"Where Do Auditory Hallucinations Come From?"--A Brain Morphometry Study of Schizophrenia Patients With Inner or Outer Space Hallucinations

Abstract

Auditory verbal hallucinations are a cardinal symptom of schizophrenia. Bleuler and Kraepelin distinguished 2 main classes of hallucinations: hallucinations heard outside the head (outer space, or external, hallucinations) and hallucinations heard inside the head (inner space, or internal, hallucinations). This distinction has been confirmed by recent phenomenological studies that identified 3 independent dimensions in auditory hallucinations: language complexity, self-other misattribution, and spatial location. Brain imaging studies in schizophrenia patients with auditory hallucinations have already investigated language complexity and self-other misattribution, but the neural substrate of hallucination spatial location remains unknown. Magnetic resonance images of 45 right-handed patients with schizophrenia and persistent auditory hallucinations and 20 healthy right-handed subjects were acquired. Two homogeneous subgroups of patients were defined based on the hallucination spatial location: patients with only outer space hallucinations (N 5 12) and patients with only inner space hallucinations (N 5 15). Between-group differences were then assessed using 2 complementary brain morphometry approaches: voxel-based morphometry and sulcus-based morphometry. Convergent anatomical differences were detected between the patient subgroups in the right temporoparietal junction (rTPJ). In comparison to healthy subjects, opposite deviations in white matter volumes and sulcus displacements were found in patients with inner space hallucination and patients with outer space hallucination. The current results indicate that spatial location of auditory hallucinations is associated with the rTPJ anatomy, a key region of the ''where'' auditory pathway. The detected tilt in the sulcal junction suggests deviations during early brain maturation, when the superior temporal sulcus and its anterior terminal branch appear and merge.

Possible dysregulation of cortical plasticity in auditory verbal hallucinations–A cortical thickness study in schizophrenia

“…The results indicate a crucial role of the right temporoparietal junction, a key region for the "where" auditory pathway, for weather voices are being heard outside or inside the head (Plaze et al, 2011).…”

Cortical thickness, surface area and folding in patients with psychogenic nonepileptic seizures

“…A number of observations and hypotheses support the idea that the cortical folding geometry is a macroscopic probe for hidden architectural organization or developmental events (Mangin et al, 2010). Advances in neuroimaging analysis methodologies have allowed the examination of local gyrification at ever increasing resolution: deviations of cortex gyrification are reported in schizophrenia (Plaze et al, 2011) and bipolar disorders (McIntosh et al, 2009). A speculative theory would be that an element of the pathophysiology of PNES can be attributed to variation in sulcal morphology in the insula, but further research is needed.…”

Principal Component Regression Predicts Functional Responses across Individuals

“…To better illustrate potential differences between predictability and average activation, we display the average functional signal for two nearby ROIs of the supra-marginal gyrus (x, y, z = 65, −27, 23 and 65, −37, 23 mm respectively): both show the same amount of activation across eleven contrasts, but the most anterior one is much more predictable than those of the posterior one. A straightforward explanation is that the anterior region is much more consistently defined in the MNI space as the border of the post-central gyrus, while the posterior one is a region that does not get a consistent definition, and is more variable anatomically and functionally [10,11].…”