John Evenden

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RATIONALE Impulsive behaviour is a component of psychiatric disorders such as bipolar disorder, attention deficit hyperactivity disorder (ADHD), or personality disorders. Most experimental studies on impulsive behaviour punish impulsive choices by loss or delay of reward. In the present study, impulsive behaviour was punished by an explicitly aversive(More)
RATIONALE Psychosis and psychotomimetic drugs result in a disorganisation of the structure of thought and behaviour. Normalising these is one of the objects of antipsychotic therapy, and methods for predicting such a therapeutic effect would be of value. OBJECTIVE The effects of a number of psychotomimetic agents were examined on the way in which rats(More)
There is a need for novel anxiolytics, which are effective, but do not cause sedation, tolerance, and rebound anxiety on discontinuation. To investigate a procedure that can be used to assess these characteristics preclinically, rats were initially trained to press a lever at a high rate to obtain food. Once trained, periods of punishment were introduced in(More)
Many similarities exist between the overconsumption of food, which results in obesity, and drug addiction. The present study investigated the effects of anorectic drugs on responding maintained by high incentive, but nutritionally unnecessary, food reinforcers using an FI15(fixed-ratio 10:S) schedule of reinforcement, similar to that used in studies on the(More)
RATIONALE Working memory impairment is a core symptom of schizophrenia, but no existing treatment remediates this deficit. Inconsistent conceptualizations and few reliable translational measures are major hindrances to understanding the neurobiology of this aspect of cognition. Using comparable task designs may help bridge clinical and preclinical research(More)
Characterization of anxiolytic drugs often employs conflict paradigms in which the drug effects on punished and unpunished responding can be compared. In this study, a fixed interval schedule generating a range of baseline response rates allowed comparison of the effects of anxiolytic drugs with those of psychotomimetic drugs on equivalent and differing(More)
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