Chinese subject-relative clauses are more difficult to process than the object-relative clauses

This paper presents an experiment that compared high and low working memory span readers' abilities to process Chinese subject-relative and object-relative clause structures in a self-paced reading paradigm. Comprehension performance results indicated that the object-relative structure was easier to understand than the subject-relative structure. Reading time results showed that participants with low working memory span read the subject-relative structures more slowly than the object-relative structures, but there was no reading time difference for the high working memory span participants. The experiment provides further evidence that the Chinese subject-relative clause structure is more difficult to process than the Chinese object-relative clause structure, especially for low working memory span individuals. Furthermore, these results support a syntactic storage account of the observed complexity difference.     

Classroom environment influences on aggression, peer relations, and academic focus

Peers serve as reinforcers and models of behavior, and consequently classrooms containing high numbers of students with poor academic skills or behavior problems are likely to promote these behaviors in individual students. This study examined how variations in social and academic classroom composition as well as the larger school context affected behavior in a normative sample of children over a 2-year period. Teachers provided ratings of individual students, which were then aggregated to form teacher-based measures of classroom environment. Concurrent and longitudinal effects of classroom and school environments on individual behaviors were examined for students in 65 classrooms in 17 schools. Poorer classroom environments were associated with poorer levels of student aggression, peer relations, and academic focus. Changes in student behavior over time could be explained by the current classroom environment.     

A graphical test for the significance of differences between frequencies from different samples

For testing the significance of differences between frequencies from different samples, an ellipse can easily be constructed on the basis of a formula developed on the assumption that both observed samples are random samples from the same parent population and that the best estimate of the true proportion is the weighted mean proportion of the two samples. The ellipse provides a very rapid method for testing pairs of frequencies.The opinions expressed in this paper are those of the authors and are not to be construed as those of the Navy Department.     

Eye movement indices of mental workload

Four investigations were carried out to assess the feasibility of using eye movement measures as indices of mental workload. In the first experiment, saccadic extent was measured during free viewing while subjects performed low, moderate and high complexity, auditory tone counting as the workload tasks. The range of saccadic extent decreased significantly as tone counting complexity (workload) was increased. In the second experiment the range of spontaneous saccades was measured under three levels of counting complexity with a visual task that did not require fixation or tracking. The results indicated that the extent of saccadic eye movements was significantly restricted as counting complexity increased. In the third experiment, the effects of practice were examined and decreased saccadic range under high tone counting complexity was observed even when significant increases in performance occurred with practice. Finally, in experiment 4, the first experiment was repeated with additional optokinetic stimulation and the saccadic range was again observed to decrease with tone counting complexity. The results indicated that the extent of spontaneous and elicited eye movements was significantly restricted as counting complexity increased. We conclude that this measure may provide a valuable index of mental workload.