Effects of altering outcome expectancies on pigeons' delayed conditional discrimination performance

An outcome-expectancy mediation theory of learning was tested in a series of transfer experiments with pigeons. The principal technique employed was a delayed two-choice conditional discrimination in which the subject's correct choice yielded a food reward on one kind of trial and a feedback tone on the other. According to the theory, this task engenders two-link mediational chains in that each conditional cue controls a particular outcome expectancy (S-E link) and the expectancy, in turn, cues a specific choice response (E-R link). Relative to the hypothetical mediators established by preceding training, transfer problems required either the same mediational chains, the alteration of one link in each chain, or the alteration of both links in both chains for optimal performance. The results of four separate transfer experiments confirmed detailed theoretical predictions, including that of an unusual nonmonotonic transfer effect. The relation of the present theory to earlier mediation theories is discussed.     

The influence of similarity between relevant and irrelevant information upon a complex identification task

This experiment sought answers to two questions: (1) Do increases in the similarity between relevant and irrelevant information present in visual stimulus patterns detrimentally influence the performance of a complex identification task, and (2) does the effect of such similarity interact with increasing amounts of irrelevant information? An analysis of the response latencies and errors indicated that identification of the relevant information in the stimulus patterns becomes significantly poorer with increasing similarity between relevant and irrelevant information and with increasing amounts of irrelevancy. The results also showed that the joint effect of similarity and irrelevancy produces a greater performance decrement than that associated with either variable alone. Practice on the task reduced the detrimental effects.     

Remembering words and how often they occurred in memory-impaired patients

Memory &; Cognition - The recent memory impairments in Korsakoff’s (KD), Huntington’s (HD), and Alzheimer’s (SDAT) diseases are qualitatively different from one another. All...     

A non-finitely based quasi-variety of De Morgan algebras

In this paper we exhibit a non-finitely based, finitely generated quasi-variety of De Morgan algebras and determine the bottom of the lattices of sub-quasi-varieties of Kleene and De Morgan algebras.Supported by Vicerrectoría Académica de la Facultad de Ciencias and by División de Investigación, Sede Bogotá of the Universidad Nacional de Colombia.Special issue of Studia Logica: Algebraic Theory of Quasivarieties Presented by M. E. Adams, K. V. Adaricheva, W. Dziobiak, and A. V. Kravchenko     

The case for existential therapy in HIV-related psychotherapy

Few topics currently evoke such debate and dynamics as HIV and AIDS. It is a phenomenon that affects people at all levels of their existence, including in their psychotherapy experience. There is an ever growing field of HIV related psychotherapy. Currently this field contains work from a cognitive behavioural focus, a systemic one, work from a psychodynamic focus and from the Group Analytic approach. In this paper the case for existential psychotherapy will be made as an important approach with a great deal to offer the field of HIV-related psychotherapy.     

A simple,inexpensive, liquid-tight swivel connection for use in chronic infusion systems

This note describes the fabrication of a simple, inexpensive, liquid-tight swivel joint for twist-free coupling of small, freely moving animals to infusion systems. The device uses a disposable hypodermic needle and syringe as the main components, and fabrication requires only readily available hand tools and minimal mechanical expertise.