Hemispheric, attentional, and processing speed factors in the treatment of developmental dyslexia

Aim of the study is to analyze the contributions of hemispheric, attentional, and processing speed factors to the effects of neuropsychological treatment of developmental dyslexia. Four groups of dyslexic children (M-type dyslexia) were treated over a period of four months. A first group (n = 9) underwent Bakker's Hemisphere-Specific Stimulation, with presentation of words in the right and left visual field. A second group (n = 7) received the same stimuli randomly in either visual hemifield. A third group (n = 8) received the same words presented centrally at fixation point. A fourth group (n = 6) received central stimuli with fixed presentation time (1500 ms). The children were tested before and after treatment on reading and spelling measures. All groups improved significantly after treatment on all variables. However, the group that was treated with centrally presented stimuli improved more than the other groups in spelling measures. A possible explanation is that rapid, simultaneous presentation to both hemispheres enhances interhemispheric exchange, which could produce an advantage in tasks requiring a high degree of integration between left and right hemispheric functions, such as spelling. The absence of significant differences in reading improvement may point to the role of memory functions or strategic factors characterizing all the treatment programs, possibly overweighing the effect of the other factors.     

Neuropsychological significance of phonetically accurate and phonetically inaccurate spelling errors in younger and older retarded spellers

The performances of two groups of retarded spellers (who were equated with respect to the level of deficient performance in spelling, but who differed in the level of phonetic accuracy of their misspellings) at two different age levels were compared to those of normal spellers who had been matched for age and WISC Performance IQ with the retarded spelling groups. The results indicated very marked differences in a number of linguistic skills between the normal spellers and the retarded spellers whose misspellings were characterized by phonetic inaccuracy. The performances of the retarded spellers who produced a preponderance of phonetically accurate misspellings differed markedly from those of the normal spellers only when the task demands involved fairly complex linguistic-cognitive operations. For the most part, the differences among the three groups were in evidence only at the older age level studied.     

Spelling development in the Spanish language

This study focused on spelling development in Spanish children from elementary grades. A sample of 1045 was selected from 2nd to 6th grade belonging to four schools in Tenerife Island with an age range between 7 and 12 years old (M = 113.8, SD = 17.6). We administered a standardized writing test that includes diverse subtests to assess spelling, ruled and not ruled, and various written composition tasks (i.e., writing a story based on vignettes, describing a character and writing a story). We calculated the average of correct spellings in each variable and school level, and we also analyzed the type of misspellings that children made across different writing tasks. We found that spelling is acquired by 4th-grade children when it is not ruled, whereas the spelling of ruled words is acquired by 5th-grade children. When we analyzed the misspellings in a dictation task, we found that the children confused spelling of the graphemes c/s/z/x. Across different writing tasks, we found that students committed more misspellings with the graphemes b/v, h y c/s/z/x before they finished the 4th elementary grade.     

Determinants of spelling ability in deaf and hearing adults: Access to linguistic structure

The extent to which ability to access linguistic regularities of the orthography is dependent on spoken language was investigated in a two-part spelling test administered to both hearing and profoundly deaf college students. The spelling test examined ability to spell words varying in the degree to which their correct orthographic representation could be derived from the linguistic structure of English. Both groups of subjects were found to be sensitive to the underlying regularities of the orthography as indicated by greater accuracy on linguistically-derivable words than on irregular words. Comparison of accuracy on a production task and on a multiple-choice recognition task showed that the performance of both deaf and hearing subjects benefited from the recognition format, but especially so in the spelling of irregular words. Differences in the underlying spelling process for deaf and hearing spellers were revealed in an analysis of their misspellings: Deaf subjects produced fewer phonetically accurate misspellings than did the hearing subjects. Nonetheless, the deaf spellers tended to observe the formational constraints of English phonology and morphology in their misspellings. Together, these results suggest that deaf subjects are able to develop an appreciation for the structural properties of the orthography, but that their spelling may be guided by an accurate representation of the phonetic structure of words to a lesser degree than it is for hearing spellers.     

