Neural representations for landmarks and faces were distributed across the HVC and HC, generalizing between imagery and perception but with distinct structures.
• Differential regional adaptation effects were observed, notably in the left parahippocampal place area (PPA), showing suppression for perceived landmarks and enhancement for imagined landmarks.
• Task- and content-dependent changes in functional coupling between the HVC and HC were identified.

Conclusions:

• The findings elucidate dynamic neural networks supporting visual perception and mental imagery in the HVC and HC.
• Distinct adaptation patterns and functional couplings highlight the nuanced differences between mental imagery and visual perception, contributing to ongoing neuropsychological debates.