Working memory delay period activity marks a domain-unspecific attention mechanism

Area of Science:

• Cognitive Neuroscience
• Neuroscience of attention
• Working memory research

Background:

• Working memory (WM) and perception share neural circuits, including selective attention.
• The tactile contralateral delay activity (tCDA) is an event-related potential (ERP) component.
• tCDA is thought to mark attention-based rehearsal of tactile information in somatosensory areas.

Purpose of the Study:

• To investigate if tCDA reflects competition for shared attention resources between WM and perceptual tasks.
• To determine if the tCDA is specific to working memory or mediated by a domain-unspecific attention mechanism.
• To examine how task priority influences the allocation of selective attention resources.

Main Methods:

• Participants performed concurrent working memory and tactile perceptual tasks using opposite hands.
• Task priority (WM higher or lower than perception) was manipulated across different blocks.
• Event-related potentials (ERPs), specifically the tCDA, were recorded and analyzed.

Main Results:

• The tCDA's polarity consistently reflected the hand associated with the currently prioritized task.
• Stimulus material for higher-priority tasks showed larger spatially selective modulations.
• Evidence suggests internal (mnemonic) and external (perceptual) selection involve distinct processes.

Conclusions:

• The tCDA is not specific to working memory but is mediated by a domain-unspecific attention mechanism.
• tCDA reflects a goal-directed bias in the allocation of selective attention.
• Functional overlap exists between working memory and perception, but internal/external selection processes differ.