Impaired cognitive flexibility in major depressive disorder: Evidences from spatial-temporal ERPs analysis

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psychiatry

Background:

• Major Depressive Disorder (MDD) is often associated with cognitive deficits.
• Cognitive flexibility, the ability to switch between different mental sets, is a key cognitive function that may be impaired in MDD.

Purpose of the Study:

• To investigate whether cognitive flexibility deficits in MDD are general or specific to emotional stimuli.
• To explore the underlying neuropsychological mechanisms of cognitive flexibility impairments in MDD using event-related potentials (ERPs).

Main Methods:

• Recruited 41 MDD patients and 42 healthy controls (HCs).
• Utilized non-emotional and emotional task switching paradigms (N-ETSP and ETSP) to assess cognitive flexibility.
• Applied microstate and source localization analysis (sLORETA) of ERPs to examine brain activity.

Main Results:

• MDD patients showed altered ERP components (P3, P2, N2) in both N-ETSP and ETSP compared to HCs.
• MDD group exhibited increased precentral gyrus activation and reduced middle occipital gyrus activation during emotional task switching.
• Deficits were more pronounced for emotional stimuli, particularly negative ones.

Conclusions:

• MDD is characterized by impaired cognitive flexibility across both emotional and non-emotional tasks.
• These deficits are associated with abnormal early attention and later task preparation stages, reflected in ERPs.
• Abnormal emotional switching costs in MDD may stem from altered perceptual control in the parietal-occipital cortex.