Abstract
Depressed patients are characterized by hypoactivity of the left and hyperactivity of the right frontal areas during the resting state. Depression is also associated with impaired decision-making, which reflects multiple cognitive, affective, and attentional processes, some of which may be lateralized. The aim of this study was to investigate brain asymmetry during a decision-making task performed in negative and positive feedback conditions in patients with Major Depressive Disorder (MDD) in comparison to healthy control participants. The electroencephalogram (EEG) was recorded from 60 MDD patients and 60 healthy participants while performing a multi-stage decision-making task. Frontal, central, and parietal alpha asymmetry were analyzed with EEGlab/ERPlab software. Evoked potential responses (ERPs) showed general lateralization suggestive of an initial right dominance developing into a more complex pattern of asymmetry across different scalp areas as information was processed. The MDD group showed impaired mood prior to performance, and decreased confidence during performance in comparison to the control group. The resting state frontal alpha asymmetry showed lateralization in the healthy group only. Task-induced alpha power and ERP P100 and P300 amplitudes were more informative biomarkers of depression during decision making. Asymmetry coefficients based on task alpha power and ERP amplitudes showed consistency in the dynamical changes during the decision-making stages. Depression was characterized by a lack of left dominance during the resting state and left hypoactivity during the task baseline and subsequent decision-making process. Findings add to understanding of the functional significance of lateralized brain processes in depression.
Highlights
Many studies have explored relationships between brain asymmetry and clinical depression, using methods including electroencephalography (EEG) and brain-imaging [1]
Given the reliability of frontal alpha asymmetry (FAA) differences in previous depression studies, we tested for side effects in each group separately, as planned comparisons, despite the lack of a significant interaction
The present findings suggest that resting FAA and event related potentials (ERPs) measures linked to specific task stages may have diagnostic value over and above task-induced alpha asymmetry, given the modest intercorrelations of the different measures
Summary
Many studies have explored relationships between brain asymmetry and clinical depression, using methods including electroencephalography (EEG) and brain-imaging [1]. Depression relates to resting alpha asymmetry [2], but the functional significance of resting state asymmetry for cognitive processing during task performance requires further investigation [3]. Experimental studies have confirmed decision-making deficits in depressed patients, findings vary somewhat across different tasks [5]. Lateralized processing such as use of language, regulation of attention, and computation of costs and benefits may contribute to depression effects on decision-making [6], but direct evidence is lacking. The present study aimed to test whether patients with major depressive disorder (MDD) differed from controls in lateralized brain responses during a decision-making task, assessed using event related potentials (ERPs) and alpha power measures
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
