Abstract
M.A. (Psychology)
Specific learning disability (SLD) implies an inability to learn in an efficient manner. An SLD child may be defined as a child with a disability in one or more of the areas of speech, language, reading writing or other school subjects, where the disability cannot be ascribed to a generally low cognitive ability, sensory disability, emotional disturbance,
cultural deprivation or bad teaching methods, but may be attributed to an underlying brain dysfunction.
One of the most important symptoms of SLD is an attentional deficit. There are, however, many questions regarding the nature and extent of the attentional deficit and this study attempted to provide more information in this area.
Possible attentional deficits may be investigated by considering a person's ability to pay attention to relevant stimuli, as well as his ability to ignore irrelevant stimuli. Two experimental conditions, attention and disregard, were set up in this study. Firstly, the
attention and disregard conditions were compared to provide a better understanding of these processes, by establishing whether the two experimental conditions produced differences in level of arousal in the subjects as reflected in the electrical activity of the brain. The primary question was then investigated, namely whether SLD children showed attentional deficits when instructed to pay attention to relevant stimuli as well as when instructed to ignore irrelevant stimuli. The secondary question considered was whether SLD children's attentional deficits were related to a lag in brain development.
These issues were investigated by comparing 57 SLD and 57 normal boys of the same age in terms of the auditory evoked potential (AEP). AEPs were analysed in terms of amplitude, latency and complexity (number of components) •
Significantly higher amplitudes were found during the attention than during the disregard condition in both SLD and normal boys. This was interpreted as an indication of an increased level of arousal during the attention condition. Longer latencies were found during the attention than during the disregard condition in both groups. This was regarded as an indication that more time was spent on information processing during the attention condition, perhaps as a result of the greater amount of information whi~h
had to be processed during this condition.
The following statistically significant differences between the SLD and normal groups were obtained. SLD boys had higher amplitudes than normal boys during the attention and especially during the disregard condition.
This suggested a higher level of arousal in SLD than in normal children. The SLD child's level of arousal is probably too high to pay efficient attention to relevant stimuli, but especially tbo high to ignore irrelevant stimuli.
There were also indications of differences in level of brain development.
SLD subjects had longer latencies and fewer components than normals.
These were regarded as indications of retarded brain development in SLD as compared with normal boys. Because of the lag in brain development, there is a slower rate of information processing as measured by latency differences, and a less differentiated style of information processing as measured by complexity differences, in SLD subjects. The lag in brain development might, in fact, be the basis for SLD boys attentional deficits.
Implications of these findings for areas such as remedial education were also discussed.