Preference for mixed versus constant delays of reinforcement: Effect of probability of the short, mixed delay

Preference for mixed versus constant delays of reinforcement was studied with a concurrent-chain procedure. Lever pressing by rats in concurrently available variable-interval 60-second initial links occasionally produced mutually exclusive terminal-link reinforcement delays. A constant delay of reinforcement (either 15 seconds or 30 seconds) composed one terminal link and mixed delays (.2 second and twice the value of the constant delay) were arranged in the other terminal link. The proportion of .2-second delays in the mixed-delay terminal link took on values of 0, .1, .25, .5, .75, .9, and 1.0 over experimental conditions. Based on relative rates of responding in the initial links, preference for the mixed delays was a negatively accelerated function of the proportion of short, mixed delays. Three of five rats preferred the mixed delays to the constant delays when the proportion of short, mixed delays was .1 or higher, and all five rats preferred the mixed delays when the proportion of short, mixed delays was .25 or higher. Neither Squires and Fantino's (1971) delay-reduction model of choice nor a model based on the harmonic mean reinforcement delay provided a close estimate of choice proportions over the range of short-delay proportions studied. The delay-reduction model underestimated choice for the mixed delays at low and intermediate proportions of short delays, and the harmonic-mean-delay model overestimated choice for the mixed delays at intermediate and high proportions of short delays.     

Effects of d-amphetamine on self-aggression and posturing in stumptail macaques

The behavioral effects of d-amphetamine sulfate were studied in adult male stumptail macaques living within a large heterogeneous group in an outdoor enclosure. Among five subjects that received a range of doses (.01 to .3 mg/kg), d-amphetamine increased self-aggressive behavior and abnormal posturing in subjects that exhibited these types of behavior prior to drug administration, but it had no effect in subjects not exhibiting those activities in the absence of the drug. For the former subjects, the dose-effect curves for self-aggression were of an inverted U-shape analogous to the effect of d-amphetamine on schedule-controlled behavior. Over the range of doses studied, the curve for abnormal posturing was monotonic. The data indicate that d-amphetamine can have effects on untrained behavior in individual animals in a quasinatural environment that are qualitatively and quantitatively similar to the behavioral effects observed in other laboratory environments, and that d-amphetamine does not evoke or increase a behavioral response in individual subjects that do not exhibit the response in the absence of the drug.     

Test of reliability of perception of parental and childhood illness behavior

This report details the reliability of perceived parental and childhood illness behavior. Three versions of the Illness Behavior Inventory were created to assess perceived illness behavior of one's mother, father, and oneself as a child. The measures were administered twice to 32 students of linguistics at a major university with a 2-wk. interval between administrations. Each measure across administrations correlated highly and significantly (.98 to .99). It was concluded that perceptions of parental and childhood illness behavior are reliable over time but their sensitivity to actual historical events remains an empirical question.     

Perception of spatial and social density

The effects of family size on the perception of three abstract rooms that differed in social and spatial density were studied. The rooms were rated on the dimensions, evaluation, spirituality, activity, and aesthetic appeal. Of the 48 subjects half were from large families with six or more members, and half were from smaller families. Family size had no effect on the perception of the rooms. The room low in spatial density was perceived most favorably, and there was no difference in the perception of a room high in social density and one high in spatial density.     

Effect of lingual vibrotactile stimulation on the averaged cortical evoked response

This study was designed to determine the feasibility of using lingual vibrotactile stimulation to elicit an averaged evoked response and to investigate the effects of two supra-threshold intensity levels of lingual vibrotactile stimulation on the electro-cortical activity of the brain. The evoked responses were analyzed according to the amplitude of N1-P2 (in microvolts). Analysis indicates that the tongue can successfully be used as a stimulus site in the elicitation of an evoked response. The amplitudes of the evoked response elicited by 2 micrometers sensation level and 5 micrometers sensation level on the tongue are essentially the same. The relative difference between these levels is not sufficient to produce significant differences in the amplitudes of their respective evoked responses.     

Lingual vibrotactile sensation magnitudes: comparison of suprathreshold responses for three different age ranges

Vibrotactile magnitude scaling was performed on three different age groups of six normal subjects each. The psychophysical method of magnitude production was used for the scaling of vibratory stimuli applied to the anterior dorsal surface of the tongue. The older subjects produced shallower upper-slope functions than the younger subjects and also showed greater response variability. Behavioral, anatomical, and physiological factors are discussed.     

Rational stage-directed therapy: A cognitive experiential system using hypnosis,imagery, cognitive restructuring,and developmental staging

Conclusion Although RSDT is a relatively new form of therapy, we believe there is reason for great optimism regarding the efficacy of the RSDT model. Communications from our colleagues using the model in a variety of settings have been very favorable. We believe the experimental studies that have been conducted on the RSDT model demonstrate that it has generated significantly better outcomes when compared with other therapeutic models and those results obtained from no therapy controls. We think the effectiveness of RSDT has been admirably demonstrated through comprehensive research designs In comparison with outcome studies conducted on other forms of therapy. We look toward the future with optimism as more practitioners begin to use the RSDT model and additional evaluation studies are conducted.     

How to deal with your most difficult client—You

Conclusion Therapists are human-and, believe it or not, fallible humans. Ideally, they are supremely well infored, highly confident, minimally disturbed, extremely ethical and rarely under- or overinvolved with their clients/Actually, they are hardly ideal. If you, as a therapist, find yourself seriously blocked in your work, look for the same kind of irrational beliefs, inappropriate feelings, and dysfunctional behaviors that you would investigate in your underachieving clints. When you ferret out the absolutistic philosophies and perfectionist demads that seem to underlie your difficulties, ask yoursell—yes,strongly ask yourself—these trenchant questions: (a) Why do Ihave to be an indubitably great and unconditionally lowed therapist?; (b) Where is it written that my clientsmust follow my teachings and absolutelyshould do what I advise?; (c) Where is the evidence that therapymust be easy and that Ihave to enjoy every minute of it?If you persist in asking important questions like these and insist on thinking them through to what are scientific and logical answers, you may still never become the most accomplished and sanest therapist in the world. But I wager that you will tend to be happier and more effective than many other therapists I could—but charitably will not—name. Try it and see!This article is adapted from an invited address presented at the 91 st Annual Convention of the American Psychological Association at Anaheim, Calif., August 1983.