Attentional deficits in head-injured children: An information processing analysis

Attentional problems of closed head-injured (CHI) children were examined using an information processing (IP) approach. Based on Sternberg's (1969) additive factor method (AFM), the study examined attentional processes in terms of four stages and their corresponding task variables. A visual-spatial choice reaction-time task was undertaken with two groups of CHI children (severe and mild to moderate) and corresponding matched control groups. Results indicated that for this task both the CHI and the normal children exhibited a similar mode of linear, sequential information processing. It was found that the severe group was impaired not only in terms of slowed motor execution but also in terms of response selection. This group showed no impairment on the feature extraction, stimulus identification, and motor adjustment stages of processing. No evidence of impairment on any of the stages was found for the mild group. The utility of the AFM and implications of these findings are discussed with reference to CHI children and to neuropsychological assessment and rehabilitation.     

Evidence for feature perturbations

Feature perturbations were proposed by Wolford (1975) to explain the pattern of errors generated by subjects in experiments involving speeded presentations. These experiments were carried out to test the notion of feature perturbations in a fairly direct fashion. The logic of the experiments involved the creation of an artificial alphabet in which feature perturbations, if they occurred, would lead to predictable error patterns. The results of the three experiments supported the notion of feature perturbations. Evidence was also found for errors which resulted from items that were correctly identified but that were reported in an incorrect order. These latter errors were shown to be distinct from errors resulting from feature perturbations.     

Natural deduction and arbitrary objects

Journal of Philosophical Logic -     

Visual working memory for simple and complex visual stimuli

Does the magical number four characterize our visual working memory (VWM) capacity for all kinds of objects, or is the capacity of VWM inversely related to the perceptual complexity of those objects? To find out how perceptual complexity affects VWM, we used a change detection task to measure VWM capacity for six types of stimuli of different complexity: colors, letters, polygons, squiggles, cubes, and faces. We found that the estimated capacity decreased for more complex stimuli, suggesting that perceptual complexity was an important factor in determining VWM capacity. However, the considerable correlation between perceptual complexity and VWM capacity declined significantly if subjects were allowed to view the sample memory display longer. We conclude that when encoding limitations are minimized, perceptual complexity affects, but does not determine, VWM capacity.     

Validating a “spurning scale” for teachers

Based on a model on helpers’ reactions to rejection of their help, a spurning scale for teachers was constructed, comprising items that examine teachers’ perception of spurning of their help/advice by students and colleagues. Three avenues were taken to assess the validity of the scale: The relationships of the spurning scores with burnout scores; the relationships of spurning scores with job (dis)satisfaction and with job turnover; and relationships of spurning scores with job stresses from different sources. In-service teachers enrolled in a teacher training program were invited to fill out a questionnaire that contained these variables. Results suggest that the spurning scale is valid.     

Altruistic Orientation in Children: Construction and Validation of the Child Altruism Inventory

The Child Altruism Inventory (CAI) consisted of 24 yes-or-no items which measured the altruistic orientation of children. The sample included 1095 Grades 2 to 6 Chinese children in Hong Kong, The test-retest and internal consistency reliabilities of the CAI were in the 0.70s. The correlations of the CAI score with the intelligence and self-esteem scores were significantly positive, while the correlations of the CAI score with the psychoticism and neuroticism scores were significantly negative. Children in classes of positive and negative social environment rated high and low on the CAI respectively. The relations of the CAI score with self-report prosocial and delinquent behavioural indices were also positive and negative respectively. The psychometric properties of the CAI are regarded as quite good.