An economical dispenser to improve control of food reinforcement in the rat

A hopper dispenser designed for the study of food reinforcement in rats is described. By using ordinary rat chow, it significantly reduces the cost of reinforcing rats with food. By preventing stockpiling, it also guarantees control of the accessibility, as well as the presentation of food.     

Modification of the rat's acoustic startle response by antecedent visual stimulation.

Male hooded and albino rats were exposed to a light flash followed at various temporal intervals by a startle-eliciting 117 db. (re 20 muN/m2) burst of white noise. The visual stimulus engendered startle response inhibition (maximally when the lead time was 64-250 msec) as well as startle response latency reduction (maximally when the lead time was 2-8 msec). The temporal functions for the effects of visual stimuli paralleled those previously reported for startle modification by acoustic events. Further study revealed that, given optimal lead times, inhibition is produced reliably by weaker visual stimuli (3 X 10-6 cd-sec/cm2) than latency reduction (3 X 10-4 cd-sec/cm2). This differential sensitivity to visual stimuli is also analogous to previously reported findings for events in the acoustic environment. It reveals that the neural mechanisms that mediate latency reduction and inhibition can be engaged by either acoustic or visual stimulation.     

A quasi-experimental investigation of message appeal variations on organ donor registration rates.

OBJECTIVE: Approximately 6,000 Americans die every year awaiting an organ transplant. Health promotion interventions may alleviate the shortage of viable organs by increasing the number of registered organ donors. This study is the first to evaluate the differential effectiveness of various organ donor messages in naturalistic settings. DESIGN: A 4 (Appeal)x4 (Exemplar)x4 (Location) counterbalanced quasi-experimental design was implemented. MAIN OUTCOME MEASURE: The behavioral outcome measure was the number of individuals who registered to be organ donors at computer kiosks. RESULTS: A number of significant main effects and interactions emerged. Most notably, of the 4 different appeals (counterargument, emotional, motivating action, dissonance), counterargument was by far the most efficacious, especially in academic-type settings (library, university, community college); the emotional appeal was most successful in hospitals. CONCLUSIONS: The findings from this study have implications for both organ donor investigations and health campaign research in general. Statistical interactions highlight the importance of evaluating multiple exemplars in multiple locations for each type of appeal when conducting health campaign research.     

Unfamiliar Untrained Observers’ Ratings of Adolescent Safety Behaviors Within Social Interactions with Unfamiliar Peer Confederates

Adolescents experiencing social anxiety often engage in safety behaviors―covert avoidance strategies for managing distress (e.g., avoiding eye contact)―that factor into the development and maintenance of their concerns. Prior work supports the psychometric properties of the Subtle Avoidance Frequency Examination (SAFE), a self-report survey of safety behaviors. Yet, we need complementary methods for assessing these behaviors within contexts where adolescents often experience concerns, namely, interactions with unfamiliar peers. Recent work indicates that, based on short, direct social interactions with adolescents, individuals posing as unfamiliar peers (i.e., peer confederates) and without assessment training can capably report about adolescent social anxiety. We built on prior work by testing whether we could gather valid SAFE reports from unfamiliar untrained observers (UUOs), who observed adolescents within archived recordings of these short social interactions. A mixed clinical/community sample of 105 adolescents self-reported on their functioning and participated in a series of social interaction tasks with peer confederates, who also provided social anxiety reports about the adolescent. Based on video recordings of these tasks, trained independent observers rated adolescents’ observed social skills, and an additional set of UUOs completed SAFE reports of these same adolescents. Unfamiliar untrained observers’ SAFE reports (a) related to adolescents’ SAFE self-reports, (b) distinguished adolescents on clinically elevated social anxiety concerns, (c) related to trained independent observers’ ratings of adolescent social skills within interactions with peer confederates, and (d) related to adolescents’ self-reported arousal within these same interactions. Our findings support use of unfamiliar observers’ perspectives to understand socially anxious adolescents’ interpersonal functioning.