Unwanted Memory Intrusions Recruit Broad Motor Suppression

Area of Science:

• Cognitive Neuroscience
• Neuroscience of Memory
• Executive Functions

Background:

• Rapid action-stopping involves global motor suppression.
• The neural mechanisms of inhibiting long-term memory retrieval are not fully understood.
• Executive control plays a crucial role in memory regulation.

Purpose of the Study:

• To investigate if inhibiting long-term memory retrieval recruits global motor suppression.
• To explore the relationship between memory suppression and action-stopping mechanisms.
• To examine the physiological correlates of preventing memory recall.

Main Methods:

• A Think/No-Think task was employed with human participants.
• Transcranial Magnetic Stimulation (TMS) measured motor-evoked potentials in an irrelevant hand.
• Participants learned word pairs and were cued to either retrieve or suppress recall.

Main Results:

• Motor-evoked potentials were reduced on No-Think trials, particularly when memory intrusions occurred.
• Behaviorally, fewer intrusions were reported on No-Think trials, decreasing with practice.
• The findings contradicted the prediction of suppression occurring only when intrusions were *not* reported.

Conclusions:

• Inhibiting long-term memory retrieval involves a rapid, broad inhibitory process akin to action-stopping.
• Memory intrusions themselves appear to trigger this executive control mechanism.
• This suggests a shared neural control mechanism for stopping actions and memories.