Integrating frequency and magnitude information in decision-making in schizophrenia: An account of patient performance on the Iowa Gambling Task

Abstract

Background The Iowa Gambling Task (IGT; Bechara, Damasio, Damasio, & Anderson, 1994) has frequently been used to assess risky decision making in clinical populations, including patients with schizophrenia (SZ). Poor performance on the IGT is often attributed to reduced sensitivity to punishment, which contrasts with recent findings from reinforcement learning studies in schizophrenia. Methods In order to investigate possible sources of IGT performance deficits in SZ patients, we combined data from the IGT from 59 SZ patients and 43 demographically-matched controls with data from the Balloon Analog Risk Task (BART) in the same participants. Our analyses sought to specifically uncover the role of punishment sensitivity and delineate the capacity to integrate frequency and magnitude information in decision-making under risk. Results Although SZ patients, on average, made more choices from disadvantageous decks than controls did on the IGT, they avoided decks with frequent punishments at a rate similar to controls. Patients also exhibited excessive loss-avoidance behavior on the BART. Conclusions We argue that, rather than stemming from reduced sensitivity to negative consequences, performance deficits on the IGT in SZ patients are more likely the result of a reinforcement learning deficit, specifically involving the integration of frequencies and magnitudes of rewards and punishments in the trial-by-trial estimation of expected value.

Motivational Deficits in Schizophrenia and the Representation of Expected Value

“…Recent findings, however, appear to indicate that motivational impairments in SZ relate more closely to PFC-driven rapid/explicit RL processes than BG-driven gradual/procedural RL processes. These observations fit with observations that: 1) rapid/explicit RL processes relate closely to PFC-dependent working memory processes (Collins and Frank, 2012); and 2) strong correlations between performance on RL tasks and standard measures of working memory/executive function (Brown et al, 2015). …”

“…Rather, recent evidence (Brambilla et al, 2013) indicates that poor performance on the IGT most likely stems from impairment in the ability to use feedback to adaptively update estimations of choice value. Specifically, SZ patients appear to show intact sensitivity to the frequency of losses, but are less able than control subjects to integrate information about the frequency and magnitude of gains and losses in order to form adaptive representations of expected value (Brown et al, 2015). …”

“…Prior studies with the BART have found that several clinical populations with impulse control deficits (such as individuals with substance dependence and individuals with attention deficit disorder; Aklin et al, 2012; Mantyla et al, 2012) show abnormal risk seeking, whereby reward seeking drives behavior in the face of ultimately certain punishment. In three studies using the BART in SZ, patients showed reduced tolerance for risk (fewer pumps), relative to controls (Brown et al, 2015; Cheng et al, 2012; Reddy et al, 2014). That is, they appeared to be abnormally sensitive to the prospect of a punishment and settled for reduced gains.…”

Probabilistic Reversal Learning in Schizophrenia: Stability of Deficits and Potential Causal Mechanisms

“…Consistent with prior studies, patients made more errors following valid positive feedback. 5,20,[41][42][43] However, in contrast to the above-noted studies, patients also responded sub-optimally following negative feedback by more often staying with the "incorrect" stimulus. A similar pattern was observed in recent studies in which patients inadequately used both positive and negative feedback for subsequent decision-making.…”

Comorbidity Between Psychiatric Diseases and Alcohol Use Disorders: Impact of Adolescent Alcohol Consumption

“…Decision making is crucial in everyday life to adapt our behavior to the changing environment. Abnormal decision making may be a key concept to understand behavioral disturbances present in depression [84], anxiety disorders [85], schizophrenia [86,87], and other mental illnesses [88].…”