Discordant Alpha-Band Transcranial Alternating Current Stimulation Affects Cortico-Cortical and Cortico-Cerebellar...

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Brain Stimulation

Background:

• Brain activity synchronization is crucial for functional neural networks.
• Alpha-band oscillations are key to inter-regional communication.
• Trans Cranial Alternating Current Stimulation (tACS) can modulate brain activity.

Purpose of the Study:

• To investigate if widespread alpha-band activity mediates causal relationships in gamma-band.
• To determine the causal role of alpha oscillations in attention networks.
• To examine the effects of non-phase-locked tACS on brain network dynamics and behavior.

Main Methods:

• A double-blind, sham-controlled study using tACS over bilateral parietal cortex.
• Analysis of alpha- and gamma-band oscillatory activity during a visual global/local attention task.
• Characterization of causal relationships within and between cortical and subcortical brain regions.

Main Results:

• tACS did not induce a behavioral deficit in the attention task.
• Modulation of causal relationships in fronto-parieto-cerebellar circuits was observed.
• No evidence supported the hypothesis of widespread alpha mediation of gamma-band causal relationships.

Conclusions:

• Olivo-cerebellar circuits may interpret discordant tACS as error signals, triggering compensatory responses.
• Cerebellar compensatory activity might explain the lack of behavioral deficits and altered network dynamics.
• Understanding cerebellar plasticity is vital for tACS clinical applications, especially for autism spectrum disorder.