Motor Memory: Revealing Conditioned Action Tendencies Using Transcranial Magnetic Stimulation

Area of Science:

• Neuroscience
• Cognitive Psychology

Background:

• Action tendencies, automatic responses to stimuli, can enhance performance but hinder goal-directed behavior when goals change.
• Controlling these automatic action tendencies is crucial for behavior modification and goal achievement.

Purpose of the Study:

• To investigate the neural mechanisms underlying conditioned action tendencies.
• To examine how cognitive control modulates these automatic responses using transcranial magnetic stimulation.

Main Methods:

• Participants underwent a training phase associating cues with responses.
• During a test phase, transcranial magnetic stimulation (TMS) was applied to the motor cortex to measure corticospinal excitability (CSE) via motor evoked potentials (MEPs).
• Participants were instructed to withhold responses to trained cues.

Main Results:

• Previously trained response cues potentiated CSE, indicating a conditioned action tendency, even when responses were withheld.
• Attention to the trained cue was necessary for this potentiation.
• Successful cognitive control over the action tendency was associated with suppression of CSE.

Conclusions:

• Well-trained cues can elicit conditioned action tendencies that prime automatic responses.
• Cognitive control mechanisms can override automaticity by modulating neural activity in the motor cortex.
• These findings offer insights into the neural basis of behavior modification and goal-directed control.