TY - JOUR
AU - Golden, Gerald S.
AB - Most investigator now agree on the existence of abnormalities of brain function in children with learning disabilities with or without hyperactivity. However, attempts to define the neurobiological substrates have been hindered by many factors. On the clinical level, learning disability is not a monolithic entity but an operational term used to define a number of specific conditions. The only common feature is difficulty with school performance in the face of normal intelligence. Until homogeneous subgroups can be defined, there is no good reason to suspect a single, discrete biological marker. Neuropathological studies are limited to 2 cases. Attempts to visualize the brain by computerized tomography have provided limited but inconsistent evidence of variations from normal hemispheric widths and asymmetries. Neurophysiological studies have succeeded in separating learning disabled children from normal controls by the application of discriminant analysis and other statistical techniques. Computer‐assisted analysis of brain bioelectrical activity has sharpened these tools. Unfortunately, the techniques have not been able to narrow the focus to single, discrete cerebral areas; rather, they have shown dysfunction in widely separated but probably interconnected regions. The only neurochemical studies available have been performed on hyperactive childŕen rather than on patients with uncomplicated learning disabilities. A hypothesis that the underlying pathophysiology involves dopamine depletion has the most support and provides an explanation for some of the therapeutic effects of psychostimulant drugs. Problems are the focus on motor aspects of hyperactivity rather than the attention deficit and heavy dependence on the use of clinical rating scales. The biochemical analyses and conclusions would be more powerful if better psychophysiological markers could be developed, including such factors as attentiveness, distractability, vigilance, attention span, and reaction time. The results of physical and neurological examinations as well as of clinical genetic studies also point toward a biological basis for learning disabilities. These clinical tools help to sharpen our focus but still provide insufficient specificity. Productive search will require close collaboration between neuropsychologists and investigators using the quantitative tools of neuroanatomy, neurophysiology, and neurochemistry.
TI - Neurobiological correlates of learning disabilities
JF - Annals of Neurology
DO - 10.1002/ana.410120502
DA - 1982-11-01
UR - https://www.deepdyve.com/lp/wiley/neurobiological-correlates-of-learning-disabilities-A0r7M90a7D
SP - 409
EP - 418
VL - 12
IS - 5
DP - DeepDyve
ER -