Pavlovian contingencies and resistance to change in a multiple schedule

According to theoretical accounts of behavioral momentum, the Pavlovian stimulus—reinforcer contingency determines resistance to change. To assess this prediction, 8 pigeons were exposed to an unsignaled delay-of-reinforcement schedule (a tandem variable-interval fixed-time schedule), a signaled delay-of-reinforcement schedule (a chain variable-interval fixed-time schedule), and an immediate, zero-delay schedule of reinforcement in a three-component multiple schedule. The unsignaled delay and signaled delay schedules employed equal fixed-time delays, with the only difference being a stimulus change in the signaled delay schedule. Overall rates of reinforcement were equated for the three schedules. The Pavlovian contingency was identical for the unsignaled and immediate schedules, and response—reinforcer contiguity was degraded for the unsignaled schedule. Results from two disruption procedures (prefeeding subjects prior to experimental sessions and adding a variable-time schedule to timeout periods separating baseline components) demonstrated that response—reinforcer contiguity does play a role in determining resistance to change. The results from the extinction manipulation were not as clear. Responding in the unsignaled delay component was consistently less resistant to change than was responding in both the immediate and presignaled segments of the signaled delay components, contrary to the view that Pavlovian contingencies determine resistance to change. Probe tests further supported the resistance-to-change results, indicating consistency between resistance to change and preference, both of which are putative measures of response strength.     

Über zwei Formen von Realismus in der Quantentheorie

On Two Types of Realism in Quantum Theory. Current realist approaches to the foundations of quantum theory emphasize the dichotomy between (Copenhagen) positivism and ‘beable’-realism. Recently it was even attempted to turn this picture into two (equally possible) histories in order to legitimate Bohmian Mechanics as a viable alternative. This paper argues that this dichotomy is philosophically inadequate and historically questionable by embedding it into the philosophical discussion on positivism and realism that has taken place since the 1920s. Logical Empiricists back then advocated empirical realism and contrasted it to absolutistic metaphysical realism. From this viewpoint David Bohm's ‘beable’-realism combines elements of Mach's sensualism with a pre-Kantian metaphysics. As Wesley Salmon's position shows, empirical realism can become quite pronounced without relapsing into Bohmian philosophy. Instead it arrives close to the GRWP-interpretation. Hence, when Bernard d'Espagnat binds both together as ‘ontological interpretations’, he blurs the borderline between empirical and metaphysical realism that his Veiled Reality has set out to draw, quite in concordance with Logical Empiricism. This revised version was published online in August 2006 with corrections to the Cover Date.     

Short-term memory in the pigeon: the previously reinforced response

Eighteen pigeons served in a discrete-trials short-term memory experiment in which the reinforcement probability for a peck on one of two keys depended on the response reinforced on the previous trial: either the probability of reinforcement on a trial was 0.8 for the same response reinforced on the previous trial and was 0.2 for the other response (Group A), or, it was 0 or 0.2 for the same response and 1.0 or 0.8 for the other response (Group B). A correction procedure ensured that over all trials reinforcement was distributed equally across the left and right keys. The optimal strategy was either a winstay, lose-shift strategy (Group A) or a win-shift, lose-stay strategy (Group B). The retention interval, that is the intertrial interval, was varied. The average probability of choosing the optimal alternative reinforced 80% of the time was 0.96, 0.84, and 0.74 after delays of 2.5, 4.0, and 6.0 sec, respectively for Group A, and was 0.87, 0.81, and 0.55 after delays of 2.5, 4.0, and 6.0 sec, respectively, for Group B. This outcome is consistent with the view that behavior approximated the optimal response strategy but only to an extent permitted by a subject's short-term memory for the cue correlated with reinforcement, that is, its own most-recently reinforced response. More generally, this result is consistent with “molecular” analyses of operant behavior, but is inconsistent with traditional “molar” analyses holding that fundamental controlling relations may be discovered by routinely averaging over different local reinforcement contingencies. In the present experiment, the molar results were byproducts of local reinforcement contingencies involving an organism's own recent behavior.     

Observer reliability as a function of circumstances of assessment

THREE FACTORS CHARACTERISTIC OF EXPERIMENTAL SETTINGS WERE HYPOTHESIZED TO INFLATE ARTIFACTUALLY THE RELIABILITY OF OBSERVATIONAL RECORDINGS: (a) knowledge by observers of when and by whom their reliability is being assessed, (b) the absence of the experimenter or a monitor to prevent cheating, and (c) computation of reliability within- (versus between-) observer group. Three groups of four observers used a standard nine-category observational code for disruptive behavior in recording from videotapes of a classroom for 22 days. Analyses revealed considerable increases in average occurrence reliability as a function of the main effects of each of the experimental factors. The specific increases in reliability associated with each of the 12 combinations of the experimental factors are presented for each category of behavior. The possible role of observer-training procedures and behavioral definitions as determiners of nonartifactual reliability is discussed.     

Effects of serial dependency on the agreement between visual and statistical inference

Comparisons between visual and time-series inferences from behavioral data show that serial dependency in scores is likely to disrupt agreement between the two methods of analysis. If researchers follow an earlier recommendation that time-series analysis be used to supplement or confirm visual analysis, this study's findings suggest that the two methods will disagree most often when the data contain high levels of autocorrelation and when reliable behavorial changes are indicated by time-series analysis.     

