Common and distinct brain networks of autoscopic phenomena.

Autoscopic phenomena—the illusion of seeing a second own body in external space—take three forms: autoscopic hallucination, heautoscopy, and out-of-body experience. Using lesion network mapping in 26 neurological patients, all three forms localized to a common brain network centered on the bilateral temporo-parietal junction. Each type also showed distinct functional connectivity patterns: out-of-body experiences connected to the angular gyrus, precuneus, and inferior frontal gyrus; autoscopic hallucinations to the precuneus, inferior temporal gyrus, and cerebellum; heautoscopy to the left inferior frontal gyrus, insula, and parahippocampus. The temporo-parietal junction is the core region for all autoscopic phenomena, with each form recruiting additional sensorimotor and self-related subnetworks.

Study at a glance

Abstract

Autoscopic phenomena (AP) are illusory own body reduplications characterized by the visual perception of a second own body in extrapersonal space, and include three main forms: autoscopic hallucination (AH), heautoscopy (HAS) and out-of-body-experience (OBE). Past research showed that lesions were heterogeneously distributed and affected many different brain regions within and across patients, while small case series suggested that AP lesions converge in temporo-parietal and parieto-occipital cortex. As only few studies investigated each form of AP separately, it remains unknown whether the three AP are characterized by common and distinct brain mechanisms. Here, we applied lesion network analysis in 26 neurological AP patients and determined their common and distinct functional connectivity patterns. We report that all localize to a single common brain network at the bilateral temporo-parietal junction, further associated with specific patterns of functional connectivity, defining each type of AP. OBE resulted from a brain network connected to bilateral angular gyrus, right precuneus, and right inferior frontal gyrus, differing from AH with a brain network connected to bilateral precuneus, inferior temporal gyrus, and cerebellum. HAS resulted from a brain network connected to left inferior frontal gyrus, left insula and left parahippocampus. The present data identify the temporo-parietal junction as the common core region for AP and show that each form of AP recruits additional specific networks, associated with different sensorimotor and self-related sub-networks.