Neural correlates of shape-color binding in visual working memory

Area of Science:

• Cognitive Neuroscience
• Neuroimaging
• Psychology

Background:

• Feature binding is crucial for representing complex objects in working memory (WM).
• The neural basis distinguishing feature processing from feature binding remains unclear.

Purpose of the Study:

• To investigate whether feature binding in WM engages distinct neural resources compared to processing individual features.
• To identify the specific brain regions involved in encoding and maintaining features and their bindings.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used in 22 healthy young volunteers.
• Participants performed a change detection task involving visual arrays of shapes, colors, or shape-color bindings.
• Judgments were made on whether features or combined features remained the same or changed between two arrays.

Main Results:

• Temporary retention of feature bindings activated additional cortical regions compared to retaining single features.
• This binding-specific activation was observed irrespective of object or feature quantity differences.
• Neural activation was prominent in parietal, temporal, and occipital cortex, excluding prefrontal cortex and medial temporal lobe.

Conclusions:

• Feature binding in visual working memory recruits distinct neural generators.
• Specialized neural resources support the integrated object binding function.
• Both individual features and their bindings are essential for representing complex objects in working memory.