title: fMRI memory assessment in healthy subjects: a new approach to view lateralization data at an individual level.
abstract: We present a comprehensive and clinically applicable fMRI test-including both a verbal and a visuospatial task-for assessment of hemispheric specific memory in the medial temporal lobe (MTL). fMRI data was collected from 15 healthy right-handed volunteers. Whole-brain activation was analyzed as well as activation in two regions of interest: the MTL and the anterior speech area. Laterality indices (LI) and LI-curves were calculated using the LI toolbox of Wilke and Lidzba, 2007. The fMRI paradigms successfully visualized memory-related activity in the MTL, the verbal memory measure also provided information of language lateralization. Eleven subjects showed left lateralized verbal encoding in the MTL, visuospatial memory activation was divided equally between left and right, and 14/15 subjects had left lateralized language. Lateralization data at the group level were consistent with previous studies, but a variety of activation effects were found at the individual level indicating differences in strategy during verbal and visuospatial processing. Further studies using the presented method are needed to determine its clinical usefulness.
authors.affiliation: Department of Neurology, Dept of Clinical Sciences, Lund University Hospital, 221 85, Lund, Sweden. maria.strandberg@med.lu.se
authors.forename: Maria
authors.initials: M
authors.lastname: Strandberg
authors.forename: Christina
authors.initials: C
authors.lastname: Elfgren
authors.forename: Peter
authors.initials: P
authors.lastname: Mannfolk
authors.forename: Johan
authors.initials: J
authors.lastname: Olsrud
authors.forename: Lars
authors.initials: L
authors.lastname: Stenberg
authors.forename: Danielle
authors.initials: D
authors.lastname: van Westen
authors.forename: Elna-Marie
authors.initials: EM
authors.lastname: Larsson
authors.forename: Ia
authors.initials: Ia
authors.lastname: Rorsman
authors.forename: Kristina
authors.initials: K
authors.lastname: Källén
mesh_terms: D000328:Adult; D000465:Algorithms; D002540:Cerebral Cortex / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007802:Language; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology; D021641:Recognition, Psychology / Q000502:physiology; D013028:Space Perception / Q000502:physiology; D013060:Speech / Q000502:physiology; D014705:Verbal Behavior / Q000502:physiology