A twisted visual field map in the primate dorsomedial cortex predicted by topographic continuity

Area of Science:

• Neuroscience
• Computational Neuroscience
• Visual System Research

Background:

• Neurons in the visual cortex have overlapping receptive fields, minimizing wiring costs.
• This arrangement is theorized to create alternating mirror and nonmirror visual field representations in adjacent cortical areas.
• This concept is crucial for subdividing the extrastriate cortex.

Purpose of the Study:

• To simulate the formation of retinotopic maps considering wiring constraints.
• To investigate if models can produce map types beyond simple alternating representations.
• To experimentally verify the existence of complex retinotopic maps in the primate extrastriate cortex.

Main Methods:

• Simulated retinotopic map formation using a computational model.
• The model balanced intra-area smoothness and inter-area congruence constraints.
• Used quantitative electrode array recordings in primates for empirical validation.

Main Results:

• The simulation model typically produced alternating mirror and nonmirror maps, consistent with primates.
• The model also generated inhomogeneous maps with sectors of opposing field signs within a single area.
• Such inhomogeneous maps were experimentally confirmed in the dorsomedial extrastriate cortex of primates.

Conclusions:

• The formation of retinotopic maps is more complex than previously assumed.
• The primate extrastriate cortex, particularly the dorsomedial region, exhibits complex, inhomogeneous visual field maps.
• This finding necessitates a re-evaluation of current models for extrastriate cortex subdivision.