CORTICAL LESIONS AFFECT THE LATE POSITIVE POTENTIAL DURING VISUAL-SPATIAL ATTENTION

Edwards, E (1), Townsend, J (2), Westerfield, M (2), Makeig, S (3), Jung, TP (3)

(1) Children’s Hospital Research Center, San Diego, CA (2) UC San Diego, La Jolla, CA (3) Salk Institute, La Jolla, CA

This study assesses the contributions of different cortical regions to the Late Positive Complex (LPC). Additional data from cerebellar lesion subjects are presented in the companion poster by Westerfield et al. Event-related potentials were recorded from twelve cortical stroke patients and age-matched controls during a visual-spatial task. The results were analyzed using both traditional peak-based methods and Independent Component Analysis (ICA). The stroke patients had lesions affecting temporal, parietal and frontal cortex. Unilateral lesions of the temporal-parietal junction were found to severely reduce the LPC bilaterally. Components of the LPC were differentially affected by lesions in the frontal and parietal lobes. These results are in agreement with the results of Knight 1997 and extend those findings to components of the LPC as derived from ICA.