Obsessive-compulsive symptoms predict increased fronto-parahippocampal synchronisation during thought suppression.

Area of Science:

• Neuroscience
• Psychology
• Cognitive Science

Background:

• Thought suppression is linked to increased intrusive thoughts in obsessive-compulsive disorder (OCD).
• Neural mechanisms of how obsessive-compulsive symptoms (OCS) affect thought suppression, especially with negative stimuli, are not fully understood.
• Investigating the role of preferential processing of negative stimuli in this context is crucial.

Purpose of the Study:

• To investigate the neural mechanisms of thought suppression in relation to OCS.
• To examine if OCS predicts altered brain connectivity during the suppression of negative words.
• To explore if preferential processing of negative stimuli mediates this relationship.

Main Methods:

• Electroencephalography (EEG) was used to record brain activity in 47 participants performing a directed forgetting task with negative and neutral words.
• Fronto-parahippocampal beta-1 synchronization was analyzed in relation to OCS during the task.
• A mediated moderation model was employed to assess the mediating role of stimulus processing bias (late positive potential).

Main Results:

• Higher OCS predicted increased fronto-parahippocampal beta-1 synchronization when participants were instructed to forget negative words.
• The effect of stimulus valence on synchronization was mediated by preferential processing of negative stimuli, evidenced by an increased late positive potential.
• This suggests a compensatory neural mechanism in individuals with higher OCS.

Conclusions:

• Individuals with higher OCS demonstrate compensatory connectivity between frontal and parahippocampal regions when suppressing negative emotional stimuli.
• This compensatory activity is influenced by preferential processing of negative stimuli and OCS severity.
• Findings provide preliminary evidence for a neural mechanism underlying persistent intrusive thoughts in OCD.