Towards a reliable repeated-measures beads task for assessing the jumping to conclusions bias

Abstract

The jumping to conclusions bias (JTC), in which some people gather less information than others before making a decision, has been linked to delusions in psychosis. JTC is usually identified via the beads task, in which a sequence of beads (the "target" sequence) is used to measure the amount of evidence participants require before making a decision. Yet, despite its common use, the reliability of the task has never been properly investigated. We investigated its reliability, and tested an alternate version which used distractor sequences to obfuscate the target sequence. Healthy participants (N = 212) were randomised into two groups. One group completed ten trials using the target sequence, while the other completed ten trials of the target sequence and three distractor sequences. Our data indicated the standard task may not be reliable over repeated measures, but that by including distractor sequences, the task becomes more believable, repeatable, and reliable. Additionally, excluding first-trial data (a "silent" practice trial) also improves repeatability. These improvements to the task are relevant to single trial studies, and will be especially useful to repeated-measures longitudinal, experimental, and treatment studies. Such repeated-measures studies are important for investigating the causal link between JTC and delusions.

Relationships Between Delusion-Like Experiences, Lack of Control, Pattern Perception, and Decision Making

“…Thus it becomes more difficult to explain the different results about the PDI score’s effect on JTC obtained by different studies by simply pointing to the difficulty of the tasks. Also, research has shown that there are several problems with the standard usage of the bead task (McLean et al., 2018).…”

How Do Delusion-Prone Individuals Respond to Disconfirmatory Evidence?

“…The task is not usually repeated as participants may become aware that the sequences are predetermined, masking their true reasoning styles. However, future studies could use a distractor version of the task (e.g., McLean, Mattiske, & Balzan, 2018) which may conceal the predetermined nature of the task, preserving participants’ reasoning styles. This would allow for greater reliability in assessing for over-adjustment, and comparability between the beads and BADE tasks.…”

Assessing Impulsivity in Humans and Rodents: Taking the Translational Road

“…Two main variables are assessed: the number of beads drawn before a decision is made, and the proportion of extreme responders (i.e., subjects who make a decision based on one or two beads) ( Dudley et al, 2016 ). Common variations of the beads task include changes in the ratios or in the jar contents ( Dudley et al, 2016 ), altering impulsive decision; or inclusion of distractor sequences ( McLean et al, 2018 ), improving reliability and repeatability ( McLean et al, 2018 ). In a meta-analysis, people with psychosis in comparison with healthy controls required less beads to make a decision and had a higher number of extreme responders.…”