Pigeons and people select efficient routes when solving a one-way "traveling salesperson" task

The authors presented people (Experiment 1) and pigeons (Experiments 2 and 3) with a large number of 1-way traveling salesperson problems that consisted of 3, 4, and 5 identical stimuli (nodes) on a computer monitor. The sequence of nodes that each traveler selected was recorded, and the distance of the route was subsequently determined. The routes the pigeons and people selected were reliably more efficient than those used by a Monte Carlo model given the same problems. The pigeons' routes were significantly less efficient than a nearest neighbor model of performance, however. In Experiment 3, pigeons were required to select a route that was within the top 33% of all possible solutions for a given problem. The pigeons' solutions were significantly more efficient than those observed in Experiment 2, in which the behavioral criterion was not imposed. The mechanisms that pigeons and people may have been using to solve the traveling salesperson problems are discussed.     

Individual differences in self-assessed health: an information-processing investigation of health and illness cognition.

In 2 studies, the relation between measures of self-assessed health (SAH) and automatic processing of health-relevant information was investigated. In Study 1, 84 male and 86 female undergraduate students completed a modified Stroop task. Results indicated that participants with poorer SAH showed enhanced interference effects for illness versus non-illness words. In Study 2, 27 male and 30 female undergraduate students completed a self-referent encoding task. Results offered a conceptual replication and extension of Study 1 by confirming the specificity of the relation between SAH measures and automatic processing of health (vs. negative or positive general trait) information. These studies provide evidence that individual differences in SAH are reflected in schematic processing of health-relevant information.     

Further remarks on the role of cognition in the comparative analysis of behavior

Recent interest in comparative psychology has stimulated much research and debate concerning cognitive processes in animal behavior. The present paper relates to this general area by treating particular issues in the analysis of comparative cognition: specifically, how cognition is inferred from animal behavior; whether the postulation of intervening cognitive processes furthers our understanding of behavior; and how rival approaches help advance the science of behavior.     

Is Racial Profiling More Benign in Medicine Than Law Enforcement?

It might seem that racial profiling by doctors raised few of the same concerns as racial profiling by police, immigration, or airport security. This paper argues that the similarities are greater than first appear. The inappropriate use of racial generalizations by doctors may be as harmful and insulting as their use by law enforcement officials. Indeed, the former may be more problematic in compromising an ideal of individualized treatment that is more applicable to doctors than to police. Yet doctors, unlike police, should not attempt to ignore race altogether. Race and ethnicity are associated with the geography of disease, with social and cultural factors relevant to disease, and, to some extent, with genetic predispositions to disease. Moreover, greater attention to the distinctive health conditions of certain racial and ethnic groups is necessary to make up for past neglect. But it will be a tricky business to steer a middle course between a naïve, reckless, or dogmatic color blindness and a stereotype-driven overreliance on race and ethnicity. In trying to steer such a course, the doctor can only hope for the day when a combination of more individualized genomic medicine and greater social equality will make it possible for her to pay less attention to race and ethnicity without detriment to her patients?? health.     

The disruption of autoshaped key pecking in the pigeon by food-tray illumination

Two experiments investigated the effect of food-tray illumination on pecking a lighted key that signalled food presentation. Pigeons key pecked less when both feeder and key stimuli preceded grain delivery than when the keylight alone signalled food. This detractive influence of grain-tray illumination did not result after prior pairings of the keylight with food. The involvement of associative and physical variables in autoshaping the pigeon's key peck is considered in light of these findings.