More on concurrent interval-ratio schedules: a replication and review.

It has been suggested that the failure to maximize reinforcement on concurrent variable-interval, variable-ratio schedules may be misleading. Inasmuch as response costs are not directly measured, it is possible that subjects are optimally balancing the benefits of reinforcement against the costs of responding. To evaluate this hypothesis, pigeons were tested in a procedure in which interval and ratio schedules had equal response costs. On a concurrent variable time (VT), variable ratio-time (VRT) schedule, the VT schedule runs throughout the session and the VRT schedule is controlled by responses to a changeover key that switches from one schedule to the other. Reinforcement is presented independent of response. This schedule retains the essential features of concurrent VI VR, but eliminates differential response costs for the two alternatives. It therefore also eliminates at least one significant ambiguity about the reinforcement maximizing performance. Pigeons did not maximize rate of reinforcement on this procedure. Instead, their times spent on the alternative schedules matched the relative rates of reinforcement, even when schedule parameters were such that matching earned the lowest possible overall rate of reinforcement. It was further shown that the observed matching was not a procedural artifact arising from the constraints built into the schedule.     

Drug-behavior interaction history: modification of the effects of morphine on punished behavior.

Squirrel monkeys were trained to respond under a multiple fixed-interval, fixed-interval schedule in which the first response after 5 min terminated a visual stimulus in the presence of which electric shocks could occur. During one component of the schedule, correlated with one color of stimulus lights, every 30th response also produced electric shock; responding was suppressed during this component to approximately 10 to 12% of that occurring in the alternate component in which responding was not punished. In contrast to previous research, morphine (0.03 to 1.0 mg/kg) increased punished responding. Unpunished responding, however, was either not affected or decreased at doses of morphine that increased punished responding. Increases in rate of punished responding also occurred when the single-schedule punishment condition was studied alone in these animals. Subsequent experimentation, which systematically analyzed the development of the rate-enhancing effects of morphine on punished responding, involved the study of drug effects in additional monkeys trained initially under a single-schedule punishment condition. The effects of morphine on punished responding were studied before, after, and then during exposure to the multiple schedule that included a component in which responding was not punished. Increases in response rate with morphine did not occur until it was administered during exposure to the multiple schedule that included a component in which responding was not punished. As with the other monkeys, once the rate increases in punished responding occurred under the multiple schedule, these effects of morphine persisted, even when the multiple schedule was removed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Attitudes to new technology in relation to social beliefs and group memberships: A preliminary investigation

Though the term “new technology” is widely used and discussed, there has been very little systematic study of attitudes to technology and their relation to other beliefs and group memberships. This article describes an initial investigation into the nature of attitudes towards new technology (n=534 undergraduates) and demonstrates that, as yet, these attitudes are only weakly structured and are not fully integrated with other social beliefs. General evaluations of the benefits of technological advance appear to be almost unrelated to beliefs about the inevitability of these advances or the desire to acquire training to deal with them. Contrary to popular expectations, evaluations of video games are unrelated to other beliefs about technology while other social beliefs are, as yet, only weakly integrated with these attitudes. This study also identifies gender differences in the assessment of potential benefits and highlights other differences attributable to academic group memberships. These finding are discussed with reference to the literature on sex-role stereotyping and group socialization processes.     

Spontaneous alternation behavior in animals: A review

Factors affecting spontaneous alternation behavior (SAB) in animals, for example, age, gender and species studied; type of apparatus and cues employed; and neuro-anatomical, neuro-chemical and motivational status of the organism, were reviewed. Despite a myriad of experiments showing interesting main effects of such variables, little research has been performed assessing the interactive affects of these factors on alternation behavior. For example, psychologists test rats in central nervous system (CNS) lesion studies, whereas psychopharmacologists tend to assess SAB in mice. Most importantly, studies have not been reported investigating the possible interactions among species, brain lesions and drugs. This is an unfortunate omission since several important alternation models include propositions relating to cholinergic and/or serotonergic coding in the hippocampus. Examination of behavioral studies revealed the primary cue for alternation among invertebrates to be body turn, whereas vertebrates rely primarily on directional and odor cues. Reference to the seeking of stimulus change remains the most compelling motivational account of why animals manifest this ubiquitious and reliable behavior pattern. This review and the unpublished studies were supported by Research Grants MH16962, MH21288, and MH36491 from the National Institute of Mental Health and the Wake Forest University Research and Publication Fund.     

