P300 amplitude in subjects with primary insomnia is modulated by their sleep quality

Objective: The hyperarousal hypothesis is evaluated while controlling the influence of the quality of sleep in the night preceding the evaluation. Method: Eleven primary insomniacs and 11 healthy age matched controls participated to the study. Participants filled in 2 weeks of sleep logs and self-monitored their subjective tension the evening before and the morning after each night. Afterwards, subjects were called in to the Lab for a recording session of the P300 ERP (oddball paradigm) once after a night of bad sleep quality (N -) and once after a night of good sleep quality (N+). Results: The main result of the present study indicated that the P300 amplitude at Fz in insomniacs resulted higher following a N - and lower following a N+ with respect to controls. Conclusions: This result suggests that cortical hyperarousal in primary insomniacs is not a stable individual characteristic, but is associated with the poor quality of their nocturnal sleep. (C) 2003 Elsevier Science Inc. All rights reserved.