The effect of light sleep on the brainstem auditory evoked potential (BAEP)

This study dealt with the latency and amplitude changes in the brainstem auditory evoked potential (BAEP) measured during periods from wake to light sleep, after stimulating both ears of 16 subjects. All 13 latencies (positive and negative) increased from the central vertex electrode (referred C7 vertebra) with statistical significance from peak VI (and II), and 8 of 13 latencies increased from the (ipsilateral) ear electrode with statistical significance from negative peak V. Furthermore, a significant decrease in amplitude occurred in peak V (ear) and in peak VIII (Cz and ear). Finally, the more typical recording of vertex to ipsilateral ear showed all 13 latencies increasing in the sleep state and nonparametric statistics showed significance in 6 of these latencies. The assumption that the latencies and amplitudes do not change from the waking to the sleeping state should be reconsidered.