Brain Meeting: Christian Ruff

Please contact ion.fil.brainmeetings@ucl.ac.uk for a Zoom link.

Risk attitude – the willingness to accept uncertainty for the possibility to gain larger rewards – is often seen as a stable personality trait akin to a ‘taste for risk’. However, this widespread notion is contradicted by findings that risk attitudes can change, and sometimes completely reverse, over different contexts and even repetitions of the identical choice problems. The neurocognitive processes giving rise to these fluctuations in risk attitude have remained elusive. In this talk, I will present a recent line of work from my lab that sheds light on these processes. In a series of experiments combining psychophysical modelling, population-receptive field modelling of fMRI data, and transcranial magnetic stimulation, we find that apparent risk attitudes do not originate from (dis)tastes for risk encoded in motivational brain systems but rather Bayesian perceptual inference on noisy magnitude representations in parietal cortex. The individual characteristics of these neuro-cognitive perceptual processes can causally account for a variety of empirical effects, including individual differences, preference reversals, context effects, and changes of risk attitudes with acute stress. Taken together, our work suggests that risk attitude may not reflect subjective valuation of uncertainty but rather perceptual mis-estimation, with profound implications for psychological, economic, and neuroscience theories of risk-taking and the corresponding clinical applications.