Influence of auditory-verbal, visual-verbal, visual, and visual-visual processing speed on reading and spelling at the end of Grade 1

This study examined cognitive processing speed through four modalities (auditory-verbal, visual-verbal, visual, and visual-visual) at the end of Grade 1 and how it influences reading and spelling. The subjects were 124 French-speaking children, selected for their contrasting performance on reading and spelling tasks. The children in the first group (N=69) were average readers; the second group of children (N=55) performed worse or much worse on all reading and spelling tasks. The experimental design consisted of a set of 10 tasks administered in two sessions. The major findings reveal that: (1) the children with reading difficulties displayed low and slow performance on most cognitive tasks, whatever the modality; (2) auditory-verbal and visual-verbal processing speed significantly predicted written language, which was not the case with the visual modalities; and (3) that visual problems did not appear to be a potential cause of reading problems in most delayed readers. The findings also confirm the independence of phonological and naming-speed skills in reading development and reading impairment.     

Comparison between Oral and Written Spelling in Alzheimer's Disease

Written and oral spelling were compared in 33 patients with Alzheimer's disease (AD) and 25 control subjects. AD patients had poorer spelling results which were influenced by orthographic difficulty and word frequency, but not by grammatical word class. Lexical spelling was also more deteriorated than phonological spelling. Moreover, oral spelling was more impaired than written spelling in AD patients, whereas no difference was present between oral and written spelling of controls. Analysis of spelling errors showed that, for controls, errors were predominantly phonologically accurate in both spelling tasks. Significantly, AD patients produced more phonologically accurate than inaccurate errors in written spelling, whereas these errors did not differ in oral spelling. In contrast to controls who produced more constant than variable responses in oral and written spelling, AD patients made more variable responses (words correctly spelled in one task but incorrectly in the other) and they showed many instances of variable errors (different misspellings from one spelling task to the other). Two stepwise regression procedures showed that written misspellings were specifically correlated with language impairment, whereas oral spelling errors were correlated with attentional and language disorders. These results suggest that AD increases the attentional demands of oral spelling process as compared to written spelling. This dissociation argues, either for a unique Graphemic Buffer in which oral spelling requires more attentional resources than written spelling or for the hypothesis of separate buffers for oral and written spelling.     

语义距离半球效应的ERP研究

以通过视觉通路呈现的汉语双字词为实验材料,操纵启动词与目标词的语义距离。在词汇决定实验中记录ERP,发现：（1）除N300外,P240亦对语义距离敏感,它可能是一种与语义加工有关的新的ERP成分;（2）P240在头皮中央偏左的部位较早出现,但在头皮右侧波幅较大;（3）N300和P240都不存在语义距离的半球效应,该结果没有证实右脑更专擅远距离语义加工的假设,表明使用汉语与使用拼音文字的脑机制存在差异。     

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.     

Hemispheric alpha asymmetries and behavioral responses of aphasic and normal subjects for the recall and recognition of active, passive, and negative sentences

The hemispheric alpha asymmetries of a group of normal males, a group of normal females, and a group of aphasic patients (fluent and dysfluent) were examined with electroencephalographic (EEG) techniques under memory conditions of recall and recognition of active, passive, and negative sentences. Aphasic patients, regardless of classification, showed right hemispheric alpha suppression across memory conditions and sentence types. Both normal groups were found to have greater left hemispheric alpha suppression for the recall memory condition and greater right hemispheric alpha suppression for the recognition memory condition (males significantly more than females). The aphasic subjects performed better on recognition tasks compared to recalled tasks and active sentences compared to transformed sentences. Results are discussed as providing evidence of the aphasic subjects' greater dependency on information processing resources of the right hemisphere in the recovery of language function. The findings are also discussed as providing support for a multiple-resources model of information processing.     

Sex differences in cerebral laterality of language and visuospatial processing

Sex differences on language and visuospatial tasks are of great interest, with differences in hemispheric laterality hypothesized to exist between males and females. Some functional imaging studies examining sex differences have shown that males are more left lateralized on language tasks and females are more right lateralized on visuospatial tasks; however, findings are inconsistent. Here we used functional magnetic resonance imaging to study thirty participants, matched on task performance, during phonological and visuospatial tasks. For each task, region-of-interest analyses were used to test differences in cerebral laterality. Results indicate that lateralization differences exist, with males more left lateralized during the phonological task and showing greater bilateral activity during the visuospatial task, whereas females showed greater bilateral activity during the phonological task and were more right lateralized during the visuospatial task. Our data provide clear evidence for differences in laterality between males and females when processing language versus visuospatial information.     

