Parsing Heuristic and Forward Search in First‐Graders' Game‐Play Behavior

Seventy‐three children between 6 and 7 years of age were presented with a problem having ambiguous subgoal ordering. Performance in this task showed reliable fingerprints: (a) a non‐monotonic dependence of performance as a function of the distance between the beginning and the end‐states of the problem, (b) very high levels of performance when the first move was correct, and (c) states in which accuracy of the first move was significantly below chance. These features are consistent with a non‐Markov planning agent, with an inherently inertial decision process, and that uses heuristics and partial problem knowledge to plan its actions. We applied a statistical framework to fit and test the quality of a proposed planning model (Monte Carlo Tree Search). Our framework allows us to parse out independent contributions to problem‐solving based on the construction of the value function and on general mechanisms of the search process in the tree of solutions. We show that the latter are correlated with children's performance on an independent measure of planning, while the former is highly domain specific.     

Responses to symptom induction exercises in panic disorder

Exposure to panic symptoms (interoceptive exposure) is often included as part of treatment for panic disorder (PD), although little is known about the relative effects of particular symptom induction exercises. This study describes responses of individuals with PD and nonclinical controls to 13 standard symptom induction exercises and 3 control exercises. Generally, individuals with PD responded more strongly to symptom induction exercises than did controls. The exercises producing the most fear included spinning, hyperventilation, breathing through a straw, and using a tongue depressor. This study also reports findings regarding specific symptoms triggered by each exercise, the percentage of participants reporting fear during each exercise, and predictors of fear.