A comparison of language deficits in learning-disabled, head-injured, and nondisabled young adults: results from an abbreviated Aphasia Screening Test.

This study used an Aphasia Screening Test (AST) abbreviated to its naming, pronunciation, and sentence interpretation items to compare groups of 60 learning-disabled (LD), 30 head-injured (HI), and 30 nondisabled (ND) young adults matched for FISQ and balanced for gender composition. The LD and HI, who did not differ, made significantly more AST errors than the ND. One-quarter to one-third of the LD and HI subjects exhibited language deficits. For the clinical groups only, AST errors, particularly pronunciation errors, were related negatively to WRAT reading and spelling scores. The Reitan and Wolfson (1988) severity ratings for AST items did not improve group discrimination.

Encoding and retrieval processes in learning-disabled, head-injured, and nondisabled young adults.

Using a multi-trial, free-recall paradigm (Rey Auditory-Verbal Learning Test; Lezak, 1983), the acquisition and retention by learning disabled (LD) young adults with a Halstead Impairment Index less than or equal to 0.3 (low LD) or greater than or equal to 0.4 (high LD) was compared with that of nondisabled and head-injured (HI) young adults. Significant group differences, particularly during the last three acquisition trials, confirmed the effectiveness of this method in revealing subtle learning and retention deficits. Analyses of Trial 1 recall showed group differences in the prerecency but not the recency portion of the serial position curve, thus implicating long-term but not short-term memory differences between the groups. Analyses of pair frequency (Sternberg & Tulving, 1977) data showed that the three clinical groups had difficulty organizing the to-be-learned material for effective retrieval. Following an interpolated task, retention was poorer for the clinical groups than for the nondisabled and varied inversely with the degree of neuropsychological impairment. Finally, during retention, the nondisabled and low LD groups retained and used the list organization established during acquisition whereas the high LD and HI groups did not.

Phonetically inaccurate spelling among learning-disabled, head-injured, and nondisabled young adults.

We applied the Boder and Jarrico (1982, The Boder Test of Reading-Spelling Patterns, New York: Grune & Stratton) criteria to the WRAT spelling list and examined the phonetically inaccurate spelling error patterns of learning-disabled (LD), head-injured (HI), and nondisabled young adults. Phonetically inaccurate (PI) errors were reliably rated (interrater r = .94) and were correlated significantly more strongly with dysphasic errors (r = .33) than with dyscopia (r = .16). ANOVA showed that LD and HI, which did not differ, made significantly more PI errors than both nondisabled and HI. These results indicate that PI errors reflect an underlying language disorder. The results also suggest that PI errors are more frequent in brain-related disorders. Finally, when group differences in cognitive ability are statistically controlled, PI errors are more common only among LD persons.