Relationship between power spectra of the awake EEG and psychomotor activity patterns measured by short-term actigraphy.

Actigraphy is a quantitative method for the measurement of motor activity. In the present study, actigraphy was used to examine psychomotor correlates of brain activity. Thirty-four psychiatric patients (17 males and 17 females) with different diagnoses participated in this investigation. Directly after EEG recording, motor activity was measured with a wrist actimeter for 15 min in patients in the sitting position. The EEG was quantified by spectrum analysis, and the power spectra as well as other EEG-derived variables were correlated with actigraphic parameters. Occipital and temporoparietal beta1 power was statistically significantly higher in patients with higher activity scores and lower in those with a high density of sleep (SB) or wake bouts (WB). A high density of SB or WB was also positively correlated with higher mean alpha power. Immobile phases measured by actigraphy were positively associated with occipital alpha and with frontal/frontopolar delta activity, preferentially on the side of the left hemisphere. Our results, while preliminary, suggest that short-term actigraphy may be apt to reflect central nervous system arousal.