Altered EEG Microstates Dynamics in Individuals with Subthreshold Depression When Generating Negative Future Events.

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Science

Background:

• Negative bias in future thinking is linked to depression.
• Abnormal default mode network (DMN) activity is observed in depressed individuals during future event generation.
• Neural dynamics during prospection in depression remain unclear.

Purpose of the Study:

• To investigate the neural dynamics of prospection in individuals with subthreshold depression (SD) using electroencephalogram (EEG) microstate analysis.
• To identify alterations in brain network dynamics associated with negative bias in SD.

Main Methods:

• EEG microstate analysis was performed on 35 individuals with SD and 35 controls during positive and negative prospection.
• Source analysis mapped microstates to DMN subsystems.
• Microstate properties (coverage, occurrence, duration) and transitions were analyzed.

Main Results:

• Four canonical microstates (A-D) were identified, overlapping with DMN subsystems.
• Individuals with SD showed altered microstate dynamics during negative prospection.
• Increased coverage, occurrence, and duration of microstate A, and decreased coverage and duration of microstates B and D were observed in the SD group.
• Altered transitions, especially involving microstate C, were noted in the SD group during negative prospection.

Conclusions:

• Altered EEG microstate dynamics indicate dysconnectivity within the DMN during negative prospection in individuals with SD.
• These findings offer insights into the neural mechanisms of negative bias in depression.
• Observed alterations may serve as potential biomarkers and therapeutic targets for depression.