Oscillatory neuronal synchronization in primary visual cortex as a correlate of stimulus selection

Area of Science:

• Neuroscience
• Visual Perception
• Computational Neuroscience

Background:

• Interocular rivalry occurs when dissimilar images are presented to each eye, leading to competition for perceptual dominance.
• Strabismic cats exhibit an inherent eye dominance, which can be exploited to bias rivalry.
• Understanding the neural mechanisms of stimulus selection is crucial for comprehending visual processing.

Purpose of the Study:

• To investigate the relationship between neural activity and perceptual dominance during interocular rivalry.
• To determine if gamma-frequency synchronization in the primary visual cortex is a neural correlate of stimulus selection.
• To explore how different biases (eye dominance, temporal offset, contrast) affect neural responses during rivalry.

Main Methods:

• Simultaneous recording of spike and local field potential activity in the primary visual cortex of strabismic cats.
• Alternating monocular and dichoptic stimulation to induce interocular rivalry.
• Manipulating rivalry competition using eye dominance, temporal offset, and contrast differences.

Main Results:

• Gamma-frequency synchronization of neural responses was enhanced when competition was biased towards the stimulus activating recorded neurons.
• Conversely, synchronization decreased when competition favored the non-activating stimulus.
• Firing rate changes were observed but were inversely related to the stimulus's competitive advantage.

Conclusions:

• Enhanced gamma-frequency synchronization in the primary visual cortex is a strong correlate of stimulus selection during interocular rivalry.
• Synchronization may serve as a mechanism for selecting visual information for further processing.
• This synchronization is hypothesized to influence firing rate changes in later visual processing stages.