Schizophrenia Bulletin Advance Access published online on August 7, 2009
Schizophrenia Bulletin, doi:10.1093/schbul/sbp081
"Where Do Auditory Hallucinations Come From?"—A Brain Morphometry Study of Schizophrenia Patients With Inner or Outer Space Hallucinations
2 INSERM, U797 Research Unit, Neuroimaging and Psychiatry, IFR49, Orsay, France
3 CEA, Neuroimaging and Psychiatry, U797 Unit, Hospital Department Frédéric Joliot and Neurospin, I2BM, Orsay, France
4 Paris-Sud University, UMR U797, Orsay and Paris 5 René Descartes University, UMR U797, Paris, France
5 Psychiatry Department (SHU), Sainte Anne Hospital, Paris, France
6 Department of Adolescent Psychopathology and Medicine, AP-HP, Maison de Solenn, Cochin Hospital, Paris, France
7 Computer-Assisted Neuroimaging Laboratory, Neurospin, I2BM, CEA, France
8 Department 3 (area 93G03)-CHS Ville-Evrard, Romain Roland Hospital, Saint-Denis, France
9 Psychiatry Department 4 (area 94G11), Paul Guiraud Hospital, Villejuif, France
10 Psychiatry Department, Chenevier-Mondor Hospital, Paris XII University and INSERM U841, Créteil, France
11 Psychiatry Department (area 91G16), Orsay hospital, Orsay, France
1To whom correspondence should be addressed; Research unit INSERM-CEA U797, 4, place du général Leclerc, F-91401 Orsay, France; tel/fax.: +33-0-1-6986-7757/7810, email: arnaud.cachia{at}gmail.com
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 = 12) and patients with only inner space hallucinations (N = 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.
Keywords: hallucinations / spatial location / brain anatomy / MRI / schizophrenia / "where pathway" / temporoparietal junction