title: Duration and not strength of activation in temporo-parietal cortex positively correlates with schizotypy.
abstract: Impaired self- and own body processing in patients with schizophrenia and individuals along the schizophrenia spectrum have been associated with dysfunctional cortical activation at the temporo-parietal junction. Here we investigated whether strength or duration of temporo-parietal junction activation during an own body processing task correlates with level of abnormal self-processing in healthy subjects as measured by the frequency of spontaneously experienced schizotypal body schema alterations (perceptual aberrations) and dissociative experiences. Participants carried out a mental imagery task with respect to their own body. Behavioral data and high density EEG were measured. EEG data were analyzed using evoked potential mapping and electrical neuroimaging. Participants completed two validated self-report questionnaires, one asking about perceptual aberration and one about dissociative experiences. The own body transformation task activated the right temporo-parietal junction at 310-390 ms. Participants' reaction times and duration of activation at the right temporo-parietal junction, but not its strength, were found to correlate positively with perceptual aberration scores. No relationship was found with dissociative experiences scores. Brain activations proceeding and following activation of the right temporo-parietal junction did not correlate with scores on either scale. The positive correlation between performance and right temporo-parietal activation in an own body transformation task with perceptual aberrations scores in our healthy population suggests that disturbances in self- and body processing in individuals along the schizophrenia spectrum might be due to prolonged, rather than stronger activation of the right temporo-parietal junction. We argue that this might reflect local pathology, pathologies in cortico-cortical connections and/or re-entry of top-down processing.
authors.affiliation: Laboratory of Cognitive Neuroscience, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
authors.forename: Shahar
authors.initials: S
authors.lastname: Arzy
authors.forename: Christine
authors.initials: C
authors.lastname: Mohr
authors.forename: Christoph M
authors.initials: CM
authors.lastname: Michel
authors.forename: Olaf
authors.initials: O
authors.lastname: Blanke
mesh_terms: D000328:Adult; D001828:Body Image; D001931:Brain Mapping; D004569:Electroencephalography; D005071:Evoked Potentials; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D010296:Parietal Lobe / Q000503:physiopathology*; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012569:Schizotypal Personality Disorder / Q000503:physiopathology*; D011795:Surveys and Questionnaires; D013702:Temporal Lobe / Q000503:physiopathology*