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 firstname.lastname@example.org
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.
Depression is one of the most common and debilitating non-motor symptoms of Parkinson's disease (PD). The neurocognitive mechanisms underlying depression in PD are unclear and treatment is often suboptimal.
We investigated the role of striatal dopamine in reversal learning from reward and punishment by combining a controlled medication withdrawal procedure with functional magnetic resonance imaging in 22 non-depressed PD patients and 19 PD patients with past or present depression.
PD patients with a depression (history) exhibited impaired reward v. punishment reversal learning as well as reduced reward v. punishment-related BOLD signal in the striatum (putamen) compared with non-depressed PD patients. No effects of dopaminergic medication were observed.
The present findings demonstrate that impairments in reversal learning from reward v. punishment and associated striatal signalling depend on the presence of (a history of) depression in PD.
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.
Email your librarian or administrator to recommend adding this to your organisation's collection.