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PubMed2005

Assessing dysfunction using refined cognitive methods.

Instruments currently being used to assess cognitive dysfunction do not grant us the granularity to pinpoint the specific cognitive impairments associated with various disorders. With the advent of sophisticated neuroimaging methods and lesion data, we are in a better position to understand the component processes of the various psychological functions. Here we describe 2 such functions and elucidate how the same refined cognitive methods that are being used to understand the processes underlying these functions can be applied to exploring dysfunctions associated with various psychological disorders.

Brain↗

PubMed2005

Common and unique components of response inhibition revealed by fMRI.

The ability to inhibit inappropriate responses is central to cognitive control, but whether the same brain mechanisms mediate inhibition across different tasks is not known. We present evidence for a common set of frontal and parietal regions engaged in response inhibition across three tasks: a go/no-go task, a flanker task, and a stimulus-response compatibility task. Regions included bilateral anterior insula/frontal operculum and anterior prefrontal, right dorsolateral and premotor, and parietal cortices. Insula activity was positively correlated with interference costs in behavioral performance in each task. Principal components analysis showed a coherent pattern of individual differences in these regions that was also positively correlated with performance in all three tasks. However, correlations among tasks were low, for both brain activity and performance. We suggest that common interference detection and/or resolution mechanisms are engaged across tasks, and that inter-task correlations in behavioral performance are low because they conflate measurements of common mechanisms with measurements of individual biases unique to each task.

Adolescent↗