Impaired discriminative fear-conditioning resulting from elevated fear responding to learned safety cues among individuals with panic disorder

Classical fear-conditioning is central to many etiologic accounts of panic disorder (PD), but few lab-based conditioning studies in PD have been conducted. One conditioning perspective proposes associative-learning deficits characterized by deficient safety learning among PD patients. The current study of PD assesses acquisition and retention of discriminative aversive conditioning using a fear-potentiated startle paradigm. This paradigm was chosen for its specific capacity to independently assess safety- and danger learning in the service of characterizing putative anomalies in each type of learning among those with PD. Though no group difference in fear-potentiated startle was found at retention, acquisition results demonstrate impaired discriminative learning among PD patients as indexed by measures of conditioned startle-potentiation to learned safety and danger cues. Importantly, this discrimination deficit was driven by enhanced startle-potentiation to the learned safety cue rather than aberrant reactivity to the danger cue. Consistent with this finding, PD patients relative to healthy individuals reported higher expectancies of dangerous outcomes in the presence of the safety cue, but equal danger expectancies during exposure to the danger cue. Such results link PD to impaired discrimination learning, reflecting elevated fear responding to learned safety cues.     

Right frontal EEG asymmetry and behavioral inhibition in infants of depressed mothers

Recent studies have shown associations between maternal psychopathology and inhibited behaviors in infants. Moreover, physiological factors have been identified as affecting the continuity of behavioral inhibition across childhood. The purpose of the present study was to examine electroencephalogram (EEG) activity and inhibited behavior in 12-month-old infants of depressed versus non-depressed and mothers. Repeated measures MANOVAs indicated that the infants of mothers with stable psychopathology had greater relative right frontal EEG asymmetry, a pattern that typically accompanies greater negative affect and greater withdrawal behaviors. Infants of affectively ill mothers also showed more proximal behaviors toward a stranger and a novel toy than infants of well mothers, but fewer non-proximal behaviors toward their mothers. These results are discussed within a framework of behavioral inhibition for infants exposed to early psychopathologies in their mothers.     

Neural correlates of Traditional Chinese Medicine induced advantageous risk-taking decision making

This fMRI study examined the neural correlates of the observed improvement in advantageous risk-taking behavior, as measured by the number of adjusted pumps in the Balloon Analogue Risk Task (BART), following a 60-day course of a Traditional Chinese Medicine (TCM) recipe, specifically designed to regulate impulsiveness in order to modulate risk-taking behavior. The 14 participants recruited for this study were randomly assigned to the experimental and control groups and the TCM recipe (Panax, 520 mg; Astragalus membranaceous Bunge, 520 mg; Masnetitum, 840 mg; Ostrea gigas Thumb, 470 mg; Thinleaf Milkwort Root Radix Polygalae, 450 mg; and Os Draconis, 470 mg) was administered, as a diet supplement, to the seven participants in the experimental group. The neural activity of the two groups was monitored by a 3T MRI scanner, before and after the 60-day treatment. Associated with the improved advantageous risk-taking behavior seen in the experimental group, significantly stronger blood oxygenation level dependent (BOLD) responses were observed in the bilateral dorsolateral prefrontal cortex (DLPFC), left putamen, left thalamus, right insula, and right anterior cingulate cortex (ACC), regions which have previously been reported as being involved in risk-taking decision making. The effect of the TCM in improving advantageous risk-taking decision making appears to have been related to the enhanced efficiency of the cognitive affective system, the PFC–ACC–insula–striatum network, which functions to inhibit impulsiveness, to sensitize reward-related information, and to allow the opportunity, during risk estimation, to evaluate potential gains and losses. The findings of this study suggest that interventions acting on factors modulating risk-taking decision making could have a beneficial effect in terms of optimizing risk-taking behavior.     

Rasch calibration of a unidimensional perfectionism inventory for sport

ObjectiveThe purposes of this study were to generate and calibrate a unidimensional sports perfectionism scale for competitive athletes using the Rasch model, and validate the scale through the convergent and known-difference validity approach.MethodThe instrument, called the Sport Perfectionism Scale (SPS), was administered to 323 undergraduate students at a university in the southeastern U.S., ranging in age from 17 to 44 yrs, who previously competed on their high school team or currently compete at the intercollegiate level.ResultsUsing the Rasch model, the level of item difficulty (i.e., most and least difficult) and the athlete's level (i.e., intensity) of perfectionism were estimated. Model-data fit was determined by Infit and Outfit statistics (≥0.5 and ≤1.5). With the exception of one item, the model fits the data well. Rasch analysis supported the measure of perfectionism in sport as a unidimensional construct. Data from the SPS were positively related with those from Stoeber, Otto, Pescheck, Becker, and Stoll's ([2007]. Perfectionism and competitive anxiety in athletes: differentiating striving for perfection and negative reactions to imperfection. Personality and Individual Differences, 42, 959–969.) Perfectionism During Competitions measure (r = 0.63), and there was a significant difference in athlete's perfectionism between levels of competition, F (3, 314) = 5.21, p = 0.002, partial eta-squared, 0.05. This result supports convergent and known-difference evidence of validity for the SPS.ConclusionsThese results lend credence to using the Rasch model as a unique approach to validate evidence of perfectionism as a unidimensional construct in competitive sport.     

On the falsifiability of matching theory.

Herrnstein's matching theory requires the parameter, k, which appears in the single-alternative form of the matching equation, to remain invariant with respect to changes in reinforcement parameters like magnitude or immediacy. Recent experiments have disconfirmed matching theory by showing that the invariant-k requirement does not hold. However, the theory can be asserted in a purely algebraic form that does not require an invariant k and that is not disconfirmed by the recent findings. In addition, both the original and the purely algebraic versions of matching theory can be asserted in forms that allow for commonly observed deviations from matching (bias, undermatching, and overmatching). The recent finding of a variable k does not disconfirm these versions of matching theory either. As a consequence, matching remains a viable theory of behavior, the strength of which lies in its general conceptualization of all behavior as choice, and in its unified mathematical treatment of single- and multialternative environments.     

Applying linear systems analysis to dynamic behavior

In this paper we present an abbreviated discussion of the linear systems analysis in the time domain. We then consider the qualitative character of the behavioral dynamics predicted using the linear form of the analysis. The analysis is then extended to a second-order form. We illustrate some relevant new features introduced by the second-order form with a special case example.