Auditory verbal hallucinations occur along a continuum from the general population to patients with psychosis, yet how sensory feedback processing and attention control interact along this continuum is unclear. By manipulating self-voice quality (from neutral to angry) and measuring brain activity with electroencephalography, the study found that hallucination proneness (HP) modulated the N100 and P200 suppression effects regardless of voice quality. Individuals with high HP showed an increased N100 response to self-generated voices and an increased P200 response to externally-generated voices, suggesting heightened error awareness and attention allocation during self-voice production due to altered sensory feedback processing and attentional control. These findings indicate that altered sensory feedback processing in self-voice production is a fundamental characteristic of the HP continuum, independent of clinical status.
Resting state brain activity is inherently non-stationary. Hidden Semi-Markov Models can characterize continuous resting state data as a sequence of recurring brain states. Previous research suggested that EEG brain state dynamics in the alpha frequency link to auditory hallucination proneness in non-clinical individuals. This study aimed to replicate those findings. Most brain states were reproducible across different data sets, confirming robust and generalizable EEG resting state dynamics. However, the association with hallucination proneness was not directly reproducible across data sets.
Hypnosis-induced depersonalization in healthy subjects reduces pain perception by dampening activity in brain regions involved in sensory and emotional processing of pain, including the somatosensory cortex, parietal cortex, prefrontal cortex, putamen, and amygdala. Pain intensity ratings dropped significantly from normal waking to the hypnotic depersonalization state. The findings suggest that depersonalization alters the neural representation of the body, potentially explaining the 'out-of-body' experience and reduced pain sensitivity. Although the small sample of 7 subjects limits generalizability, hypnotic depersonalization may help study mechanisms underlying self-injury and mind-body interactions in psychosomatic disorders.