The Transcontinental Computational Psychiatry Workgroup (TCPW) organizes a monthly web-based meeting and a computational psychiatry satellite meeting with the Society of Biological Psychiatry. We hope to foster discussion and exchange between those involved in computational psychiatry—a rapidly growing, highly multidisciplinary field.

Videos of past meetings are here.


Next workgroup meeting

Pavlovian control of escape: General effects and relevance to suicidal behaviors

Alexander Millner

  • Thursday, May 3rd 2018 at 15:00 - 16:00 UTC (Other timezones)
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If humans relied solely on instrumental control to select actions, then choices would be based on whichever action maximized advantageous outcomes. However, prior research has shown that this is not the case and, instead, given a particular context, some actions are easier to select than others. This suggests a decision controller, referred to as Pavlovian control, that rigidly selects actions in the presence of certain stimuli regardless of whether those actions maximize expected value. For example, research has shown the presence of Pavlovian biases for reward and punishment, such that a potential reward elicits action (i.e. Go) and punishment elicits action inhibition (i.e. NoGo). We extended this general framework to the context of escape, where, during an ongoing aversive state, actions are selected to escape the aversive state. We show that escape is also associated with a Pavlovian bias for action and replicate prior work showing that avoiding a punishment is associated with action inhibition. We developed a model integrating reinforcement learning and drift-diffusion models that allowed us to capture both choice and reaction time.  We tested multiple instantiations of the Pavlovian bias and found that, compared with avoid, escape pushed the DDM starting point closer to a Go response. We then tested this approach in a sample of suicidal participants. Long-standing theoretical and anecdotal accounts of suicide conceptualize it as a decision to escape aversive emotional states, yet almost no prior research has examined basic decision-making processes involving escape. We hypothesized that, compared to those with a psychiatric condition but without a history of suicidal thoughts, suicidal people would show a stronger Pavlovian bias to escape and results supported the hypothesis. If there is time, I will also discuss future directions for this work.

 

 

 

 

 

 

Alexander Millner, PhD
Postdoctoral Fellow
Department of Psychology
Harvard University