Inhibitory and facilitatory effects of cue onset and offset

The response speed to a visual target is modulated by the position of previous events (cues) even if their position is not predictive of the target position. The modulation has been considered biphasic, with an early facilitatory and a later inhibitory component. We conducted three experiments that investigated the importance of the onset and offset features of the cue for the facilitatory and inhibitory effects and estimated their separate and joint effects. The two possible target locations, one in the right and one in the left visual field, were indicated by two empty boxes, and the cue consisted of the onset and/or offset of an arrowhead located just under one of the two boxes. Different time intervals were used between cue and target. Subjects were instructed to ignore the cue and to respond to the target (a cross inside one of the two boxes). The data showed only consistent effects of inhibition (inhibition of return) with the long intervals, but the pattern was different depending on the cue type. The amount of inhibition was much greater when the onset of the cue was followed by its offset. Apparently, inhibition of return depended on the dynamic changes of the cue. Received: 23 October 1996 / Accepted: 3 June 1997     

Laterality effects, levels of processing, and stimulus properties

Two hypotheses of hemispheric specialization are discussed. The first stresses the importance of the kind of processing to which the stimulus is subjected, and the second stresses the importance of the nature of the stimulus. To test these hypotheses, four experiments were carried out. In Experiment 1 verbal material was employed in a same-different classification task, and an overall right visual field superiority was found. Experiment 2, in which verbal stimuli were subjected to visuospatial transformations (i.e. mental rotations), yielded no laterality effect. In Experiment 3 geometrical figures were employed in a classification task similar to that of Experiment 1, and an overall left visual field superiority was found. In Experiment 4 both verbal and geometric stimuli were employed. The results showed a significant interaction between field of presentation and nature of the stimulus and no interaction between field of presentation and level of processing.     

The interplay of community and family risk and protective factors on adjustment in young adult immigrants

We examined the direct and interactive effects of community violence and both family cohesion and conflict on collective efficacy and aggressive behaviours among immigrant young adults. Participants included 221 young adults (ages 18–26; mean age = 21.36; 45.7% female, 190 born outside the U.S.) who completed self-report measures of their exposure to neighbourhood violence, social cohesion, collective efficacy and prosocial behaviours toward friends and strangers. Results, in general, showed that community violence and family cohesion were positively associated with collective efficacy whereas community violence and family conflict were positively associated with aggressive behaviours. Family cohesion and conflict also moderated the links between community violence and aggressive behaviours. Discussion focuses on the interplay of community and family processes and the relations to adjustment of immigrant young adults.     

Newborns’ preference for up–down asymmetrical configurations

The present study was aimed at investigating whether, because of a differential sensitivity between the upper and the lower visual fields, in a visual preference task newborns would orient more frequently and look longer at patterns with a great number of high–contrast areas in the upper or lower visual field. Newborns were presented with three pairs of geometrical stimuli, each composed of a pattern with a greater number of elements in the upper part or a pattern with more elements in the lower part. The results showed a reliable preference for the stimuli that had more elements in the upper than in the lower part. The evidence obtained suggests the possibility that, at birth, the visibility of a stimulus depends not only on its sensory properties, but also on its structural characteristics.     

The mental representation of numerical fractions: real or integer?

Numerical fractions are commonly used to express ratios and proportions (i.e., real numbers), but little is known about how they are mentally represented and processed by skilled adults. Four experiments employed comparison tasks to investigate the distance effect and the effect of the spatial numerical association of response codes (SNARC) for fractions. Results showed that fractions were processed componentially and that the real numerical value of the fraction was not accessed, indicating that processing the fraction's magnitude is not automatic. In contrast, responses were influenced by the numerical magnitude of the components and reflected the simple comparison between numerators, denominators, and reference, depending on the strategy adopted. Strategies were used even by highly skilled participants and were flexibly adapted to the specific experimental context. In line with results on the whole number bias in children, these findings suggest that the understanding of fractions is rooted in the ability to represent discrete numerosities (i.e., integers) rather than real numbers and that the well-known difficulties of children in mastering fractions are circumvented by skilled adults through a flexible use of strategies based on the integer components.     

Exercise commitment and proneness to eating disorders in a group of physical education teachers

The study examined the association of exercise commitment with proneness to eating disorders in 50 physical education teachers who had been practicing various aerobic sports at least three times a week for at least 5 years. Significant coefficients were found between Commitment to Exercise Scale scores, the number of weekly training sessions, and scores on the Eating Disorders Inventory-2 scales measuring Maturity Fears, Social Insecurity, Perfectionism, and Asceticism. However, no relationship was found between the Commitment to Exercise Scale and the Eating Disorders Inventory-2 variables measuring anorexic tendencies (such as Drive for Thinness, Body Dissatisfaction, and Bulimia). Findings suggest the presence of some psychological factors common to both anorexic tendencies and excessive exercising but not complete overlap, so a rather more complex pattern of relationships appears to be mediated by sex and personality characteristics.     

Mereology and time travel

Philosophical Studies - Core principles of mereology have been questioned by appealing to time travel scenarios. This paper questions the methodology of employing time travel scenarios to argue...     

Effect of task presentation on students’ performances in introductory statistics courses

Research on academic learning indicates that many students experience major difficulties with introductory statistics and methodology courses. We hypothesized that students’ difficulties may depend in part on the fact that statistics tasks are commonly viewed as related to the threatening domain of math. In two field experiments which we carried out in the ecological context of introductory statistics courses, the representation of a statistics task administered to undergraduate students in Psychology (Study 1; n = 127) and Biology (Study 2; n = 166) was manipulated. In both studies we found that students who reported the least favorable prior attainments in math had their performance thwarted when the task was presented as related to the math domain, whereas no performance impairment was observed when the task was presented as related to the verbal/linguistic domain. Implications of the findings for the design and delivery of introductory statistics and research methodology courses are discussed.

Response demands and the recruitment of heuristic strategies in syllogistic reasoning

Two experiments investigated whether dealing with a homogeneous subset of syllogisms with time-constrained responses encouraged participants to develop and use heuristics for abstract (Experiment 1) and thematic (Experiment 2) syllogisms. An atmosphere-based heuristic accounted for most responses with both abstract and thematic syllogisms. With thematic syllogisms, a weaker effect of a belief heuristic was also observed, mainly where the correct response was inconsistent with the atmosphere of the premises. Analytic processes appear to have played little role in the time-constrained condition, whereas their involvement increased in a self-paced, unconstrained condition. From a dual-process perspective, the results further specify how task demands affect the recruitment of heuristic and analytic systems of reasoning. Because the syllogisms and experimental procedure were the same as those used in a previous neuroimaging study by Goel, Buchel, Frith, and Dolan (2000), the result also deepen our understanding of the cognitive processes investigated by that study.     

The measurement of left—right asymmetries in the Simon effect: A fine-grained analysis

The spatial Simon effect is often asymmetric, being greater on one side than on the other. To date, not much attention has been paid to these asymmetries, and explanations of the Simon effect do not take them into account. In the present article, we attempt to clarify the statistical implications of the asymmetries so as to provide a useful tool for future empirical investigation. Starting with examples from our laboratory and previous well-known studies, we point out the consequences of ignoring the asymmetries in the Simon effect. We suggest an alternative data analysis that might render the results clearer. Finally, through a comparison of left- and right-handed subjects, we demonstrate that asymmetries in the Simon effect are linked to the lateralization of processes involved in the Simon task—that is, attention and response selection. This approach provides a strong argument against collapsing data from the two sides to measure the Simon effect.