Dissonant Representations of Visual Space in Prefrontal Cortex during Eye Movements

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Systems Neuroscience

Background:

• The frontal eye field (FEF) is crucial for visual processing and eye movement control.
• Understanding how visual space is represented and dynamically updated in the FEF is essential for explaining visual perception during natural behaviors.

Purpose of the Study:

• To investigate the neural dynamics of spatial representations in the FEF using local field potentials (LFPs) and spiking activity.
• To determine how these spatial representations change during the course of eye movements.

Main Methods:

• Recorded local field potentials (LFPs) and neuronal spikes in the FEF of subjects performing visual tasks.
• Analyzed spatial information content across different LFP frequency bands (alpha, low-gamma, high-gamma) and spiking activity.
• Derived receptive fields (RFs) from different signal types and examined their organization and dynamics before and during eye movements.

Main Results:

• Spatial information in FEF LFPs was concentrated in alpha and high-gamma bands, with minimal signal in the low-gamma band.
• During fixation, spatial information from alpha and high-gamma bands and spiking activity was consistent across cortical layers.
• Receptive fields (RFs) derived from alpha and high-gamma bands were initially retinotopically organized and correlated with spiking RFs.
• However, alpha and high-gamma RFs dissociated before eye movements; high-gamma and spiking RFs shifted towards the movement goal, while alpha RFs lagged.

Conclusions:

• Different frequency bands within the FEF encode spatial information distinctly.
• Dynamic changes in alpha and high-gamma receptive fields suggest distinct roles in visual spatial updating during eye movements.
• These findings provide insights into the neural mechanisms underlying dynamic spatial representations crucial for visual perception.