Computer speech-based training of literacy skills in neurologically impaired children: a controlled evaluation.

Twenty-two reading-disabled children were randomly assigned to one of four training conditions to evaluate the effectiveness of a computer speech-based system for training literacy skills. The sample included 17 children with significant neurological impairment of various etiologies (including spina bifida and hydrocephalus, seizure disorder, brain tumors, cerebral palsy, and head injury) and five developmental dyslexics. The training employed a "talking" computer system that provides synthesized speech feedback during the course of learning. The training conditions included three word recognition and spelling-training programs and a math-training control program. Three different literacy-training procedures were compared, with the size of the trained print-to-sound unit varying as letter-sound (LSD: train-->t/r/ai/n); onset-rhyme (OR: train-->tr/ain) and whole word units (WW: train-->train). All literacy-training groups made significant gains in word recognition and spelling, with the LSD- and OR-trained subjects making the greatest word recognition gains on the words that could be trained with segmented speech feedback (i.e., words with regular spelling-to-sound patterns). All literacy-training groups demonstrated significant transfer on uninstructed rhymes of instructed regular words, with the greatest degree of transfer achieved by the LSD-trained subjects. These findings suggest that the neurologically impaired children were able to profit from instructional procedures that segment the printed word into units corresponding to onsets, rhymes, and phonemes and that this segmentation training may facilitate transfer-of-training for them.

Treatment, subtype, and word type effects in dyslexic children's response to remediation.

Children diagnosed as accuracy-disabled or rate-disabled readers (Lovett, 1984a, 1986, 1987) were randomly assigned to one of three treatment conditions providing training in word recognition and decoding skills (DS), oral and written language (OWLS), or classroom survival skills (an alternative treatment control). The experimental treatment programs exerted a positive treatment effect on the word recognition performances of both groups, but treatment-specific changes in contextual reading and oral language skill were not observed. Pre- and post-treatment comparisons on an experimental word recognition task revealed a post-test advantage for DS-trained children of both subgroups. Accuracy-disabled readers demonstrated treatment-specific gains for both orthographically regular words (e.g., wade) and for exception words (e.g., broad), with their gains greater on exception words. Rate-disabled children demonstrated treatment-specific gains only for exception words, but exhibited these gains following both the DS and the OWLS treatments. Although both experimental treatment programs were associated with a positive outcome for the rate disabled subgroup, DS training was associated with relatively greater treatment gain. These data suggest that the critical variables underlying the effectiveness of the DS treatment include the specific lexical knowledge these disabled readers acquired, their greater reliance on an orthographic pattern procedure in word recognition, and/or the fact that newly acquired items were practiced to a point approximating automatization.

Methylphenidate increases selectivity of visual scanning in children referred for hyperactivity.

Visual scanning patterns were investigated in 32 children referred for symptoms of hyperactivity in a double-blind crossover comparison of methylphenidate and placebo treatments. Total errors, response latency, and visual fixations were recorded as the child scanned computer-generated visual matching-to-sample problems. Results indicated that the number of fixations on the standard stimulus in the matching task was significantly larger in the methylphenidate state. Drug treatment also resulted in a significant increase in the number of systematic comparisons between the standard and the variants in the task. However, the increased selectivity of attention to the standard stimulus was not accompanied by a reduction of total errors. It was suggested that the stimulant drug may increase attentional selectivity even when such a shift fails to produce improvement in task performance.

The effects of lexical and semantic information on same-different visual comparison of words.

Previous research has indicated that phonemic and orthographic factors cannot account for the fact that words (clear/clear) are responded to more rapidly than orthographically legal nonwords (creal/creal) in a same-different visual comparison task. However, the role of semantic and lexical factors is less certain. The effects of semantic similarity on both same and different judgments were evaluated in several experiments. In the first experiment, subjects were not any slower on semantically related (rang/rung) than on unrelated (rang/rank) different judgments even with a 3,000-msec interval between the first and second word. In Experiment 2, subjects based their judgments on whether or not the first letter of each word was visually identical. Same judgments were not any faster for semantically related than unrelated items even though other evidence indicated that subjects were processing the whole word and not just the first letter. Experiment 3 showed that the word/orthographically legal nonword difference could be replicated with the first-letter visual comparison task employed in Experiment 2. These and related results were discussed with reference to the idea that the word/orthographically legal nonword difference is due to the facilitating effects of a lexical entry upon the encoding, but not the comparison of an item.

Locus of the effect of a distinguishing feature in a memory search task.

Subjects memorized one to four 8- or 16-sided random forms in a memory search task. The positive set forms ("yes" response) differed in number of sides from the negative set forms ("no" response) for the different set (DS) group, but this distinguishing feature was not available to the same set (SS) group. Mean reaction time increased as a linear function of log(2) of the positive set size for both groups, but the increase was greater for the SS than the DS group, suggesting that memory search rather than an encoding stage of information processing was influenced by the availability of a distinguishing feature. In a transfer task which followed, new forms were introduced in which the positive and negative set forms differed in number of sides for both groups. In this task, the two groups did not differ in memory search, but in encoding. It was proposed that (a) availability of a distinguishing feature influences search time because the information specifying the number of sides of the set of memorized forms can be used to influence the speed with which individual forms are examined in memory; (b) previous experience with a distinguishing feature influences encoding because the DS group had learned to extract the information specifying the set of memorized forms (not the information specifying individual forms) more efficiently than the SS group.