Online Foraging and Energy Conservation: Volatility Manipulation.

Clinical depression frequently develops in response to unremittingly painful or stressful circumstances, and is often associated with feelings of exhaustion and energy depletion which can motivate behavioural withdrawal or avoidance. Limiting exploration in a harsh or unrewarding environment can be an adaptive strategy, but may have the unintended consequence of reducing access to new information that might signal a change in environmental contingencies, and therefore maintaining depression through the maintenance of negative beliefs and predictions. An additional unintended consequence of behavioural withdrawal is the loss of environmentally-occurring reward (enjoyable sensory stimulation, feelings of achievement on completing an activity, positive social interaction etc.) and this deprivation of reward may also contribute to depression maintenance. We have developed a foraging task which has allowed us to study decision-making about resource conservation and its relation to explorative behaviour and reward learning in the lab (Study 1, in preparation), and are now generalising the task to an online version. We additionally aim to employ a new design paradigm, where we will manipulate the volatility of reward distributions throughout the task. This will allow us to understand which mental health characteristics may be associated with adopting more reflexive (model-free) or reflective (model-based) belief-updating frameworks upon facing environmental volatility (See Knox, Otto, Stone & Love, 2011).