Choice between delayed reinforcers and fixed-ratio schedules requiring forceful responding.

This experiment measured pigeons' choices between delayed reinforcers and fixed-ratio schedules in which a force of approximately 0.48 N was needed to operate the response key. In ratio-delay conditions, subjects chose between a fixed-ratio schedule and an adjusting delay. The delay was increased or decreased several times a session in order to estimate an indifference point--a delay duration at which the two alternatives were chosen about equally often. Each ratio-delay condition was followed by a delay-delay condition in which subjects chose between the adjusting delay and a variable-time schedule, with the components of this schedule selected to match the ratio completion times of the preceding ratio-delay condition. The adjusting delays at the indifference point were longer when the alternative was a fixed-ratio schedule than when it was a matched variable-time schedule, which indicated a preference for the matched variable-time schedules over the fixed-ratio schedules. This preference increased in a nonlinear manner with increasing ratio size. This nonlinearity was inconsistent with a theory that states that indifference points for both time and ratio schedules can be predicted by multiplying the choice response-reinforcer intervals of the two types of schedules by different multiplicative constants. Two other theories, which predict nonlinear increases in preference for the matched variable-time schedules, are discussed.     

How much processing do nonattended stimuli receive? Apparently very little, but...

The early versus late selection issue in attention models was examined by means of a new methodology. Through cues or precues, attention was directed to one location of a multistimulus visual display and, while attention was so engaged, the identity of a stimulus located at a different position in the display was changed. By varying the time after display onset before the stimulus was changed, we controlled the preview time that the original stimulus was represented on the retina. Then, using a marker cue, we directed the subject's attention to the location of the changed stimulus. The subject's response was a timed discrimination between two possible target letters. The data of main interest was the effect of preview time upon the subject's latency in identifying the new target that appeared in the changed location. We found that the preview time of the original stimulus, before RT was affected to the new target, depended upon whether the original stimulus was a neutral (noise) letter or whether it was the alternative target. When the original stimulus was a noise letter, RTs to the new target were just as fast as those obtained in the control condition in which the target was present throughout the preview interval and did not change its identity. Significant effects upon RT were obtained at preview times of 83 msec when the original stimulus was one of the targets that changed to the alternative target. Preview times also varied as a function of precuing. Preview times were correspondingly shortened when the first cue occurred 50 msec before display onset, thus providing an extra 50 msec for attention to be directed to the first display location. The results were interpreted in terms of two separate information-processing systems in the human: an automatic system and an attentional system. Even though a stimulus may have been automatically processed, when the attention system is directed to that stimulus, processing starts at the beginning again.     

Concurrent validity of the motor domain of the Vineland Adaptive Behavior Scales

The concurrent validity of the motor domain from the Vineland Adaptive Behavior Scales was estimated using scores from the Peabody Developmental Motor Scales as criteria. A moderately high correlation between the measures was obtained. Implications, particularly for preschool children, were discussed.     

Insulin and dextrose effects on fixed-interval behavioral thermoregulation in albino rats

This study is a systematic replication of the effects of insulin doses on operant behavior reinforced (in an earlier study) by fixed-ratio schedules of microwave (MW) reinforcement. In this study, insulin and dextrose doses were administered (ip) prior to fixed-interval 2-min. schedules of MW reinforcement in rats tested in a cold environment. Six Sprague-Dawley rats were conditioned to regulate their thermal environment with 5-sec. exposures of MW radiation (SAR = 0.34 Watts/kg/(mW/cm2) under the FI-2' schedules. Humulin-regular insulin and 50% solutions of dextrose were administered (ip) alternately with saline control sessions for 8-hr. durations. A within-subjects, repeated-measures 4 x 8 x 3 factorial analysis of variance design showed that insulin doses suppressed operant responding for heat, which confirmed the results of the earlier study under a different schedule. In addition, high doses of dextrose had similar suppressing effects on operant responding for heat. The data are interpreted in terms of the discriminative properties of increased thermogenesis produced by the insulin and dextrose doses. The suppressing effects were more pronounced for the first two hours, yet they persisted for approximately six hours of the 8-hr. sessions.     

