Disrupting Short-Term Memory Maintenance in Premotor Cortex Affects Serial Dependence in Visuomotor Integration

Area of Science:

• Neuroscience
• Cognitive Science
• Human Behavior

Background:

• Human behavior is influenced by past experiences, leading to biases in perception and action.
• Serial dependence, where previous trial information biases current responses, is a well-documented phenomenon.
• The neural mechanisms underlying serial dependence, particularly the role of short-term memory, remain under investigation.

Purpose of the Study:

• To investigate the neural basis of serial dependence in a visuomotor task.
• To test the hypothesis that memory traces in visual or motor regions contribute to serial dependence.
• To determine if transcranial magnetic stimulation (TMS) can modulate serial dependence by disrupting neural activity.

Main Methods:

• Participants performed a coincident timing task involving intercepting moving targets.
• Transcranial magnetic stimulation (TMS) was applied to the dorsal premotor cortex (PMd) and the visual motion processing region (hV5/MT+).
• The effect of TMS on serial dependence was compared to a control stimulation condition.

Main Results:

• Participants exhibited serial dependence, biasing their responses towards the speed of previous targets.
• TMS applied to the dorsal premotor cortex (PMd) significantly reduced serial dependence.
• TMS applied to the visual motion processing region (hV5/MT+) did not affect serial dependence.

Conclusions:

• The dorsal premotor cortex (PMd) plays a causal role in maintaining short-term memory traces that contribute to serial dependence in visuomotor tasks.
• These memory traces are blended with current information, biasing behavior.
• This suggests that brain regions involved in processing information also participate in its short-term memory maintenance.