Contextual Modulation of Semantic Coherence in vmPFC Patients' Mental Constructions

Area of Science:

• Neuroscience
• Cognitive Psychology
• Computational Linguistics

Background:

• The ventromedial prefrontal cortex (vmPFC) is implicated in semantic memory and schema implementation for event construction.
• Damage to the vmPFC may impair the ability to generate coherent mental events.

Purpose of the Study:

• To investigate the role of the vmPFC in semantic coherence during event construction.
• To determine if vmPFC damage leads to reduced semantic coherence in mentally constructed events, and if this effect is cue-dependent.

Main Methods:

• Participants with vmPFC damage and controls mentally constructed events using object cues.
• Reanalyzed a dataset where participants used sentence cues.
• Measured semantic coherence using transformer-based sentence embeddings (S-BERT, E5 Multilingual, E5 Italian).

Main Results:

• vmPFC patients showed reduced local coherence and increased cue connectedness with object cues.
• With sentence cues, vmPFC patients exhibited preserved or enhanced local and global coherence.
• Lexical diversity was reduced in vmPFC patients with object cues.

Conclusions:

• vmPFC integrity is crucial for schema activation under minimal cue conditions.
• Extended cues can facilitate schema activation, but vmPFC damage may lead to essentialized schemas, resulting in overly coherent mental constructions.