Probabilistic reasoning in deluded, depressed and normal subjects : effects of task difficulty and meaningful versus non-meaningful material

摘要: Background. Research indicates that deluded patients ‘jump to conclusions’ on probabilistic reasoning tasks. Two experiments were carried out with suffering from persecutory delusions and depressed normal controls in order determine whether this response bias is affected by task difficulty the meaningfulness of materials. Methods. Tasks variants those employed Huq et al . (1988) Garety (1991). In Experiment 1, subjects judged which two bags a sequence coloured beads had been taken from. Difficulty was manipulated varying ratios bags. 2, neutral condition required judgements about drawn whereas, meaningful conditions, judge personality characteristics described one individuals. Results. estimates certainty varied difficulty, there no evidence ‘jumping group. all groups reached an initial level reduced their following disconfirmatory more quickly conditions. Both clinical expressed higher levels early trials, greater magnitude reduction information. These group differences evident conditions than Conclusions. Probabilistic materials both subjects. Observed abnormalities not specific