Categories and particulars: prototype effects in estimating spatial location

A model of category effects on reports from memory is presented. The model holds that stimuli are represented at 2 levels of detail: a fine-grain value and a category. When memory is inexact but people must report an exact value, they use estimation processes that combine the remembered stimulus value with category information. The proposed estimation processes include truncation at category boundaries and weighting with a central (prototypic) category value. These processes introduce bias in reporting even when memory is unbiased, but nevertheless may improve overall accuracy (by decreasing the variability of reports). Four experiments are presented in which people report the location of a dot in a circle. Subjects spontaneously impose horizontal and vertical boundaries that divide the circle into quadrants. They misplace dots toward a central (prototypic) location in each quadrant, as predicted by the model. The proposed model has broad implications; notably, it has the potential to explain biases of the sort described in psychophysics (contraction bias and the bias captured by Weber's law) as well as symmetries in similarity judgments, without positing distorted representations of physical scales.     

What is educational theory and how to make it?

An analysis is provided detailing the conditions for the appropriate theoretical study of the object of educational science: pedagogy.     

Reducing the effects of adjacent distractors by narrowing attention.

Three experiments explored the gradual narrowing of visual attention to a letter target when other letters were positioned close by. The method by which attention was narrowed involved presenting a digit target immediately prior to the latter target and in the same location for progressively shorter durations and requiring the subject to identify both the digit target and the letter target before responding. The response time data from the first 2 experiments indicated that shorter durations of the digit reduced the amount of information processed from noise letters positioned on either side of the letter target. In the third experiment, in which separation of letters was increased slightly, the response times indicated that the information from flanking noise letters may have been virtually eliminated.     

Encoding dimensions of subject-performed tasks

Summary In an experiment modelled upon the classical paradigm on release from proactive interference (PI), subjects were required to remember series of actions they had performed (e.g., roll the ball, fold the paper). The objects involved in these subject-performed tasks (SPTs) served as a basis for build-up and release of PI. The objects used in the first few trials of the experiment belonged to the same class (e.g., parts of the body), causing a build up of PI. A shift to a different class of objects (e.g., kitchen utensils) along four different dimensions (taxonomic category, weight, color, and size) was introduced to cause a release of PI. On the basis of PI-release experiments with words it was expected that shifts in taxonomic category would result in a greater release than shifts within any of the physical dimensions. However, the results revealed that the amount of PI release was, in general, larger than expected, and essentially the same for all four dimensions investigated. The results are discussed in terms of the nature of the memory representation of SPTs, and with regard to possible processing differences between SPTs and verbal information. In addition, methodological suggestions for furthering the understanding of the encoding and storage of action events are advanced.     

Acquisition of a relative class concept by an African gray parrot (Psittacus erithacus): discriminations based on relative size

We report that an African gray parrot (Psittacus erithacus), Alex, responds to stimuli on a relative basis. Previous laboratory studies with artificial stimuli (such as pure tones) suggest that birds make relational responses as a secondary strategy, only after they have acquired information about the absolute values of the stimuli. Alex, however, after learning to respond to a small set of exemplars on the basis of relative size, transferred this behavior to novel situations that did not provide specific information about the absolute values of the stimuli. He responded to vocal questions about which was the larger or smaller exemplar by vocally labeling its color or material, and he responded "none" if the exemplars did not differ in size. His overall accuracy was 78.7%.     

Emotion, physiology, and expression in old age

Emotion-specific autonomic nervous system (ANS) activity was studied in 20 elderly people (age 71-83 years, M = 77) who followed muscle-by-muscle instructions for constructing facial prototypes of emotional expressions and relived past emotional experiences. Results indicated that (a) patterns of emotion-specific ANS activity produced by these tasks closely resembled those found in other studies with younger Ss, (b) the magnitude of change in ANS measures was smaller in older than in younger Ss, (c) patterns of emotion-specific ANS activity showed generality across the 2 modes of elicitation, (d) emotion self-reports and spontaneous production of emotional facial expressions that occurred during relived emotional memories were comparable with those found in younger Ss, (e) elderly men and women did not differ in emotional physiology or facial expression, and (f) elderly women reported experiencing more intense emotions when reliving emotional memories than did elderly men.     

The role of personality and socio-economic status in the stress–illness relation: A longitudinal study

Although a wide variety of factors have been found to be related to health in some way, researchers on the subject of health generally fail to integrate findings of other research disciplines within their own line of research. This study has attempted to bring together two research disciplines: (a) research on personality and health, and (b) research on socio-economical differences in health. Personality factors as well as social class have been found to mediate the stress-illness relation. Based on empirical and theoretical considerations, we proposed a simple model for the occurrence and course of disease. The personality factors studied were neuroticism, locus of control, and self-esteem. Socio-economic status (SES) was represented by education level, occupation status, and income. Health was operationalized as the number of somatic diseases. The research questions were investigated (using t-tests andpath analysis) in a longitudinal set of data that were collected between 1970 and 1984 among 245 subjects in the normal population. Neuroticism appeared to be an important mediator of the stress-illness relation. Of the SES variables, occupation and education served as mediators; education was especially infuential on the course of disease. The role of neuroticism is discussed.     

Random error in additive decompositions of multiattribute utility

Decomposition is a common strategy for dealing with the complexity of multiattribute decision problems. A cognitively demanding task is broken down into tasks requiring simpler, perhaps easier, judgments which can then be aggregated. But individual judgments can be inconsistent in systematic or random fashion and when aggregated there is the possibility of propagation of this inconsistency. In this paper inconsistency in the form of random error is investigated in the context of additive decomposition of multiattribute utility. The process of aggregation of random error is studied and a comparison made with random error in holistic estimates of multiattribute utility. Conditions under which decomposition improves the consistency of the multiattribute utility estimate are presented and discussed.     

MULTIDIMENSIONAL SCALING OF LARGE CHROMATIC DIFFERENCES BY NORMAL AND COLOR-DEFICIENT SUBJECTS

The following two articles offer a glimpse at current experimental psychology in the Soviet Union, normally screened from the English-speaking world by all but impenetrable language barriers. The accompanying Commentary by Tarow Indow helps place these contributions in the framework of contemporary work on the psychophysics of color perception.   Abstract —
Fifteen normal trichromatic subjects, two protanopes, and two deuteranopes judged pairs of successively presented foveal color stimuli. Multidimensional scaling of the data yielded estimates of a three-dimensional space with axes interpreted as red–green, blue-yellow, and white-black. For color-deficient subjects, the average radius of the space differed from that of normals, being smaller for the protanopes and larger for the deuteranopes. For both types of color deficiency, the blue-yellow axis was stretched relative to the red-green, more strongly in the protanopes. The findings are taken to support the generality of a "spherical" model.