Intersubject variability and induced gamma in the visual cortex: DCM with empirical Bayes and neural fields

This article describes the first application of a generic (empirical) Bayesian analysis of between‐subject effects in the dynamic causal modeling (DCM) of electrophysiological (MEG) data. It shows that (i) non‐invasive (MEG) data can be used to characterize subject‐specific differences in cortical microcircuitry and (ii) presents a validation of DCM with neural fields that exploits intersubject variability in gamma oscillations. We find that intersubject variability in visually induced gamma responses reflects changes in the excitation‐inhibition balance in a canonical cortical circuit. Crucially, this variability can be explained by subject‐specific differences in intrinsic connections to and from inhibitory interneurons that form a pyramidal‐interneuron gamma network. Our approach uses Bayesian model reduction to evaluate the evidence for (large sets of) nested models—and optimize the corresponding connectivity estimates at the within and between‐subject level. We also consider Bayesian cross‐validation to obtain predictive estimates for gamma‐response phenotypes, using a leave‐one‐out procedure

Following the genes: a framework for animal modeling of psychiatric disorders

The number of individual cases of psychiatric disorders that can be ascribed to identified, rare, single mutations is increasing with great rapidity. Such mutations can be recapitulated in mice to generate animal models with direct etiological validity. Defining the underlying pathogenic mechanisms will require an experimental and theoretical framework to make the links from mutation to altered behavior in an animal or psychopathology in a human. Here, we discuss key elements of such a framework, including cell type-based phenotyping, developmental trajectories, linking circuit properties at micro and macro scales and definition of neurobiological phenotypes that are directly translatable to humans

The Influence of Diagnosis on Psychotherapy Missed Opportunities in a Veteran Population

Objective: Canceled or unattended psychotherapy sessions are a source of concern for patients, providers, and health-care systems. Veterans are particularly likely to experience mental health problems, and yet they are also especially susceptible to variables leading to premature termination of services. Method: This study examined a large (n = 2285) sample of veterans receiving psychotherapy services to determine if mental health diagnosis had an impact upon missed psychotherapy opportunities. Results: There were differential cancelation rates for individuals with different classes of disorder, and the total number of appointments a person scheduled changed the nature of the effect. Conclusions: Health-care administrators and treatment providers should consider the specific effects of individuals with differing diagnoses when planning courses of treatment and coordinating care

A gripper for delicate edible manipulation

The general manipulation of delicate edible products requires of specific grippers able to firmly grasp these kind of products without damaging them. To address this problem we follow a soft and variable-stiffness approach. In this paper we design and construct successive gripper prototypes which fingers are composed of rigid and soft parts. The stiffness of the soft parts can be modified using the jamming principle. The gripper properties are experimentally evaluated using a subset of NIST benchmarks. This allows to obtain comparable and standardised results, used to improve the initial gripper design. In addition a new benchmark, the edible grasping benchmark, is proposed and used to measure the performance of the grippers while grasping fruits and vegetables. The final gripper prototype overcomes the problems observed in fruit and vegetable picking systems. It has been demonstrated in the experimental tests that the gripper has sufficient payload and adaptability to grasp several edibles without damage