Priming vs. rhyming: orthographic and phonological representations in the left and right hemispheres

The right cerebral hemisphere has long been argued to lack phonological processing capacity. Recently, however, a sex difference in the cortical representation of phonology has been proposed, suggesting discrete left hemisphere lateralization in males and more distributed, bilateral representation of function in females. To evaluate this hypothesis and shed light on sex differences in the phonological processing capabilities of the left and right hemispheres, we conducted two experiments. Experiment 1 assessed phonological activation implicitly (masked homophone priming), testing 52 (M=25, F=27; mean age 19.23years, SD 1.64years) strongly right-handed participants. Experiment 2 subsequently assessed the explicit recruitment of phonology (rhyme judgement), testing 50 (M=25, F=25; mean age 19.67years, SD 2.05years) strongly right-handed participants. In both experiments the orthographic overlap between stimulus pairs was strictly controlled using DICE [Brew, C., & McKelvie, D. (1996). Word-pair extraction for lexicography. In K. Oflazer & H. Somers (Eds.), Proceedings of the second international conference on new methods in language processing (pp. 45-55). Ankara: VCH], such that pairs shared (a) high orthographic and phonological similarity (e.g., not-KNOT); (b) high orthographic and low phonological similarity (e.g., pint-HINT); (c) low orthographic and high phonological similarity (e.g., use-EWES); or (d) low orthographic and low phonological similarity (e.g., kind-DONE). As anticipated, high orthographic similarity facilitated both left and right hemisphere performance, whereas the left hemisphere showed greater facility when phonological similarity was high. This difference in hemispheric processing of phonological representations was especially pronounced in males, whereas female performance was far less sensitive to visual field of presentation across both implicit and explicit phonological tasks. As such, the findings offer behavioural evidence indicating that though both hemispheres are capable of orthographic analysis, phonological processing is discretely lateralised to the left hemisphere in males, but available in both the left and right hemisphere in females.     

Construction and learning to spell

Little is known about the way in which children learn the rules of literacy. We argue that children’s learning about orthographic rules can be the result of their own constructions. We provide longitudinal evidence on Greek children’s understanding of the morphophonemic rules for the spelling of the /o/ and /e/ vowel sounds in stems and inflections. These sounds can be spelled with more than one phonetically acceptable grapheme. When the vowel sound represents part of an inflection or the inflection itself, the grammatical status of the word is the key to the right choice between the alternative spellings. In contrast, no such morphemic rule applies when the sound is part of the stem morpheme. The spelling of each of these vowel sounds in the stem must rely on rote learning. Our results suggest that children go through a three-step developmental sequence in learning how to spell /o/ and /e/ in inflections: initially they adopt only one spelling for each vowel sound. Later, when they add the alternative spelling to their repertoire, they overgeneralize it to inappropriate words. Eventually, they restrict the alternative spellings to the grammatically appropriate words. We argue that these overgeneralizations, which have also been found in English, French and Portuguese spelling, indicate that children at first try to extend an existing rule, based on grapheme–phoneme conversion, for the new spelling. This slight change produces new experiences for them which allow them to construct a higher-level morphophonemic spelling rule.     

The influence of gender, handedness, and performance level on specialized cognitive functioning

Individual differences in performance on neuropsychological tests were analyzed across age (prepubertal to adult), gender, and handedness groups and examined for performance level as a moderating variable. No differences were observed for the factor structure of these tests across ages and between genders, suggesting similar cognitive structures among these groups. Significant differences in performance were observed between males and females and, to a lesser extent, between right and left handers. Of interest, were significant Gender x Handedness and Gender x Handedness x Level (of performance) interactions seen especially in the older (postpubertal and adult) subjects. High performing, right handed males and left handed females performed better on visuospatial tasks while left handed males and right handed females performed better on verbosequential tasks.     

Model Implementation and Classroom Achievement in the Northern Cheyenne Behavior Analysis Follow Through Project

The effects of implementation of the Behavior Analysis Model of Follow Through on the achievement of Native American elementary school children were examined. Model implementation was determined from auditor and consuItant reports. Outcome data were taken from the Wide Range Achievement Test with both cohort and non-cohort children. The data were aggregated by grade level (Kg-3rd) and by classroom (N = 16). The overall results revealed that at or above grade level achievement in reading, arithmetic, and spelling was associated with model implementation. This effect was significant (p .01) except for cohort spelling. Nonmodel implementation was related to below grade level classroom achievement a majority of the time. Implications of the findings to Native American education and previous evaluations of FoIlow Through were made.     

