Brain region white matter associations with visual selective attention.

To understand how normal variations in white matter relate to cognition, magnetization transfer imaging ratios (MTR) of a hypothesized neural network were associated with a test of visual selective attention (VST). Healthy adults (N = 16) without abnormal signal on brain scans viewed a version of DeSchepper and Treisman's test of VST (1996) with two levels of processing (novel shape matching with and without distractors, contingency feedback). A hypothesized neural network and component regions was significantly associated with accuracy and response times when distractors were present, with betas predicting 55% of variance in accuracy, and 59% of response times. MTR for anterior and posterior cingulate, prefrontal region, and thalami comprised a model predicting 55% of accuracy when distractors were present, and the anterior cingulate accounted for the majority of this effect. Prefrontal MTR predicted longer response times which was associated with increased accuracy. Distal neural areas involved in complex, processing-driven tasks (error processing, response selection, and variable response competition and processing load) may be dependent on white matter fibers to connect distal brain regions/nuclei of a macronetwork, including prefrontal executive functions.