Sleep Studies

Dense array EEG research on neurological disorders, such as epilepsy and schizophrenia, has suggested that, in some cases, the neuropathology of the disorder may be seen most clearly during sleep. To research the neurophysiology of these disorders, we need a better understanding of the neural mechanisms of normal sleep.

Child sleeping in the Geodesic Sensor Net


Seizures in Sleep

In our studies of nocturnal onset seizures, we have observed the remarkable effect of seizures emerging from the normal neurophysiological phenomenon of cortical slow oscillations of sleep.


Brain waves and brain images.
In this image, a one-second epoch of EEG is shown for each of 256 channels, arrayed on the page as would be seen looking down on the head. The seizure is indicated by the large discharges (brain waves) at the top middle of the page (forehead). In the topographic map (circle at right), the blue region shows one of the discharges of the seizure (a negative wave), and the GeoSource MRI plot (left) shows the source of the discharge estimated in the medial frontal pole.

The American Journal of Psychiatry magazine.

Sleep Disorder in Schizophrenia

Research at Wisconsin Sleep has shown the importance of dense array EEG in characterizing the sleep disorders of schizophrenia.

Ferrarelli, F., Huber, R., Peterson, M.J., Massimini, M., Riedner, B.A. et al.(2007). Reduced sleep spindle activity in schizophrenia patients. Am J Psychiatry, 164(3), 483-492.