Face processing impairments and delusional misidentification

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psychiatry

Background:

• Delusional misidentification syndromes (DMS) are rare neuropsychiatric disorders.
• Patients with DMS often exhibit profound alterations in recognizing familiar individuals.
• The precise nature of face processing deficits in DMS remains incompletely understood.

Purpose of the Study:

• To investigate the face processing capabilities of patients diagnosed with Frégoli syndrome and intermetamorphosis.
• To determine if specific deficits in facial recognition, emotional expression identification, and facial memory are associated with these syndromes.
• To explore the relationship between face processing impairments, delusional misidentification, and underlying brain injury.

Main Methods:

• Detailed neuropsychological assessments of face processing abilities were conducted.
• Tasks included recognition of emotional facial expressions, identification of familiar faces, matching unfamiliar faces, and memory for unfamiliar faces.
• Four patients with DMS (one Frégoli, three intermetamorphosis) were evaluated.

Main Results:

• The Frégoli patient (GC) demonstrated impaired familiar face identification and severe deficits in matching unfamiliar faces across different disguises.
• Two intermetamorphosis patients (SL, GS) exhibited impaired face processing abilities.
• One intermetamorphosis patient (JS) performed within normal limits on all face processing tasks.

Conclusions:

• Face processing impairments are not universal across all patients with delusional misidentification syndromes.
• Specific deficits in facial recognition and matching may be linked to Frégoli syndrome and some forms of intermetamorphosis.
• These findings contribute to understanding the neural underpinnings of DMS and their impact on social cognition.