Remember how to use it: Effector-dependent modulation of spatial working memory activity in posterior parietal cortex

Area of Science:

• Cognitive Neuroscience
• Neuroimaging
• Human Brain Function

Background:

• Working memory (WM) is crucial for linking perception and action, involving sensori-motor associations.
• Research suggests WM is influenced by the effector used for future behavioral responses.
• The posterior parietal cortex (PPC) plays a role in both spatial WM and motor preparation.

Purpose of the Study:

• To investigate if effector information impacts sensory stimulus maintenance in WM.
• To examine WM-related activity in the PPC when response effector is known but response planning is not immediate.
• To determine if PPC activity differs based on verbal vs. manual response requirements.

Main Methods:

• Human functional magnetic resonance imaging (fMRI) was employed.
• Participants performed a spatial WM task with a match-to-sample comparison.
• Stimuli were maintained in memory for subsequent verbal or manual responses.

Main Results:

• fMRI activity in the bilateral anterior intraparietal sulcus was higher during manual response trials.
• This finding supports the hypothesis that PPC engagement increases when motor preparation is relevant.
• WM maintenance of spatial information is modulated by the anticipated motor context.

Conclusions:

• Sensory material maintenance within WM is optimized based on the relevant upcoming motor context.
• The brain prepares for specific effectors, influencing how information is held in working memory.
• These findings highlight the intricate interplay between memory, perception, and action planning in the PPC.