Delta oscillatory responses as a general electrophysiological biomarker for cognitive disorders

Abstract

Background: In the last decade research on delta oscillatoryresponses invaded the literature. One of thefirst research on thisarea showed that delta responses increase upon cognitive load(Başar and Stampfer 1985). After this preliminary result, manyresearchers have shown that delta responses are related to attention,perception, decision making and working memory processes. Ourgroup and other groups in the literature indicated that the deltaresponses in different patient groups were decreased duringcognitive load in comparison to healthy controls. In a recent reviewwe have described that decrease of delta responses could be acandidate of a general electrophysiological biomarker for neuropsy-chiatric disorders (Güntekin and Başar 2015). Delta responses weredecreased in Alzheimer’s disease, in Mild Cognitive impairment(MCI) in bipolar disorder patients and as well as in schizophreniapatients during cognitive load in comparison to healthy controls. Inthe present study we analyze the delta responses in Parkinson’sdisease with and without cognitive deficits