How time shapes cognitive control: A high-density EEG study of task-switching

Area of Science:

• Neuroscience
• Cognitive Psychology

Background:

• Task-switching is a key paradigm for studying cognitive control.
• The switch cost (longer reaction times in switch trials) is a primary measure, but its neural underpinnings and temporal dynamics remain unclear.
• Understanding the neural basis of cognitive control and its modulation by practice is crucial.

Purpose of the Study:

• To investigate the spatiotemporal neural dynamics of cognitive control during task-switching using high-density EEG.
• To examine how the switch cost and its modulation over time (time-on-task effect) are reflected in brain activity.
• To identify specific cortical regions involved in these cognitive control mechanisms.

Main Methods:

• High-density electroencephalography (EEG) was employed to record brain activity.
• Participants performed a task-switching paradigm to elicit switch costs and time-on-task effects.
• Event-related potentials (ERPs) and source localization techniques were used to analyze neural dynamics.

Main Results:

• The switch cost decreased with task practice.
• Switch-related event-related responses (switch-positivity and switch-negativity) increased with practice, with switch-negativity showing a larger effect.
• Source analysis revealed increased activation in the left middle and superior frontal gyrus over time.

Conclusions:

• Task practice enhances cognitive control, leading to reduced switch costs and altered neural dynamics.
• The observed changes in frontal lobe activation reflect more efficient cognitive processing and proceduralization of the task.
• High-density EEG is effective in revealing the spatiotemporal dynamics of cognitive control mechanisms during task-switching.