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Biomedical subjects

H L Swanson

Publications and source records attributed to H L Swanson.

At least 37 records · Page 2Linked to original sources
PubMed1989

Working memory in skilled and less skilled readers.

This study assessed skilled and less skilled readers' working memory performance. Fifty skilled and less skilled readers at two age levels were presented with sentence span and concurrent memory tasks. The span task results indicated that working memory differences exist between reading groups. The concurrent task revealed performance deficits for less skilled readers across verbal and nonverbal conditions, suggesting a central processing deficiency. Age differences were isolated to skilled readers. It was concluded that less skilled readers' working memory deficiencies were pervasive in the sense that they involve deficiencies in memory components related to central executive processing.

Attention↗
PubMed1989

The effects of central processing strategies on learning disabled, mildly retarded, average, and gifted children's elaborative encoding abilities.

The purpose of these studies was to examine potential central processing strategy differences among subgroups of children on a series of elaborative encoding tasks. To this end, two experiments included four ability groups (slow learners, learning disabled, average, and intellectually gifted children) who recalled words embedded in sentences. In general, the results suggest that lower verbal and learning ability subgroups recalled less information during elaboratorive encoding conditions than higher ability groups. More importantly, however, the results indicated that lower ability groups differed from higher ability groups in how they shared, discriminated, and selectively allocated resources between the central and secondary recall tasks. The results were discussed within a framework that views individual differences in encoding as reflecting central processing (i.e., resource monitoring) deficiencies.

Aptitude↗
PubMed1988

Characteristics of frequently cited articles in mental retardation.

The purpose of this article was to identify and characterize prominent journal publications in the field of mental retardation from 1976 to 1985. Based on the frequency of citations in the Social Science Citation Index, 24 prominent articles were identified. Prominent (i.e., frequently cited) articles were compared with randomly selected articles on a number of characteristics (e.g., funding source, research, design, statistical method). Implications related to the characteristics and quality of articles that influence the mental retardation field were discussed.

Humans↗
PubMed1987

What learning-disabled readers fail to retrieve on verbal dichotic tests: a problem of encoding, retrieval, or storage?

Three theoretical models were assessed as a framework for capturing learning-disabled readers' faulty word retrieval. To this end, learning-disabled and skilled readers were compared on verbal dichotic listening tasks for free recall and cued recall of word lists organized by semantic, phonemic, and structural features. The results indicated that disabled readers were comparable on free recall but were inferior to skilled readers on cued recall. No ability group differences were found for categorical and noncategorical recall intrusions during the cued recall phase. Cued recall performance was further analyzed for individual differences in memory trace structure (via the Tulving & Watkins, 1975, reduction method), ear asymmetry, and the allocation of attention to word features prior to cuing. Results indicated that during the cued recall phase, disabled readers' memory traces were inferior in structure to those of skilled readers, even though the two ability groups produced comparable symmetrical recall patterns for the ear presentations. Further, disabled readers had lower selective attention scores for the interhemispheric processing of information prior to cuing than did skilled readers. Taken together, the results suggest that, prior to cued recall, disabled readers suffer from attentional difficulties during interhemispheric processing, which in turn influences the structural formation of their memory trace.

Child↗
PubMed1987

The effects of self-instruction training on a deaf child's semantic and pragmatic production.

Effects of self-instruction training on the communication skills of a profoundly hearing-impaired child were studied. Self-instruction training included modeling a series of problem-solving steps in order to direct communication production. Communication production was operationalized as signed semantic and pragmatic functions. A multiple baseline was used to assess treatment and generalization (treatment variations of person and setting) effects. There was evidence to suggest that self-instruction was immediately effective on pragmatic behaviors but such behaviors were reduced when another person administered treatment. In contrast, self-instruction training had a gradual influence on semantic behaviors and those effects were maintained when treatment included a different person and setting. Implications of the clinical study were discussed.

Behavior Therapy↗
PubMed1987

The combining of multiple hemispheric resources in learning-disabled and skilled readers' recall of words: a test of three information-processing models.

Three theoretical models (additive, independence, maximum rule) that characterize and predict the influence of independent hemispheric resources on learning-disabled and skilled readers' simultaneous processing were tested. Predictions related to word recall performance during simultaneous encoding conditions (dichotic listening task) were made from unilateral (dichotic listening task) presentations. The maximum rule model best characterized both ability groups in that simultaneous encoding produced no better recall than unilateral presentations. While the results support the hypothesis that both ability groups use similar processes in the combining of hemispheric resources (i.e., weak/dominant processing), ability group differences do occur in the coordination of such resources.

