Visual attention and perceptual grouping

Perceptual organization is thought to involve an analysis of bothtextural discontinuities andperceptual grouping. In earlier work, we found that textural discontinuities were detected normally even when visual attention was engaged elsewhere. Here we report how perceptual grouping is affected when visual attention is engaged by a concurrent visual task. To elicit perceptual grouping, we used the Gestalt demonstrations of grouping on the basis of proximity and of similarity. Four tasks were investigated, some requiring the observer to discriminate between horizontal and vertical grouping, and some requiring the observer to merely detect the presence or absence of grouping. Visual attention was engaged at the center of the display by a form identification task. The detection of a textural discontinuity served as a control task. Concurrent form identification conflicted with all four grouping tasks, resulting in a significant reduction of grouping performance in each case. No performance reduction was observed when either form identification or grouping discrimination was combined with the detection of a textural discontinuity. These results suggest that perceptual grouping and form identification compete for visual attention, whereas the detection of a textural discontinuity does not.     

Divorce in the kibbutz: Past and present

In the kibbutz today, there are no ideological or economic barriers to prevent a couple from deciding to divorce. Both husband and wife are assured continued economic security and equal opportunities for co-parenting, thus reducing fears of disruption in the daily contact with the children. In spite of these favorable circumstances, marital breakups in the kibbutz are less frequent than in the larger cities in Israel. In recent years, however, at a time when a stronger and more intensive family life has gained legitimacy within the kibbutz structure, there is a marked tendency toward a rise in the rate of divorce. In this article we analyze the possible causes of the variations in the frequency of divorce within the kibbutz framework.The authors express appreciation to Esther Mivtzari, a psychologist on the staff of the Kibbutz Child and Family Clinic and a member of the religious kibbutz Ein-Tzurim, for assistance in gathering data on divorce in the religious kibbitzum.     

Effects of early hospital-based intervention on mothers and their preterm infants

Mothers of eight Israeli preterm infants were exposed to a standardized but individualized intervention during their stay in the hospital and before their infants were discharged. Mothers and infants in the intervention group were compared to eight control subjects using various outcome measures. While the intervention did not affect maternal personal attitudes and feelings, it positively affected the mother-infant interactions and mothers' perceptions of their infants. The importance of individualized interventions with parents of preterm infants is discussed.     

Detection versus discrimination of visual orientation

The role of focused attention in vision is examined. Recent theories of attention hypothesize that serial search by focal attention is required for discrimination between different combinations of features. Experiments are reported which show that the mixture of a few (less than five) horizontal and vertical line segments embedded in an aggregate of diagonal line segments can be rapidly counted (also called 'subitizing') by a parallel (preattentive) process, while the discrimination between horizontal and vertical orientation requires serial search by shifting focal attention to each line segment. Thus detecting and counting targets that differ in orientation can be done in parallel by a preattentive process, whereas knowing 'what' the orientation of a target is (horizontal or vertical, ie of a single conspicuous feature) requires a serial search by focal attention.     

Grading the ‘cultural literacy’ project

The essay examines the argument advanced by E.D. Hirsch, Jr., for instituting ‘cultural literacy’ as a fundamental priority of schools. A number of confusions and equivocations in Hirsch's reasoning are identified, and the propensity of his project to indoctrinate is exposed. Among the features of Hirsch's argument shown to be troubling are his shifting construal of ‘language’, his inconsistency about the requirements of cultural literacy, and his uncritical relation to traditional images of the American past and present. The upshot is to raise the question why Hirsch's project has elicited wide support and praise.     

Mediating Effects of Perceived Personal Control in Coping With a Health Threat: The Case of Genetic Counseling1

The potential impact of perceived personal control on coping with a medical threat was investigated in genetic counseling, a clinical setting where issues of personal control are central. Data were collected from 72 counselees at a genetic clinic before, immediately after, and 1 month after initiating genetic counseling. Findings supported the hypothesized mediating model. Higher perceived control (cognitive-interpretive and decisional) and satisfaction with genetic counseling mediated between genetic counseling and the use of less emotion-focused coping strategies. Problem-focused coping was predicted only directly by counselees' knowledge of their problem after genetic counseling. Changes in emotion-focused coping were related to perceived increases in positive affect 1 month later, while changes in use of problem-focused coping were related to perceived decreases in both positive and negative affect.     

Referenzsemantik in der Partnermodellierung

How can we explain that an assertion on something perceived can be understood in the same manner by somebody who cannot perceive that scene? This problem bases the interest in computational linguistics in how listener modeling could possibly be harmonized with reference semantics. Mental images substituting real perception appear as a way out. The architecture of the listener model has to be adapted to the creation and use of such pictorial data structures. Furthermore, the relation between the latter and a verbal (i. e., propositional) representation must be understood. The resulting architecture of a listener model with reference semantics can be employed to solve communicational problems from three general classes in a better way, as is demonstrated by an example implementation.     

Fractal geometry—The case of a rapid career

The first fractal constructions appeared in mathematics in the second half of the 19th century. Their history is divided into two periods. The first period lasted 100 years and is a good example of the method of proofs and refutations discovered by Lakatos. The modern history of these objects started 20 years ago, when Mandelbrot decided to create fractal geometry, a general theory concentrated on specific properties of fractals. His approach has been surprisingly effective. The aim of this paper is to examine the reasons for Mandelbrot's success and for the present popularity of fractals. They are now known not only in mathematics but also in many fields of natural, social and applied sciences, and even in the arts.