Delta power in sleep in relation to neuropsychological performance in healthy subjects and schizophrenia patients.

Delta power in sleep is of increasing interest because of its association with waking performance in neuropsychological tests. In schizophrenia, this link might be impaired because of a decrease in delta power in sleep and pronounced cognitive deficits. The authors analyzed delta power in sleep and neuropsychological performance in 16 patients with schizophrenia on stable medication with amisulpride and 17 healthy subjects. In healthy subjects, the authors found significant positive correlations between morning performance in declarative memory, procedural learning, and attention and delta power, especially in frontal channels. The authors interpret these results in terms of dysfunctions of thalamocortical and prefrontal networks in schizophrenia.