Gesture subtype-dependent left lateralization of praxis planning: an event-related fMRI study.

TitleGesture subtype-dependent left lateralization of praxis planning: an event-related fMRI study.
Publication TypeJournal Article
Year of Publication2009
AuthorsBohlhalter, S, Hattori N, Wheaton L, Fridman E, Shamim E A., Garraux G, and Hallett M
JournalCereb Cortex
Date Published2009 Jun
KeywordsAdult, Aged, Brain Mapping, Female, Functional Laterality, Gestures, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Motor Skills, Movement

Ideomotor apraxia is a disorder mainly of praxis planning, and the deficit is typically more evident in pantomiming transitive (tool related) than intransitive (communicative) gestures. The goal of the present study was to assess differential hemispheric lateralization of praxis production using event-related functional magnetic resonance imaging. Voxel-based analysis demonstrated significant activations in posterior parietal cortex (PPC) and premotor cortex (PMC) association areas, which were predominantly left hemispheric, regardless of whether planning occurred for right or left hand transitive or intransitive pantomimes. Furthermore, region of interest-based calculation of mean laterality index (LI) revealed a significantly stronger left lateralization in PPC/PMC clusters for planning intransitive (LI = -0.49 + 0.10, mean + standard deviation [SD]) than transitive gestures (-0.37 + 0.08, P = 0.02, paired t-tests) irrespective of the hand involved. This differential left lateralization for planning remained significant in PMC (LI = -0.47 + 0.14 and -0.36 + 0.13, mean + SD, P = 0.04), but not in PPC (-0.56 + 0.11 and -0.45 + 0.12, P = 0.11), when both regions were analyzed separately. In conclusion, the findings point to a left-hemispheric specialization for praxis planning, being more pronounced for intransitive gestures in PMC, possibly due to their communicative nature.

Alternate JournalCereb. Cortex
PubMed ID18796430
PubMed Central IDPMC2677648

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