Analysis of Gamma Entrainment on Healthy and Dementia Subjects Using Hjorth Complexity of Various EEG Frequency Bands in Time–Frequency Domain

The number of patients suffering from dementia is increasing day by day and Alzheimer’s disease is one of the forms of dementia that causes loss of memory and decrement in the ability of a person to perform his/her daily life activities. This paper proposes a classification framework in which a comparison of the various EEG frequency bands of healthy and diseased dementia volunteers is performed. The framework consists of wavelet convolution, time–frequency analysis, feature extraction, and comparison of various EEG frequency bands using Hjorth Complexity. As per the analysis performed on various frequency bands, Hjorth Complexities of the delta band, theta band, and alpha band of diseased subjects are greater than that of a healthy subject; whereas the Hjorth complexities of beta and gamma bands of diseased subjects are lower than that of a healthy subject. Hence, we can say that a person suffering from Alzheimer’s disease shows a higher value of Hjorth Complexity in the delta, theta, and alpha band as compared to a healthy volunteer when entrained with gamma frequency to synchronize brain oscillations.