Alien Intentionality in Schizophrenia

At present, the mainstream of cognitive neuroscience literature on alien intentionality (AI) symptoms in schizophrenia is divided between research into perceptual-motor AI (primarily motor passivity and auditory verbal hallucinations), in which the dominant theory is self-monitoring deficit, and cognitive AI (delusions of alien control/persecution), in which the dominant theory is reasoning biases and deficits. Both theories have some support in data, but they also have numerous limitations, suggesting the need for novel approaches to the problem. A review of the phenomenological literature on AI suggests novel hypotheses which go beyond the perceptual-motor/cognitive division: First, there appears to be a “family similarity” across the range of AI symptoms, including delusions and auditory verbal hallucinations as well as a range of other AI symptoms (e.g., alien emotion, sense of alien self). This suggests that a superordinate mechanism may underlie all AI symptoms (rather than unrelated mechanisms underlying the perceptual-motor vs. cognitive symptoms). Second, full-blown AI symptoms appear to emerge only after an early illness period of “delusional mood” characterized by incipient degradation of normal perceptual and self experiences. This suggests the possibility that AI symptoms emerge in response to these early experiences. Based on these observations, it is hypothesized that AI symptoms reflect the brain’s effort to make or find meaning in response to the breakdown of existing meaning structures. Across inferential domains (perceptual, motor, motivational, cognitive), AI themes emerge because the brain takes an “intentional stance” toward finding/making meaning. That is, ambiguous stimuli are perceived and inferred as resulting from the goals, desires, and beliefs of an intending agent. It is hypothesized that this occurs because the intentional stance is a neurally fine-tuned default explanatory framework that can flexibly integrate otherwise incompatible information within an internally consistent account. We conclude by presenting neuroimaging evidence which supports the intentionalist stance as a possible triggering mechanism of auditory verbal hallucinations.