Resting-State EEG Alteration Over the Loreta Z-Score Neurofeedback in Aphasia

Abstract

Objectives. Aphasia is an acquired language disorder resulting from a brain injury which affects the brain’s electrical activity. Neurofeedback (NFB) is known to synchronize neural oscillations and normalize brain wave abnormalities in several disorders. In this study, we aimed to investigate EEG signals in aphasia and the possible positive effect of Loreta z-score neurofeedback (LZNFB) treatment on improving EEG disturbances and symptoms in aphasia. Methods. Thirteen chronic aphasics and 10 unimpaired nonaphasic subjects were investigated in this study. Clinical assessments were used for the aphasic group at baseline and after 15 sessions of LZNFB to illustrate behavioral improvement. To estimate signal disruption and its alteration over the treatment, EEG signals were acquired referred to as resting-state eyes-closed condition in aphasic group during pretreatment and posttreatment as well as in the nonaphasic control group. We then investigated brain complexity and phase-amplitude coupling (PAC) in groups and compared the results. Results. Our EEG findings were congruent with clinical improvement and showed that after treatment, complexity and PAC changed to a normal level. Conclusion. We conclude that LZNFB treatment was effective in decreasing EEG disturbances and symptoms in aphasia. We think that our findings in complexity and PAC could provide important insights into the electrophysiological profile in aphasia and its alterations after treatment.