To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Pathological gambling (PG) is an impulse control disorder characterized by excessive monetary risk seeking in the face of negative consequences. We used tools from the field of behavioral economics to refine our description of risk-taking behavior in pathological gamblers. This theoretical framework allowed us to confront two hypotheses: (1) pathological gamblers distort winning probabilities more than controls; and (2) pathological gamblers merely overweight the whole probability range.
Eighteen pathological gamblers and 20 matched healthy participants performed a decision-making task involving choices between safe amounts of money and risky gambles. The online adjustment of safe amounts, depending on participants' decisions, allowed us to compute ‘certainty equivalents’ reflecting the subjective probability weight associated with each gamble. The behavioral data were then fitted with a mathematical function known as the ‘probability weighting function’, allowing us to disentangle our two hypotheses.
The results favored the second hypothesis, suggesting that pathological gamblers' behavior reflects economic preferences globally shifted towards risk, rather than excessively distorted probability weighting. A mathematical parameter (elevation parameter) estimated by our fitting procedure was found to correlate with gambling severity among pathological gamblers, and with gambling affinity among controls.
PG is associated with a specific pattern of economic preferences, characterized by a global (i.e. probability independent) shift towards risky options. The observed correlation with gambling severity suggests that the present ‘certainty equivalent’ task may be relevant for clinical use.
Belief inflexibility is a thinking style observed in patients with schizophrenia, in which patients tend to refute evidence that runs counter to their prior beliefs. This bias has been related to a dominance of prior expectations (prior beliefs) over incoming sensory evidence. In this study we investigated the reliance on prior expectations for the processing of emotional faces in schizophrenia.
Eighteen patients with schizophrenia and 18 healthy controls were presented with sequences of emotional (happy, fearful, angry or neutral) faces. Perceptual decisions were biased towards a particular expression by a specific instruction at the start of each sequence, referred to as the context in which stimuli occurred. Participants were required to judge the emotion on each face and the effect of the context on emotion discrimination was investigated.
For threatening emotions (anger and fear), there was a performance cost for facial expressions that were incongruent with, and perceptually close to, the expression named in the instruction. For example, for angry faces, participants in both groups made more errors and reaction times (RTs) were longer when they were asked to look out for fearful faces compared with the other contexts. This bias against sensory evidence that runs counter to prior information was stronger in the patients, evidenced by a group by context interaction in accuracy and RTs for anger and fear respectively.
Overall, the present data suggest an overdependence on prior expectations for threatening stimuli, reflecting belief inflexibility, in schizophrenia.
Email your librarian or administrator to recommend adding this to your organisation's collection.