Weber's Law influences numerical representations in rhesus macaques (Macaca mulatta)

We present the results of two experiments that probe the ability of rhesus macaques to match visual arrays based on number. Three monkeys were first trained on a delayed match-to-sample paradigm (DMTS) to match stimuli on the basis of number and ignore continuous dimensions such as element size, cumulative surface area, and density. Monkeys were then tested in a numerical bisection experiment that required them to indicate whether a sample numerosity was closer to a small or large anchor value. Results indicated that, for two sets of anchor values with the same ratio, the probability of choosing the larger anchor value systematically increased with the sample number and the psychometric functions superimposed. A second experiment employed a numerical DMTS task in which the choice values contained an exact numerical match to the sample and a distracter that varied in number. Both accuracy and reaction time were modulated by the ratio between the correct numerical match and the distracter, as predicted by Weber's Law.     

Stages of change in anxiety: psychometric properties of the University of Rhode Island Change Assessment (URICA) scale

Readiness for change is increasingly cited as an important variable in the health behaviours literature, yet there remains a dearth of research related to this construct in mental health. This study examined the psychometric properties of the University of Rhode Island Change Assessment (URICA) scale in two samples. In Study 1 (n = 252), undergraduates completed the URICA and were administered measures of hopelessness, the consequences of worry, self-esteem, anxious symptomatology, and social desirability. The reliability and validity of the URICA were generally supported, although the goodness-of-fit with the intended subscales was only moderate. The Precontemplation, Contemplation and Maintenance subscales correlated as expected with ancillary measures, but the Action subscale did not. In Study 2 (n = 81), individuals with panic disorder were administered the URICA at initial assessment and following cognitive behavioural therapy. The URICA demonstrated excellent reliability, significantly predicted treatment retention and dropout, and showed modest utility for predicting treatment outcome. Confirmatory factor analysis, however, revealed an inadequate fit to the intended subscales. The implications of these findings are discussed and directions for future research highlighted.     

A comparison of personality function among patients with seasonal depression, nonseasonal depression, and nonclinical participants

Although a large body of research has accumulated concerning the relationship between nonseasonal depression and personality, comparatively few studies have examined the relationship between seasonal affective disorder (SAD) and personality. This study compared dimensional aspects of personality in patients diagnosed with SAD (N = 60), nonseasonal depression (N = 273), and nonclinical controls (N = 297) using the Dimensional Assessment of Personality Pathology (DAPP-BQ; Livesley & Jackson, in press). Analysis by ANCOVA indicated that significant between-group differences occurred in several of the 18 DAPP-BQ dimensions, with patients with SAD exhibiting personality psychopathology that was intermediate between the nonclinical sample and patients with nonseasonal depression. The results demonstrated that the traits associated with seasonal and nonseasonal depression differ in degree, not kind.     

Gender,Race, and Speech Style Stereotypes

Considerable research has shown that people have stereotypical beliefs about the speech and communication style of women and men. There is less research about stereotypes of Black people's speech, and none that jointly or comparably investigates communication stereotypes as a function of both gender and race. In this study, White college students (n = 111) rated a fictional character's speech on 36 pairs of words characteristic of communication style (e.g., emotional–unemotional) and also generated dialogue for the character. Targets' race and sex were varied. Results showed that beliefs about speech style were stronger for race than gender. Black speakers, both women and men, were rated as more direct and emotional, and less socially appropriate and playful, than White speakers. The dialogue generated by participants for Black speakers was less grammatical and more profane than for White speakers. Gender effects were consistent with earlier research but suggest a weakening of stereotypes; women's speech was seen as somewhat less direct and more emotional than men's speech. Beliefs about speech and communication style are important because they may function not only to describe what is but to prescribe what should be in social interaction.     

Reactions of male subordinates to the sex-role congruency of immediate supervision

Male subjects (N=90) worked under supervision for two hours. A 2×2×2 factorial design was employed so that the supervisor was male or female, autocratic or democratic, and possessed a sex-role congruent or incongruent job title. The hypotheses were supported in part: For female supervision only, the more traditionally incongruent the situation, the more unfavorable were the reactions elicited. This finding was true, however, only for subordinates' verbal comments and not for their task performance or written evaluation of the supervisor. Discussion of the specific hypotheses is provided and an alternate explanation concerning the supervisors' alleged prior experience is offered. A more dynamic approach to the study of leader—subordinate relationships — especially in light of the implications for acceptance of female supervision offered by this study — is advocated.     

The acquisition of taste aversions in humans

A written questionnaire or an interview was given to 517 undergraduates concerning their acquisition of illness-induced (taste) aversions to foods and drinks. The subjects reported 415 aversions, with 65% of the subjects reporting at least one aversion. The aversions were more likely to be reported as having been formed through forward rather than simultaneous or backward conditioning, and long-delay learning was frequent. The aversions usually formed to the taste of the foods, rather than the appearance or other aspects of the foods. Extinction appeared more effective in decreasing the aversions than did forgetting. The illness responsible for the aversion's forming was usually attributed to the subsequently aversive food, but for 21% of the reported aversions subjects were sure that something else had caused their illness. Aversions were more likely to have formed to relatively less familiar and less preferred foods. Aversions were also more likely to form between the ages of 13 and 20. Generalization of the aversions to similar foods occurred in 29% of the cases. Approximately one fourth of the aversions were to alcoholic beverages. Finally, instances of aversions forming without food or drink consumption and instances of observational learning were reported. The data were quite similar to laboratory taste aversion data collected using other species and can help in optimizing taste aversion treatments of eating and drinking disorders. Taste aversions among humans are frequent and strong.     

A simple and inexpensive telemetry system for measuring deep body temperature in rodents

An easily constructed telemetry system for measuring deep body temperatures in rodents is described and data collected with the system is presented. The system allows continual monitoring of core temperature without interfering with concomitant behavioral or physiological measurements.     

The effect of repeated testing on judgement bias in domestic dogs (Canis familiaris)

Animal Cognition - Judgement bias paradigms are increasingly being used as a measure of affective state in dogs. Approach to an ambiguous stimulus is commonly used as a measure of affect, however,...