Helmholtz lecture Henrik Ehrsson, October 27: Sensing one’s own body: causal inference of body ownership

Helmholtz lecture Henrik Ehrsson (Department of Neuroscience, Karolinska Institutet):

Title: Sensing one’s own body: causal inference of body ownership  

Abstract: How do we develop a continuing and coherent perception of our own body, district from the external world? This lecture explores the computational principles and neural mechanisms behind the multisensory perception of one’s own body, also known as the sense of body ownership. I will discuss findings from psychophysics experiments based on the rubber hand illusion, which serves as a model system for studying body ownership. These experiments reveal that the likelihood of experiencing the illusion of a fake hand as one’s own increases with visual or proprioceptive noise, as predicted by a causal inference model. Additionally, I will describe a study conducted using functional magnetic resonance imaging, which identified how activity in posterior parietal cortices can predict an individual’s likelihood of experiencing the illusion according to the Bayesian model. Moreover, insights into the underlying neural mechanisms are obtained through direct electrophysiological recordings of the human cortex using electrocorticography. Collectively, these studies demonstrate the significance of Bayesian causal inference in the perception of body ownership, emphasizing the importance of multisensory integration and the influence of uncertainty.