Evidence for scanning with unilateral visual presentation of letters

When letters and words are presented tachistoscopically, material from the right visual field (RVF) can be reported more accurately than that from the left visual field (LVF). The RVF superiority may reflect either left hemispheric dominance for language or directional scanning. Previous studies have deliberately focused on the cerebral asymmetry factor while "controlling" scanning and, thus, have cast some doubt on the potency of the scanning factor. Two experiments were conducted to show that scanning can induce a RVF superiority comparable to that often associated with cerebral asymmetry. The first experiment required bilingual subjects to report six English or six Hebrew letters, shown briefly in either the LVF or RVF, with order of report controlled. A RVF superiority found with English characters was matched by an equal but opposite LVF effect with Hebrew. In a second experiment, five English characters were shown briefly in either the LVF or RVF, and subjects had to identify a single character indicated by a post exposural cue. Using a spatial cue to by pass scanning, there were no field differences; with an ordinal position cue--a procedure thought to force scanning--there was a strong RVF superiority. The results show clearly that scanning can induce visual field differences.     

The word-superiority effect under conditions that approximate reading

Observers detected a briefly flashed target letter embedded in word, pronounceable nonword, and unpronounceable nonword contexts. The word context facilitated perception under both holistic and analytical processing strategies; the facilitative effect was enhanced when processing was analytical.     

Patterns of discipline enforcement and the perception of justice in two educational frameworks in Israel

The purpose of the present study was to examine the types of discipline enforcement measures employed in the Israeli elementary and junior high schools, and their fairness as viewed by students. The central hypothesis was that patterns of discipline enforcement vary considerably depending on school characteristics. These patterns, in turn, together with students' sex, socioeconomic and ethnic background, and academic status within the school, determine students' perceptions of justice concerning misbehavior management. It was found that junior high school teachers rely more on problem-centered, and elementary school teachers rely more on relationship-centered techniques of discipline enforcement. However, in spite of these differences and the report of about half of the students that they personally had been unfairly treated, the majority of the respondents reported that the punishments employed in their school were generally fair, and that the severity of punishments was in the right proportion to the severity of the misconduct. Students' traits have accounted for only a small percentage of the variance of the various dimensions of justice that were examined. It has been suggested that students' perceptions of justice are related to an overall tendency to perceive schools' authority as legitimate rather than to schools' structural characteristics, misbehavior management techniques, and students' traits. Several possible bases of schools' legitimation are discussed.     

Differences in academic performance at school depending on handedness: matter for neuropathology?

Two studies found that left-handed children had significantly poorer academic records than did right-handed children, though the effect was small. Study 1 provided evidence that, for some academic disciplines, the important difference appeared to be between those children whose family history of handedness was concordant with their own handedness and those children whose family history of handedness was discordant with their own handedness. The inclusion of gender in asymmetry research was bolstered by Study 2. When predicting idiosyncrasies in left-handers' cognitive performance, it should be borne in mind that left-handers form a minority group as well as a neurologically distinct one.     

Temporal pattern of agonist-antagonist EMG activity during rapid limb movements in man

Analysis of elbow-extension movements, executed at maximal velocity, show positive correlations of timing of agonist-antagonist EMG activity with both movement velocity and displacement. Results indirectly support the notion that the antagonist musculature provides a braking force to arrest rapid limb movements.     

Effects of delayed conditioned reinforcement in chain schedules.

The contingency between responding and stimulus change on a chain variable-interval 33-s, variable-interval 33-s, variable-interval 33-s schedule was weakened by interposing 3-s delays between either the first and second or the second and third links. No stimulus change signaled the delay interval and responses could occur during it, so the obtained delays were often shorter than the scheduled delay. When the delay occurred after the initial link, initial-link response rates decreased by an average of 77% with no systematic change in response rates in the second or third links. Response rates in the second link decreased an average of 59% when the delay followed that link, again with little effect on response rates in the first or third links. Because the effect of delaying stimulus change was comparable to the effect of delaying primary reinforcement in a simple variable-interval schedule, and the effect of the unsignaled delay was specific to the link in which the delay occurred, the results provide strong evidence for the concept of conditioned reinforcement.