pubmed-article:829063 | pubmed:abstractText | In ten male students the EEG occipital activity was recorded during a visuo-motor task consisting of pursuit-tracking. The degree of task difficulty varied systematically depending on the modification of the transfer function of control element dynamics. The EEG data were evaluated by serial spectral analysis. The distribution functions of the total power estimates and their minima and maxima reflect the dynamics of the regulation of cortical vigilance and permit to differentiate the degree of effort which corresponds to the varying degree of task difficulty. The study of task-irrelevant acoustically evoked potentials showed that with increasing cortical activation the amplitudes of N1-P2 and P2-N2 are diminished. These results might suggest that evoked potentials induced by task-irrelevant stimuli can serve as indicators of the neuronal capacity available for information processing that is not task-oriented. | lld:pubmed |