Boundary completion in illusory contours: interpolation or extrapolation?

Most computational and neural-style models of contour completion (ie illusory and occluded contours) are based on interpolation: the filling in of an edge between two visible edges. The results of three experiments suggest an alternative conception, that units are formed as a result of extrapolation from visible edges. In three experiments, subjects reported illusory contours between standard illusory-contour inducing elements and forms that do not, by themselves, induce illusory contours. We suggest that these forms are not a special case of inducing elements but that they represent a different class--receiving elements. Receiving elements are forms that can receive an illusory contour but cannot generate one, and they can alter contour formation. In experiment 1, receiving elements increased the judged clarity of illusory contours. In experiment 2, illusory edges were seen to connect to corners, line ends, and even the edges of circles. Boundary formation in motion displays also appears to be based on extrapolation. In experiment 3, subjects reported that small moving dots altered the formation of spatiotemporally defined boundaries. Implications for higher-order operator and network models of boundary formation are discussed.     

Inhibition and working memory: effect of acute sleep deprivation on a random letter generation task]

The literature contains inconsistent data on the effects of acute sleep deprivation on the superior cognitive functions. The primary purpose of this study is to determine the effectiveness of inhibition, one of the functions of the working memory executive centre (EC), over an extended, 36-hour waking period. Inhibition is a cognitive mechanism whereby individuals ignore non-relevant information recorded in their working memory. We also tested the effects of a 36-hour period of acute sleep deprivation on simple reaction time. Twelve young, healthy volunteers (M = 21.5 years, sigma = 2.3) performed a random generation task involving letters and a simple reaction time psychomotor test over four sessions held at 10-hour intervals. Each participant was assigned a "constant routine." Participants were kept awake in a prone position within a room whose environment was held strictly constant (light, noise, temperature, meals, etc.). This control procedure provided assurance that any variation in participant performance was solely caused by sleep deprivation. The random generation task, nearly two minutes in length, consisted in verbally producing a sequence of 100 letters in a random fashion (i.e. by inhibiting, for example, alphabetical order) and by keeping to a set rhythm. Our assumption was that capacity for inhibition diminished as the number of hours of sleep deprivation increased. The simple reaction test, 10 minutes in length, involved pressing a button as swiftly as possible to cause a black square to disappear from a screen. In this case our assumption was that acute sleep deprivation alters simple reaction time. Analysis of variance (ANOVA) through repeated measures using the "sessions" factor as an intra-subject variable showed no significant changes in randomization indices of the random generation task, contrary to analysis of average simple reaction times. Participants' reaction times deteriorated over the first two minutes of the test during the night they were deprived of sleep. It would seem that the contradictory results of previous studies of the effects of acute sleep deprivation on the inhibition function would be due to errors in factor identification. In conclusion, the inhibition function, as measured during the performance of a brief task, seems to remain intact during an extended, 36-hour waking period. Simple reaction time assessed by means of a brief psychomotor test is affected during a night of sleep deprivation. The working-memory inhibition executive function shows greater resistance to acute sleep deprivation than does psychomotor reaction time for the performance of short tasks.     

Concurrent validity of the Peabody Picture Vocabulary Test-Third Edition as an intelligence and achievement screener for low SES African American children

Authors tested the validity of the Peabody Picture Vocabulary Test-Third Edition (PPVT-III) as a screening measure for intelligence and achievement. The PPVT-III and Kaufman Assessment Battery for Children (KABC) were administered to 416 African American children of low socioeconomic status in a counterbalanced design. Results indicated that the PPVT-III correlated .58 with the KABC Mental Processing Composite (MPC) score; however, participants scored significantly lower (M = 8.3 points) on the PPVT-III than on the MPC. Although receiver operating characteristic (ROC) analyses supported the use of the PPVT-III as a valid intellectual and achievement screener, the selection of a single cutoff score for the PPVT-III was problematic. The purpose of the screening program should guide selection of a cutoff score for the PPVT-III.     

Semantic priming in Alzheimer's dementia: evidence for dissociation of automatic and attentional processes

The nature of the semantic memory deficit in dementia of the Alzheimer's type (DAT) was investigated in a semantic priming task which was designed to assess both automatic and attention-induced priming effects. Ten DAT patients and 10 age-matched control subjects completed a word naming semantic priming task in which both relatedness proportion (RP) and stimulus-onset asynchrony (SOA) were varied. A clear dissociation between automatic and attentional priming effects in both groups was demonstrated; however, the DAT subjects' pattern of priming deviated significantly from that of the normal controls. The DAT patients failed to produce any priming under conditions which encouraged automatic semantic processing and produced facilitation only when the RP was high. In addition, the DAT group produced hyperpriming, with significantly larger facilitation effects than the control group. These results suggest an impairment of automatic spreading activation in DAT and have implications for theories of semantic memory impairment in DAT as well as models of normal priming.     

