Attentional modulation of visual processing in adult dyslexia: a spatial-cuing deficit

Anumber of researchers have suggested that deficient visual attention may play a causal role in dyslexia. However, traditional methods for investigating this assertion have been limited by the conflation of sensory and attentional factors and the inability to isolate large attentional effects. In this study, we sought to overcome these problems by combining spatial cuing with a visual search task measuring psychophysical thresholds. In normal readers, uncued search performance was characterized by a strong dependence on the number of elements in the stimulus array. Cuing the location of the target removed much of this effect, suggesting attentional facilitation of performance. Although dyslexic participants' performance in uncued search was nearly identical to that of normal readers, all dyslexic participants failed to gain the same effect of cuing that normal readers did. However, dyslexic participants did not differ from normal readers on tests of magnocellular function, suggesting that this spatial-cuing deficit is not merely a secondary consequence of magnocellular dysfunction.     

Factor Structure of the Self-Report Strength and Difficulties Questionnaire in a Diverse U.S. Sample

Journal of Psychopathology and Behavioral Assessment - The Strengths and Difficulties Questionnaire (SDQ) is a widely used mental health screening instrument developed in the United Kingdom that...     

THE REDUCTION OF SELF INJURY IN TWO ADOLESCENTS WITH PROFOUND RETARDATION BY THE ESTABLISHMENT OF A SUPPORTED ROUTINE

Two experiments applied a conceptualization of competence to the treatment of self injury in two adolescents with profound retardation. In Experiment 1, a multiple baseline design across two activity periods was used to assess the effects of reinforcing completion of a five-step packaging routine on repetitious facial hitting in one participant. The rate of facial hits decreased when teachers reduced the latency between a pause by the participant and a prompt from the teacher to continue, pauses having been observed to be followed often by sequence errors, and sequence errors by facial hitting. In Experiment 2, a reversal design was used to compare the effects on head hitting and hand biting by substituting a premeal and dining routine in a second participant. The new routine replaced a largely instructional routine that required discriminations, receptive language, and motor performances not likely to emerge in the participant's repertoire. Discontinuation of the instructional routine reduced self injury; institution of the new routine permitted the development of a highly independent series of performances without reoccurrence of self injury. The combined results of the two experiments point to the potentially evocative nature of common teaching approaches and techniques, and the habilitative effects of designing performance expectations with greater prognosis for acquisition.     

The tale is in the tail: an alternative hypothesis for psychophysical performance variability in dyslexia

Dyslexic groups have been reported to display poorer mean performance than groups of normal readers on a variety of psychophysical tasks. However, inspection of the distribution of individual scores for each group typically reveals that the majority of dyslexic observers actually perform within the normal range. Differences between group means often reflect the influence of a small number of dyslexic individuals who perform very poorly. While such findings are typically interpreted as evidence for specific perceptual deficiencies in dyslexia, caution in this approach is necessary. In this study we examined how general difficulties with task completion might manifest themselves in group psychophysical studies. Simulations of the effect of errant or inattentive trials on performance produced patterns of variability similar to those seen in dyslexic groups. Additionally, predicted relationships between the relative variability in dyslexic and control groups, and the magnitude of group differences bore close resemblance to the outcomes of a meta-analysis of empirical studies. These results suggest that general, nonsensory difficulties may underlie the poor performance of dyslexic groups on many psychophysical tasks. Implications and recommendations for future research are discussed.     

The validity of psychomotor vigilance tasks of less than 10-minute duration

The 10-min psychomotor vigilance task (PVT) has often been used to assess the impact of sleep loss on performance. Due to time constraints, however, regular testing may not be practical in field studies. The aim of the present study was to examine the suitability of tests shorter than 10 min. in duration. Changes in performance across a night of sustained wakefulness were compared during a standard 10-min PVT, the first 5 min of the PVT, and the first 2 min of the PVT. Four performance metrics were assessed: (1) mean reaction time (RT), (2) fastest 10% of RT, (3) lapse percentage, and (4) slowest 10% of RT. Performance during the 10-min PVT significantly deteriorated with increasing wakefulness for all metrics. Performance during the first 5 min and the first 2 min of the PVT deteriorated in a manner similar to that observed for the whole 10-min task, with all metrics except lapse percentage displaying significant impairment across the night. However, the shorter the task sampling time, the less sensitive the test is to sleepiness. Nevertheless, the 5-min PVT may provide a viable alternative to the 10-min PVT for some performance metrics.     

Early receptive and productive language skills in preterm and full-term 8-month-old infants

Early receptive and productive language skills were examined for preterm low birthweight infants and full-term normal birthweight infants from middle-class homes. Nineteen preterm infants and 19 full-term infants were observed in a laboratory setting at the gestationally corrected age of 8 months. To avoid the frequent confound between prematurity and low socioeconomic status, mothers of the two groups of infants were matched on educational levels. Regression analyses were used to assess the relative influence of infant cognitive skills, infant sociability, infant birth status, and the mothers' language input as possible predictors of infant receptive language and vocal behavior. Receptive language skills were associated with higher cognitive performance, greater sociability, and preterm birth. Productive language skills were associated with higher cognitive performance. On the basis of this research, the prognosis for language development in preterm infants raised in middle-class homes appears to be excellent.This research was aided by Social and Behavioral Sciences Research grant No. 12-11 from the March of Dimes Birth Defects Foundation and supported by DHHS Grant HD03352. Computing was provided by the Waisman Center Computing Facility at the University of Wisconsin-Madison. Donna Boylan, Sue DaPra, Maria Kleczewski, Michal Rubin, Susan Silverber, and Paula VanLaanan assisted with data collection.