Jumping to conclusions and perceptions in early psychosis: Relationship with delusional beliefs

Abstract

Introduction. Previous research has suggested that biases in cognitive processes involved in everyday reasoning may contribute to the development of delusional beliefs. The aim of this study was to explore jumping to conclusions (JTC), a data-gathering bias, and jumping to perceptions (JTP), a bias towards believing ambiguous perceptual events are real and external.

Methods. Individuals with current delusions (n=17), remitted delusions (n=17), both recruited from an early psychosis service, and nonclinical participants (n=35) were compared on a probabilistic reasoning task, an auditory perceptual bias task, and the Barely Visible Words task.

Results. The deluded participants did not demonstrate the expected JTC bias; therefore the relationship between JTC and JTP could not be examined. However, both clinical groups exhibited a JTP bias on the auditory perceptual bias task. In contrast, the lowered perceptual threshold for threat displayed by the control group was absent in the clinical groups.

Conclusions. These results suggest that the JTP bias may be a trait characteristic in those with a propensity to delusions, and that these individuals may also show a bias away from threat.

Keywords:

• Delusions
• Early psychosis
• Jumping to conclusions
• Jumping to perceptions
• Reasoning

Notes

¹ D-prime (d′ was not calculated because earlier studies in the field did not find any differences between the groups in their sensitivity in detecting the voice when it was actually present (Bentall & Slade, 1985; Rankin & O'Carroll, 1995).

²The first author was a researcher on the Prevention of Relapse in Psychosis trial (Garety et al., 2008) and was trained to a high level of interrater reliability.