Multimodal therapy in an inpatient setting

Inpatient Multimodal Therapy (imt) is a residential treatment program, lasting a maximum of 36 weeks, for patients with severe neurotic symptoms. A group of 44 chronic obsessive-compulsive patients and a group of 40 chronic phobic patients were treated in order to assess the outcome and the process of treatment and to identify prognostic factors associated with the effect. At follow-up—on average, eight months after discharge—it was found that 60% had improved, 32% had remained the same, and 8% had deteriorated, indicating that, in general, the treatment was beneficial. That these effects were long-lasting is supported by the fact that, at follow-up, 78% of all patients were no longer receiving treatment, 18% were receiving outpatient or day treatment, and 4% were receiving inpatient treatment. Phobic patients appear to have gained more from the multimodal approach than did obsessive-compulsive patients, as indicated by the fact that the severity of symptoms decreased as they improved in rational thinking, assertiveness, and arousal. By contrast, obsessive-compulsive patients relapsed more than phobic patients did. This was attributed to the fact that the former gained less from the rational-emotive training, denied problems with assertiveness, and did not practice the acquired relaxation skills. It further appeared that a favorable outcome could be induced in patients who (1) expressed relatively mild symptoms in this otherwise severe group, (2) reported relatively few additional complaints, (3) could clearly indicate interpersonal problems, and (4) did not use psychotropic drugs. These prognostic factors are so widespread that not much weight can be ascribed to them. Yet they are useful for indication ofimt until better predictors are found.     

Computing stress

This article is based on a review of recent literature on “computing stress”; that is, on the psychological stress effects of working with computer systems. Current research into the sources of computer-related stress has tended to concentrate on those employees who operate Visual Display Units (VDUs), either on a full-time professional basis as word-processor (WP) operators, data-entry clerks, secretaries, or those dealing with enquiries from the public; or employees who use the VDU irregularly as part of their other duties. A few studies have looked at specific occupation groups, such as printers (Kalimo & Lepp?nen, 1985), information technology professionals (programers and analysts), process workers, and college students (Sproull, Kiesler, & Zubrow, 1984). Generally, however, research has been carried out on office workers, more often women, carrying out administrative tasks. An attempt is made to identify those potential work-related stressors that have been isolated by these studies, and also included are criticisms of the general methodologies used in many of them. The terms “visual display unit,” “visual display terminal,” VDU, VDT, and “terminal” are used interchangeably.     

The relative contributions of rods and cones in sensory memory under photopic and scotopic conditions

Brief presentations of letter arrays were probed by bar markers within or outside the fovea after various time delays. Figural information presented to the foveal region was retained better under a photopic condition than information in the parafoveal region, but under a scotopic condition parafoveal information demonstrated superior retention. However, decay rates over time of all functions were similar, demonstrating that figural information in the rods and cones decays at similar rates.     

Induction by reinforcer schedules.

Traditional strategies for determining whether a reinforcer schedule enhances the occurrence of an activity are reviewed and critically evaluated. A basic assumption underlying these strategies is that it is possible to isolate the effect of reinforcer intermittency on schedule induction. It is concluded that this is not, in fact, possible. An alternative approach is proposed that emphasizes the inductive effects of the reinforcer schedule as a unit and the effects of particular aspects of the reinforcer schedule (e.g., interreinforcer interval, repetition of the reinforcer, reinforcer magnitude).     

Smoking and academic performance

Smokers and nonsmokers were compared on three aspects of academic achievement. Although exactly the same percentage of smokers and nonsmokers passed the first-year university examination, smokers obtained significantly higher marks. Similarly, smokers achieved significantly higher marks in their final year examinations in comparison with nonsmokers. Finally, a comparison of the tutorial essay marks of the smokers and nonsmokers again showed that smokers obtained significantly higher marks than nonsmokers. These data are consistent with the idea that ambitious students adopt smoking in the belief that it will help them study and sustain concentration.