Alpha and theta mechanisms operating in internal-external attention competition

Area of Science:

• Neuroscience
• Cognitive Psychology
• Electrophysiology

Background:

• Attention allows prioritization of information, operating internally or externally.
• Alpha and theta brain oscillations are known to play roles in attentional processes.
• Understanding attention under continuous distractor conditions is vital for real-life scenarios.

Purpose of the Study:

• To investigate the roles of alpha and theta oscillations during internal attention, external attention, and internal-external attention competition.
• To explore scalp-level and regional brain activity, as well as functional connectivity, during these attentional states.
• To elucidate the neural mechanisms underlying the brain's ability to manage competing attentional demands.

Main Methods:

• Electroencephalography (EEG) was recorded from healthy participants at rest and during three attentional tasks: internal (mental math), external (picture viewing), and competition (math with pictures).
• Analysis included spectral power of alpha and theta oscillations at the scalp and cortical regions of interest (ROIs).
• Functional directed connectivity was assessed using spectral Granger Causality.

Main Results:

• Frontal midline theta power increased during mental task execution, particularly during competition, suggesting enhanced executive control.
• Alpha power in visual ROIs decreased during external attention but returned to near-rest levels during competition, indicating reduced visual processing.
• Connectivity analyses revealed anterior cingulate cortex involvement and bidirectional alpha influences between frontal and visual regions, potentially mitigating distraction.

Conclusions:

• Frontal midline theta and anterior cingulate cortex are key in executive control during demanding internal tasks.
• Alpha oscillations and frontal-visual connectivity are crucial for suppressing external distractors during internal attention.
• This research provides insights into brain mechanisms for managing attention in complex, real-world environments.