Ongoing neural oscillations influence behavior and sensory representations by suppressing neuronal excitability

Area of Science:

• Neuroscience
• Cognitive Science
• Computational Neuroscience

Background:

• Adaptive behavior relies on processing external stimuli.
• Trial-by-trial variability in neural and behavioral responses to identical stimuli is a key challenge in neuroscience.
• Ongoing fluctuations in neuronal excitability are hypothesized to cause this variability.

Purpose of the Study:

• To investigate the relationship between prestimulus alpha oscillations, neuronal excitability, and sensory processing variability.
• To determine how alpha oscillations impact task performance and neural stimulus representations.

Main Methods:

• Intracranial electrophysiology in neurosurgical patients.
• Auditory discrimination task with visual cues.
• Analysis of prestimulus alpha oscillations, broadband high-frequency activity (neuronal excitability), reaction times, and neural stimulus encoding.

Main Results:

• Strong prestimulus alpha+ oscillations correlated with a low excitability state (reduced broadband high-frequency activity).
• This low excitability state was associated with slower reaction times.
• Reduced neural stimulus encoding strength was observed during high alpha+ oscillation states.

Conclusions:

• Prestimulus alpha+ oscillations modulate neuronal excitability.
• Fluctuations in excitability, driven by alpha+ rhythms, contribute to trial-by-trial variability in behavior and neural representations.
• Understanding these dynamics is crucial for explaining sensory processing variability.