Span of apprehension in learning disabled boys.

Abstract

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.