Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)


This research compared the short-term memory deficit and the verbal ability deficiency theories of reading disability by examining reaction time performance of good readers and inferior readers in both primary and secondary memory tasks, using a combination of the Sternberg memory scanning paradigm and the Brown-Peterson distractor tasks. One hundred ninety-two Louisiana State University students from the psychology and remedial reading departments were randomly assigned to one of eight experimental groups. Subjects received test material of either four or two item memory sets. The 48 test trials consisted of three trials from each of 16 different categories, with trials grouped together within categories. This manipulation produced an interference effect with the first trial of a category representing low interference and the third trial representing high interference. Negative and positive probes were represented equally with negative probes chosen from the current taxonomic category. Reaction times of poor readers were greater than those of good readers. The readers display comparable semantic interference effects, and there was no consistent pattern in error percentages among the two types of readers. Overall, the results support the short-term memory deficiency theory of reading disability with the dysfunction located at the encoding stage of processing. No support for the verbal ability deficit theory was obtained.