Cerebral Cortex↗
PubMed1986

Do semantic memory deficiencies underlie learning disabled readers' encoding processes?

This study investigates the extent to which learning disabled readers' atypical encoding relates to their deficiencies in semantic memory. Inferences related to ability group performance were based on the assumption that encoding involves the matching of incoming information against a featural representation of that information in semantic memory. To this end, learning disabled and nondisabled readers in two age groups were compared on dichotic listening recall tasks that included orienting and nonorienting instructions. Orienting instructions directed children's attention toward semantic, phonemic, or structural word features. Dependent measures were lateralization, free recall, retrieval organization, and selective attention. The efficiency of allocating attentional resources was inferred from correlations between central and incidental recall. Primary results included the following: Disabled and nondisabled readers' ear asymmetry differences were dependent upon age, orienting instructions, and type of word list; disabled readers' recall and organization scores were lower than skilled readers'; however, both ability groups benefitted from orienting instructions compared to nonorienting instructions; during orienting instructions, disabled readers were less able than skilled readers to divide their attention between target and nontarget word features, especially during interhemispheric processing conditions; and the relative efficiency of allocating attentional resources differed qualitatively between the two ability groups. The results suggest that ability group variations reflect the structure of the memory trace in interaction with ear presentation and encoding processes. It is inferred that disabled readers' inferior memory traces reflect the quantity and internal coherence of information stored in semantic memory as well as the means by which such information is accessed.

Attention↗
PubMed1984

Semantic and visual memory codes in learning disabled readers.

Two experiments investigated whether learning disabled readers' impaired recall is due to multiple coding deficiencies. In Experiment 1, learning disabled and skilled readers viewed nonsense pictures without names or with either relevant or irrelevant names with respect to the distinctive characteristics of the picture. Both types of names improved recall of nondisabled readers, while learning disabled readers exhibited better recall for unnamed pictures. No significant difference in recall was found between name training (relevant, irrelevant) conditions within reading groups. In Experiment 2, both reading groups participated in recall training for complex visual forms labeled with unrelated words, hierarchically related words, or without labels. A subsequent reproduction transfer task showed a facilitation in performance in skilled readers due to labeling, with learning disabled readers exhibiting better reproduction for unnamed pictures. Measures of output organization (clustering) indicated that recall is related to the development of superordinate categories. The results suggest that learning disabled children's reading difficulties are due to an inability to activate a semantic representation that interconnects visual and verbal codes.

Adolescent↗
PubMed1983

A developmental study of vigilance in learning-disabled and nondisabled children.

To test the proposition that learning-disabled children manifest a sustained attentional deficit, the Continuous Performance Test was administered to learning-disabled and nondisabled children at three age levels. Children were tested on three task lengths (5, 10, and 15 minutes) and two modalities (auditory and visual) in which dependent measures were correct detections and false responses, d' and B values. As expected, learning-disabled children male fewer correct detections and more false responses and were less sensitive (d') to critical stimuli than were nondisabled children at all ages. There was also evidence to indicate that learning-disabled children apply different response criteria across age when compared to nondisabled children. B values varied significantly across age, group, modality, and time on task; d' remained relatively unchanged across time periods. The popular notion that learning-disabled and younger subjects start a vigilance task with the same capacity as nondisabled older children but show a decline in attention as time on task increases was not supported.

Adolescent↗
PubMed1983

Hemispheric specialization in learning disabled readers' recall as a function of age and level of processing.

This study was designed to test the inadequacy of two theoretical accounts of learning disabled readers' memory deficiencies. Two age groups of learning disabled and nondisabled readers were compared on diotic and dichotic listening recall tasks for semantically organized, phonemically organized, and categorically unrelated word lists presented in either the left, right, or both ears. Dependent measures were free recall, serial recall, recall organization, and hierarchical organization. As expected, recall increases were a function of age, group, and level of word processing. However, the results clearly demonstrated that age and group recall differences were an interaction of both mode of presentation and level of processing. The recall differences between reading groups were attributed to word knowledge (superordinate categorization) rather than recall organization within cerebral hemispheres or differences in hemispheric capacity, per se.

Adolescent↗