Alpha power modulation during periods with rapid oculomotor activity in human REM sleep

ALPHA activity attenuation (blocking) over occipital regions is an electrop hysiological index of cortical activation associated with visual attention and waking mental imagery. The present work focused on exploring whether th e human REM background alpha activity was modulated, attending to tonic- (w ithout rapid oculomotor activity) and phasic-REM periods (with a prominent burst of REMs). The obtained results revealed that the background alpha act ivity showed a decreased spectral power over occipital brain regions during phasic-REM in comparison with tonic-REM periods. This result suggests an a ctive visual processing caused by the complex mental imagery generated duri ng periods of oculomotor activity in human REM sleep. NeuroReport 10:1817-1 820 (C) 1999 Lippincott Williams & Wilkins.