On the relation between metacontrast masking and suppression of visible persistence

Does the introduction of additional contours in a display sequence (an operation known to reduce the strength of suppression in metacontrast) also reduce suppression of visible persistence? In three experiments, duration of visible persistence was estimated by a method in which successful performance depends on the temporal integration of a pattern whose elements are displayed in two successive frames. In this procedure, the arrival of the trailing frame is known to exert a suppressive influence on the visible persistence of the leading frame. Embedding the elements of the leading frame within additional contours (a line grid) reduced the degree of suppression exerted by the trailing frame. This did not occur when the grid was part of the trailing display. We conclude that suppression of visible persistence and metacontrast masking belong to the same class of events.     

Sex roles and friendship patterns

The purpose of this study is to examine the relationships among sex, sex role orientation, and friendship. Based on the Bem Sex Role Inventory, 164 participants were categorized as either androgynous (17 males; 29 females), traditional (36 males; 39 females), or undifferentiated (26 males; 17 females) in their sex role orientation. Participants reported the number of close male and female friends, and responded to several questionnaires: interpersonal trust of male and female friends, communal and exchange orientations, affective and activity attributes associated with male and female friends, loneliness, and friendship satisfaction. Results indicate that close friends tended to be same sex, even though females had more close friends overall than did the males. Androgyny was related to characteristics that enhance the development and maintenance of close friendships, such as a communal orientation and positive conceptions of friends, while the undifferentiated orientation was related to less relationship enhancing orientations and a less rewarding interpersonal milieu. The study confirms that sex and sex role orientation are important factors in both quantitative and qualitative aspects of friendship during young adulthood.Portions of this paper were presented at the annual convention of the Southwestern Psychological Association, Houston, Texas, April 13, 1989. We appreciate the extensive help of an anonymous reviewer on earlier versions of this paper.     

Perfect MV-algebras are categorically equivalent to abelianl-groups

In this paper we prove that the category of abelianl-groups is equivalent to the category of perfect MV-algebras. Furthermore, we give a finite equational axiomatization of the variety generated by perfect MV-algebras.Presented byDaniele Mundici     

A Playroom Observation Procedure to Assess Children with Mental Retardation and ADHD

Forty-two children (ages 6 to 12 years old) with moderate mental retardation to borderline intellectual functioning were studied in a laboratory playroom setting to determine whether children identified as ADHD (attention deficit hyperactivity disorder) or controls differed on activity and attentional measures. Children with ADHD were further divided into ADHD + conduct problems (ADHD + CD) and ADHD-only subgroups (with an ADHD-combined group comprising children of both subgroups). An interval recording system was used to code observations of independent play and a restricted academic task. Results indicated that the ADHD-combined group was significantly more vocal and engaged in a significantly greater number of toy changes than controls during independent play. Significant group differences were also noted during the restricted academic task, with the ADHD-combined and ADHD + CD groups more off-task and engaging in a greater number of toy touches than controls. Discriminant analyses found independent play measures to predict group membership in 70 percent of cases (ADHD-combined vs. controls), but in only 64 percent of cases using measures from the restricted academic task. No significant findings resulted when the ADHD subjects were further divided into two subgroups. Despite some inconsistent findings, such laboratory-based observations may be of value in the diagnosis of ADHD in children with moderate mental retardation to borderline intellectual functioning.     

Mill's Fallacies: Theory and Examples

In noting contemporary neglect of Mill's work on fallacy, Hansen and Pinto say that his account is tied more closely to scientific methodology than to problems of public discourse and everyday argumentation. This paper re-examines Mill's fallacies from a rhetorical perspective, assessing the extent to which his examples – drawn from the domains of popular superstition, science, philosophy, and public discussion – fit his theoretical structure. In articulating the relationship between Mill's philosophical assumptions and the discursive practices of the fields from which he draws his examples, it will suggest the ambiguities in Mill's mentalistic, rationalistic, inductivist approach and the inescapable rhetoricity of his examples.     

Disputing clients' irrational beliefs

This paper describes and illustrates a conceptual framework developed to assist novice REBT therapists with enlarging their disputational repertoire. First, four disputational strategies are described and illustrated. Then four disputational styles of presenting the strategies to the client are also described and illustrated. Then the disputational strategies and the disputational styles are combined within a conceptual framework to assist the developing REBT therapist in generating a variety of disputes for a single IB. Finally, the conceptual framework is applied to the IB of the case of Karen from Dryden and Digiuseppe'sPrimer on Rational Emotive Therapy to yield thirty-two separate disputes (sixteen disputes for the premise of the IB, and sixteen disputes for the derivative) of the IB.     

Hemispheric symmetry in duration of visible persistence

Nine right-handed subjects performed a visual task requiring perceptual integration of a pattern whose parts were displayed sequentially in time. Correct performance on the task depended critically on the simultaneous visibility of all parts of the pattern; duration of visible persistence could therefore be gauged by varying the duration of the temporal interval between successive portions of the display. The pattern was displayed either foveally or parafoveally in either visual field. Analysis of overall performance and of distribution of errors at each temporal interval revealed more accurate performance for foveal displays but no hemispheric asymmetries in duration of visible persistence. These and other results reported in the literature are interpreted in terms of Moscovitch’s (1979) information-processing model of hemispheric functioning.     

Duration of visible persistence in relation to range of spatial frequencies

Five experiments examined the relationship between range of spatial frequencies contained in a visual display and duration of visible persistence. The high spatial frequency contents of the display were reduced by defocusing the image at the retina. Duration of visible persistence was measured by a task that required perceptual integration of a pattern whose parts were displayed sequentially in time. Experiments 1 and 2 showed that progressive reductions in the high-frequency contents of the display produced corresponding decrements in the duration of visible persistence. Experiments 3, 4, 5 showed that decrements in the duration of visible persistence could not be attributed to changes in the apparent size or in the brightness of the display brought about by defocusing. The results were interpreted in terms of the temporal response properties of perceptual mechanisms attuned to separate ranges of spatial frequencies. Strong parallels were drawn with the multichannel theory of visual information processing proposed by Breitmeyer and Ganz.