Cocaine use disorder in females is associated with altered social decision-making: a study with the prisoner's dilemma and the ultimatum game

Unfairness sensitivity and equity in severe alcohol use disorder: Insights from the ultimatum game

OBJECTIVES

Severe alcohol use disorder (SAUD) is characterized by social interaction difficulties that play a key role in the persistence of this addictive state. Biased social decision-making might underpin such interpersonal problems. Previous studies exploring social decision-making in SAUD used the ultimatum game - an economic game evaluating sensitivity to unfairness (for the responder) and equity (for the proposer) - and showed increased unfairness sensitivity in SAUD. However, these studies used one-shot designs that are not representative of real-life interactions and focused only on responders, letting much of the phenomenon unexplored.

METHODS

Thirty-five recently detoxified patients with SAUD and 34 matched control participants played four iterated ultimatum games, with variations according to the role (responder vs. proposer) and strategy used by their virtual opponent (fair/easy vs. unfair/difficult). Participants then completed social cognition tasks and psychopathological questionnaires.

RESULTS

As responders, patients with SAUD did not reject fair or unfair offers more often than controls, which contradicts the unfairness sensitivity previously highlighted in one-shot ultimatum games. As proposers, patients with SAUD made more generous offers than controls and did not adapt to their opponent's strategy, which resulted in poorer economic outcomes.

CONCLUSIONS

Patients with SAUD do not display an unfairness sensitivity but are less able to adapt to their opponent, which has detrimental consequences, namely poorer outcomes. They behave differently during one-shot and repeated interactions, probably because - due to their social cognition impairments - they need more time to understand their opponent and overcome their a priori social biases.

To produce or not to produce? Contrasting the effect of substance abuse in social decision-making situations

Substance use disorders (SUD) have been related to high criminal justice costs, expensive healthcare, social impairment, and decision-making deficits. In non-social decision-making tasks, people with SUD tend to take more risks and choose small immediate rewards than controls. However, few studies have explored how people with SUD behave in social decision-making situations where the resources and profits depend directly on participants' real-time interaction, i.e., social foraging situations. To fulfill this gap, we developed a real-time interaction task to (a) compare the proportion of producers (individuals who tend to search for food sources) and scroungers (individuals who tend to steal or join previously discovered food sources) among participants with SUD and controls with respect to the optimal behavior predicted by the Rate Maximization Model, and (b) explore the relationship between social foraging strategies, prosocial behavior, and impulsivity. Here participants with SUD (n = 20) and a non-user control group (n = 20) were exposed to the Guaymas Foraging task (GFT), the Social Discounting task (SD), and the Delay Discounting task (DD). We found that participants in the control group tended to produce more and obtain higher profits in contrast to substance abuser groups. Additionally, SD and DD rates were higher for scroungers than producers regardless of the group. Our results suggest that producers tend to be more altruistic and less impulsive than scroungers. Knowing more about social strategies and producers' characteristics could help develop substance abuse prevention programs.

People's dispositional cooperative tendencies towards robots are unaffected by robots' negative emotional displays in prisoner's dilemma games

The study explores the impact of robots' emotional displays on people's tendency to cooperate with a robot opponent in prisoner's dilemma games. Participants played iterated prisoner's dilemma games with a non-expressive robot (as a measure of cooperative baseline), followed by an angry, and a sad robot, in turn. Based on the Emotion as Social Information model, we expected participants with higher cooperative predispositions to cooperate less when a robot displayed anger, and cooperate more when the robot displayed sadness. Contrarily, according to this model, participants with lower cooperative predispositions should cooperate more with an angry robot and less with a sad robot. The results of 60 participants failed to support the predictions. Only the participants' cooperative predispositions significantly predicted their cooperative tendencies during gameplay. Participants who cooperated more in the baseline measure also cooperated more with the robots displaying sadness and anger. In exploratory analyses, we found that participants who accurately recognised the robots' sad and angry displays tended to cooperate less with them overall. The study highlights the impact of personal factors in human-robot cooperation, and how these factors might surpass the influence of bottom-up emotional displays by the robots in the present experimental scenario.

Factors of influence in prisoner's dilemma task: a review of medical literature

The Prisoner's Dilemma (PD) is one of the most popular concepts amongst the scientific literature. The task is used in order to study different types of social interactions by giving participants the choice to defect or cooperate in a specific social setting/dilemma. This review focuses on the technical characteristics of the PD task as it is used in medical literature and describes how the different PD settings could influence the players' behaviour. We identify all the studies that have used the PD task in medical research with human participants and distinguish, following a heuristic approach, seven parameters that can differentiate a PD task, namely (a) the opponent parties' composition; (b) the type of the opponent as perceived by the players; (c) the interaction flow of the game; (d) the number of rounds; (e) the instructions narrative and options that are given to players; (f) the strategy and (g) the reward matrix and payoffs of the game. We describe how each parameter could influence the final outcome of the PD task and highlight the great variability concerning the settings of these parameters in medical research. Our aim is to point out the heterogeneity of such methods in the past literature and to assist future researchers with their methodology design.

Recent cocaine use and memory impairment in HIV

Both Human Immunodeficiency Virus (HIV) and cocaine use have been associated with impairment in neuropsychological functioning. The high comorbidity between HIV and cocaine use highlights the importance of ascertaining whether there is a compounding effect of cocaine use in individuals with HIV. Among neuropsychological domains impacted by HIV, verbal memory deficits have received substantial attention partly because they have been associated with declines in functional status in HIV positive individuals. We collected California Verbal Learning Test-II data from HIV participants who met lifetime diagnostic criteria of cocaine abuse and/or dependence (HIV/CocDx+, N = 80 & HIV/CocDx-, N = 30, respectively) and those with and without recent cocaine use, which was confirmed by toxicology analysis (HIV/Coc+, N = 56 & HIV/Coc-, N = 57, respectively). The Item Specific Deficit Approach (ISDA) was employed to determine any additional cocaine-associated deficits in encoding, consolidation, and retrieval, which attempts to control for potential confounding factors of memory such as attention. Using conventional methods of evaluating memory profiles, we found that the HIV/Coc + group demonstrated worse learning, immediate and delayed free recall, and recognition in contrast to the HIV/Coc - group; although using the ISDA, we found that encoding was the only significant difference between HIV/Coc + and HIV/Coc-participant, with HIV/Coc - performing better. Our data suggest that for individuals with HIV, cocaine use is associated with a temporary decline in verbal memory, is characterized by greater encoding deficits, and these effects may reduce with abstinence. Clinically, our findings suggest that reduced encoding is the likely contributor to verbal memory decline in HIV/Coc + and these effects are partially reversible-at least to the level of their HIV/Coc - counterparts.