Two Directions in a Search for Symmetry in Rats

The Psychological Record - Two methodologies that have been successful in producing emergent symmetry in some nonhuman species include multiple exemplar training (sea lions) and successive...     

Evaluating the influence of postsession reinforcement on choice of reinforcers

Factors that influence reinforcer choice have been examined in a number of applied studies (e.g., Neef, Mace, Shea, & Shade, 1992; Shore, Iwata, DeLeon, Kahng, & Smith, 1997; Tustin, 1994). However, no applied studies have evaluated the effects of postsession reinforcement on choice between concurrently available reinforcers, even though basic findings indicate that this is an important factor to consider (Hursh, 1978; Zeiler, 1999). In this bridge investigation, we evaluated the influence of postsession reinforcement on choice of two food items when task responding was reinforced on progressive-ratio schedules. Participants were 3 children who had been diagnosed with developmental disabilities. Results indicated that response allocation shifted from one food item to the other food item under thinner schedules of reinforcement when no postsession reinforcement was provided. These findings suggest that the efficacy of instructional programs or treatments for problem behavior may be improved by restricting reinforcers outside treatment sessions.     

Further examination of factors that influence preference for positive versus negative reinforcement

Factors that influence choice between qualitatively different reinforcers (e.g., a food item or a break from work) are important to consider when arranging treatments for problem behavior. Previous findings indicate that children who engage in problem behavior maintained by escape from demands may choose a food item over the functional reinforcer during treatment (DeLeon, Neidert, Anders, & Rodriguez-Catter, 2001; Lalli et al., 1999). However, a number of variables may influence choice between concurrently available forms of reinforcement. An analogue for treatment situations in which positive reinforcement for compliance is in direct competition with negative reinforcement for problem behavior was used in the current study to evaluate several variables that may influence choice. Participants were 5 children who had been diagnosed with developmental disabilities and who engaged in problem behavior maintained by escape from demands. In the first phase, the effects of task preference and schedule of reinforcement on choice between a 30-s break and a high-preference food item were evaluated. The food item was preferred over the break, regardless of the preference level of the task or the reinforcement schedule, for all but 1 participant. In the second phase, the quality of the break was manipulated by combining escape with toys, attention, or both. Only 1 participant showed preference for the enriched break. In the third phase, choice of a medium- or low-preference food item versus the enriched break was evaluated. Three of 4 participants showed preference for the break over the less preferred food item. Results extend previous research by identifying some of the conditions under which individuals who engage in escape-maintained behavior will prefer a food reinforcer over the functional one.     

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.