Modulating cortical excitability and cortical arousal by pupil self-regulation

Area of Science:

• Neuroscience
• Cognitive Science
• Psychophysiology

Background:

• Central arousal, regulated by brainstem nuclei, critically impacts cognitive functions.
• The locus coeruleus is a key regulator of central arousal, with its activity linked to pupil dynamics.
• Previous work established volitional control over the locus coeruleus via pupil-based biofeedback.

Purpose of the Study:

• To investigate if pupil-based biofeedback influences electrophysiological markers of brain function.
• To examine the effects of pupil self-regulation on cortical excitability, cortical arousal, and P300 responses.

Main Methods:

• Combined pupil-based biofeedback with single-pulse transcranial magnetic stimulation (spTMS).
• Utilized electroencephalography (EEG) and an auditory oddball task.
• Measured cortical excitability, EEG spectral slope (cortical arousal marker), and P300 event-related potentials.

Main Results:

• Pupil self-regulation significantly modulated cortical excitability.
• EEG spectral slope, a marker of cortical arousal, was significantly altered by pupil biofeedback.
• P300 responses to target tones, linked to locus coeruleus activity, were modulated by pupil self-regulation.

Conclusions:

• Pupil-based biofeedback is a viable method for modulating fundamental aspects of brain function, including arousal.
• This non-invasive technique offers potential for future therapeutic applications in neurological and psychiatric disorders.
• Further research is needed to explore the efficacy of pupil biofeedback in clinical populations.