Visual guidance for hand advance but not hand withdrawal in a reach-to-eat task in adult humans: reaching is a composite movement

Many animal species use reaching for food to place in the mouth (reach-to-eat) with a hand, and it may be a primitive movement. Although researchers (I. Q. Whishaw, 2005; A. N. Iwaniuk & I. Q. Whishaw, 2000; M. Gentiluci, I. Toni, S. Chieffi, & G. Pavesi, 1994) have described visual guidance of reaching in both normal and brain-injured human and nonhuman primates, researchers have not described the contribution of vision during advance of the limb to grasp food and during withdrawal of the limb with food to the mouth. To evaluate visual contributions, the authors monitored eye movements in young adults as they reached for food with and without vision. Participants visually engaged the target prior to the 1st hand movement and disengaged it as the food was grasped. Visual occlusion slowed limb advance and altered digit shaping but did not affect withdrawal. The dependence on visual control of advance but not withdrawal suggests that the reach-to-eat movement is a composite of 2 basic movements under visual and tactile/proprioceptive guidance, respectively.     

Group size,group status and trait valence as determinants of intergroup bias: Stereotyping in Finland and Sweden

The effects of group size, group status and trait valence (positive or negative stereotypes of in‐ and outgroup) on intergroup bias was studied in nation‐wide probability samples of majority and minority groups in Finland and Sweden, (N = 2479). Ethnolinguistic vitality was used as a proxy for status. It is argued that the specific history of real‐life intergroup relations has to be duly acknowledged when predicting main and interactive effects on intergroup bias in natural contexts. Supporting the predictions made, numerical group size showed a stable main effect; members of numerical minorities showed more bias than members of numerical majorities, regardless of trait valence. While status had no main effect, there was a significant interaction between status and size as well as between status and trait valence: intergroup bias was highest in the high status minority, and low status groups showed less bias than high status groups on negatively valenced traits. In fact, minority members showed the reverse of PNAE. In addition, majority members favoured the outgroup on negatively valenced traits, but favoured their ingroup on positively valenced traits. Different explanations for these results are discussed. Copyright © 2008 John Wiley & Sons, Ltd.     

What is behind a summary-evaluation decision?

Research in psychology has reported that, among the variety of possibilities for assessment methodologies, summary evaluation offers a particularly adequate context for inferring text comprehension and topic understanding. However, grades obtained in this methodology are hard to quantify objectively. Therefore, we carried out an empirical study to analyze the decisions underlying human summary-grading behavior. The task consisted of expert evaluation of summaries produced in critically relevant contexts of summarization development, and the resulting data were modeled by means of Bayesian networks using an application called Elvira, which allows for graphically observing the predictive power (if any) of the resultant variables. Thus, in this article, we analyzed summary-evaluation decision making in a computational framework.     

Insensitivity of visual short-term memory to irrelevant visual information

Several authors have hypothesized that visuo-spatial working memory is functionally analogous to verbal working memory. Irrelevant background speech impairs verbal short-term memory. We investigated whether irrelevant visual information has an analogous effect on visual short-term memory, using a dynamic visual noise (DVN) technique known to disrupt visual imagery (Quinn & McConnell, 1996b). Experiment 1 replicated the effect of DVN on pegword imagery. Experiments 2 and 3 showed no effect of DVN on recall of static matrix patterns, despite a significant effect of a concurrent spatial tapping task. Experiment 4 showed no effect of DVN on encoding or maintenance of arrays of matrix patterns, despite testing memory by a recognition procedure to encourage visual rather than spatial processing. Serial position curves showed a one-item recency effect typical of visual short-term memory. Experiment 5 showed no effect of DVN on short-term recognition of Chinese characters, despite effects of visual similarity and a concurrent colour memory task that confirmed visual processing of the characters. We conclude that irrelevant visual noise does not impair visual short-term memory. Visual working memory may not be functionally analogous to verbal working memory, and different cognitive processes may underlie visual short-term memory and visual imagery.     

Direct‐Supervision and Remote‐Supervision Jails: A Comparative Study of Psychosocial Factors1

The direct‐supervision style correctional facility has been offered as a design that provides a better atmosphere for staff and inmates. Prior research has shown minor support in favor of the general environment created by direct‐supervision facilities. However, the claims of benefits associated with direct supervision far outweigh the number of empirical research studies on the design. This research examined corrections officers' and inmates' feelings of boredom, perceived control, aggression, attitudes toward each other, and stress in a direct‐supervision style facility and a remote‐supervision style facility. Results from 164 inmates and 82 correctional officers showed that staff in the direct‐supervision facility reported elevated levels of perceived control, less anger and hostility, and less boredom.     

Grouping puts figure-ground assignment in context by constraining propagation of edge assignment

Figure-ground organization involves the assignment of edges to a figural shape on one or the other side of each dividing edge. Established visual cues for edge assignment primarily concern relatively local rather than contextual factors. In the present article, we show that an assignment for a locally unbiased edge can be affected by an assignment of a remote contextual edge that has its own locally biased assignment. We find that such propagation of edge assignment from the biased remote context occurs only when the biased and unbiased edges are grouped. This new principle, whereby grouping constrains the propagation of figural edge assignment, emerges from both subjective reports and an objective short-term edge-matching task. It generalizes from moving displays involving grouping by common fate and collinearity, to static displays with grouping by similarity of edge-contrast polarity, or apparent occlusion. Our results identify a new contextual influence on edge assignment. They also identify a new mechanistic relation between grouping and figure-ground processes, whereby grouping between remote elements can constrain the propagation of edge assignment between those elements. Supplemental materials for this article may be downloaded from http://app.psychonomic-journals.org/content/supplemental.