Intersubject variability in cortical activations during a complex language task.

Journal Article (Clinical Trial;Journal Article)

Intersubject variability in the functional organization of the human brain has theoretical and practical importance for basic and clinical neuroscience. In the present study, positron emission tomography (PET) and anatomical magnetic resonance imaging (MRI) were used to study the functional anatomy of language processes. Intersubject variability in task-induced activations in six brain regions was assessed in 20 normal subjects (10 men and 10 women) for frequency of occurrence, location, intensity, and extent. A complex, but well-studied task (overt verb generation) was compared to a simple baseline (visual fixation) to induce activations in brain areas serving perceptual, motoric, and cognitive functions. The frequency of occurrence was high for all selected brain areas (80-95%). The variability in response location in Talairach space, expressed as the standard deviation along each axis (x, y, z), ranged from 5.2 to 9.9 mm. This variability appears to be uniformly distributed across the brain, uninfluenced by regional differences in the complexity of gyral anatomy or mediated behavior. The variability in response location, expressed as the average Euclidean distances (averaged across subjects) about mean locations of activations, varied from 9.40 to 13.36 mm and had no significant differences by region (P>0.05, beta = 0.20). Intensity variability was also relatively small and homogenous across brain regions. In contrast, response extent was much more variable both across subjects and across brain regions (0.79 to 1.77, coefficient of variation). These findings are in good agreement with previous PET studies of intersubject variability and bode well for the possibility of using functional neuroimaging to study neural plasticity subsequent to congenital and acquired brain lesions.

Full Text

Duke Authors

Cited Authors

  • Xiong, J; Rao, S; Jerabek, P; Zamarripa, F; Woldorff, M; Lancaster, J; Fox, PT

Published Date

  • September 2000

Published In

Volume / Issue

  • 12 / 3

Start / End Page

  • 326 - 339

PubMed ID

  • 10944415

International Standard Serial Number (ISSN)

  • 1053-8119

Digital Object Identifier (DOI)

  • 10.1006/nimg.2000.0621


  • eng

Conference Location

  • United States