29 November 2023: Using Virtual Hallucinations to understand the Sense of Reality

Roy Salomon
Department of Cognitive Science
University of Haifa

We all rely on our senses to convey veridical information about the world around us, which we call “Reality”. However, distortions of reality in the form of hallucinations or illusions originating from neurological, psychiatric, pharmacological or psychological origins are prevalent. Thus, the sense of reality, the capacity to discriminate between true and false perceptions of the world, is a central criterion for neurological and psychiatric health. Despite the critical role of the sense of reality in our daily life, little is known about how this is formed in the mind and brain. The UnReal project explores the phenomenological, computational and neural processes underlying the Sense of Reality (SoR). We employ a specialized immersive virtual reality environment along with psychophysical paradigms to construct personalized “virtual hallucinations”. These “virtual hallucinations” are then used to modify the sense of reality while recording behavioral, ocular and neurophysiological responses to these perturbations of reality. Our results show differential behavioral and physiological responses to virtual hallucinations across different domains indicating divergent underlying models of reality. Developmental experiments along with computational modeling allowed us insight into the evolution of the sense of reality. This work may help to define a neurocognitive model of reality across healthy and clinical populations, and shed new light upon the fundamental philosophical question of “how do we know what is real?”.

View a recording of this session here.