PROJECT A: SPECIFICATION OF THE PREDICTOR DOMAIN AND DEVELOPMENT OF NEW SELECTION/ CLASSIFICATION TESTS

A major goal of the Army Selection and Classification Project was to develop an experimental predictor battery that would best supplement the Armed Forces Vocational Aptitude Battery for making selection and classification decisions for entry-level enlisted personnel. That is, what predictor measures would best serve the needs of all the jobs in an entire selection/classification system? This paper describes the characteristics of the new test battery and the procedures that were used to develop it. The major steps in the procedure were a structured literature search using a standard protocol, an extensive expert judgment study of expected true validities for a population of predictor variables against a population of performance components, fabrication of modularized software and a special response pedestal for computerized measurement of perceptual and psychomotor abilities, evaluations of experimental measures in three iterative pilot tests and one major field test, and a series of reviews by a panel of scientific advisers. The test battery that resulted from this 2 1/2-year development effort is described. The basic psychometric properties of each measure, as determined in a large concurrent validation sample, are also described.     

Dream images as a technique for the study of creative processes

For a group of 12 established artists who participated in 12 discussions it appears that quantitative and qualitative analyses of dream images constitute a useful method. Artists' creative processes can be explored through their dream images.     

Clinical multiplicity of cerebrovascular disorders in childhood

A group of 107 children with vascular diseases of the nervous system aged 3-14 years have been studied. In 100 children of the study group acute disturbances of the brain blood circulation have been found, out of which 37 children were with transitory ischemic attacks; 29 were found to be with brain ischaemia; 22-with haemorrhages (7 cases with subarchnoidal, 9 cases with intracerebral and 6 cases with subarachnoidal-parenchimatose); 5 children had wenous thromboses; 7 children were with spinal strokes. In other 7 children we found the presence of Sturge-Weber syndrome. Congenital vascular malformations have been found in 32 children (30%), out of which 16 children (15%) with loops and stenosis of the extracranial segments of the internal carotid artery, and another 16 children (15%) with AV-malformations. Congenital and acquired heart diseases are found to be primary cause for the strokes in 12 children (11%). Considerable is the rate of the epileptic seizures in the acute stage of the strokes as well as of the residual epileptic syndromes.     

Concentration camp imprisonment and psychological traumatization

The author reports on a Norwegian investigation extending over more than 30 years, which showed that, apart from a few exceptions, all former concentration camp inmates and prisoners in Nazi jails manifest permanent physical and psychic damage. On the basis of these findings the Norwegian government has established a generous statutory compensation program. Unlike its counterpart in the Federal Republic of Germany, this program does not require applicants to demonstrate the cause of illness or its consequences in each case. The method of the investigation is presented in detail.     

Dealing with (bypassing) the difference

The author presents different psychoanalytic conceptualizations of gender difference. She reviews the controversy between Freud and Jones and discusses in detail the views put forward by Montrelay, a student of Lacan, who relates early linguistic development to gender-specific differences in closeness between the child and the "mother's body".     

Alcohol challenge with sons of alcoholics: a critical review and analysis

Studies are reviewed in which response to acute administration of alcohol was compared between individuals with and without family histories of alcoholism (FH+, FH-). This research represents a search for a psychobiological marker for alcoholism. A methodological critique of the procedures reported in this literature is then presented. Finally, a conceptual model is suggested in which differences in the response to alcohol between FH+ individuals and FH- individuals must be understood in relation to time after drinking alcohol. This Newtonian differentiator model proposes that sons of alcoholics exhibit acute sensitization as blood alcohol level rises and acute tolerance as blood alcohol level falls, compared with sons of nonalcoholics. Therefore, FH+ subjects find alcohol more rewarding because they accentuate the pleasurable, excitatory aspects of initial intoxication and attenuate the feelings of anxiety and depression that predominate as blood alcohol levels drop.