Dissociation of decision-making under ambiguity and decision-making under risk in patients with Parkinson's disease: A neuropsychological and psychophysiological study

The Role of Feedback in Decision Making

“…PD's tended to show that when experiencing high losses they often failed to shift to a better strategy compared to HCs (Brand et al, 2004). Moreover, when directly comparing the IGT with the GDT, PD's showed poorer performance on the GDT than the IGT (Euteneuer et al, 2010). However, the proportion of occasions in which they shifted strategies after experiencing losses was equivalent in both tasks, and EDRs for both tasks were lower after losses, but were at comparable levels to HCs after gains.…”

“…Though it is important to note that their sample size was small, and the data was not presented in such a way as to determine any incremental improvements over successive trials. With respect to this, there are contradictory reports that overall trials PDs show improved card selection and equivalent rates of learning to HCs (Euteneuer et al, 2010), whereas there is also evidence suggesting that over blocks of trials practice only marginally improves performance as compared to HCs (Czerneki et al, 2002). However, in Czerneki et al (2002) participants performed the IGT twice, and only in the second repetition was there evidence of advantageous card selection even in HCs.…”

“…Some have shown that PDs' overall winnings are substantially less than HCs, as indicated by failure to select the advantageous deck (Czerneki et al, 2002;Kobayakawa et al, 2008;Mimura et al, 2006). But, others have shown that the overall success in maximizing earnings is equivalent in both HCs and PDs (Euteneuer et al, 2010;Poletti, et al, 2010;Thiel et al, 2003). While Euteneuer et al (2010) showed that behavioral performance was the same, when comparing PDs with HCs on electrodermal response (EDRs) which indexes emotional/stress responses, they found that HCs showed higher anticipatory EDRs before choosing disadvantageous decks, whereas PDs showed lower anticipatory responses.…”

“…In www.intechopen.com contrast, the IGT has generated mixed findings, and so it is unclear what can be inferred. Euteneuer et al (2010) claimed that the IGT and its close cousin the GDT engage the limbicorbitofrontal striatal loop because both tasks involve some emotional processing because of their reward structures. Given that in PDs there are impairments to this system, this candidate explanation could account for why it is that in both tasks, PDs show lower physiological responses to emotional outcomes, albeit specific to negative outcomes.…”

Decisions, Decisions: The Neurobiology of the effects of Dopamine Replacement Therapy on Decision-Making in Parkinson’s Disease

“…Brand et al (2004) found that PD patients on medication had reduced use of negative feedback (learning from losses) and worse performance on the task compared to controls. Similarly, PD patients on medication in addition to making risky choices had lower electrodermal responses to losses (Euteneuer et al, 2009). Thus, previously-discussed insensitivity to negative feedback, driven by an overdosed limbic loop, may be responsible for poor GDT performance.…”