Stimulus control of differential-reinforcement-of-low-rate responding

Five pigeons were given single-stimulus training on an 8-sec differential-reinforcement-of-low-rate schedule followed by steady-state generalization training using 12 wavelength stimuli. Three birds had a high percentage of reinforced responses on the training schedule and flat generalization gradients of total responses. The birds with fewer reinforced responses had much steeper generalization gradients. Generalization gradients plotted as a function of both stimulus wavelength and interresponse time showed that for most birds, stimulus control was restricted to responses with long interresponse times. Responses with very short interresponse times were not under stimulus control and there was some evidence of inhibitory control of short interresponse times. Interresponse-times-per-opportunity functions, plotted as a function of stimulus wavelength, showed that stimulus wavelength controlled the temporal distribution of responses, rather than the overall rate of response. The data indicate that the differential-reinforcement-of-low-rate schedule generates several response categories that are controlled in different ways by wavelength and time-correlated stimuli, and that averaging responses regardless of interresponse-time length obscures this control.     

Moving with the in-crowd: Cooperation and interpersonal entrainment in in- vs. out- groups

Current Psychology - Interpersonal entrainment or moving together in time, has been shown to cultivate pro-social behaviours amongst those who take part. Converging evidence suggests that its...     

Perceptions of infant boys' behavior and mental health: Relation to infant attachment

Two studies were conducted to determine the impact of infants' attachment classifications and behaviors on naive adults' impressions of their behavior and mental health. In Study 1, three groups of 44 adults viewed a videotape of episode 8 of the Strange Situation for either an avoidant, a resistant, or a secure male infant. After viewing the videotape, they made judgments about aspects of the infant's mental health. Adults viewed the resistant baby as less socially competent and more negative in affect than the other two babies and the secure baby as the least independent of the three babies. Parents rated babies as more intelligent than did nonparents. In Study 2, 15 parents were matched on race and gender with 15 nonparents. All adults viewed a videotape of the reunions of two secure, two avoidant, and two resistant male infants. Avoidant babies were viewed as more socially competent and independent than secure babies and the C2 baby was viewed as the least intelligent, least independent, least socially competent, and most affectively negative of the infants. Results are interpreted as underscoring the need to educate parents and paraprofessionals about the importance of infant distress and physical contact with parents.     

An empirically derived scoring system for intermale aggression in mice

Scoring systems used to assess intermale aggression have been characterized by arbitrary scales and wide variability in the behaviors selected for measurement. The use of such different systems severely limits the ability of investigators to make meaningful comparisons among studies and indicates that there is a need for a common, statistically derived evaluative system for intermale aggression. We measured the frequency and duration of five major components of agonistic behavior exhibited by intact males toward olfactory bulbectomized stimulus males and then analyzed the data using a number of univariate and multivariate procedures. The results were used to generate two statistically based scoring systems, one a short-form index and the other a composite index for more detailed studies of aggression. It is hoped that these statistically derived systems will be adopted by other investigators to increase methodological congruence in the field.     

Forgetting to remember: the functional relationship of decay and interference

Functional decay theory proposes that decay and interference, historically viewed as competing accounts of forgetting, are instead functionally related. The theory posits that (a) when an attribute must be updated frequently in memory, its current value decays to prevent interference with later values, and (b) the decay rate adapts to the rate of memory updates. Behavioral predictions of the theory were tested in a task-switching paradigm in which memory for the current task had to be updated every few seconds, hundreds of times. Reaction times and error rates both increased gradually between updates, reflecting decay of memory for the current task. This performance decline was slower when updates were less frequent, reflecting a decrease in the decay rate following a decrease in the update rate. A candidate mechanism for controlled decay is proposed, the data are reconciled with practice effects, and implications for models of executive control are discussed.     

Milliseconds matter: an introduction to microstrategies and to their use in describing and predicting interactive behavior

Interactive behavior is constrained by the design of the artifacts available (e.g., a mouse and button) as well as by the ways in which elementary cognitive, perceptual, and motor operations can be combined. Any 2 basic activities, for example, (a) moving to and (b) clicking on a button, can be combined to yield a limited number of microstrategies. The results of an experimental study suggest that alternative microstrategies can be deployed that shave milliseconds from routine interactive behavior. Data from a usability study are used to explore the potential of microstrategies for (a) bracketing the range of individual performance, (b) profiling individual differences, and (c) diagnosing mismatches between expected and obtained performance. These 2 studies support the arguments that the microstrategies deployed can be sensitive to small features of an interface and that task analyses at the millisecond level can inform design.     

Risky driving behavior: a consequence of motion adaptation for visually guided motor action

The authors examined the effect of adaptation to expansion on overtaking maneuvers in a driving simulator. Following driving on a straight empty road for 5 min, drivers initiated overtaking substantially later (220-510 ms) than comparable maneuvers made following viewing a static scene or following 5 min of curve driving. Following adaptation to contraction (produced by driving backward), observers initiated overtaking significantly sooner. The removal of the road texture significantly reduced the size of the adaptation effect. The authors propose that these changes in overtaking behavior are due to misestimation of the time headway produced by local adaptation of looming detectors that signal motion-in-depth for objects near the focus of expansion. This adaptation effect may increase the risk of rear-end collisions during highway driving.     

Psychometric properties of the Revised Child Anxiety and Depression Scale in a clinical sample

This study examined the psychometric properties of the Revised Child Anxiety and Depression Scale (RCADS) in a clinical sample of 513 youth referred for mental health assessment at a university clinic. Internal consistency and factor analysis provided support for the factorial validity of the RCADS. Convergent and discriminant validity tests against both clinical interview and self-report criteria also suggested favorable properties of the RCADS. In comparative tests with traditional measures of anxiety and depression, the RCADS generally showed greater correspondence to specific diagnostic syndromes. Clinical cutoffs are reported for the purposes of future clinical and research applications.