Ignorance or awareness of changes measured in a probabilistic inference task

Abstract

A cognitive bias often reported for schizophrenia is the tendency to make decisions based on little evidence, namely the jumping to conclusions (JTC) bias. The beads task (Huq et al., 1988) is the most commonly used task to investigate the JTC and different attempts were made to explain the JTC. One proposition is that patients might miscomprehend the task and assume volatility, i.e. a change of the task environment, where there is none (Balzan et al., 2012). In our task we explicitly stated volatility, i.e. the environment may change. We tested patients with schizophrenia, autism diagnosis disorder and healthy controls. It has been demonstrated that when making decisions in volatile environments humans follow Bayesian rules (Nassar et al., 2010). We thus base our analysis on a Bayesian approach to identify the contribution of expected and unexpected uncertainty on an agent’s behaviour.