Conducting industrial and organizational psychological research: institutional review of research in work organizations

Although informed consent is a primary mechanism for ensuring the ethical treatment of human participants in research, both federal guidelines and American Psychological Association ethical standards recognize that exceptions to it are reasonable under certain conditions. However, agreement about what constitutes a reasonable exception to informed consent is sometimes lacking. We presented the same protocols to samples of respondents drawn from 4 populations: Institutional review board (IRB) members, managers, employees, and university faculty who were not members of IRBs. Differences in perceptions of IRB members from the other samples with respect to the risks of the protocols without informed consent and on the feasibility of conducting the research in employment organizations are discussed in terms of implications for industrial and organizational psychology research.     

Shaping the Field of Theology and Science: A Critique of Nancey Murphy

Nancey Murphy is a key second-generation figure in the field of religion and science. Through a variety of responsibilities, some of which are reviewed here, she has worked as a discipline builder over the last fifteen years. After trying to convey the general spirit of Murphy's work, the author focuses on five areas where readers might resist her conclusions, including her "postmodern" theory of scientific (and religious) knowledge and truth, her treatment of theology and science as "separate but equal," and her defense of physicalism.     

The effects of a programme of training in structured group counselling

This study examined the effects of a programmes of experiential training in structured group counselling, based on the approach of Sheldon Rose. Participants were 32 undergraduate and graduate students, divided into three groups, who participated in the group work as part of a course in Core Counseling skills. The groups met for two hours per week for eight weeks. At the end of each exercise the participants completed a 12-item questionnaire giving their evalution and experience of the exercise they had just finished. The questionnaires were initially factors analysed and produced three main factg43ors, labelled task orientation, cohesion and conflict. Factor scores were used for all subsequent analyses. A series of one-way analyses of variance showed how the groups reacted to the different exercises, and discriminant analysis was used to determine how the climate and method of the individual groups could be differentially characterised in terms of the questionnaire factors. It was concluded that the membership of structured groups may be a major determinant of the group climate and experience.     

Preference after training with differential changeover delays

Pigeons were trained on a multiple schedule in which each component consisted of concurrent variable-interval (VI) 30-s VI 60-s schedules. The two components of the multiple schedule differed only in terms of the changeover delays (COD): For one component short CODs were employed, and in the second component long CODs were used. After approximate matching was obtained in each component, probe tests involving new combinations of stimuli were presented (e.g., the VI 30-s schedule from each component) to determine how the different CODs affected preference. Despite shorter CODs producing higher changeover rates, the COD value had no systematic effect on preference on the probe trials. However, differences in reinforcement rate always produced preference for the schedule with the higher reinforcement rate. The results thus show that the the pattern of changeover behavior per se is not a critical determinant of choice in the probe-trial procedure.     

Escaping Homelessness: The Influences of Self-Efficacy and Time Perspective on Coping With Homelessness1

This study explored whether self-efficacy and time perspective of homeless adults (N= 82) living in a shelter affected their coping strategies related to obtaining housing and employment. Participants with high self-efficacy searched more for housing and employment and stayed at the shelter for a shorter duration, whereas participants with low self-efficacy were more likely to request an extension of their stay at the shelter. Those high on future orientation had shorter durations of homelessness and were more likely to enroll in school and to report gaining positive benefits from their predicament, whereas those with a high present orientation had more avoidant coping strategies. Despite the predictive power of self-efficacy and future orientation of proactive search behaviors, there were no predictors of obtaining stable housing, which is a scarce resource in the area. However, a high present orientation predicted obtaining temporary housing. A present temporal perspective may be adaptive in finding short-term solutions to an unstable situation, such as homelessness. The role of time perspective in crisis situations is discussed, as well as the severe environmental constraints on the exercise of personal control over reality dictated by social, economic, and political forces.     

Wilhelm Reich in Soviet Russia: Psychoanalysis,Marxism, and the Stalinist reaction

Abstract

In 1929, Wilhelm Reich lectured on “Psychoanalysis as a natural science” before the Communist Academy in Moscow; he was the only Freudian-trained Central European psychoanalyst to do so. That same year, his article “Dialectical materialism and psychoanalysis” was published in the Academy's journal, Under the Banner of Marxism, in both Moscow and Berlin. By this time, Reich's involvement with political activism aligned with the Austrian Communist Party was increasing, while simultaneously psychoanalysis in the Soviet Union was in decline. Our paper places these events in their proper historical context and includes a discussion of the various attempts to determine the compatibility of psychoanalysis and Marxism. We offer analyses of both the article, “Dialectical materialism and psychoanalysis,” and the lecture, “Psychoanalysis as a natural science,” and the reactions to both by Reich's Russian critics. We show the ways in which responses to his lecture foreshadow what becomes the standard Soviet assessment of psychoanalysis. As an appendix to this paper, we provide the first English translation of the Russian account of his lecture, as published in the Herald of the Communist Academy.