Exploring the limits of peripheral vision for the control of movement

The role played by peripheral visual information in the control of aiming movements is not fully understood, as is indicated by the conflicting results reported in the literature. In the present study, the authors tested and confirmed the hypothesis that the source of the conflict lies in the portion of the visual peripheral field that has been under scrutiny in the different studies. Participants (N = 60) moved a computer mouse from a fixed starting position to 1 of 3 targets under varied vision conditions. The portion of the peripheral visual field that best ensured directional accuracy of a sweeping movement was found to be located between 20 degrees and 10 degrees of visual angle, whereas the area found to favor directional accuracy of an aiming movement comprised 30 degrees through 10 degrees of visual angle.     

Worries and values

Relations of individuals' value priorities to their worries are investigated in seven samples from four cultural groups (N = 1,441). A social-cognitive analysis suggests that value priorities influence worries by increasing attention to and perception of threats to valued goals. On this basis, we generate hypotheses relating two types of worries, micro (about self and its extensions) and macro (about society and world), to 10 types of values. As predicted, giving priority to self-transcendence values (universalism and benevolence) is associated with low micro and high macro worry, whereas giving priority to self-enhancement values (power, hedonism, and--to a lesser degree--achievement) is associated with high micro and low macro worry. Meaningful associations are also found for other values. Values account for substantially more variance in macro than in micro worries.     

Confirmatory factor analyses of the full and short versions of the Marlowe-Crowne Social Desirability Scale

Over the years, researchers have developed various short versions of the Marlowe-Crowne Social Desirability Scale (D. P. Crowne & D. Marlowe, 1960). The authors used confirmatory factor analyses (J. L. Arbuckle, 1997) as well as item and scale analyses to evaluate the adequacy of the full version and various short versions. Overall, the results from 232 Canadian undergraduates showed (a) that all the short versions in the present study are a significant improvement in fit over the 33-item full scale and (b) that W. M. Reynolds's (1982) Forms A and B are the best fitting short versions. No gender differences were found for the full scale or any of the short versions. The results show that the full scale could be improved psychometrically and that the psychometrically sound short versions should be available because they require less administration time than the full scale.     

Comparison of selected perceptual variables for backpacks with internal and external frames

Differences in perceptions of comfort, exertion, balance, and heart rate were investigated with two types of backpack. Subjects were 20 male volunteers (M age = 24.3 yr., SD: 3.6, M height = 180.02 cm, SD: 8.0, and M weight = 86.46 kg, SD: 14.84). Following oral briefing and practice trials, each subject was fitted at random with either an internal- or external-frame backpack containing 18.2 kg. By random, cross-over design, subjects completed a 30-m simulated hiking trial consisting of 16 separate obstacles designed to resemble actual off-trail hiking. Trials were conducted in a controlled environment with the walking intensity regulated by a metronome. Upon completion of each trial, the subjects rated the experience on perceived comfort, balance and stability, and rating of perceived exertion. Heart rate was recorded immediately prior to and following each trial. Analysis yielded a significant difference only on rating of perceived exertion in favor of the internal-frame backpack. Under limited circumstances, these data suggest that both types of backpacks provide similar comfort and balance and stability; however, internal frames in backpacks may reduce perceived exertion during short, demanding hikes.     

Attribution of aggression to acts: a four-factor model

Factors determining why acts are regarded as aggressive were investigated in a sample of 303 subjects (140 males, 163 females, M age = 17.7 yr., SD = 1.4). A model was tested, according to which people base their attribution of aggression to acts on four factors: (1) intention (yes/no), (2) reason (attack/defense), (3) injury (death/injury/no injury), and (4) mode (weapon/bare hands/nonphysical means). All four factors contributed to the explanation of attribution of aggression, and the order of importance was the one mentioned above, intention being most important. The interaction between intention and reason was the second most important, contributing more than reason alone. The findings are consistent with the severity of punishment in sentences for different crimes of violence.     

Opinion on AIDS prevention and education among rural secondary school pupils in the northern province of South Africa

The study investigated perceptions of AIDS prevention and education among 308 Grade 11 pupils (132 boys and 176 girls), secondary school pupils (mainly Northern Sotho and Tsonga) in the Northern Province of South Africa. They were chosen randomly from three rural schools in Mankweng district and were ages 17 to 25 years (M age = 19.1 yr., SD = 2.8). Analysis of ratings given on items of a questionnaire on AIDS prevention and education indicated that 'Isolating people who are HIV positive' and 'How to protect yourself from getting HIV/AIDS' received the highest ratings. Factor analysis extracted three factors on AIDS education explaining 48% of the variance. The items loading strongly on the first factor were use of condoms (.54), giving information (.53), finding a cure (.52), and no sex outside marriage (.42). On AIDS education two factors were extracted accounting for 52% of the variance. The first factor had significant item loadings for 'sexual behaviour and HIV/AIDS' (.75), 'knowledge of self-protection' (.68), 'how AIDS/HIV affects the body' (.66), and 'alcohol and sexual behaviour'. These findings should contribute to the development of health promotion initiatives directed at AIDS/HIV.     

