An example of discovery research involving the transfer of stimulus control

The initial purpose of the present study was to replicate procedures for teaching preschool children to recruit attention at appropriate times by having an experimenter signal the availability and unavailability of attention (i.e., arrange a multiple schedule involving reinforcement and extinction; Tiger & Hanley, 2004). Following the development of discriminated social responding, the schedule-correlated stimuli were removed (i.e., a mixed schedule of reinforcement was arranged). However, discriminated responding continued during these conditions. Further evaluation suggested that stimulus control over children's social responding had transferred from the schedule-correlated stimuli to the delivery of reinforcement. The effect of a history of reinforcement under multiple-schedule conditions on performance under mixed schedules was then replicated with 2 participants in a reversal design. These findings suggest that following experience with schedule-correlated stimuli, these stimuli may be removed with only modest disruption to discriminated responding.     

In Search of a Conceptualization of Multiple Sclerosis: A Historical Perspective

A thorough understanding of Multiple Sclerosis (MS) is necessary to offer individuals informed options for treatment and planning. To assist in this quest, the following historical analysis examined how MS has been conceived from the 14th century through the early 20th century. Primary sources were consulted whenever possible, and many of the original archival materials were accessed by the first author (MB) during an on-site visit to the Rare Book Room of the New York Academy of Medicine. There is a striking similarity between how MS symptoms have presented throughout history compared with the 21st century. Sensorimotor and cognitive sequelae have been observed in patients since the 1800s. Cognitive symptoms were acknowledged in the 1800s, but disregarded in the early 1900s and were not given recognition again until the latter part of the 20th century. If conceptualizations of MS are inaccurate, patients will not be served well. In contrast to the shared symptomatology across time, early conceptualizations of etiology and treatment choices differed dramatically from today, a genuine reflection of the times in which they were created.     

The Fallacy of Many Questions: On the Notions of Complexity, Loadedness and Unfair Entrapment in Interrogative Theory

The traditional fallacy of many questions, also known as the fallacy of complex question, illustrated by the question, "Have you stopped sexually harassing your students?", has been known since ancient times, but is still alive and well. What is of practical importance about this fallacy is that it represents a tactic of entrapment that is very common in everyday argumentation, as well as in special kinds of argumentation like that in a legal trial or a parliamentary debate. The tactic combines the use of loaded questions with the complexity of the question. A key notion is that of the presupposition of the question. How to deal with such questions is a point of departure for interrogative theory, and for any attempts to construct formal dialogues of a kind that can be used as normative models of argumentation.     

The multiple self: working with dissociation and trauma

This paper describes a patient who appears to have a chronic dissociative personality disorder. Renewed clinical interest in dissociative disorders had arisen in North America in the 1980s, in part due to the influence of the Women's Movement which had highlighted the incidence of child sexual abuse. The early psychological observations of Janet, Freud and Jung on hysterical patients who displayed dissociative phenomena were similar to those displayed by the patient. consideration is given to theoretical understanding of the condition, taking into account the views of the earlier theorists and object-relations theory. The possibility of trauma, in particular childhood sexual abuse, as a causative factor in dissociative disorders is discussed.     

Contrast and undermatching with regular or irregular alternation of components

Behavioral contrast and response-ratio sensitivity to reinforcement were compared in multiple schedules in which components alternated strictly or according to a pseudorandom sequence. Average component durations in the two regimes were always 60 s, and order of presentation of component alternation regimes was counterbalanced across subjects. In Part 1, the reinforcer rate in one component was reduced from 60 per hour to zero, while that in the other component was unchanged. Positive behavioral contrast occurred in the constant component in that response rates increased, but neither the reliability nor the magnitude of contrast was affected by the manner in which components alternated. Part 2 was similar, except that a number of different reinforcer rates were used in the varied component. Neither contrast nor sensitivity of response ratios to changes in reinforcer ratios depended on the regime of component alternation. Thus, the predictability in time of future reinforcement conditions, which is a feature of regular multiple scheduling, does not appear to be a determinant of multiple-schedule performance.     

Linear relations amongk sets of variables

A family of solutions for linear relations amongk sets of variables is proposed. It is shown how these solutions apply fork=2, and how they can be generalized from there tok3.The family of solutions depends on three independent choices: (i) to what extent a solution may be influenced by differences in variances of components within each set; (ii) to what extent the sets may be differentially weighted with respect to their contribution to the solution—including orthogonality constraints; (iii) whether or not individual sets of variables may be replaced by an orthogonal and unit normalized basis.Solutions are compared with respect to their optimality properties. For each solution the appropriate stationary equations are given. For one example it is shown how the determinantal equation of the stationary equations can be interpreted.     

