Byron P. Rourke

Neuropsychological significance of variations in patterns of academic performance: verbal and visual-spatial abilities.

Forty-five 9- to 14-year-old children with learning disabilities whose WISC Full Scale IQs fell within the range of 86–114 were divided into three groups on the basis of their patterns of reading, spelling, and arithmetic achievement. Group 1 was composed of children who were uniformly deficient in reading, spelling, and arithmetic; children in Group 2 were relatively adept at arithmetic as compared to their performance in reading and spelling; Group 3 was composed of children whose reading and spelling performances were average or above, but whose arithmetic performance was relatively deficient. The performances of these children on 16 dependent measures were compared. The performances of Groups 1 and 2 were superior to that of Group 3 on measures of visual-perceptual and visual-spatial abilities; Group 3 performed at a superior level to that of Groups 1 and 2 on measures of verbal and auditory-perceptual abilities. The results are discussed in terms of the relationships between varying patterns of academic abilities and patterns of brain-related behaviors, and the nature of the neuropsychological abilities that may limit performance on arithmetic calculation tasks.

Arithmetic Disabilities, Specific and Otherwise A Neuropsychological Perspective

From a neuropsychological perspective, this article summarizes research that addresses some of the developmental interactions of disabilities in reading, spelling, and mechanical arithmetic. The focus is on two subtypes of children with learning disabilities who exhibit equally impaired levels of arithmetic achievement, but with vastly different patterns of neuropsychological assets and deficits. Qualitative as well as quantitative analyses lead to the conclusion that one of these patterns of neuropsychological assets and deficits (i.e., the nonverbal learning disabilities syndrome; NLD) leads—at the same time and in much the same manner—to specific patterns of impairment in mechanical arithmetic and in psychosocial functioning. The other pattern (Group R-S) is found to lead to particular patterns of academic deficits (including arithmetic), but not to any particular level or type of psychosocial dysfunction. The manifestations of the NLD profile in various types of neurological disease, disorder, and dysfunction are also explored.

Central processing deficiencies in children: Toward a developmental neuropsychological model

Abstract A recent theoretical position (Goldberg & Costa, 1981) is employed as a framework for a neurodevelopmental model of central processing deficiencies in children. The model, which emphasizes differences between right-hemisphere and left-hemisphere systems, is shown to embrace a wide variety of behavioural phenomena that have been observed in normal children and in various subtypes of learning-disabled children. Dynamic factors operative within the development of both normal and disabled learning are addressed and incorporated.

Syndrome of nonverbal learning disabilities: The final common pathway of white-matter disease/dysfunction?

Abstract The nonverbal learning disabilities (NLD) syndrome is described, and a model designed to encompass its complex manifestations is derived on the basis of the theory of Goldberg and Costa (1981), as extended by Rourke (1982). The commonality exhibited by children and adolescents suffering from a variety of types of neurological disease, disorder, and dysfunction is viewed as their shared deficiencies in the white- matter functions necessary for intermodal integration. Some theoretical and clinical implications of this model are discussed, including the possibility that there may be a continuum of developmental neurological disease and neuropsychiatric disturbance characterized by variations in the severity of the NLD syndrome and its hypothesized relationship to white-matter dysfunction.

Principal Identifying Features of the Syndrome of Nonverbal Learning Disabilities in Children

The identifying features of the syndrome of nonverbal learning disabilities (NLD) were examined with a view to determining their relative discriminant validity. A stepwise linear discriminant function analysis of children with NLD (n = 29), children with reading and spelling disabilities (Group R-S; n = 27), and a group of nonclinical children (NC; n = 27) on 15 neuropsychological variables yielded a subset of scores on four tests (Target Test; Trail Making Test, Part B; Tactual Performance Test; and Grooved Pegboard Test) that accurately (>95%) discriminated the NLD group from the R-S and NC subjects. Of the neuropsychological features of NLD described by Rourke (1987, 1988b, 1989), deficits in visual-perceptual-organizational psychomotor coordination and complex tactile-perceptual skills appeared to be most representative (in the sense of most discriminative) of the NLD syndrome in the children examined. These are also the dimensions that are considered to be “primary” in the NLD model (Rourke, 1989). Replication of these results, employing children with other clinical disorders, is necessary.

Disabilities of Arithmetic and Mathematical Reasoning Perspectives From Neurology and Neuropsychology

Current research on brain–behavior relationships in disabilities of arithmetic and mathematical reasoning is reviewed from both a neurological and a neuropsychological perspective. Although no entirely satisfactory statement of the relationship between arithmetic skills and brain functions has yet emerged, investigators in this area have provided evidence regarding the involvement of some brain systems in processes of calculation. Also, the developmental importance of right- versus left-hemisphere integrity for the mediation of arithmetic learning and performance has been suggested. We propose that an account of brain–behavior relationships in children intended to explain and predict developmental disabilities of arithmetic learning needs to address several important content and processing distinctions in order to (a) encompass empirically derived subtypes of children with learning disabilities who exhibit difficulties with arithmetic and (b) provide adequate direction for future subtyping and intervention research.

Identification of subtypes of retarded readers: A neuropsychological, multivariate approach

Abstract Subtypes of reading-disabled children were identified by means of a multivariate classification procedure. These subtypes are described in terms of their differential patterns of performance on a comprehensive battery of neuropsychological measures. Comparisons are made with subtypes identified by previous investigators, and some hypotheses with respect to the neuropsychological implications of the results are presented.

The Validity of Discrepancy-Based Definitions of Reading Disabilities

This study addressed the validity of distinguishing children with reading disabilities according to the presence or absence of discrepancies between intelligence test scores and academic achievement. Three definitions of reading disability were used to provide criteria for five groups of children who (a) met a discrepancy-based definition uncorrected for the correlation of IQ and achievement; (b) met a discrepancy-based definition correcting for the correlation of IQ and achievement; (c) met a low achievement definition with no IQ discrepancy; (d) met criteria a and b; and (e) met none of the criteria and had no reading disability. Comparison of these five groups on a set of 10 neuropsychological tests corrected for correlations with IQ showed that group differences were small and accounted for little of the variability among groups. These results question the validity of segregating children with reading deficiencies according to discrepancies with IQ scores.

A Childhood Learning Disability that Predisposes Those Afflicted to Adolescent and Adult Depression and Suicide Risk

A particular subtype of learning disability (nonverbal learning disability) is described. This subtype of individuals with learning disability is seen to be at particular risk for depression and suicide. The origins of the study of this subtype of learning disability, its incidence in various forms of neurological disease, disorder, and dysfunction, and its behavioral and socioemotional manifestations (including its association with significant internalized forms of psychopathology) are described. A case history of a young woman who manifests this disability and who has attempted suicide on three occasions is also presented.

The syndrome of nonverbal learning disabilities: Developmental manifestations in neurological disease, disorder, and dysfunction

Abstract The syndrome of Nonverbal Learning Disabilities (NLD) is characterized by deficient performances in visual-spatial-organizational abilities, complex psychomotor and tactile-perceptual skills (both usually more marked on the left side of the body), and conceptual/problem-solving abilities. Over the course of development, above-average facility in single-word reading and spelling and below-average skills in mechanical arithmetic are evident. Extreme difficulties in dealing with novel and otherwise complex material are especially apparent. Automatic, rote language skills become increasingly well developed and socio-emotional disturbances of the internalized variety become increasingly more apparent with advancing years. These and other developmental manisfestations of the NLD syndrome are examined within the context of several types of neurological disease/developmental disabilities, including cranio-cerebral trauma, hydrocephalus, and autism, and are related to a developmental model (Rourke, 1987) ...