Search behaviour of cats (Felis catus) in an invisible displacement test: cognition and experience

An invisible displacement test was administered to cats in order to test the hypothesis that search behaviour in this species is influenced by their limited capacity for object permanence as well as by their previous experience with the environment. Experiment 1 compared three groups of cats in a five-choice hiding task in which the hiding places could be discriminated by their spatial positions. Two groups received a visible displacement training before the invisible displacement test and one group did not. Experiment 2 compared two groups of trained subjects in the same task, but the hiding places could be discriminated by spatial and visual cues. The results confirmed that cats are unable to solve problems with invisible displacements. The visible displacement training improved their performance, but was not sufficient to make them succeed. Experience with the hiding potential of the covers also gives more persistence to search behaviour. Finally, the distribution of search attempts is not determined by the proximity to the target and is influenced only partially by the subjects' previous experience. Like Stage 5 infants, cats rely mainly on their immediate perception. They search for an object in the last location they have seen it disappear or under the nearest cover from this location.     

Film-induced negative affect triggers overeating in restrained eaters

We tested the effects of film-induced negative affect (i.e., exposure to a frightening film) in 60 women classified as either restrained or unrestrained eaters on the basis of their responses to the Revised Restraint Scale (Herman & Polivy, 1980). Exposure to the frightening film, in contrast to a neutral film, was associated with increases in anxiety, sadness, and anger. High restraint subjects exposed to the frightening film ate more than did equally restrained subjects exposed to a neutral film or low restraint subjects exposed to either film. Thus, negative affect triggered overeating among restrained eaters. Although unrestrained eaters exposed to the frightening film ate less than those who viewed the neutral film, this difference was not statistically significant. These results suggest that negative affect may prompt overeating in persons who attempt to restrict their caloric intake.     

Selective processing of threat cues in posttraumatic stress disorder

Vietnam combat veterans with (n = 15) and without (n = 15) posttraumatic stress disorder (PTSD) performed a modified Stroop task in which they named the colors of neutral words (e.g., INPUT), positive words (e.g., LOVE), obsessive-compulsive disorder (OCD) words (e.g., GERMS), and PTSD words (e.g., BODYBAGS). In contrast to normal controls, PTSD patients took significantly longer to color-name PTSD words than to color-name neutral, OCD, and positive words. Because Stroop interference reflects involuntary semantic activation, it may provide a quantitative measure of intrusive cognitive activity--the hallmark symptom of PTSD.     

Changes in information as a function of a culturally appropriate smoking cessation community intervention for Hispanics

Tested a 7-month, media-based, community intervention among Hispanics in San Francisco designed to change levels of information on the damaging effects of cigarette smoking and on the availability of culturally appropriate cessation services. Three community-wide surveys of Hispanics were conducted with independent random samples, two as baselines (n = 1,660 and 2,053) and one postintervention (n = 1,965). Results showed that changes in the level of awareness of cessation services had taken place after implementation of the intervention. Furthermore, those changes took place primarily among the less acculturated Spanish-speaking Hispanics who were the target of the intervention. The changes in information reported here demonstrate that a culturally appropriate information dissemination campaign that utilizes multiple channels can produce changes in a community's level of information even when the campaign is implemented for a relatively short period.     

Tracks and affordances: The sources of a physical ontology

How is meaning assigned to those terms in a theory which are remote from direct observational instantiation? Models and analogies play a role, but close examination of theories in high energy physics shows that the design of experimental apparatus also influences the interpretation of such terms. Certain apparatus favours certain kinds of effects, and this affects the way mathematical theories are interpreted. In particular track producing apparatus becomes involved with theories in which photonic terms are picked out in the theory. A further conceptual constraint is thus introduced. It is argued that this situation favours the interpretation of dispositional properties as affordances rather than as simple dispositions.     

The role accorded to the public by philosophers of science 1

The role accorded to the public by scientists and philosophers of science has undergone an essential historical change in the last three centuries. Public participation in (witnessing of) scientific experiments was considered an important requirement for 17th century experimenters (e.g. for Boyle or Pascal). The cognitive role played by lay persons was later substantially downgraded; witnessing went out of fashion, while science became more and more esoteric and a matter for experts only. Part of this process was that all scientific disciplines became intensively compartmentalized and in consequence a rather puzzling or even paradoxical situation appeared: that the scientists themselves were and are being reduced epistemically to the status of lay persons, outside of their proper field of expertise (as was pointed out by J. Hardwig). The paper deals with some cognitive aspects of this historical process.