Tolworth Hospital

Aversive processing plays a central role in human phobic fears and may also be important in some symptoms of psychosis. We developed a temporal-difference model of the conditioned avoidance response, an important experimental model for aversive learning which is also a central pharmacological model of psychosis. In the model, dopamine neurons reported outcomes that were better than the learner expected, typically coming from reaching safety states, and thus controlled the acquisition of a suitable policy. The model accounts for normal conditioned avoidance learning, the persistence of responding in extinction, and critical effects of dopamine blockade, notably that subjects experiencing shocks under dopamine blockade, and hence failing to avoid them, nevertheless develop avoidance responses when both shocks and dopamine blockade are subsequently removed. These postulated roles of dopamine in aversive learning can thus account for many of the effects of dopaminergic modulation seen in laboratory models of psychopathological processes.

Introduction. Theories of delusions often underplay the role of their content. With respect to persecutory delusions, taking threat as fundamental suggests that models of threat-related, aversive learning, such as the Conditioned Avoidance Response (CAR) task, might offer valid insights into the underlying normal and abnormal processes. In this study, we reappraise the psychological significance of the CAR model of antipsychotic drug action; and we relate this to contemporary psychological theories of paranoia. Methods. Review and synthesis of literature. Results. Anticipation and recall of aversive events are abnormally accentuated in paranoia. Safety (avoidance) behaviours may help perpetuate and fix persecutory ideas by preventing their disconfirmation. In addition, patients may explain negative events in a paranoid way instead of making negative self-attributions (i.e., in an attempt to maintain self-esteem). This defensive function only predominates in the overtly psychotic patients. The “safety behaviours” of paranoid patients, their avoidance of negative self-attributions, and the antiparanoid effect of antipsychotic medication all resonate with aspects of the CAR. Conclusions. The CAR appears to activate some normal psychological and biological processes that are pathologically activated in paranoid psychosis. Paranoid psychological defences may be a result of basic aversive learning mechanisms, which are accentuated during acute psychosis.

Four trainees describe their expectations, experiences and learning from their clinical placement with older people as part of their doctoral course in clinical psychology.

After many years of hard work and training, the transition from trainee to consultant is potentially challenging. Having successfully negotiated the hurdles of preregistration training, the MRCPsych examination and the specialist registrar (SpR) interview, trainees have to pass one final signpost to mark the end of their formal training – securing their first substantive consultant psychiatrist post. Despite overall vacancy rates of about 12% for consultant psychiatrists in the UK (Royal College of Psychiatrists, 2002), competition can be intense for some posts.

Abstract The recent history of animal welfare is discussed with particular reference to the ethical and scientific factors which have influenced and will continue to influence the development of pig husbandry systems.The Farm Animal Welfare Advisory Committee report on the original codes of recommendations for the welfare of livestock, including the code for pigs, a review by the Farm Animal Welfare Council (FAWC) and the re-issue of the code for pigs in 1983, the 1980/81 report of the House of Commons Agriculture Committee and the recent FAWC proposals for legislation are examined in some detail.Research work that has been undertaken in pig welfare is mentioned and finally, reference is made to the various protagonists in the debate, not forgetting the pig itself. There is no attempt to draw any definitive conclusions.

Laboratory and field trials were conducted to determine the efficacy of the candidate rodenticide flupropadine against the house mouse (Mus musculus L.). In laboratory feeding tests, family groups of wild mice maintained in pens and conditioned to feeding on plain foods were offered flupropadine at either 0.10%, 0.15%, 0.18% or 0.20% in pinhead oatmeal bait. Overall mortalities in replicated 21-day treatments were 66/71 (93.0%), 71/79 (89.9%), 72/76 (94.7%) and 69/75 (92.0%) respectively. In 17 field trials carried out against mice infesting farm buildings, flupropadine was used at 0.10%, 0.15% and 0.18% in oatmeal bait. Mean treatment success, estimated from live-capture and mortality data, was 88.6%, 96.2% and 96.6% respectively. Flupropadine was found to be as near effective against mice as calciferol/warfarin and the second-generation anticoagulant rodenticides difenacoum, bromadiolone and brodifacoum. In further comparison with the anticoagulants, treatment with flupropadine bait achieved markedly quicker control.