16 Dec 2015: DYT1 dystonia increases risk taking in humans (including a short primer on reinforcement learning)

Yael Niv
Princeton Neuroscience Institute and Psychology Department
Princeton University

In the past couple of decades reinforcement learning has emerged as a central framework for thinking of trial and error learning in the basal ganglia. However, it has been difficult to link synaptic modification to overt behavioral changes. Rodent models of DYT1 dystonia, a single-mutation motor disorder, demonstrate increased long-term potentiation and decreased long-term depression in corticostriatal synapses. Computationally, such asymmetric learning predicts risk taking in probabilistic tasks. Here we test DYT1 dystonia patients on a simple reinforcement learning task, and demonstrate abnormal risk taking correlated with disease severity, thereby implicating striatal plasticity in shaping choice behavior in humans. Our results are also relevant to the CCNP community as they suggest (and demonstrate) that behavioral tasks married to precise computational models may provide a non-invasive window to diagnosing and characterizing underlying neurological and mental disorders.

9 Dec 2015: Why/When might variation in treatment be therapeutic?

Susan Murphy
HE Robbins Distinguished University Professor of Statistics,
Research Professor, Institute for Social Research & Professor of Psychiatry
University of Michigan

Mobile Health concerns the use of mobile devices for both collecting real-time data, for processing these data and for delivering real-time treatment. Some of these treatments are accessible via the device 24/7 whereas other treatments are intended to be pushed adaptively and just-in-time to the user. Might there be therapeutic effect provided by varying whether or not to push a treatment or to varying the type of treatment? A potential therapeutic role of variation is inconsistent with the usual model of a Markov Decision Process. How do we rectify this inconsistency?

2 Dec 2015: Disorganization in Schizophrenia: Convergence of Clinical and Experimental Data with Information Theory and Neurobiology

Steve Silverstein
Professor of Psychiatry, Rutgers Robert Wood Johnson Medical School, and
Director of Research, Rutgers University Behavioral Health Care

Schizophrenia is a heterogeneous syndrome in terms of symptoms and course of illness.  While much work has focused on understanding the nature of psychotic symptoms, and to a lesser extent negative symptoms, the highly disabling disorganization syndrome has received little attention.  This presentation will begin by giving clinical examples of disorganization in thought, language, and perception.  Experimental data will then be used to demonstrate examples of disorganization in perception, their relationships to thought disorder, and the view that each of these is a manifestation of a canonical processing impairment involving coordination of cognitive activity based on context. The information theoretic concept of coherent infomax will then be described as a way to formally understand contextual modulation of perceptual and cognitive activity, and its failures in schizophrenia.
Implementation of the neural goal function of coherent infomax via apical amplification and dis-amplification will be described, as will the implications of this view for an understanding of schizophrenia.

18 Nov 2015: A Trans-Diagnostic Approach to Understanding Compulsive Behavior

Claire Gillan
Sir Henry Wellcome post-doctoral fellow
NYU and University of Cambridge
Prominent theories suggest that compulsive behaviors characteristic of obsessive-compulsive disorder (OCD) and addiction are driven by shared deficits in goal-directed control, which confers vulnerability for developing rigid habits. However, recent work has shown that these deficits extend far beyond these archetypal compulsive disorders, casting doubt over the specificity of this effect to disorders of compulsivity. This lack of specificity is unfortunately ubiquitous in psychiatry research, a result, we would argue, of the fact that psychiatric diagnostic categories do not reflect the most discrete and neurobiologically informative phenomena. We investigated if the link between clinical phenotype and goal-directed deficits could be more precisely delineated from a trans-diagnostic perspective. Using a novel, data-driven approach comprising large-scale online testing of variation in psychiatric symptoms and neurocognitive performance in two independent samples, we found evidence that compulsivity is a trans-diagnostic trait, predictive of individual differences in goal-directed deficits. These data showcase a powerful new methodology and highlight the potential of a dimensional, biologically grounded approach to psychiatry research.

Inaugural CCNP Seminar held November 18, 2015

The first CCNP seminar was held at Rutgers University Behavioral Health Care on November 18, 2015. Yael Niv (Princeton) and Steve Silverstein (Rutgers) welcomed faculty, staff, and trainees from both universities (and beyond!) and discussed the goals of the collaboration. Following the introduction, Claire Gillan, Sir Henry Wellcome post-doctoral fellow at NYU and University of Cambridge, gave a presentation on “A Trans-Diagnostic Approach to Understanding Compulsive Behavior”.