Attention and cognitive load modulate motor resonance during action observation

Area of Science:

• Neuroscience
• Cognitive Psychology
• Motor Control

Background:

• Observing actions triggers a motor resonant (MR) response within the parieto-frontal Action Observation Network (AON).
• The influence of cognitive factors on the AON's MR response remains incompletely understood.

Purpose of the Study:

• To investigate how attention and cognitive load affect the AON's MR response during action observation.
• To explore the mechanisms underlying attention-modulated motor resonance.

Main Methods:

• Utilized transcranial magnetic stimulation (TMS) to elicit motor evoked potentials (MEPs) in specific hand muscles (OP, ADM).
• Manipulated attention (selective, covert) and cognitive load during central and peripheral observation of hand grasping actions across three experiments.

Main Results:

• Selective attention in central vision facilitated MEPs in the thumb's opponent muscle (OP) but not the little finger's abductor (ADM).
• Covert attention in peripheral vision significantly reduced or abolished MEP modulation, indicating diminished MR.
• Reducing cognitive load by pre-viewing actions before peripheral presentation with covert attention restored accurate MR responses.

Conclusions:

• Cognitive processes, particularly attention and cognitive load, significantly modulate the AON's motor resonance.
• Peripheral action observation is more susceptible to cognitive load, potentially impairing the MR response.
• Strategies to decrease cognitive effort can restore motor resonance during complex action observation tasks.