Equivalence relations and the reinforcement contingency

Where do equivalence relations come from? One possible answer is that they arise directly from the reinforcement contingency. That is to say, a reinforcement contingency produces two types of outcome: (a) 2‐, 3‐, 4‐, 5‐, or n‐term units of analysis that are known, respectively, as operant reinforcement, simple discrimination, conditional discrimination, second‐order conditional discrimination, and so on; and (b) equivalence relations that consist of ordered pairs of all positive elements that participate in the contingency. This conception of the origin of equivalence relations leads to a number of new and verifiable ways of conceptualizing equivalence relations and, more generally, the stimulus control of operant behavior. The theory is also capable of experimental disproof.     

Traumatic Brain Injury as a Risk Factor for Alzheimer's Disease: A Review

Accumulating epidemiological evidence implicates traumatic brain injury as a pathogenic agent in the development of Alzheimer's disease (AD). Considering the increase in the prevalence of both traumatic brain injury and AD in recent times, the possibility that brain trauma may provoke the early development of AD has important implications for health service planning, preventative efforts, and medico-legal compensation settlements. This paper evaluates the plausibility of the proposed link between traumatic brain injury and AD, largely by way of exploring a theoretical perspective advanced by Satz (1993) and considering recent contributions from the epidemiological, neuropathological, and biochemical literature that are pertinent to this issue. The literature reviewed provides sufficient support and empirical vindication to give credence to the proposed association between these two neuropsychological entities at the statistical, theoretical, and biological level.     

The use of genetic test information in insurance: The argument from indistinguishability reconsidered

In the bioethical literature, discrimination in insurance on the basis of genetic risk factors detected by genetic testing has been defended and opposed on various ethical grounds. One important argument in favour of the practice is offered by those who believe that it is not possible to distinguish between genetic and non-genetic information, at least not for practical policy purposes such as insurance decision-making. According to the argument from indistinguishability, the use of genetic test information for insurance purposes should be permitted, because genetic test information is no different from non-genetic medical information in any relevant respect, therefore it would be inconsistent to prohibit the former whilst permitting the latter. This paper discusses and defends this argument and suggests a new, more tenable foundation.     

A Pathological View of Disease

This paper is a response to Christopher Boorse's recent defense of hisBiostatistical Theory (BST) of health and disease. Boorse maintains that hisconcept of theoretical health and disease reflects the ``consideredusage of pathologists.' I argue that pathologists do not use ``disease' inthe purely theoretical way that is required by the BST. Pathology does notdraw a sharp distinction between theoretical and practical aspects ofmedicine. Pathology does not even need a theoretical concept of disease. Itsfocus is not theoretical, but practical; pathology's goal is to contribute tothe healing of patients. Pathology, even experimental pathology, is notvalue-free. Not only ``disease' but also such terms as ``nerve' and ``organ'are laden with conceptual values.     

Managing one's body using self-management techniques: practicing autonomy

This paper discusses some of the anthropological andphilosophical features of the use of self-managementplans by patients with a chronic disease, focusing onpatients with asthma. Characteristics of thistechnologically mediated form of self-care arecontrasted with the work of Mauss and Foucault on bodytechniques and techniques of self. The similaritiesand differences between self-management of asthma andFoucault's technologies of self highlight some of theways in which self-management contributes tomodifications in the definitions of patients andphysicians. Patients, in measuring their lungfunction, first come to rely on measurements more thanon felt disturbances, but next, felt disturbancesbecome modified by previous measurements. Physicians,on the other hand, see their role changed from expertto being a participant in a joint treatment. It isargued that the concept of agency is more appropriatefor describing the advantage of self-management forpatients than autonomy.     

The variability of practice hypothesis in motor learning: does it apply to Alzheimer's disease?

Based on Schmidt's (1975) variability of practice hypothesis, this study examined acquisition and transfer of a gross motor skill, namely tossing, in 58 patients with Alzheimer's disease (AD) and 58 healthy older adults under constant, blocked, and random practice conditions. While healthy older adults were able to learn the tossing task equally well under the three practice conditions, only AD patients receiving constant practice showed significant improvements. Tests of intermediate transfer yielded the expected random practice advantage in healthy controls but not AD patients. None of the practice conditions facilitated intermediate transfer in AD patients; however, constant practice did benefit these impaired individuals on tests of near transfer. These results indicate that the variability of practice hypothesis does not extend to AD patients. As motor learning and transfer were clearly a function of constant practice, future attempts to retrain basic activities of daily living in AD patients should emphasize consistency in training.     

Adjusting To a New Racial Climate: Maintenance of Personal Integrity

This paper will focus on the writer’s experience as a native New Yorker relocating to Montgomery, Alabama. The writer will share how he adjusted and coped with overt discrimination and racism in the context of the high school in which he attended there-a majority white high school on the “other” side of town. The writer will share how he employed the following coping mechanisms as methods of adjusting to his new environment: translating emotional experiences into words (relaxation and talk therapy), involvement with other black positive peers, careful assessment before acting, withdrawal and avoidance, and consuming African-American literature.     

Simultaneous visual discrimination in Asian elephants

Two experiments explored the behavior of 20 Asian elephants (Elephas aximus) in simultaneous visual discrimination tasks. In Experiment 1, 7 Burmese logging elephants acquired a white+/black- discrimination, reaching criterion in a mean of 2.6 sessions and 117 discrete trials, whereas 4 elephants acquired a black+/white- discrimination in 5.3 sessions and 293 trials. One elephant failed to reach criterion in the white+/black- task in 9 sessions and 549 trials, and 2 elephants failed to reach criterion in the black+/white- task in 9 sessions and 452 trials. In Experiment 2, 3 elephants learned a large/small transposition problem, reaching criterion within a mean of 1.7 sessions and 58 trials. Four elephants failed to reach criterion in 4.8 sessions and 193 trials. Data from both the black/white and large/small discriminations showed a surprising age effect, suggesting that elephants beyond the age of 20 to 30 years either may be unable to acquire these visual discriminations or may require an inordinate number of trials to do so. Overall, our results cannot be readily reconciled with the widespread view that elephants possess exceptional intelligence.     

Bridging the gap between brain and behavior: cognitive and neural mechanisms of episodic memory

The notion that non-human animals are capable of episodic memory is highly controversial. Here, we review recent behavioral work from our laboratory showing that the fundamental features of episodic memory can be observed in rats and that, as in humans, this capacity relies on the hippocampus. We also discuss electrophysiological evidence, from our laboratory and that of others, pointing to associative and sequential coding in hippocampal cells as potential neural mechanisms underlying episodic memory.