Michael E. Murray

Review: neurophysiologic aspects of developmental dyslexia.

The disorder of developmental dyslexia is reviewed. Clinical manifestations, symptom patterns, and classification systems are outlined. Neuropsychological dimensions of dyslexia, including maturational lag, impaired cerebral dominance, EEG, evoked potential, biochemical correlates, and neuroanatomic abnormalities are discussed with reference to theoretical and research findings.

Span of Apprehension in Learning Disabled Boys

The spans of apprehension of learning disabled and normal boys were compared by means of a forced-choice letter recognition task developed by Estes (1965). This task provides an estimate of the span, which is relatively insensitive to either memory or motivational influences. In experiment 1 the span size was found to be the same for both groups when visual “noise” was absent. In the presence of noise, span size for the learning disabled boys was reduced. It is argued that this reduction in span size represents a true deficit in atrention. In experiment 2, the influence of variations in the amount of physical similarity between signal and noise letters on the spans of both groups were compared to determine whether noise letters act as more potent distractors for the learning disabled boys. The results indicate that the spans of both groups were influenced equivalently No evidence for a distractibility explanation was obtained.

Visual Persistence and Information Pick-up in Learning Disabled Children

Psychophysical tasks were used to test two possible explanations for the lower spans of apprehension observed for learning disabled subjects by McIntyre, Murray, Coronin, and Blackwell (1978). In Experiment 1, the length of visual persistence was found to be less for LD subjects. In Experiment 2, the rate of information pick-up was found to be slower for LD subjects. Clearly, either or both of these explanations may account for the lowered spans of apprehension observed for LD subjects by McIntyre et al. The implications of these results for the reading difficulties encountered by LD children and for remediation techniques involving saccadic eye movement training are discussed.

The Relationship between Personality Adjustment and Success in Remedial Programs in Dyslexic Children.

Abstract Dyslexic and a normal group consisting of 104 children each were matched with reference to age, income, intelligence, and sex. Specific personality dimensions including self-concept, achievement motivation, general manifest anxiety, test anxiety, and behavior deviance were measured. Dyslexic children showed poorer adjustment in all areas of personality. Comparison of results within the dyslexic group showed that children who are successful in remedial training show better emotional adjustments than unsuccessful dyslexic children. A stepwise multiple regression analysis employing personality variables and overall success in remedial language training was computed. Classroom behavior and self concept were found to correlate with success and yielded a multiple correlation of .544. Results are discussed with reference to remediation and treatment.

An analysis of visual-motor problems in learning disabled children

The nature of visual-motor problems in learning disabled children was examined in four conditions designed to determine whether more errors were made by learning disabled children, and whether the errors were primarily perceptual, conceptual, motoric, or some combination of these in nature. The same two groups of children were used in each condition. One group contained 20 children (mean age = 10 years, 7 months) who had been diagnosed as learning disabled. The control group contained 20 children who were matched with the learning disabled children on age, sex, IQ, and SES. The learning disabled children evidenced visual-motor problems under a visual-motor condition that was modeled after the Bender Visual Motor Gestalt Test. In three other conditions, the visual-perceptual, perceptual-conceptual, and motor-coordinative components of the visual-motor condition were examined separately. The results of these conditions indicated that the visual-perceptual and perceptual-conceptual components of the visual-motor system were intact for the learning disabled children; however, both the motor-coordinative component and the integration between the visual-perceptual and the motor-coordinative components were disturbed. The implications of these results for the visual-motor problems of learning disabled children were discussed.

Visual selective attention in learning disabled and normal boys

Learning disabled and normal control boys were compared in a reaction time task that required same-different judgments about the size or shape of visually presented geometric forms. In one condition, the subject was told which aspect (either size or shape) to judge before the presentation of the forms; in the other condition, the subject was told which aspect to judge after the forms were presented. The results indicated that the reaction times of the learning disabled boys were significantly slower than those of the normal controls in both conditions. Evidently, deficits in selectivity are characteristic of learning disabled boys at the levels of both sensory-perceptual input and short-term memory.

Diagnostic Psychological Testing for Reading/Learning Disorders in Preschool Children.

ABSTRACT The assessment of preschool children who are at risk for having specific language/learning disorders when they enter school is a complex undertaking which must involve examining a wide variety of developmental processes. In addition to a thorough medical, developmental and academic history, the clinician should obtain data regarding perceptual‐motor functioning, language and cognitive development, nominal recall, cerebral dominance and directionality, sequential memory, and the integrity of basic sensory modalities. Although the diagnosis of potential learning disorders in preschool children 1s difficult because of the variability in developmental rate of young children, a systematic evaluation of the developmental functions which are classically associated with learning disabilities allows the psychologist to make a responsible and generally accurate statement of the childs current functioning and future potential