title: Integration of "what" and "where" in frontal cortex during visual imagery of scenes.
abstract: Imagination is a key function for many human activities, such as reminiscing, learning, or planning. Unravelling its neuro-biological basis is paramount to grasp the essence of our thoughts. Previous neuroimaging studies have identified brain regions subserving the visualisation of "what?" (e.g. faces or objects) and "where?" (e.g. spatial layout) content of mental images. However, the functional role of a common set of involved regions - the frontal regions - and their interplay with the "what" and "where" regions, has remained largely unspecified. This study combines functional MRI and electroencephalography to examine the full-brain network that underlies the visual imagery of complex scenes and to investigate the spectro-temporal properties of its nodes, especially of the frontal cortex. Our results indicate that frontal regions integrate the "what" and "where" content of our thoughts into one visually imagined scene. We link early synchronisation of anterior theta and beta oscillations to regional activation of right and central frontal cortices, reflecting retrieval and integration of information. These frontal regions orchestrate remote occipital-temporal regions (including calcarine sulcus and parahippocampal gyrus) that encode the detailed representations of the objects, and parietal "where" regions that encode the spatial layout into forming one coherent mental picture. Specifically the mesial superior frontal gyrus appears to have a principal integrative role, as its activity during the visualisation of the scene predicts subsequent performance on the imagery task.
authors.affiliation: Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands. aline.deborst@maastrichtuniversity.nl
authors.forename: Aline W
authors.initials: AW
authors.lastname: de Borst
authors.forename: Alexander T
authors.initials: AT
authors.lastname: Sack
authors.forename: Bernadette M
authors.initials: BM
authors.lastname: Jansma
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Esposito
authors.forename: Federico
authors.initials: F
authors.lastname: de Martino
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Valente
authors.forename: Alard
authors.initials: A
authors.lastname: Roebroeck
authors.forename: Francesco
authors.initials: F
authors.lastname: di Salle
authors.forename: Rainer
authors.initials: R
authors.lastname: Goebel
authors.forename: Elia
authors.initials: E
authors.lastname: Formisano
mesh_terms: D000293:Adolescent; D000328:Adult; D004569:Electroencephalography; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D059907:Functional Neuroimaging; D006801:Humans; D007092:Imagination / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D055815:Young Adult