Should I try something new for lunch today? Should I quit my job and explore the world with a backpack?
To navigate today’s dynamic world, people have to make tricky decisions to adapt behaviour. Often, decisions include a trade-off between exploring an uncertain environment for the potential to improve beyond the current situation on the one hand and using familiar reward sources on the other. While healthy individuals may effortlessly resolve such so-called ‘explore-exploit’ dilemmas, this might be more tricky for those suffering from alcohol use disorders (AUD) or binge-eating disorder (BED). These people might not be so good at balancing these decisions, preferring more repetitive choices over strategic exploratory decisions. For instance, instead of considering other alternatives, they may show an increased tendency to make the same choices despite a disadvantageous outcome.
A study led by Laurel Morris, a PhD student from the Department of Psychiatry , investigated the behavioral mechanisms underlying exploration versus exploitation. This was done in the context of monetary gain and loss across a range of subjects, including people suffering from AUD and obese individuals with and without BED . This study, published in Neuropsychopharmacology, yielded several key findings.
Participants with AUD showed reduced exploratory behaviour across gain and loss environments, meaning they stuck with a familiar option more option. This lead to poorer exploitatory choices, potentially maintaining a negative-reinforcement cycle of addiction as they continue to engage in the same cycle of poor decision-making. These findings may also explain how particular negative environmental influences (i.e. being trapped in toxic social circles) facilitate the repetition of behaviours with certain outcomes, such as pathological drinking.
Although there were no differences in exploratory behaviours between obese subjects (with and without BED) and healthy volunteers, the BED group showed enhanced exploratory behaviours particularly in the loss domain . This pattern is consistent with the idea that excessive reward system activation could trigger a negative feedback loop. This could also explain the current finding of heightened sensitivity to losses in individuals with AUD, but not in BED. Alcohol has a greater influence on the reward system than food does, and this finding could have clinical implications.
In order to examine the neural underpinnings of exploration, the authors acquired resting state functional MRI data from healthy individuals. More exploratory decisions in the context of reward were associated with frontal polar cortex (FPC) and ventral striatal connectivity. The FPC is located at the outermost periphery of the hierarchical prefrontal control regions, and is thus well placed to orchestrate higher level, strategic and flexible decisions. In addition, the ventral striatum may be involved in recognising the reward and gains of a potential outcome for an exploratory choice (i.e. weighing the prospect of career advancements after moving to a new city).
We spoke to Laurel about the significance of her latest publication: “Our study found important distinctions between disorders of compulsivity and by capturing these dysfunctional behavioral constructs, our findings could be crucial for the successful management of symptoms and treatment strategies.”
Written by Elijah Mak.