Whodunit – A novel video-based task for the measurement of jumping to conclusions in the schizophrenia spectrum

Abstract

Jumping to conclusions (JTC) is implicated in the formation and maintenance of the positive symptoms of psychosis and over the years has become a prominent treatment target. Yet, measures designed to detect JTC are compromised by a number of limitations. We aimed to address some of these shortcomings with a new video-based "Whodunit task" among participants scoring high and low on the Community Assessment of Psychic Experiences (CAPE).We recruited a large sample (N = 979) from the general population who were divided into subgroups high vs. low on psychotic-like experiences (PLE), matched for depression and background characteristics. In the Whodunit task, participants were asked to rate the likelihood that one out of six suspects was the perpetrator of a crime (deliberately ambiguous with no clear clues until the end). The primary measure was the number of sequences-to-decision (STD).In line with the hypothesis, participants scoring high on the CAPE positive subscale displayed significantly lower STD and a higher rate of JTC. Response confidence in the assessments was elevated in the PLE-High group. The number of overall decisions was also significantly elevated for the PLE-High group. No group differences were found when comparing those scoring high versus low on depression. The STD index correlated significantly with a corresponding index from another JTC task.The study presents a new paradigm for the measurement of data gathering in the schizophrenia spectrum. Speaking to its validity, the Whodunit task was correlated with another JTC measure. Future research should test abbreviated versions of the paradigm, preferably using multiple trials with differing topics/emotional themes.