title: Medial temporal lobe activity at recognition increases with the duration of mnemonic delay during an object working memory task.
abstract: Object working memory (WM) engages a disseminated neural network, although the extent to which the length of time that data is held in WM influences regional activity within this network is unclear. We used functional magnetic resonance imaging to study a delayed matching to sample task in 14 healthy subjects, manipulating the duration of mnemonic delay. Across all lengths of delay, successful recognition was associated with the bilateral engagement of the inferior and middle frontal gyri and insula, the medial and inferior temporal, dorsal anterior cingulate and the posterior parietal cortices. As the length of time that data was held in WM increased, activation at recognition increased in the medial temporal, medial occipito-temporal, anterior cingulate and posterior parietal cortices. These results confirm the components of an object WM network required for successful recognition, and suggest that parts of this network, including the medial temporal cortex, are sensitive to the duration of mnemonic delay.
authors.affiliation: King's College London, Institute of Psychiatry, Section of Neuroimaging, London, United Kingdom. m.picchioni@iop.kcl.ac.uk
authors.forename: Marco
authors.initials: M
authors.lastname: Picchioni
authors.forename: Pall
authors.initials: P
authors.lastname: Matthiasson
authors.forename: Matthew
authors.initials: M
authors.lastname: Broome
authors.forename: Vincent
authors.initials: V
authors.lastname: Giampietro
authors.forename: Mick
authors.initials: M
authors.lastname: Brammer
authors.forename: Birgit
authors.initials: B
authors.lastname: Mathes
authors.forename: Paul
authors.initials: P
authors.lastname: Fletcher
authors.forename: Steven
authors.initials: S
authors.lastname: Williams
authors.forename: Philip
authors.initials: P
authors.lastname: McGuire
mesh_terms: D000328:Adult; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology; D001931:Brain Mapping; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D009415:Nerve Net / Q000033:anatomy & histology / Q000502:physiology*; D009434:Neural Pathways / Q000033:anatomy & histology / Q000502:physiology; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology; D011930:Reaction Time / Q000502:physiology*; D021641:Recognition, Psychology / Q000502:physiology*; D013702:Temporal Lobe / Q000033:anatomy & histology / Q000502:physiology*; D013997:Time Factors