Cortical oscillatory dynamics and decision deficits in suicidal behavior

PUBLIC HEALTH RELEVANCE:

When faced with a crisis, some people but not others transition from thinking about suicide to acting on these thoughts. This project will use a formal theoretical framework combined with electroencephalography to test the hypothesis that individuals at risk for suicide become cognitively overwhelmed under challenging life circumstances and make poor choices as a result. The anticipated impact of this proposal includes the identification of more precise targets for cognitive clinical interventions.

PROJECT SUMMARY:

Suicide is a complex issue and understanding why people attempt suicide is difficult. Despite many research efforts, progress in understanding and preventing suicide has been slow for several reasons. First, this may be due in part to the limitations of current theories that rely on verbal descriptions of mental processes rather than mathematical models. Frameworks grounded in learning theory and decision neuroscience, such as reinforcement learning, provide a promising approach for uncovering the cognitive and decision-making processes involved in suicide.

Second, when someone is considering how to act in a crisis, they are faced with increased demands on decision-making. These demands are imposed by the need to consider multiple decision options, high levels of uncertainty, and limited time for decision-making. Current neural models of suicide risk do not take into account the dynamic nature of decision-making in real-life situations. In contrast, electrical recordings of brain activity combined with reinforcement learning may help to better understand the brain mechanisms involved in real-time decision-making.

This project uses a reinforcement learning task with a validated computational model to examine the decision-making processes involved in suicide. It also examines the neural encoding of reinforcement history in attempted suicide by focusing on the alpha, beta, and theta oscillations involved in working memory and cognitive control. The ways in which mood, stress, and neural activity influence behavior are also being investigated. We are recruiting a total of 120 adults with varying histories of suicidal thinking and attempts from inpatient, outpatient, and community settings.