Paul Garrud

Pituitary-adrenal hormones and extinction of rewarded behaviour in the rat.

Abstract Food-deprived Wistar rats were trained to run down an alley for food reward. When they had reached asymptote, they were put into extinction and the effects of a number of hormones, injected in extinction, were examined. Porcine ACTH 1–39, synthetic ACTH 1–24 and ACTH 4–10 all retarded extinction; corticosterone and ACTH 4–10 (7-D-Phe) enhanced extinction; desglycinamide vasopressin and synthetic oxytocin had no effect on extinction. An increase in response vigour on the first day of extinction, compared with acquisition asymptote, was observed in all placebo conditions; ACTH 1–24 and ACTH 4–10 reduced themagnitude of this effect; ACTH 4–10 (7-D-Phe) increased the magnitude of this effect.

Successful overshadowing and blocking in hippocampectomized rats

Overshadowing (Experiment 1) and blocking (Experiment 2) were investigated using a conditioned suppression paradigm in rats. Neither hippocampectomy nor cortical control lesions affected the extent to which a salient stimulus overshadowed a less salient one. Nor did the lesions affect the extent to which a stimulus that was highly correlated with shock overshadow a stimulus that was less well correlated with shock. Finally, the lesions did not alter the extent to which a previously reinforced stimulus blocked conditioning to another stimulus when both were presented as a reinforced compound stimulus. It is thus possible for hippocampectomized rats to show apparently normal overshadowing and blocking, at least under some testing conditions.

Impact of Facial Paralysis on Patients With Acoustic Neuroma

Objective To assess the psychological distress, the ways of coping with that stress, and the self‐esteem of patients with facial paralysis after acoustic neuroma surgery. Possible predictors and associations between these measures were also explored.

The effects of chlordiazepoxide HCl administration upon punishment and conditioned suppression in the rat.

Rats were trained to lever press for sucrose on a random interval (RI) 64-s schedule. During a 55 min session there were four 3 min “intrusion periods” signalled by a flashing house-light. In experiment 1 there were two groups matched for baseline response rate. During the intrusion periods one group received response-independent footshock on an independent RI64 schedule; the other group received responsecontingent shock on this schedule. Shock intensity was varied for each rat to match degree of response suppression between the two groups. Chlordiazepoxide HCl (CDP) in doses 0.5–5 mg/kg alleviated response suppression equally in both groups. Experiment II followed the same procedure, except that all animals had the same shock intensity, producing greater response suppression in the response-contingent shock groups. CDP alleviated response suppression more in the response-contingent shock groups, significantly so at 5 mg/kg, nonsignificantly at 1 mg/kg. These results suggest that previous reports that CDP differentially alleviates the response suppression produced by response-contingent shock are an artefact of rate dependency.

Adaptation After Facial Surgery: Using the Diary as a Research Tool

We conducted a small-scale qualitative diary study to gather accounts from five facial cancer surgery patients. Participants were asked to record their experiences, thoughts, and feelings for up to 1 year, as they underwent and recovered from their surgery and adapted to living with alterations in their appearance. In this article, we consider evidence relating to the diary as a research tool and discuss our experiences of issues arising with the qualitative diary method employed in this study.These include comparability with interview data, factors affecting the quantity and quality of data (novelty, personal significance, and individual writing styles), chronological storytelling, and barriers to writing (visual difficulties and depression).

Non‐verbal communication: evaluation of a computer‐assisted learning package

Summary. A computer‐assisted learning (CAL) package was developed on non‐verbal communication. Its effectiveness was evaluated by comparing learning based on use of the package with that based on a didactic lecture covering the same topic. A class of 151 first‐year medical students was divided into two groups, balanced for gender and home/overseas students. One group was asked to use the CAL package, the other group attended the lecture. Knowledge was assessed one week later by a written test, and reactions to using the CAL package were obtained via a questionnaire. Each group was then allowed and encouraged to use the other resource and then asked about their preferences for type of resource at the end of term. Mean score on the knowledge test was reliably better in the CAL group. In addition, scores increased as the time spent using the CAL package increased: this relationship was highly significant. Use of the CAL package varied from 15 to 120 minutes (median 45). Users reported that it was easy to operate, was an adequate or good resource for learning about the subject, and was a good or reasonable use of their time. After using both types of learning resource half the students judged the CAL package more useful for learning about the subject, and half preferred it to the lecture (the other half had the opposite judgement and preference). This study provides evidence that a CAL package can effectively substitute for traditional didactic teaching in a medical school. Good quality CAL, however, requires substantial resources and high calibre staff to develop and maintain it.

