Maintained avalanche dynamics during task-induced changes of neuronal activity in nonhuman primates

Area of Science:

• Neuroscience
• Computational Neuroscience
• Systems Neuroscience

Background:

• Neuronal activity in the cortex exhibits complex spatiotemporal patterns during sensory processing, cognitive tasks, and motor actions.
• The statistical regularities governing these widespread neuronal transients, particularly during behavior, remain largely uncharacterized.
• Neuronal avalanches, characterized by scale-invariance, have been observed during ongoing brain activity, but their role during active behavior is less understood.

Purpose of the Study:

• To investigate whether neuronal avalanches exhibit scale-invariance during active motor and cognitive tasks.
• To determine if task-related changes in neuronal activity affect the scale-invariance properties of neuronal avalanches.
• To explore methods for recovering scale-invariance in neuronal activity during behavior.

Main Methods:

• Recorded extracellular unit activity and local field potentials (LFPs) using high-density microelectrode arrays in nonhuman primate premotor and prefrontal cortex.
• Analyzed neuronal avalanches, focusing on negative LFP deflections (nLFPs), during motor and cognitive tasks.
• Employed 'adaptive binning' to adjust temporal resolution based on task-induced changes in nLFP rate to analyze scale-invariance.

Main Results:

• Neuronal activity and nLFPs showed consistent rate changes at individual electrodes during tasks.
• nLFP clusters across the array deviated from scale-invariance during task performance compared to ongoing activity.
• Adaptive binning successfully recovered scale-invariance in nLFP clusters during behavioral tasks.
• LFP synchronization measures and computer simulations corroborated these findings.

Conclusions:

• Neuronal avalanches during active cortical processing exhibit scale-invariance when analyzed with an adaptive temporal resolution.
• Task-related modulations in neuronal firing rates influence the observed scale-invariance of neuronal avalanches.
• The findings suggest that optimization principles governing neuronal avalanches during ongoing activity may also apply to cortical information processing during behavior.