title: Imitation and speech: commonalities within Broca's area.
abstract: The so-called embodiment of communication has attracted considerable interest. Recently a growing number of studies have proposed a link between Broca's area's involvement in action processing and its involvement in speech. The present quantitative meta-analysis set out to test whether neuroimaging studies on imitation and overt speech show overlap within inferior frontal gyrus. By means of activation likelihood estimation (ALE), we investigated concurrence of brain regions activated by object-free hand imitation studies as well as overt speech studies including simple syllable and more complex word production. We found direct overlap between imitation and speech in bilateral pars opercularis (BA 44) within Broca's area. Subtraction analyses revealed no unique localization neither for speech nor for imitation. To verify the potential of ALE subtraction analysis to detect unique involvement within Broca's area, we contrasted the results of a meta-analysis on motor inhibition and imitation and found separable regions involved for imitation. This is the first meta-analysis to compare the neural correlates of imitation and overt speech. The results are in line with the proposed evolutionary roots of speech in imitation.
authors.affiliation: Department of Experimental Psychology and Ghent Institute for Functional and Metabolic Imaging, Faculty of Psychology and Educational Sciences, Ghent University, Henri Dunantlaan 2, 9000, Ghent, Belgium, kuehn@mpib-berlin.mpg.de.
authors.forename: Simone
authors.initials: S
authors.lastname: Kühn
authors.forename: Marcel
authors.initials: M
authors.lastname: Brass
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gallinat
mesh_terms: D005625:Frontal Lobe / Q000033:anatomy & histology / Q000502:physiology*; D059907:Functional Neuroimaging / Q000379:methods; D006225:Hand / Q000502:physiology; D006801:Humans; D007100:Imitative Behavior / Q000502:physiology*; D016013:Likelihood Functions; D008959:Models, Neurological; D013060:Speech / Q000502:physiology*