Cocaine Dependent Individuals and Gamblers Present Different Associative Learning Anomalies in Feedback-Driven Decision Making: A Behavioral and ERP Study.

Ana Torres,Alberto Megías,Andrés Catena,Antonio Maldonado,Antonio Cándido,José C Perales

doi:10.3389/fpsyg.2013.00122

Abstract

Several recent studies have demonstrated that addicts behave less flexibly than healthy controls in the probabilistic reversal learning task (PRLT), in which participants must gradually learn to choose between a probably rewarded option and an improbably rewarded one, on the basis of corrective feedback, and in which preferences must adjust to abrupt reward contingency changes (reversals). In the present study, pathological gamblers (PG) and cocaine dependent individuals (CDI) showed different learning curves in the PRLT. PG also showed a reduced electroencephalographic response to feedback (Feedback-Related Negativity, FRN) when compared to controls. CDI’s FRN was not significantly different either from PG or from healthy controls. Additionally, according to Standardized Low-Resolution Electromagnetic Tomography analysis, cortical activity in regions of interest (previously selected by virtue of their involvement in FRN generation in controls) strongly differed between CDI and PG. However, the nature of such anomalies varied within-groups across individuals. Cocaine use severity had a strong deleterious impact on the learning asymptote, whereas gambling intensity significantly increased reversal cost. These two effects have remained confounded in most previous studies, which can be hiding important associative learning differences between different populations of addicts.

Highlights

Response-outcome association learning tasks have been widely used to explore the cognitive and biological underpinnings of neuropsychiatric disorders (e.g., Everitt et al, 2001; Clark et al, 2004; Redish et al, 2007)
The present study focuses on the coincidences and divergences between gambling and cocaine addiction, with regard to the anomalies they generate in reversal learning performance
The 3 × 2 mixed ANOVA on the feedback-related negativity (FRN) score yielded significant main effects of group, F (2, 57) = 4.04, MSE = 1.39, p < 0.03, η2 = 0.12, and Channel, F (1, 57) = 20.19, MSE = 0.45, p < 0.01, η2 = 0.26, being the largest FRN score observed at FCz

Summary

Introduction

Response-outcome association learning tasks have been widely used to explore the cognitive and biological underpinnings of neuropsychiatric disorders (e.g., Everitt et al, 2001; Clark et al, 2004; Redish et al, 2007). Some types of patients are slower than normal to readjust their preferences after a reversal. This increased reversal cost has been interpreted as a sign of goal-disengaged, habit-driven, error-insensitive, or perseverative behavior (Clarke et al, 2005, 2008). In many studies pre-asymptotic and asymptotic effects have not been dissociated (see Tsuchida et al, 2010; Torres et al, submitted; for similar arguments), there is broad consensus that the sort of dynamic decision-making processes involved in reversal learning tasks is crucial to understand the neuropsychology of addictive disorders (Ersche et al, 2008; Camchong et al, 2011; Izquierdo and Jentsch, 2012; Leeman and Potenza, 2012; Lucantonio et al, 2012). As shown in this work, reversal learning tasks tackle on the type of balanced feedback sensitivity and learning flexibility that are needed for adaptive decision making in real life

Methods

Results

Conclusion