Measuring self-efficacy among drug-involved probationers

Self-efficacy has been shown to be related to outcomes from interventions for alcohol and tobacco abuse but relatively little attention has been focused on it in evaluations of treatment for illicit drug abuse. Almost no research has examined offenders involved with drugs. The current study, therefore, adapted the Alcohol Abstinence Self-efficacy Scale of DiClemente, Carbonari, Montgomery, and Hughes and administered it to 250 probationers mandated to 6 months of residential treatment. With some modifications, confirmatory factory models replicated four previously reported dimensions, e.g., Negative Affect, Social/Positive, Physical and Other Concerns, Cravings and Urges. Findings also indicated high construct validity for the Alcohol Abstinence Self-efficacy Scale as adapted here. Studies are needed to examine the use of self-efficacy as a prospective measure of treatment progress and to explore its association with outcomes from corrections-based treatment.     

Family and individual correlates of academic goal orientations: social context differences in South Africa

This study examined relationships between distal social contexts, parents' support for learning, self-concept, and adolescents' academic goal orientations. Data were collected from 435 female and 410 male 18-yr.-old South Africans. Multistage regression analyses indicated that family social status and rural/urban locality had unmediated relations with the adolescents' learning and performance goal orientations. In addition, parent and self-concept measures combined to have small independent associations with the adolescents' academic goal orientations.     

One Frog, Two Frog, Red Frog, Blue Frog: Factors Affecting Children's Syntactic Choices in Production and Comprehension

Two experiments are reported which examine children's ability to use referential context when making syntactic choices in language production and comprehension. In a recent on-line study of auditory comprehension, Trueswell, Sekerina, Hill, and Logrip (1999) examined children's and adults' abilities to resolve temporary syntactic ambiguities involving prepositional phrases (e.g., “Put the frog on the napkin into ¨”). Although adults and older children used the referential context to guide their initial analysis (pursuing a destination interpretation in a one-frog context and a modifier interpretation in a two-frog context), 4 to 5-year olds' initial and ultimate analysis was one of destination, regardless of context. The present studies examined whether these differences were attributable to the comprehension process itself or to other sources, such as possible differences in how children perceive the scene and referential situation. In both experiments, children were given a language generation task designed to elicit and test children's ability to refer to a member of a set through restrictive modification. This task was immediately followed by the “put” comprehension task. The findings showed that, in response to a question about a member of a set (e.g., “Which frog went to Mrs. Squid's house?”), 4- to 5-year-olds frequently produced a definite NP with a restrictive prepositional modifier (e.g., “The one on the napkin”). These same children, however, continued to misanalyze put instructions, showing a strong avoidance of restrictive modification during comprehension. Experiment 2 showed that an increase in the salience of the platforms that distinguished the two referents increased overall performance, but still showed the strong asymmetry between production and comprehension. Eye movements were also recorded in Experiment 2, revealing on-line parsing patterns similar to Trueswell et al.: an initial preference for a destination analysis and a failure to revise early referential commitments. These experiments indicate that child–adult differences in parsing preferences arise, in part, from developmental changes in the comprehension process itself and not from a general insensitivity to referential properties of the scene. The findings are consistent with a probabilistic model for uncovering the structure of the input during comprehension, in which more reliable linguistic and discourse-related cues are learned first, followed by a gradually developing ability to take into account other more uncertain (or more difficult to learn) cues to structure.     

On associations between computers and restaurants: Rapid learning of new associations on a conceptual implicit memory test

A novel event-based conceptual implicit memory test was designed to tap the development of new associations between objects and ad hoc categories. At study, participants were presented with a plausible story that linked an incongruous object (computer) with an ad hoc category (restaurant). At test, participants judged whether a given object was typically found in a restaurant. In Experiment 1, judgment time was significantly slower for the incongruous object (computer) when the story had previously linked the computer to the restaurant, relative to when it had not. Experiment 2 replicated this effect and ruled out the alternative interpretation that this interference effect was attributable to a general slowing of responses to all studied items. Unlike in prior studies, this demonstration of associative priming cannot be attributed to perceptual priming or to test awareness in memory-intact participants. The paradigm therefore offers a unique opportunity to study single-trial conceptual learning in memory-intact and memory-impaired populations.