On the detectability of straight lines in visual noise: An extension of French’s paradigm into the millisecond domain

We report the results of a study that investigated the effects of four experimental parameters on the tachistoscopic detectability of dotted lines in a noisy background consisting of dynamic patterns of identical dots. Characteristics of the lines that were explored included dot spacing, dot numerosity, and line orientation. Dot spacing was shown to be the most powerful parameter in determining the masking effect: the closer the dots, the more easily the line was detected. Increasing the number of the dots was also effective in increasing the detectability of a line, but only up to a limit of five dots. The orientation of the line, on the other hand, did not alter its detectability. Increasing the density of the visual masking noise monotonically reduced the detectability of the line. These studies are an extension of French’s (1953, 1954) work, differing mainly in the fact that the stimulus material was presented tachistoscopically rather than in a mode that allowed prolonged (up to 5 sec) examination of the figures. Thus, they put the results in a domain in which physiological interpretations may be more critically evaluated. A comparison of the results suggests that essentially the same sorts of cognitive mechanisms are operating in the millisecond domain as in the longer exposures. This suggests that simple neurological models utilizing the concept of feature filters or detectors may be being prematurely applied to relatively complex perceptual processes.     

An improved circuit for control of LED luminance

The light-emitting diode (LED) is becoming increasingly popular as a luminance source in behavioral research. We describe a simple, inexpensive LED driver circuit that produces luminances almost linearly proportional to an input voltage. Negative feedback provides a stable output. Unlike previous designs, the LED is ground referenced.     

Production of graphic symbol sentences by individuals with aphasia: efficacy of a computer-based augmentative and alternative communication intervention

The study employed a single-subject multiple baseline design to examine the ability of 9 individuals with severe Broca's aphasia or global aphasia to produce graphic symbol sentences of varying syntactical complexity using a software program that turns a computer into a speech output communication device. The sentences ranged in complexity from simple two-word phrases to those with morphological inflections, transformations, and relative clauses. Overall, results indicated that individuals with aphasia are able to access, manipulate, and combine graphic symbols to produce phrases and sentences of varying degrees of syntactical complexity. The findings are discussed in terms of the clinical and public policy implications.     

Body Size Beliefs and Weight Concerns Among Mothers and Their Adolescent Children

African American and White mother/adolescent pairs were examined for familial associations in body size and weight concerns. Mothers' and adolescents' estimates of adolescents' body mass index (BMI) were significantly correlated. Compared to boys, girls had greater body dissatisfaction, higher weight concerns, and perceived higher family/friend weight concerns. By race, White adolescents had more body dissatisfaction and greater concern about weight than African American adolescents. Four items explained 70.4% of the variance in adolescents' weight concern scores: adolescents' weight management practices, mothers' reports of adolescents' saying they were too fat, adolescents' perceptions of family/friends' weight concerns, and adolescents' body dissatisfaction. Our study suggests White girls are more concerned about their weight and perceive greater weight and dieting concerns among family/friends than African American girls.     

Generational Conversion? The Role of Religiosity in the Politics of Evangelicals

The political environment for evangelical Protestants has changed substantially since the Christian Right reached its apex, as a more issue and ideologically diffuse political environment has emerged. The present study tests two different theoretical perspectives on whether these contextual changes may have altered Millennial evangelicals’ political perspectives vis‐à‐vis those of previous generations of evangelicals. On the one hand, theoretical perspectives related to differential political socialization processes across generations would lead to expectations of generational change among evangelicals. On the other hand, theoretical perspectives related to social identity theory would suggest far less change across generations. Using Pew's 2007 U.S. Religious Landscape Survey, we test these expectations by comparing the relationships between religiosity and political attitudes across three generations of evangelicals. Ordered probit and logistic regression models estimate the impact of religiosity on various political attitudes. These models reveal that Millennial evangelical religiosity continues to be strongly related to Republican Party identification and opposition toward abortion, which is largely consistent with the social identity perspective. Generational change is most evident in a variety of nonsocial issues in which religiosity is associated with less conservatism among Millennials. Additional analysis using the 2012 Religion and Politics Survey with a smaller sample of Millennial evangelicals confirms these results.     

Sources of variability in apparent-contrast measurements made by brightness matching

The apparent contrast of backward- and forward-masked spatial sinusoids was measured by a brightness-matching technique suggested by Davidson (1966), designed to be free of artifacts associated with earlier matching methods. Data variability was relatively large due predominantly to (1) fluctuations in masking-interval duration, and (2) changes in the O’s criteria produced by the salient temporal and spatial differences between test and comparison fields. Several other potential sources of data variability were found to be negligible.     

Torque,lateral preference,and cognitive ability in primary-grade children

It has been suggested that torque, the tendency to draw circles in the clockwise direction, is related to left-handedness and is a marker for psychopathology. Results of recent studies conflict with this hypothesis hut are weakened by imprecise definition and unreliable assessment of torque. Measures of torque, lateral preference, and cognitive ability were administered to 181 children in kindergarten and first grade. As reported previously, rate of torque decreased with age and was greater among males. Children with complete clockwise or counter-clockwise circling at both assessments differed in pattern but not in overall level of cognitive ability No differences were found in strength, direction, or concordance of hand and foot preference. Results of this and other studies are seen as inconsistent with proposals that torque is symptomatic of psychopathology.     

Pragmatics of measuring recognition memory: applications to dementia and amnesia

This article has two purposes. The first is to describe four theoretical models of yes-no recognition memory and present their associated measures of discrimination and response bias. These models are then applied to a set of data from normal subjects to determine which pairs of discrimination and bias indices show independence between discrimination and bias. The following models demonstrated independence: a two-high-threshold model, a signal detection model with normal distributions using d' and C (rather than beta), and a signal detection model with logistic distributions and a bias measure analogous to C. C is defined as the distance of criterion from the intersection of the two underlying distributions. The second purpose is to use the indices from the acceptable models to characterize recognition memory deficits in dementia and amnesia. Young normal subjects, Alzheimer's disease patients, and parkinsonian dementia patients were tested with picture recognition tasks with repeated study-test trials. Huntington's disease patients, mixed etiology amnesics, and age-matched normals were tested by Butters, Wolfe, Martone, Granholm, and Cermak (1985) using the same paradigm with word stimuli. Demented and amnesic patients produced distinctly different patterns of abnormal memory performance. Both groups of demented patients showed poor discrimination and abnormally liberal response bias for words (Huntington's disease) and pictures (Alzheimer's disease and parkinsonian dementia), whereas the amnesic patients showed the worst discrimination but normal response bias for words. Although both signal detection theory and two-high-threshold discrimination parameters showed identical results, the bias measure from the two-high-threshold model was more sensitive to change than the bias measure (C) from signal detection theory. Three major points are emphasized. First, any index of recognition memory performance assumes an underlying model. Second, even acceptable models can lead to different conclusions about patterns of learning and forgetting. Third, efforts to characterize and ameliorate abnormal memory should address both discrimination and bias deficits.     

Psycho-Spiritual Integrative Therapy for Women with Primary Breast Cancer

Breast cancer presents physical and psychological challenges, but can also result in posttraumatic growth (PTG). Twenty-four women completed Psycho-Spiritual Integrative Therapy (PSIT) treatment and completed assessments for PTG and QOL before, immediately following, and 1 month after treatment. Women showed improvement (p?相似文献