Theme 1 | (COVID-19 related) mental health care

Asymmetric effects of acute stress on learning to maximize reward value and minimise action cost

Stella Voulgaropoulou

Stella Voulgaropoulou1, Fasya Fauzani1, Thérèse van Amelsvoort1, Dennis Hernaus1

School for Mental Health and Neuroscience, Faculty of Health Medicine and Life Science, Maastricht University, Maastricht, Netherlands

Repeated exposure to stress has consistently been associated with the development of psychiatric disorders. One transdiagnostic symptom often present in disorders associated with stress exposure, including depression and addiction, is altered representation of cognitive or physical effort, thought to impact goal-directed behaviour. How acute stress affects cost-benefit computations in humans, however, has not been investigated to date.

80 healthy humans aged 18-32 were randomly exposed to the Maastricht Acute Stress Task stress (2°C water, arithmetics, negative evaluative feedback) or no-stress control condition (n=40/group). Next, all participants completed an instrumental learning paradigm during which they learned to select images associated with frequent monetary rewards and/or to avoid images with high action cost (3s of pre-calibrated maximum grip force).

Acute stress was associated with greater learning to maximize rewards compared to minimize action costs (group-by-trial type interaction F=6.53, p=.01; trial type main effect in stress condition t=5.40, p<.001), an effect that was also observed during the presentation of novel contexts than those learned during the task (trial type main effect in stress condition t=-2.23, p=0.03). In addition, acute stress group had increased win-stay rates compared to lose-shift (t=-3.73, p<0.001) and exhibited higher likelihood of staying on reward learning than effort learning trials after selecting the optimal stimulus relative to controls [t(78)=-2.28, p<0.025]

Here we show for the first time that exposure to acute stress leads to a decision-making policy that favours reward value maximisation over action minimisation, which may be driven by changes in sensitivity to positive (reward/effort avoidance) rather than negative outcomes. These results provide formal mechanisms linking stress exposure to alterations in the ability to intergrade costs and benefits, relevant to psychiatric disorders associated with altered goal-directed behaviour. Further analyses using computational modelling and pupillometry data can provide first insights into latent mechanisms that may mediate these effects.

The School for Mental Health and Neuroscience (MHeNs) strives to advance our understanding of brain-behaviour relationships by using an approach integrating various disciplines in neuro- and behavioural science, medicine, and the life sciences more widely. MHeNs performs high-impact mental health and neuroscience research and educates master's students and PhD researchers. MHeNs performs translational research, meaning practical collaboration between researchers in the lab and in the hospital. MHeNs is one of six graduate schools of the Faculty of Health, Medicine and Life Sciences (FHML) aligned to the Maastricht University Medical Centre+ (MUMC+).