Thurstone's discriminal processes fifty years later

Four issues are discussed concerning Thurstone's discriminal processes: the distributions governing the representation, the nature of the response decision rules, the relation of the mean representation to physical characteristics of the stimulus, and factors affecting the variance of the representation. A neural schema underlying the representation is proposed which involves samples in time of pulse trains on individual neural fibers, estimators of parameters of the several pulse trains, samples of neural fibers, and an aggregation of the estimates over the sample. The resulting aggregated estimate is the Thurstonian representation. Two estimators of pulse rate, which is monotonic with signal intensity, are timing and counting ratios and two methods of aggregation are averaging and maximizing. These lead to very different predictions in a speed-accuracy experiment; data indicate that both estimators are available and the aggregation is by averaging. Magnitude estimation data are then used both to illustrate an unusual response rule and to study the psychophysical law. In addition, the pattern of variability and correlation of magnitude estimates on successive trials is interpreted in terms of the sample size over which the aggregation takes place. Neural sample size is equated with selective attention, and is an important factor affecting the variability of the representation. It accounts for the magical number seven phenomenon in absolute identification and predicts the impact of nonuniform distributions of intensities on the absolute identification of two frequencies. 1977 Psychometric Society Presidential Address. This work was supported in part by a grant of the National Science Foundation to Harvard University. I wish to express my appreciation to S. Burbeck, D. M. Green, M. Shaw, and B. Wandell for their useful comments on an earlier draft of this paper.     

Psychophysics of key-peck duration in the pigeon

The duration of the pigeon's key peck was differentially reinforced in either a trials or a free-operant procedure. Mean emitted peck duration was a power function of the duration required for food delivery to occur. The exponents of the power function differed considerably from those observed in earlier research involving longer duration responses in pigeons and other species. The coefficients of variation also did not correspond with those of the earlier research on other responses, nor did consideration of the durations actually reinforced resolve the differences. Duration was neither a function of response rate nor of intermittency of reinforcement. Key-peck duration was changed in an orderly way by differential reinforcement. However, it appeared to be more strongly determined by its duration in the absence of differential reinforcement than were longer duration responses.     

Discriminability of fixed-ratio schedules for pigeons: effects of payoff values

Three pigeons, previously trained to discriminate different numbers of responses (fixed ratios), were tested under different reinforcement contingencies (payoff matrices) at two levels of sensitivity. For one subject, relative reinforcement magnitude was varied—at first, across sessions and then, at midsession by reversing values—without exteroceptive cues. For another, relative reinforcement magnitude and/or probability was varied every 50 trials with cues by correlating different payoff matrices with different key colors. For the third subject, relative reinforcement probability was varied more frequently with cues—in the limit, at random—to demonstrate stimulus control of response bias on a trial-by-trial basis. A signal-detection analysis showed that bias changed with payoffs, for as many as seven different matrices, while sensitivity remained unchanged. The obtained functions (receiver operating characteristics) were similar under different payoff conditions, which suggests that a single mechanism controls bias. However, they differed enough in slope to require a relatively complex account (e.g., the general Gaussian model of detection theory).     

Protection of animal research subjects

The use of experimental animals, mostly rodents, in biomedical research and especially in oncology and immunology should be acknowledged with respect, recognizing the contribution of animal experimentation in the fascinating scientific progress in these disciplines of research. It is an obligation of the investigator to justify the scientific and ethical aspects of each study requiring the use of animals. The international guiding principles for using animals in biomedical research are well defined and have been distributed worldwide by the International Council for Laboratory Animal Science (ICLAS) since 1956, when this Organization was founded. In Poland the ICLAS philosophy and principles are highly respected and were implemented firstly by the members of the Commission on Biology of Experimental Animals appointed in 1962 by the Department of Medical Science of the Polish Academy of Science in Warsaw. Animal Protection Acts, first proclaimed in 1928 were gradually modified and improved. Actual legislation (enacted in 1997, 2003 and 2005) is consistent with EU Directives (86/609/EEC) and follows the internationally recommended principles that include ICLAS guidelines concerning animal welfare and care condition in biomedical research. The problem of “alternative methods” is briefly discussed. Dr. Donald Boisvert, CCAC — Canadian Council on Animal Care A lecture on the subject of this paper was presented at the 6th International Bioethics Conference entitled ‘The Responsible Conduct of Basic and Clinical Research’, held in Warsaw, Poland, 3–4 June 2005. The author is the National Representative of Polish Academy of Science to the International Council for Laboratory Animal Science (ICLAS) and a Member of the ICLAS Governing Board.     

Reasonable Partiality and Animal Ethics

Moral psychology is often ignored in ethical theory, making applied ethics difficult to achieve in practice. This is particularly true in the new field of animal ethics. One key feature of moral psychology is recognition of the moral primacy of those with whom we enjoy relationships of love and friendship – philia in Aristotles term. Although a radically new ethic for animal treatment is emerging in society, its full expression is severely limited by our exploitative uses of animals. At this historical moment, only the animals with whom we enjoy philia – companion animals – can be treated with unrestricted moral concern. This ought to be accomplished, both for its own sake and as an ideal model for the future evolution of animal ethics.     

Family of the forest: Fatal enmeshment and other systems issues in the animal world

While the observation of non-human animal behavior has been a major means of developing psychological theories, it has been rarely used by marriage and family therapists to devise or explain systemic ideas. Jane Goodall's multigenerational research on the Flo family of wild chimpanzees in Gombe, Tanzania, as presented in her own and other's writing, and especially in Hugo van Lawick's documentary film,People of the Forest, offers a clear example of how systems concepts' application to animal families may have theoretical, pedagogical, and clinical utility.My thanks to my good friend, Violet Richman, who suggested the subject for this paper.     

Editorial

This article provides a critique of the IWC's traditional focus on anthropocentric conservation in the governance of whaling. It is argued that this position, which relies on accepting the view that we have no direct moral duties to whales, is out of step with the moral status that now tends, in theory and practice, to be granted to animals. More specifically, anthropocentric conservation conflicts with the widespread acceptance, in theory and practice, that non-human animals such as whales have moral standing, that what we do to them matters to them directly. This does not mean that whaling should necessarily be prohibited on ethical grounds, although the animal welfare analysis of whaling sketched in this article does suggest that, on balance, it is difficult to defend morally. Rather, it is being claimed that it is morally objectionable to deny, as the whaling nations do, that the IWC ought to be mandated to consider the welfare implications of whaling.     

Estructura social y conductas de saludo en dos especies de babuinos

Resumen

Independientemente de la proximidad taxonómica, dentro del género Papio existen distintas formas de estructura social. Al mismo tiempo se encuentran diferencias cuantitativas y cualitativas en los repertorios de conducta de las dos especies estudiadas (P. hamadryas y P. cynocephalus), concretamente en los movimientos de salutación.

Se buscó una relación entre dichas estructuras sociales y los respectivos movimientos de saludo que aparecían como característicos de cada especie. La estructura social podría modificarse rápidamente por las presiones ambientales, por lo que serían necesarios nuevos repertorios conductuales en consonancia con el cambio y al mismo tiempo que éste.

Al menos en niveles tan altos de la escala evolutiva, los individuos son capaces de organizar sus conductas según su posición respecto al conjunto del grupo y adecuarlas para acceder a los distintos nichos sociales. Por tanto, no es posible adscribir a la conducta una función exclusiva, sino que dependería de la idiosincrasia individual y de los distintos escalones sociales característicos de una determinada estructura social.