Conditioned suppression of a positively reinforced shuttle response

Rats were trained to run up and down an alleyway for sucrose reinforcement on a variable interval schedule. Differential aversive classical conditioning with auditory CSs was then conducted in a separate apparatus (“off the baseline”) prior to those CSs being presented while the subjects were responding for sucrose in the alleyway. Once the effects of the CSs had extinguished, shock was reintroduced following one CS but not the other (“on the baseline” differential aversive classical conditioning). Both “off the baseline” and “on the baseline” conditioning resulted in conditioned suppression to the CS followed by shock, but little effect of the CS followed by no shock was found. In the “on the baseline” phase, total suppression of baseline responding occurred at moderate US intensities, and this appeared to result from the subject avoiding the location at which he was last shocked. At lower values, both baseline response rate and relative suppression ratio were functions of US intensity. The results are discussed in relation to the effects found in similar experiments using avoidance baselines.

Overshadowing of a stimulus–reinforcer association by an instrumental response

In two experiments, rats were first exposed to pairings of a clicker and food; they were subsequently, in order to measure the effectiveness of the clicker as a conditioned reinforcer, given the opportunity to press a lever which turned the clicker on. For one group of animals the food originally delivered in the presence of the clicker had been contingent on their performance of an instrumental response (running in a running wheel); for a second the contingency between clicker and food had been purely classical. Although the actual correlation between clicker and food was identical for the two groups, the clicker was a less effective conditioned reinforcer for the first group than for the second. In a third experiment, all animals were initially required to run to obtain food in the presence of the clicker, but one group received additional trials on which food was delivered contingent on running in the absence of the clicker. This group showed less tendency to lever press for the clicker than a second group that had received free food on trials when the clicker was not presented. The results of all three experiments suggest that conditioning to the clicker could be overshadowed if the occurrence of food was more reliably predicted by the execution of an instrumental running response; they thus support the view that instrumental conditioning depends on the establishment of an association between response and reinforcer similar to the association between stimulus and reinforcer underlying classical conditioning.

Coming to Terms A Grounded Theory of Adaptation to Facial Surgery in Adulthood

Facial surgery is associated with both functional difficulties and disfigurement, and there is evidence to show that psychosocial outcomes vary widely between individuals. This article reports the findings of a grounded theory study of the predictors and process of adaptation to facial surgery in adulthood. Interviews and focus groups were conducted with 29 facial surgery survivors. Four super-ordinate data categories were generated, namely ‘Demands’,‘Resources’, ‘Responding and managing’ and ‘Consequences’. A model of adaptation was developed which reflected the inter-relationships apparent between these categories. Data extracts are presented to illustrate the grounding of the model in participants’ accounts, and the model is discussed with reference to previous theory and research.

Comparative attainment of 5-year undergraduate and 4-year graduate entry medical students moving into foundation training.

BackgroundGraduate entry medicine is a recent innovation in UK medical training. Evidence is sparse at present as to progress and attainment on these programmes. Shared clinical rotations, between an established 5-year and a new graduate entry course, provide the opportunity to compare achievement on clinical assessments. To compare completion and attainment on clinical phase assessments between students on a 4-year graduate entry course and an established 5-year undergraduate medicine course.MethodsOverall completion rates for the 4 and 5 year courses, fails at first attempt, and scores on 14 clinical assessments, were compared between 171 graduate-entry and 450 undergraduate medical students at the University of Nottingham, comprising two graduating cohorts. Percentage assessment marks were converted to z-scores separately for each graduating year and the normalised marks then combined into a single dataset. Z-score transformed percentage marks were analysed by multivariate analysis of variance and univariate analyses of variance for each summative assessment. Numbers of fails at first attempt were analysed aggregated across all assessments initially, then separately for each assessment using χ2.ResultsCompletion rates were around 90% overall and significantly higher in the graduate entry course. Failures of assessments overall were similar, but a higher proportion of graduate entry students failed the final OSLER. Mean performance on clinical assessments showed a significant overall difference, made up of lower performance on 4 of 5 knowledge-based exams (as well as higher performance on the first exam) by the graduate entry group, but similar levels of performance on all the skills-based and attitudinal assessments.ConclusionsHigh completion rates are encouraging. The lower performance in some knowledge-based exams may reflect lower prior educational attainment, a substantially different demographic profile (age, gender), or an artefact of the first 2 years of a new graduate entry programme.