Personal disturbance scale: factor structure confirmed in a large nonclinical sample

The two-component structure of anxiety and depression items of the short form Personal Disturbance Scale, reported in an earlier clinical study of 480 adult psychiatric patients, was substantially replicated in a large nonclinical sample of 758 adults.     

Speechreading skill and visual movement sensitivity are related in deaf speechreaders

Individual speechreading abilities have been linked with a range of cognitive and language-processing factors. The role of specifically visual abilities in relation to the processing of visible speech is less studied. Here we report that the detection of coherent visible motion in random-dot kinematogram displays is related to speechreading skill in deaf, but not in hearing, speechreaders. A control task requiring the detection of visual form showed no such relationship. Additionally, people born deaf were better speechreaders than hearing people on a new test of silent speechreading.     

Interaction of task readiness and automatic retrieval in task switching: Negative priming and competitor priming

When subjects switch between tasks, performance is slower after a task switch than after a task repetition, even when preparation time is long. We report two experiments that support the idea that a large part of these residual task shift costs can be due to stimulus-cued retrieval of previous task episodes. We demonstrate that there are two different factors at work: (1) facilitation of response to the current distractor stimulus, appropriate to the previously relevant, competing task (competitor priming), and (2) impaired processing of previously suppressed responses (negative priming). Negative priming was contingent on the size of the stimulus set, suggesting that distractor suppression comes into effect only if the distractors are highly activated. Importantly, both types of interference interacted with task readiness: Whereas in the nondominant task (picture naming), switch and nonswitch trials were equally affected, the dominant task (word reading) showed priming effects on switch trials only. Thus, the retrieval of previous processing episodes has a selective impact on situations in which task competition is high.     

Attention and expertise in multiple target tracking

An experiment is reported examining the role of attention and expertise in multiple target tracking. It compares the ability of professional radar operators (experts) and undergraduate students (novices) to acquire and track subsets of randomly moving targets amongst distractors, and respond appropriately to a probe. Participants undertook this tracking task alone then, subsequently, in conjunction with a second, digit categorization task. For half the participants, the second task commenced prior to the tracking task's target acquisition phase, for the remainder after. Results suggest experts are better than novices across all conditions. Further, a comparison of results between the two dual task conditions indicates that attentional resources make a contribution to target tracking in both novices and experts, but only appear to make a contribution to target acquisition in novices. The results have implications for theories of multiple target tracking; the selection of radar operators; and the monitoring of their training. Copyright © 2004 John Wiley & Sons, Ltd.     

Some symmetric,invariant measures of multivariate association

A distinction is drawn between redundancy measurement and the measurement of multivariate association for two sets of variables. Several measures of multivariate association between two sets of variables are examined. It is shown that all of these measures are generalizations of the (univariate) squared-multiple correlation; all are functions of the canonical correlations, and all are invariant under linear transformations of the original sets of variables. It is further shown that the measures can be considered to be symmetric and are strictly ordered for any two sets of observed variables. It is suggested that measures of multivariate relationship may be used to generalize the concept of test reliability to the case of vector random variables.     

Interrelationships among subject variables believed to predict cerebral organization

A variety of subject variables have been proposed as having predictive value for determining cerebral organization. Subject variables proposed as likely candidates include strength of handedness, familial sinistrality, writing posture, and sex. The present study examined the interrelationships among these variables by means of a questionnaire given to 847 undergraduates.     

Intra-Individual Variability of Normal and Educable Mentally Retarded Children on a Coincidence Timing Task

A visual coincidence timing task was used to compare the level of performance (constant error) and the intra-individual variability of 100 normal and 100 educable mentally retarded children. The mean performance of the intellectually normal children on this task was significantly superior to that of the retarded children, and the intra-individual variability of the latter was significantly greater than that of the former. The hypothesis that high intra-individual variability and depressed level of performance are closely associated was not supported.     

The Christian experience and interpretation of the early Muslim conquest and rule

The Christian experience of the Muslim conquest and early rule is described in the writings of contemporary historians, church leaders and other writers. These writings provide a range of perspectives and interpretations of that era, determined to some extent by the political situation and the sectarian affiliation of the writer. A survey of these interpretations demonstrates a general lack of awareness of the religious nature of Islam in the early Umayyad period in the seventh century CE. The Arabs are initially seen as looting and plundering invaders and then as a political force demanding taxes but also dispensing justice and protection. While they are seen to have religious links to the Jews, their major religious significance lies in the Christian interpretation of their invasion as a divine punishment for the sins of the Christian communities. Christian writings reflect a growing awareness of Islam as a religion towards the end of this period during the first half of the eighth century, with specific references to the Qur'an and Muslim beliefs.     

Differential relationships of extraversion,impulsivity, and sociability to study habits

Reanalysis of data on library study habits presented by J. B. Campbell and C. W. Hawley (Journal of Research in Personality, 1982, 16, 139–148) revealed differential utility for the EPI extraversion scale and its components, impulsivity and sociability. Individuals studying in locations that provided greater external stimulation had significantly higher extraversion and impulsivity, but not sociability, scores than individuals studying elsewhere in the library. Impulsivity was more strongly associated than sociability with preferred noise levels, frequency of study breaks, and importance and preferred levels of socializing opportunities, but less strongly associated with preferred levels of crowdedness. Findings are discussed in terms of the interpretation, reliabilities, and theoretical context of the subscales.