Auditory Cortex Characteristics in Schizophrenia: Associations With Auditory Hallucinations

Area of Science:

• Neuroimaging
• Psychiatry
• Neuroscience

Background:

• Previous neuroimaging studies link smaller auditory cortex volume to auditory hallucinations (AH) in schizophrenia.
• Reduced cortical volume may stem from decreased cortical thickness or surface area, indicating distinct neuropathologies.
• This study investigates the relationship between auditory cortex thickness and surface area with AH in schizophrenia spectrum patients.

Purpose of the Study:

• To determine if auditory hallucinations in schizophrenia are associated with reduced cortical thickness or surface area in specific auditory cortex regions.
• To differentiate the contributions of cortical thickness versus surface area to auditory cortex abnormalities in schizophrenia patients with and without a history of AH.

Main Methods:

• Magnetic resonance imaging (MRI) was used to assess mean cortical thickness and surface area in auditory cortex regions (Heschl's gyrus, planum temporale, superior temporal gyrus).
• Schizophrenia spectrum patients (n=194) with (AH+, n=145) and without (AH-, n=49) a lifetime history of AH were compared.
• These patient groups were also compared to 279 healthy controls.

Main Results:

• Patients with a history of AH showed significantly thinner cortex in the left Heschl's gyrus (HG) compared to those without AH.
• No significant differences in cortical thickness were found in the planum temporale or superior temporal gyrus.
• Auditory cortex surface area did not differ significantly between patient groups across all investigated regions.

Conclusions:

• Auditory hallucinations in schizophrenia are associated with reduced cortical thickness, specifically in the left Heschl's gyrus, rather than reduced surface area.
• These findings support the hypothesis that structural abnormalities within the auditory cortex contribute to the pathophysiology of auditory hallucinations in schizophrenia.
• The results highlight the importance of cortical thickness as a potential neurobiological marker for auditory hallucinations in schizophrenia spectrum disorders.