Assessing Anxiety through Games
Team: Noah Okada, Lixiang Xu, Dean Mobbs
Fear broadly categorizes an array of cognitive and physiological states associated with present and identifiable threats. Understanding the processes that mediate fear can help to elucidate fundamental questions about human emotion and decision-making. Anatomical research in rodent models has revealed that the neurobiological systems that underlie changes in threat proximity can be mapped along a hierarchical continuum. Such studies have revealed that predatory threats evoke responses in anxiety circuits including the ventromedial prefrontal cortex (vmPFC), hippocampus, and basolateral amygdala regions. By contrast when under attack, activity is evoked in fear circuits that include the mid-cingulate cortex, central amygdala, hypothalamus, and periaqueductal gray (PAG), regions involved in flight.
The Task
The PredationGame
Building upon these non-human models, we developed a virtual predation paradigm (predation game) to study human defensive behaviors across changing levels of threat imminence. This paradigm was developed using the Unity Game Engine to create immersive environments that could be deployed remotely online and in fMRI experiments. The paradigm consisted of a hexagonal grid-based environment with varying levels of danger and reward relative to the proximity of an artificially intelligent predator. While immersed in the environment, participants were tasked with collecting maximal rewards while escaping the attack of the predator.
The Experiments
Experiments
To validate this model, we conducted a remote experiment in 400 healthy controls, followed by an fMRI experiment in 5 subjects. We hypothesized that the intensity of a potential threat would relate to intensity in the vmPFC-hipp-amyg circuit and that activity in this circuit, which has been linked to anxiety, will also correlate positively with thigmotaxis. Preliminary findings support these hypotheses and reveal the efficacy of this paradigm in enabling the study of fear and anxiety circuitry in the human brain. The development and further testing of this paradigm will enable researchers to better characterize the neurobiological circuits that coordinate fear and anxiety expanding our capacity to understand and treat the neurobiological dysfunctions that result in affective disorders.