Information on Information: Recent Curriculum Reform

Recent curriculum reform in western educational systems has seen a major emphasis on electronic technology, but reform literature seldom problematises the form that this new education should take in this new mode of information. From the particular case of New Zealand it is argued that knowledge has been replaced by information, knowing that (something is the case) by knowing how (acquiring skills), while electronic writing tends to be treated as a mere extension of print literacy. However, the information economy is a major force restructuring not only the curriculum but, also, our social and cultural relations, established notions of knowledge, authority, and rights, and our notions of subjectivity. The purpose of this paper is to problematise this move to information in the new electronic technologies.     

The Biomedical Paradigm and the Nobel Prize: Is It Time for a Change?

An examination of the early history of Nobel Committee deliberations, coupled with a survey of discoveries for which prizes have been awarded to date – and, equally revealing, discoveries for which prizes have not been awarded – reveals a pattern. This pattern suggests that Committee members may have internalized the received, biomedical model and conferred awards in accord with the physicalistic premises that ground this model. I consider the prospect of a paradigm change in medical science and the possible repercussions of such a change on the distribution of Nobel prizes within the domain of physiology or medicine. For expository purposes, I contrast a model based on a science of pathophysiology with one based on a science of pathopsychophysiology. I propose a means whereby members might minimize the potentially blinding effects of model-dependence and come to evaluate medical discoveries from an inter-model rather than an exclusively intra-model perspective. By bringing to light questions rarely asked and proposing answers, I seek to open a dialogue and furnish a vehicle by which the putative delimiting effects of model-dependence might be overcome.     

Drug discrimination under a concurrent schedule.

Three pigeons were trained to discriminate a 5.0 mg/kg dose of pentobarbital from saline under a two-key concurrent schedule with responding on the key associated with the presession injection, under both stimulus conditions, producing four times as many reinforcers as responding on the other key. This concurrent schedule resulted in approximately 70% responding to the higher reinforcement key under the pentobarbital stimulus and approximately 30% responding to that key under the saline stimulus. During testing, then, the pigeons were able to dose-dependently emit higher (>70%) or lower (<30%) values than were established under the control conditions. Dose-response curves were determined for pentobarbital (twice), methamphetamine, phencyclidine, chlordiazepoxide, and the combination of pentobarbital and the barbiturate antagonist bemegride. The results obtained with pentobarbital and chlordiazepoxide showed that, as the dose increased, pentobarbital-appropriate responding also increased. Methamphetamine produced relatively flat dose--response curves, whereas phencyclidine administration produced inconsistent effects on responding. The combination of the training dose of pentobarbital with increasing doses of bemegride produced a decrease in pentobarbital-appropriate responding. The results also showed that the dose-response curves for pentobarbital and chlordiazepoxide, instead of being all or none, were graded functions of the drug dose.     

Gleaning in the field of dual scaling

Some historical background and preliminary technical information are first presented, and then a number of hidden, but important, methodological aspects of dual scaling are illustrated and discussed: normed versus projected weights, the amount of information accounted for by each solution, a perfect solution to the problem of multidimensional unfolding, multidimensional quantification space, graphical display, number-of-option problems, option standardization versus item standardization, and asymmetry of symmetric (dual) scaling. Contrary to the common perception that dual scaling and similar quantification methods are now mathematically transparent, the present study demonstrates how much more needs to be clarified for routine use of the method to arrive at valid conclusions. Data analysis must be carried out in such a way that common sense, intuition and sound logic will prevail.Presidential Address delivered at the Annual Meeting of the Psychometric Society, Banff Centre for Conferences, Banff, Alberta, Canada, June 27–30, 1996. The work has been supported in part by a grant from the Natural Sciences and Engineering Research Council of Canada. I am grateful to Ira Nishisato for his comments, Ingram Olkin and Yoshio Takane for important references, and Liqun Xu for computational help.     

Freud's theory of paranoid delusion based on the Schreber case contrasted with related theories

The historic importance of Freud's analysis of the Schreber case is acknowledged, even though the theory it expounds is largely disavowed. The theory ascribes the cause of paranoid delusion to homosexual impulses unresolved in infancy or early childhood. This paper summarizes Freud's monograph on Schreber and contrasts his theory with the views of various revisionists. The writers focus on the Freudian concept of projection, which is intended to explain how much meaning can become reversed under the impetus of stress, and the reversal lead to delusional thinking. Based on their work in family therapy, where they observed one form of pathogenic relating termed learning to be possessed, the writers concluded that this form was also based on a type of projection which could culminate in delusional ideation. A relationship between learning to be possessed and H. S. Sullivan's theory of paranoid transformation is described. A learning factor is present in several of the psychological theories advanced to explain delusion, and the factor is akin to if not identical with Freud's concept of projection.Gerald Zuk, PhD, is in private practice at 25316 Pacy Street, Santa Clarita, California 91321-3343. Carmen Zuk, MD, is a child psychiatrist-partner affiliated with the Southern California Permanente Medical Group at its psychiatric clinic in Van Nuys, California. Both may be reached by telephone at (805) 252-7702.