The neural correlates of picture naming: a VBM study of CT images
In: NeuroImage, 2009
Online
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Zugriff:
Introduction Neuropsychological researchers have long been interested in relating the location of a patient's lesion to her cognitive impairment (e.g. Broca, 1861). Previous studies have primarily relied on small patient numbers, manual procedures for symptom-lesion mapping and binary data (Davidoff and De, 1994; DeLeon et al., 2007; Luzzatti et al., 2006; Tranel et al., 1997). Furthermore, the above studies did not control for potential confounds due to covarying factors, such as levels of attention; all of these factors may have contributed to the inconsistencies in the current literature. Here, we combined robust, automated lesion analysis procedures and standard CT imaging to investigate the neural networks involved in object naming in a clinically-relevant setting. Extensive prior research suggests that structures within the left ventral visual stream, anterior temporal and frontal cortex play a key role in mediating object naming (Humphreys et al., 1999; Martin, 2007; Price et al., 1996). Methods We tested 80 acute stroke patients using the object naming task from the Birmingham University Cognitive Screening (BUCS(Humphrey et al., 2007)). All patients underwent a CT scan as part of their clinical evaluation. Data were analysed using SPM5 SPM8b. The CT images were normalized to a CT template, the skull was removed. Subsequently the images were segmented and normalized again; finally the segmented grey matter (GM) images were smoothed using a 12mm Gaussian kernel (Fig. 1). The GM images were entered into a regression analysis that modeled subjects’ performance on the picture naming task; age, gender, mini-mental state and depression were included as covariates of no interest. (1) Using mass-univariate voxel-based morphometry (VBM), we tested at every single voxel for reduction in GM volume that was positively predicted by subjects’ picture naming performancen. (2) Combining Multivariate Bayesian Decoding (MVB(Friston et al., 2008) with smooth priors) and Bayesian model comparison, we compared the ability of ...
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The neural correlates of picture naming: a VBM study of CT images
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Autor/in / Beteiligte Person: | Rotshtein, P. ; Douis, H. ; Bickerton, W. ; Riddoch, J. ; Noppeney, U. ; Humphreys, G. |
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Zeitschrift: | NeuroImage, 2009 |
Veröffentlichung: | 2009 |
Medientyp: | unknown |
DOI: | 10.1016/S1053-8119(09)71889-0 |
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