Stimulus properties of conspecific behavior

Two experiments identified the conditions in which the behavior of one bird acquired discriminative control of the behavior of a second bird. The schedule-controlled behaviors of the “stimulus” bird were differentially correlated with the components of a multiple schedule according to which the pecking of an “experimental” bird produced food. In Experiment 1, three pairs of pigeons acquired a successive discrimination and two reversals with the conspecific stimuli. Experiment 2 included a control condition in which no systematic relationship existed between the conspecific stimuli and the component schedules. While differential responding during the components of the multiple schedule was again found when the conspecific stimuli were available, differential responding did not occur in the control condition. Test conditions included in the experiments indicated that (a) the differential responding was not dependent on the discriminative properties of reinforcement, (b) the pecking of the stimulus and experimental birds was temporally interrelated, (c) the visual conspecific stimuli were critical to the maintenance of the discrimination, and (d) the observed stimulus control immediately generalized to an unfamiliar conspecific.     

Percentage reinforcement and choice

Pigeons responded on identical concurrent variable-interval schedules (choice phase), producing outcomes of either periodic reinforcement schedules always terminating in reinforcement (reliable schedule) or otherwise identical schedules providing reinforcement on only a percentage of instances (percentage reinforcement schedule). Comparisons of this type constituted two assessments of the generality of preference for percentage reinforcement reported by Kendall (1974). In a third set of conditions, a reliable schedule was pitted against a percentage reinforcement schedule in which the more negative outcome was a leaner schedule of reinforcement (rather than nonreinforcement, as in the other two conditions). In all three types of conditions, the schedule providing the higher rate of reinforcement was preferred. Results from a subsequent manipulation suggest that Kendall's contrasting results may have depended on the fact that the stimuli in his choice phase (unlit keys) were physically identical to the stimulus correlated with the nonchosen outcome in his outcome phase.     

ESTABLISHMENT OF NONDELUSIONAL RESPONSES IN A SOCIALLY WITHDRAWN CHRONIC SCHIZOPHRENIC1

Multiple treatment interventions including instructions, modelling, timeout, avoidance of repetition, and reinforcement were successful in establishing factual answers to personal background questions in a withdrawn and socially unresponsive chronic schizophrenic. The subject had previously persisted in giving only delusional responses to these questions. A multiple-baseline design across verbal replies to personal background questions demonstrated that the changes in behavior were brought about by the treatment interventions. During baseline, the subject was reinforced for any response to four questions. The experimental interventions were then introduced for the first question and moved sequentially to an additional question when the subject's responses reached the criterion of at least 80% correct for two consecutive sessions. Introduction of the experimental interventions produced an increase from a baseline level of zero to at least 80% correct for each question. The use of the token reinforcement procedure was faded out after the subject was able to answer all four questions correctly at least 80% of the time for two consecutive sessions. Fading of the token reinforcement procedure was accomplished by using increasingly intermittent schedules of token reinforcement during the last seven sessions. In the final session, no tokens were used to reinforce the subject's responding. Nine-, ten-, and 12-month followup interviews were conducted to evaluate the maintenance of treatment gains. Maintenance was found to be complete at the nine- and 10-month followups, but at the 12-month followup interview, the subject answered one question incorrectly. This study replicates an investigation previously reported in this journal.     

Multiple-probe technique: a variation on the multiple baseline

Multiple-baseline and probe procedures are combined into a “multiple-probe” technique. The technique is designed to provide a thorough analysis of the relationship between an independent variable and the acquisition of a successive-approximation or chain sequence. It provides answers to the following questions: (1) What is the initial level of performance on each step in the training sequence? (2) What happens if sequential opportunities to perform each next step in the sequence are provided before training on that step? (3) What happens when training is applied? (4) What happens to the performance of remaining steps in the sequence as criterion is reached in the course of training each prior step? The technique features: (1) one initial probe of each step in the training sequence, (2) an additional probe of every step after criterion is reached on any training step, and (3) a series of “true” baseline sessions conducted just before the introduction of the independent variable to each training step. Intermittent probes also provide an alternative to continuous baseline measurement, when such measurement during extended multiple baselines (1) may prove reactive, (2) is impractical, and/or (3) a strong a priori assumption of stability can be made.