Social factors influence haloperidol-induced catalepsy in rat

This study employed manipulations which presumably influence social interactions in rats: (1) paired housing with a heavier conspecific and (2) exposure to the odors of other rats. The dependent variable was the akinetic state induced by haloperidol, a neuroleptic and dopamine antagonist. In Experiment 1, adult male Long-Evans hooded rats were matched by weight and caged alone or in pairs with one rat 30 g heavier than its cagemate. All rats received haloperidol (1.5 mg/kg) and catalepsy testing. Heavy rats showed more catalepsy than the lighter member of pairs or weight-matched, singly housed controls. In Experiment 2, adult male rats were left unrecaged or were recaged into cages with bedding recently soiled by females or other adult males. After haloperidol (1.0 mg/kg), the rats exposed to bedding soiled by other adult males showed more catalepsy than did the control groups. Thus, the results of both experiments indicated that social factors can influence the akinesia induced by dopamine antagonists.     

The development of sensitivity to biological motion in noise

We investigated developmental changes in sensitivity to biological motion by asking 6-year-olds, 9-year-olds, and adults (twenty-four in each group) to discriminate point-light biological motion displays depicting one of a variety of human movements from scrambled versions of the same displays. When tested without noise dots, participants at all ages performed near ceiling levels and no differences in accuracy were found among the three age groups. Age differences emerged in the second task, in which we used a staircase procedure to determine threshold values of the number of noise dots that could be tolerated in producing a percentage correct value corresponding to a d' value of 1.4. Sensitivity to biological motion improved linearly with age (p < 0.01), with 6-year-olds performing significantly more poorly than adults. This immature performance contrasts with adult-like accuracy by 4 years of age for sensitivity to global motion (Parrish et al, 2005 Vision Research 45 827-837). The comparison implies an immaturity at 6 years of age in the neural networks involved specifically in the processing of biological motion, networks that may include the superior temporal sulcus (STS).     

Some effects of methylphenidate on stimulus control of ratio avoidance behavior in the rat

After exposure to an avoidance schedule which included a warning signal, a rat was placed on a multiple schedule in which the first component was the same as before, i.e., a single response reset the response-shock interval, delaying shock, and the second component differed only in that four bar-presses were required to postpone shock. A fixed ratio requirement of four responses (FR 4) generated behavior resembling a fixed ratio requirement of one response (FR 1) since responding was controlled by the warning signal but more shocks were received. At a dosage of 2 mg/kg, methylphenidate given intraperitoneally decreased shock frequency during FR 4 periods while FR 1 behavior was not affected; at 4 mg/kg, stimulus control of avoidance responding was impaired during both components. Results at 4 mg/kg were partially confirmed by two animals exposed to an FR 4 avoidance schedule which included a warning signal but with different parameters. Response distributions showed that methylphenidate increased response rates in the absence of the warning signal, i.e., stimulus control of ratio-avoidance behavior was impaired although the increased response rates reduced shock frequency. One hour later responses again occurred more frequently during the signal than in its absence but shocks were less frequent than during control (non-drug) periods.     

The relation between feelings of knowing and the number of neighboring concepts linked to the test cue

We investigated whether feeling-of-knowing judgments are influenced by the number of different neighboring concepts linked to the test cue in long-term memory as measured using association norms. The purpose was to evaluate contrasting predictions made by the partial-retrieval hypothesis and the competition hypothesis. The partial-retrieval hypothesis assumes the more neighboring concepts activated by the test cue, the higher the feeling of knowing. In contrast, the competition hypothesis assumes that feelings of knowing are sensitive to competition between neighboring concepts, and it predicts that the fewer neighboring concepts activated by the cue, the higher the feeling of knowing. The findings were compatible with the competition hypothesis showing that both feeling-of-knowing and prediction-of-knowing ratings always were higher, the fewer different concepts were linked to the test cue. We obtained an identical pattern of results using different kinds of cues including taxonomic category names, ending sounds, and meaningfully related associates. We consider different ways that these findings could be reconciled with the partial-retrieval hypothesis, and we also discuss implications for other explanations of feeling-of-knowing effects.     

The Roles of Social Media Use and Friendship Quality in Adolescents’ Internalizing Problems and Well-being

Journal of Happiness Studies - Adolescents spend increasing amounts of time using social media, but whether social media use has a beneficial or harmful role in internalizing problems and...     

Issues in psychotherapeutic encounters of patients suspected of post-traumatic stress disorder malingering

The literature indicates on high rates of post-traumatic stress disorder (PTSD) malingering in various mental health settings but only few articles relate to therapeutic encounters with this population. The aim of this article is to present some of the difficulties that characterize psychotherapeutic encounters with patients suspected of PTSD malingering, and to examine the vicissitudes of significant elements of psychotherapy during these complex clinical situations. Some therapeutic interventions and indications that may help therapists to distinguish between patients with exaggerated symptomatology who suffer from true mental distress, and from full malingerers are also provided. It is argued that therapists and policy makers should relate to PTSD malingering more seriously due to the negative consequences of this phenomenon.     

Examining the positive effects of rapport building: When and why does rapport building benefit adult eyewitness memory?

Most investigative interviewing protocols recommend building rapport with cooperative adult witnesses to increase the accuracy of their reports. Although a few recent studies support the benefits of rapport building on adult witness recall, no study has examined whether the timing of rapport in relation to post-event misinformation affects recall accuracy, and whether these effects are related to witness anxiety levels throughout the interview. The present study provided two hundred and thirty-three undergraduates with a videotaped mock crime followed by building high or low rapport either before or after they received post-event misinformation. All witnesses were then interviewed about the mock crime. Results indicated that high rapport before misinformation increased the amount of accurate information reported in a subsequent witness interview compared to low rapport. However, these recall benefits were not due to a reduction in anxiety. Theoretical implications and practical recommendations for police interviewing practices are discussed.