Basic stimulus processing alterations from top-down cognitive control in depression drive independent temporal...

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Science

Background:

• Major depressive disorder (MDD) is associated with perceptual alterations beyond emotional processing.
• These changes may involve basic stimulus features, contributing to perceptual bias and anhedonia.

Purpose of the Study:

• To investigate blood oxygen-level-dependent (BOLD) signal changes in perceptual processing in MDD patients.
• To characterize brain networks involved in processing naturalistic stimuli and identify MDD-related alterations.

Main Methods:

• Utilized multi-echo functional magnetic resonance imaging (fMRI) in 39 MDD patients and 36 healthy controls.
• Extracted and analyzed temporally independent BOLD signal components correlated with naturalistic movie stimuli.
• Localized brain networks associated with significant group differences in perceptual processing.

Main Results:

• Identified two components with significant group differences: one for auditory features (sound pressure level) and one for visual features (temporal contrast).
• MDD-associated deficits were primarily observed in higher-order processing areas like the dorsal prefrontal cortex and insula.
• The visual feature deficit extended to non-visual primary sensory cortices and motor system hubs in MDD.

Conclusions:

• Basic sensory processing deficits are an inherent feature of MDD, potentially contributing to anhedonia and negative perceptual bias.
• Dysfunction in MDD predominantly affects higher-order processing and cross-modal sensory integration, indicating impaired top-down control.
• Interventions targeting the prefrontal cortex may restore control over both emotional and sensory processing hubs.