Contralateral delay activity reveals dimension-based attentional orienting to locations in visual working memory

Area of Science:

• Cognitive Psychology
• Neuroscience
• Visual Perception

Background:

• The storage of items in visual working memory (WM) is debated, with ongoing discussion about whether items are stored independently or interactively.
• Understanding the role of physical context in WM representations is crucial for resolving this debate.

Purpose of the Study:

• To investigate whether physical context influences the formation of WM representations.
• To explore the interactive nature of item storage in visual working memory.

Main Methods:

• Participants viewed bilateral memory displays with lateralized singleton items and distractors.
• Items were defined either within the same or different visual feature dimensions.
• Electrophysiological recordings (contralateral delay activity) were used to measure WM access.

Main Results:

• Memory search was interactively determined by dimensional context and set size.
• A dimension-specific cost slowed search when targets were defined across dimensions, particularly for larger set sizes.
• This cost correlated with increased contralateral delay activity, indicating altered WM access.

Conclusions:

• Findings provide electrophysiological evidence for hierarchically structured WM representations.
• Results challenge the view that items in WM are encoded in isolation.
• Physical context plays a significant role in the interactive nature of visual working memory.