Dissociating frontal and temporal correlates of phonological and semantic fluency in a large sample of left hemisphere stroke patients

Publication date: Available online 25 April 2019Source: NeuroImage: ClinicalAuthor(s): Charlotte S.M. Schmidt, Kai Nitschke, Tobias Bormann, Pia Römer, Dorothee Kümmerer, Markus Martin, Roza M. Umarova, Rainer Leonhart, Karl Egger, Andrea Dressing, Mariachristina Musso, Klaus Willmes, Cornelius Weiller, Christoph P. KallerAbstractPrevious lesion studies suggest that semantic and phonological fluency are differentially subserved by distinct brain regions in the left temporal and the left frontal cortex, respectively. However, as of yet, this often implied double dissociation has not been explicitly investigated due to mainly two reasons: (i) the lack of sufficiently large samples of brain-lesioned patients that underwent assessment of the two fluency variants and (ii) the lack of tools to assess interactions in factorial analyses of non-normally distributed behavioral data. In addition, previous studies did not control for task resource artifacts potentially introduced by the generally higher task difficulty of phonological compared to semantic fluency.We addressed these issues by task-difficulty adjusted assessment of semantic and phonological fluency in 85 chronic patients with ischemic stroke of the left middle cerebral artery. For classical region-based lesion-behavior mapping patients were grouped with respect to their primary lesion location. Building on the extension of the non-parametric Brunner-Munzel rank-order test to multi-factorial designs, ANOVA-type analyses r...
Source: NeuroImage: Clinical - Category: Radiology Source Type: research