Correlated variability and its attentional modulation depend on anatomical connectivity

Area of Science:

• Neuroscience
• Computational Neuroscience
• Visual Processing

Background:

• Shared variability among visual cortical neurons impacts perception.
• Attention's role in modulating this variability is complex and not fully understood.
• The influence of anatomical connectivity on shared variability remains largely untested.

Purpose of the Study:

• To investigate how anatomical connectivity influences shared spiking variability in the primary visual cortex (V1).
• To determine if attention modulates shared variability differently based on neuronal connection type (excitatory vs. inhibitory).

Main Methods:

• Simultaneous recording of neuronal activity in V1 of monkeys performing a visual attention task.
• Inference of anatomical connectivity using spiking cross-correlations.
• Analysis of spike count correlations under conditions of directed and undirected attention.

Main Results:

• Attention did not alter spike count correlations in unconnected V1 neuron pairs.
• Excitatory connected V1 neurons showed reduced spike count correlations with attention.
• Inhibitory connected V1 neurons exhibited high, attention-invariant spike count correlations.
• Correlated variability in excitatory circuits depended on neuronal contrast tuning.

Conclusions:

• Shared neural variability is dependent on the specific type of anatomical connectivity within neuronal circuits.
• Attention selectively reduces shared variability in excitatory circuits, even when overall effects in V1 are subtle.
• Anatomical connectivity is a critical factor in understanding attentional modulation of neural variability.