Modulation of aperiodic EEG activity provides sensitive index of cognitive state changes during working memory task

Area of Science:

• Neuroscience
• Cognitive Science
• Electrophysiology

Background:

• Understanding cognitive processes requires analyzing both periodic (oscillatory) and aperiodic brain activity.
• Electrophysiological signals, like EEG, offer insights into neural dynamics during cognitive tasks.

Purpose of the Study:

• To investigate how periodic and aperiodic electrophysiological components reflect working memory processes.
• To determine the relationship between spectral components and cognitive demands during tasks.

Main Methods:

• Utilized electroencephalography (EEG) to record brain activity in 57 participants performing an n-back task.
• Analyzed both periodic and aperiodic components of the EEG spectrum to assess spatiotemporal dynamics.

Main Results:

• Both periodic and aperiodic activities showed distinct task-related dynamics linked to cognitive demands.
• Changes attributed to theta oscillations might be influenced by shifts in the aperiodic spectral slope.
• Aperiodic activity modulation offers a potentially more sensitive index of cognitive state changes.

Conclusions:

• Aperiodic activity modulation is crucial for accurately representing the neural basis of cognition.
• Findings challenge conventional views on low-frequency oscillations in cognitive processing.
• Routine EEG baseline correction may obscure significant modulations in continuous working memory tasks.