title: Neural correlates of shape-color binding in visual working memory.
abstract: The present study addressed an outstanding issue regarding feature binding in working memory (WM): whether this function engages specific resources relative to those required to process individual features. We investigated the brain regions supporting the encoding and maintenance of features and bindings in a change detection task, in which 22 healthy young volunteers remembered visual arrays of abstract shapes, colors or shape-color bindings while undergoing fMRI. After an unfilled delay they saw a second array and judged whether the features or combination of features presented across the two arrays were the same or different. Temporary retention of feature bindings was found to involve additional cortical regions compared with retaining single features, regardless of whether the number of objects or the number of features differed between feature-only and binding conditions. This binding-specific activation is consistent with the involvement of different neural generators that collectively support visual temporary memory for features and for feature bindings. Regions within the parietal, temporal and occipital cortex, but not within the prefrontal cortex or the medial temporal lobe, appear to support the integrated object binding function investigated in this study. Our findings suggest that both individual features and their binding within integrated objects are used to represent complex objects in WM.
authors.affiliation: Human Cognitive Neuroscience and Centre for Cognitive Ageing and Cognitive Epidemiology, Psychology Department, University of Edinburgh, United Kingdom; Scottish Dementia Clinical Research Network, NHS Scotland, Scotland, United Kingdom; Alzheimer Scotland Dementia Research Centre, Scotland, United Kingdom. Electronic address: mprodri1@staffmail.ed.ac.uk.
authors.forename: Mario A
authors.initials: MA
authors.lastname: Parra
authors.affiliation: Human Cognitive Neuroscience and Centre for Cognitive Ageing and Cognitive Epidemiology, Psychology Department, University of Edinburgh, United Kingdom.
authors.forename: Sergio
authors.initials: S
authors.lastname: Della Sala
authors.affiliation: Human Cognitive Neuroscience and Centre for Cognitive Ageing and Cognitive Epidemiology, Psychology Department, University of Edinburgh, United Kingdom.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Logie
authors.affiliation: Human Cognitive Neuroscience and Centre for Cognitive Ageing and Cognitive Epidemiology, Psychology Department, University of Edinburgh, United Kingdom; Centre for Cognitive and Neural Systems, University of Edinburgh, United Kingdom.
authors.forename: Alexa M
authors.initials: AM
authors.lastname: Morcom
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000098:blood supply / Q000502:physiology*; D001931:Brain Mapping; D003118:Color Perception / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: Conjunctive representations; Feature integration; Unitization; Working memory binding; fMRI