Discriminability between alternatives in a switching-key concurrent schedule

Six pigeons were trained to discriminate between two intensities of white light in a symbolic matching-to-sample procedure. These stimuli were then used to signal which schedule was available on the main key in a switching-key concurrent schedule. The concurrent schedules led to a symbolic matching-to-sample phase in which the subject identified the concurrent schedule to which it last responded before a reinforcer could be obtained. The concurrent schedules were varied across conditions. Discriminability, measured during the symbolic matching-to-sample performance, was high throughout and did not differ across the two procedures. Performance in the concurrent schedules was like that typically obtained using these schedules. Delays were then arranged between completion of the concurrent schedules and presentations of the symbolic matching-to-sample phase. A series of conditions with an intervening delay of 10 s showed that both concurrent-schedule performance and symbolic matching-to-sample performance were affected by the delay in a similar way; that is, choice responding was closer to indifference.     

Effects of modelling on children''s pretend play

The effects of modelling on pretend play were studied in children between 2.6 and 3.6 years of age by examining changes both in the action and language-based expressions of pretending. Three modelled scenes were demonstrated with the same realistic toys used by the child in the pre-modelling phase. The results gave support to the idea of the effectiveness of modelling. The effects of the modelled scenes were clearest among children whose pre-modelling play consisted of object-centred actions including few of pretending. The post-modelling play of this subgroup showed better quality of action and language categories and integration measures. Among the decentred players no significant action benefit could be achieved. This might have been an outcome of the contextual limits of the toy material and of the drop of play motivation caused by the model interruption. However, these children expressed verbal pretending revealing significant pre-post effects for inventive utterances.     

Statistical consistency and hypothesis testing for nonmetric multidimensional scaling

The properties of nonmetric multidimensional scaling (NMDS) are explored by specifying statistical models, proving statistical consistency, and developing hypothesis testing procedures. Statistical models with errors in the dependent and independent variables are described for quantitative and qualitative data. For these models, statistical consistency often depends crucially upon how error enters the model and how data are collected and summarized (e.g., by means, medians, or rank statistics). A maximum likelihood estimator for NMDS is developed, and its relationship to the standard Shepard-Kruskal estimation method is described. This maximum likelihood framework is used to develop a method for testing the overall fit of the model.     

Choice between reliable and unreliable outcomes: mixed percentage-reinforcement in concurrent chains.

Pigeons' choices between alternatives that provided different percentages of reinforcement in mixed schedules were studied using the concurrent-chains procedure. In Experiment 1, the alternatives were terminal-link schedules that were equal in delay and magnitude of reinforcement, but that provided different percentages of reinforcement, with one schedule providing, reinforcement twice as reliably as the other. All pigeons preferred the more reliable schedule, and their level of preference was not systematically affected by variation in the absolute percentage values, or in the magnitude of reinforcement. In Experiment 2, preference for a schedule providing 100% reinforcement over one providing 33% reinforcement increased systematically with increases in the duration of the terminal links. In contrast, preference decreased systematically with increases in the duration of the initial links. Experiment 3 examined choice with equal percentages of reinforcement but unequal delays to reinforcement. Preference for the shorter delay to reinforcement was not systematically affected by variation in the absolute percentage of reinforcement. The overall pattern of results supported predictions based on an extension of the delay-reduction hypothesis to choice procedures involving mixed schedules of percentage reinforcement.     

Observing responses maintained by conditional discriminative stimuli.

In a conditional discrimination procedure, pigeons' observing responses were analyzed to examine whether two color stimuli (blue or red), conditionally related to whether each of two line stimuli (vertical or horizontal) accompanied reinforcement or nonreinforcement, functioned as conditioned reinforcers. If a variable-interval (VI) 10-s requirement was fulfilled, an observing response produced onset of a color stimulus. A little later, a line stimulus was presented independently of responding, added to the color stimulus to form a compound stimulus. If 55 s elapsed with a response not having occurred either through 55 s or after the variable-interval 10-s had timed out, one of the color-line compound stimuli was presented independently of responding. To control for sensory reinforcement effects and for earlier entrance to the later link, a simple discrimination procedure also was conducted in which reinforcement was not correlated with the color stimuli but with the line stimuli only. As in the conditional discrimination, the observing response also could produce earlier presentation of blue or red. The observing response occurred more frequently during the conditional discrimination than during the simple discrimination. The results were related to different theoretical accounts of conditioned reinforcement, particularly the information hypothesis.     

The effect of negative stimulus presentations on observing-response rates

Theories of observing differ in predicting whether or not a signal for absence of reinforcement (S−) is capable of reinforcing observing responses. Experiments in which S− was first removed from and then restored to the procedure have yielded mixed results. The present experiments suggest that failure to control for the direct effect of presenting S− may have been responsible. Pigeons and operant procedures were used. Experiment 1 showed that presentations of S−, even when not contingent on observing, can raise the rate of an observing response that was reinforced only by presentations of a signal (S+) that accompanied a schedule of food delivery. Experiment 2 showed that this effect resulted from bursts of responding that followed offsets of S−. Experiment 3 showed that, when the presence of S− was held constant, lower rates occurred when S− was dependent on, rather than independent of, observing. These results support theories that characterize S− as incapable of reinforcing observing responses.     

Religiosity and Secular and Ascetic Deviance

According to the antiascetic hypothesis, religiosity should be strongly related to behaviors that violate ascetic standards (getting drunk and using marijuana), but only weakly related to behaviors that violate social standards (violence and stealing). Using the second wave of the National Study of Youth and Religion, I tested the antiascetic hypothesis using a question about the most important basis for deciding what is morally right or wrong. Contrary to the antiascetic hypothesis, individuals who believe that God's law is the most important for deciding what is morally right or wrong, compared to those who believe that society is the most important, are not less likely to get drunk or use marijuana. Furthermore, for getting drunk and marijuana use, differences in behavior are not the result of different ethical standards (ascetic or social), but rather differences in the willingness to uphold those standards (is it OK to break moral rules).     

Working with patients with disruptions in symbolic capacity1

This article focuses on understanding and working with patients who have poorly developed symbolic capacity, or for whom symbolic capacity has been disrupted due to trauma, particularly as it pertains to the use of reverie and interpretation in the analytic process. Many patients who present for Jungian analysis will initially present with deficits in symbolic functioning. This situation results in necessary limitations or modifications in utilizing traditional Jungian techniques such as dream analysis, active imagination, sand tray and other expressive art techniques. The initial phase of analytic work with these patients requires a focus on developing their symbolic capacity before traditional Jungian techniques can be utilized effectively. During the paper Jung's concept of ‘the symbolic attitude’ will be examined as well as the conceptual models of Wilfred Bion and other post-Bionians who outline theories and method for cultivating symbolic capacity and reflective functioning in patients for whom these capacities are impaired or poorly developed.