Elsevier, Psychiatry Research: Neuroimaging, 3(221), p. 249-250
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Hallucinations are commonly defined as "perceptual experi-ences in the absence of sensory input". Hallucinations, one of the major first rank symptoms of schizophrenia (SZ) spectrum dis-orders, include bodily hallucinations (BH), which may encompass tactile, somatic, visceral, proprioceptive, kinesthetic, vestibular, coenesthetic, nociceptive, sexual or thermal experiences. Although the underlying mechanisms of BH have not been established, four neuroimaging case reports have described pathophysiological correlates of BH (Shergill et al., 2001; Bär et al., 2002; Jardri et al., 2008; Geoffroy et al., 2012). According to these case reports, three patients had SZ (Shergill et al., 2001; Bär et al., 2002; Jardri et al., 2008) and the fourth patient had delusional parasitosis (Geoffroy et al., 2012). In each report, per-hallucinatory functional magnetic resonance imaging (fMRI) revealed increased functional activation of the somatosensory cortices during BH. Two fMRI raw datasets were made available by the authors after email contacts (Geoffroy et al., 2012; Jardri et al., 2008). Strikingly, poor overlap was observed between the identified overactive areas when the avail-able functional maps for BH were projected onto a unique normalized template. This observation supports the concept that BH phenomenology is linked to the cortical somatotopic organization.