Brain DC potential changes of computerized tasks and paper/pencil tasks

Analysis of slow cortical potentials and their topography is currently discussed as an indication of cortical activity associated with cognitive operations/performance. In this paper, changes of the EEG DC potential were analyzed in two computerized tasks (correcting typing errors, performing Excel) and two paper/pencil tasks (correcting typing errors, a cognitive test) to assess mental load related to ergonomical and task characteristics. DC recordings were analyzed for the mean values of baseline and the first and the second 4 min of each task from 24 persons. A 2 (computer usage experience low vs. high)x4 (Task)x3 (Time: baseline, first half of task, second half)x6 (Lead) MANOVA of DC potential changes (DCPCs) showed at F3, F4 and C3 positive DCPCs for paper/pencil tasks and negative DCPCs for computerized tasks. Ratings of task difficulty were related to high vs. low task demands, whereas DCPCs were related to task medium, time on task and lead. Highly experienced persons showed a pronounced left-right difference at parietal locations and at frontal and central locations related to task medium by trend. Results were interpreted as higher cortical activation associated with mental load caused by additional attentional/controlling demands of computerized tasks.