LISP: An introduction and some great programs

Some of the advantages of LISP and some of its unsavory reputation are discussed. Some LISP programs in a variety of areas (chemistry, medicine, question answering, natural language, mathematics, airline tariffs, etc.) are briefly described.     

The perception of an optical flow projected on the ground surface

In most experiments in which the importance of visual control on postural stability is studied, optical stimuli attached to vertical surfaces are used. Analyses of long-term standing readjustments generally involve back-and-forth movements of a visual scene or its projection on vertical circular screens. In a natural environment, however, visual information is largely available from the ground. The aim of the experiment reported was to assess the effect of a flow pattern simulating an open outdoor setting on motion perception and postural control. Subjects were presented with an optical texture projected onto the ground. Periods of motionless texture alternated with equivalent durations of unidirectional flows. The change of position of the subject's centre of gravity over time was recorded on a force platform. Results show that the direction of body sway corresponded with that of texture motion. Important aftereffects, as shown in linear vection experiments, were also observed. However, the latency of postural responses was much shorter than with prolonged unidirectional flows produced in other locations of the visual environment. The hypothesis of an ecological specificity of the flows perceived on the ground during terrestrial displacements is discussed.     

Extraversion and task properties as determinants of incidental recall

The present research investigated in a dual task design the effects of extraversion level and structural task properties on the recall of an incidentally learned text. First, the hypothetical relation between arousal level and attentional selectivity was tested. Second, the relation between structural levels in the text and recall of text elements was studied. It was found that (a) extraverts performed significantly better on incidental recall compared to introverts; (b) the nuclear sentences at the top of the hierarchical structure were the best recalled sentences, independently of arousal level; (c) the effect of differences in arousal on recall was only significant in case of the top sentences. The effect was absent in case of specificúsecondary sentences.     

Patient variable biases in clinical judgment: conceptual overview and methodological considerations

Specific conceptual factors are presented as having contributed to the negative findings of past psychotherapy bias research. Among these factors are the restrictive nature of both the definition of bias and the model of the biased clinician. A review of published studies of several patient variable biases (e.g., gender, race/ethnicity, and age) indicated that bias may best be defined in broader terms and that its occurrence may be more circumscribed than originally conceived. In addition, the lack of a theoretical perspective in this area of research is noted and the applicability of some social cognitive processes is discussed. Methodological factors are also considered, and recommendations for future research are offered.     

Response to commentaries on “A neurobiological model for near-death experiences”

This work has received financial support from FONDECYT (Project 1111-88). The authors also acknowledge the helpful comments of Dr. Bruce Cassels.     

Adaptation and vulnerability in high-risk adolescents: An examination of environmental mediators

The relationship of characteristics of the social environment to the adaptation of adolescents from high-risk predisposing environments was examined. Specifically, the degree to which adolescents' perceptions of various dimensions of their family and school environment as well as sources of social support related to differential levels of personal well-being and academic adjustment was explored. Multiple regression analyses revealed differences in the salience of the dimensions of the social environment as a function of the particular sphere of functioning under consideration. Implications of the findings for developing a model for understanding the relative vulnerability of individuals at risk as well as of the design of preventive interventions are discussed.     

Social structure features in three inbred strains of mice, C57Bl/6J, Balb/cj, and NIH: a comparative study

Some features of social living were investigated in three inbred strains of mice: C57Bl/6j, Balb/cj, and NIH. Five social behaviors--Aggression, Submission, Allogrooming, Social Rest and Rest Alone, as well as Wheel Running Activity--were recorded 2 h daily for a week, in 26 groups of seven male mice living in an enriched environment. Dominants and subordinates among strains shared some behavioral characteristics, but strain contributions upon social structure were also detected. Similarities among strains included the appearance of a single dominant mouse per group rated as the most aggressive, besides from being the animal presented with most Submissions. Allogrooming was more frequent among subordinates than among dominants and subordinates. Differences among strains were that agonistic behavior among subordinates was higher in the Balb/cj and NIH groups than in the C57Bl/6j mice. NIH mice were recorded in Rest Alone more often than mice from the other strains. C57Bl/6j dominants showed higher rates of Wheel Running Activity than subordinates.     

Assessment of antisocial behaviour in children and adolescents: new data with the ASB scale

Information is given about a series of studies with Allsopp and Feldman's ASB scale (1976) in its Spanish version, which compliments the information collected in Silva, Martorell and Clemente (1986a). It deals with test-retest reliability with an interval of 12 months; with comparisons between anonymous and non-anonymous data, and comparison between self-evaluation and evaluation by others. The results support the metric quality of the ASB scale, inviting revision of some of the common criticisms made of these types of instruments.     

Maps between some different kinds of contraction function: The finite case

In some recent papers, the authors and Peter Gärdenfors have defined and studied two different kinds of formal operation, conceived as possible representations of the intuitive process of contracting a theory to eliminate a proposition. These are partial meet contraction (including as limiting cases full meet contraction and maxichoice contraction) and safe contraction. It is known, via the representation theorem for the former, that every safe contraction operation over a theory is a partial meet contraction over that theory. The purpose of the present paper is to study the relationship more finely, by seeking an explicit map between the component orderings involved in each of the two kinds of contraction. It is shown that at least in the finite case a suitable map exists, with the consequence that the relational, transitively relational, and antisymmetrically relational partial meet contraction functions form identifiable subclasses of the safe contraction functions, over any theory finite modulo logical equivalence. In the process of constructing the map, as the composition of four simple transformations, mediating notions of bottom and top contraction are introduced. The study of the infinite case remains open.