Solution of the intermediate size problem by pigeons

Pigeons learned to respond to the middle-sized member (S^D) of a set of three simultaneously presented stimuli with responses to the S^D reinforced on a VI 1 schedule. They were then tested for several days with other sets of three stimuli. One procedure presented reinforcements on a VI 1 schedule during the test independent of the stimulus chosen when a reinforcement was programmed. The tests were also given under extinction conditions. With the testing carried out with extinction, preference consistently was for the test stimulus most similar in physical size to the S^D. However, when the tests were with reinforcement, random responding resulted. Another effect of testing with reinforcement was an increase in incorrect responding with the training set. Such a test procedure was unsatisfactory for determining the effective aspect of the S^D. The conclusion, based on the data of the extinction series, was that pigeons learned the intermediate size problem on the basis of the discrimination of absolute stimulus properties.     

Escape behavior under continuous reinforcement as a function of aversive light intensity

In 11 male albino rats, lever-pressing responses, maintained under a CRF escape schedule with light as the aversive stimulus, were examined at each of five intensities, viz., 2.5, 18, 105, 190, and 386 ft-C. The function relating reciprocal of latency of the escape response to aversive light intensity passed through a maximum.     

The detection of malingering in neuropsychological assessment

Although malingering, or the manipulation of data by the patient, is a problem commonly faced by neuropsychologists, there has been little systematic investigation of this problem. This paper reviews the literature on the detection of malingering in assessment instruments commonly used by clinical neuropsychologists. Criticism of previous research is discussed, and suggestions are made both for future research and for clinical practice.     

Prevalence of personality disorders among bulimics,nonbulimic binge eaters,and normal controls

We examined the comorbidity of bulimia and personality pathology among college women. Subjects included women (n=23) meeting DSM-III-R criteria for bulimia nervosa (bulimics), women (n=23) who reported binge eating but did not fulfill the criteria for bulimia nervosa (binge eaters), and women (n=23) who did not binge eat (normals). The subjects completed an assessment battery consisting of the Personality Disorders Examination and the SCID as well as the Beck Depression Inventory, the Rosenberg Self-Esteem Index, and measures of impulsivity and self-defeating tendencies. Fourteen of 23 bulimics (61%) met criterion for a personality disorder using DSM-III-R Axis II criteria. In comparison, 3 of 23 (13%) binge eaters and 1 of 23 (4%) normal subjects received an Axis II diagnosis. Borderline and self-defeating diagnoses were the predominant personality disorders in 96% of the bulimics exhibiting clinically significant personality pathology. Bulimics also exhibited significantly more depression, impulsivity, and self-defeating behavior and lower self-esteem than binge eaters and normals. The findings are discussed within a conceptual framework that posits an interaction between personality pathology and restrained eating.     

Preemployment screening procedures: How human resource managers perceive them

A survey of Human Resource practitioners' perceptions of pre-employment screening procedures was conducted. The results indicated differences between tests in terms of perceived accuracy and offensiveness, as well as other attributes. Regression analyses suggested that beliefs about validity, the number of other companies using these procedures, perceived offensiveness of the test, and ease in passing the test were important factors in the willingness to use a particular test. Conversely, perceptions regarding the discriminatory impact of the test and the cost of using the test generally were not related to willingness to use the test. Limitations of this study, which was primarily exploratory, are noted.     

Near-death experiences and the measurement of blood gases

Although cerebral anoxia is not thought to be responsible for triggering near-death experiences (NDEs), the issue is not so clear in the case of hypercapnia. Detection of normal blood gases in Michael Sabom's (1982) case study seems to be the major reply to suggestions that hypercapnia may have a causal role in NDEs. We argue, however, that routine arterial measures of blood gases are not a reliable indicator of cerebral levels.     

Statistical simulation on microcomputers

The statistical simulation program DATASIM is designed to conduct large-scale sampling experiments on microcomputers. Monte Carlo procedures are used to investigate the Type I and Type II error rates for statistical tests when one or more assumptions are systematically violated-assumptions, for example, regarding normality, homogeneity of variance or covariance, mini-mum expected cell frequencies, and the like. In the present paper, we report several initial tests of the data-generating algorithms employed by DATASIM. The results indicate that the uniform and standard normal deviate generators perform satisfactorily. Furthermore, Kolmogorov-Smirnov tests show that the sampling distributions ofz, t, F, χ², andr generated by DATASIM simulations follow the appropriate theoretical distributions. Finally, estimates of Type I error rates obtained by DATASIM under various patterns of violations of assumptions are in close agreement with the results of previous analytical and empirical studies; These converging lines of evidence suggest that DATASIM may well prove to be a reliable and productive tool for conducting statistical simulation research.