Modeling the spatiotemporal cortical activity associated with the line-motion illusion in primary visual cortex

Area of Science:

• Computational neuroscience
• Systems neuroscience
• Visual cortex modeling

Background:

• The primary visual cortex operates in a dynamic state of intermittent desuppression (IDS).
• Spontaneous cortical activity is coherent and can be observed using voltage-sensitive dye imaging.
• The Hikosaka line-motion illusion (LMI) involves illusory motion perception.

Purpose of the Study:

• To investigate the functional significance of the IDS cortical operating points.
• To explore the neural mechanisms underlying the Hikosaka LMI in a computational model.
• To compare the model's response to the LMI stimulus with its response to a moving square stimulus.

Main Methods:

• Large-scale computational modeling of the primary visual cortex.
• Incorporation of orientation-specific, long-range couplings and slow NMDA conductances.
• Analysis of model response to the Hikosaka LMI stimulus and a moving square stimulus.
• Comparison of model results with in vivo voltage-sensitive dye imaging data.

Main Results:

• The computational model replicates the spatiotemporal activity patterns observed experimentally for both the LMI and moving square stimuli.
• The model demonstrates that the LMI phenomenon arises from the interplay of LMI input structure, NMDA-type cortical coupling, and NMDA conductance-voltage correlations within the IDS state.
• A strong agreement was found between the model's simulated cortical activity and experimental findings.

Conclusions:

• The intermittent desuppression (IDS) state is crucial for processing illusory motion.
• The model provides a plausible physiological mechanism for the Hikosaka line-motion illusion, involving NMDA receptor dynamics and network connectivity.
• These findings suggest a neural basis for preattentive illusory motion perception in the visual cortex.