Effect of task complexity on motor and cognitive preparatory brain activities

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psychophysiology

Background:

• Motor and cognitive preparation are crucial for responding to stimuli.
• Event-related potentials (ERPs) provide insights into neural processes preceding actions.
• Distinguishing between simple and complex tasks is essential for understanding cognitive load.

Purpose of the Study:

• To investigate differences in motor and cognitive preparation between simple and complex visual motor discriminative response tasks (DRTs).
• To analyze pre-stimulus event-related potentials, specifically the Bereitschaftspotential (BP) and prefrontal negativity (pN).
• To explore the impact of task complexity on neural preparation.

Main Methods:

• Recorded scalp electroencephalography (EEG) to measure event-related potentials (ERPs).
• Compared performance and ERPs in simple-DRT (2 stimuli) and complex-DRT (4 stimuli).
• Analyzed pre-stimulus ERP components: central Bereitschaftspotential (BP) and prefrontal negativity (pN).

Main Results:

• Behavioral performance was faster and more accurate in the simple-DRT.
• Both BP and pN components exhibited earlier onset and larger amplitudes in the complex-DRT.
• The complex-DRT demanded greater motor and cognitive preparation in premotor and prefrontal areas.

Conclusions:

• Task complexity significantly influences the neural preparation preceding motor responses.
• The prefrontal negativity (pN) component is sensitive to task complexity and may be underdeveloped in simpler tasks.
• Findings highlight the importance of task design in ERP research on pre-stimulus activity.