Phonology acquired through the eyes and spelling in deaf children

Hearing and deaf children, ranging in age from 6 years 8 months to 14 years 4 months, and matched for general spelling level, were required to spell high-frequency and low-frequency words. Of interest was performance in relation to degree of exposure to Cued Speech (CS), which is a system delivering phonetically augmented speechreading through the visual modality. Groups were (a) hearing children, (b) deaf children exposed early and intensively to CS at home (CS-Home), and (c) deaf children exposed to CS later and at school only (CS-School). Most of the spelling productions of hearing children as well as of CS-Home children were phonologically accurate for high-frequency as well as for low-frequency words. CS-School children, who had less specified phonological representations, made a lower proportion of phonologically accurate spellings. These findings indicate that the accuracy of phonological representations, independent of the modality (acoustic versus visual) through which spoken language is perceived, determines the acquisition of phonology-to-orthography mappings. Analyses of the spelling productions indicate that the acquisition of orthographic representations of high precision depends on fully specified phonological representations.     

Sex differences in the lateralization of spatial abilities: a spatial component analysis of extreme group scores

Sex differences in the cerebral lateralization of two discrete components of spatial processing were investigated in high and low ability males and females using the dual-task paradigm. In the first phase of the experiment, the results indicated a pattern of right hemispheric control for a spatial visualization component, regardless of sex and ability level. In the processing of the spatial orientation component of spatial ability, high ability males and females showed left hemispheric lateralization, whereas low ability males and females displayed right hemispheric control. In the second phase of this study, it was observed that high ability females and low ability males may use a verbal mediation strategy in processing spatial visualization tasks. No verbal mediation effects were found for the spatial orientation component.     

Selective attention to color and location: An analysis with event-related brain potentials

Event-related brain potentials (ERPs) were recorded from subjects as they attended to colored bars that were flashed in random order to the left or right of fixation. The task was to detect slightly smaller target bars having a specified color (red or blue) and location (left or right). The ERP elicited by stimuli at an attended location contained a sequence of phasic components (P122/N168/N264) that was highly distinct from the sequence associated with selection on the basis of color (N150-350/P199/P400-500). These findings suggested that spatially focused attention involves a gating or modulation of evoked neural activity in the visual pathways, whereas color selection is manifested by an endogenous ERP complex. When the stimulus locations were widely separated, the ERP signs of color selection were hierarchically dependent upon the prior selection for spatial location. In contrast, when the stimulus locations were adjacent to one another, the ERP signs of color selection predominated over those of location selection. These results are viewed as supporting “early selection” theories of attention that specify the rejection of irrelevant inputs prior to the completion of perceptual processing. The implications of ERP data for theories of multidimensional stimulus processing are considered.     

Hemispheric alpha asymmetries of stuttering males and nonstuttering males and females for words of high and low imagery

Alpha hemispheric asymmetries of nonstuttering males, nonstuttering females, and stuttering males were explored with electroencephalographic procedures during exposure to two lists of one-syllable words which the subjects were required to recall following presentation. One word list contained low-imagery words while the other contained high-imagery words. Stuttering males were found to have significantly less alpha in their right hemispheres, suggesting right hemispheric processing strategies. This finding was interpreted as supporting the “segmentation dysfunction” explanation of stuttering suggested by Moore and Haynes (1979b). Nonstuttering males showed less left than right alpha while nonstuttering females revealed no difference between their right and left hemispheres. Differences between nonstuttering males and females are discussed as being task and stimuli dependent relative to the segmental/nonsegmental nature of both task and stimuli. Differential hemispheric asymmetries for words of high or low-imagery were not observed.     

Phonologic Mediation Is Fundamental to Reading: Evidence from Beginning Readers

Three tasks were employed to investigate the role of assembled phonology in beginning readers. In two proofreading tasks, children had more trouble finding pseudohomophone misspellings (stimuli with phonology identical to that of a word) than control misspellings (stimuli that do not share their phonology with a word). In a lexical-decision task, they had more trouble deciding that pseudohomophone misspellings were non-words than deciding that control misspellings were non-words. Finally, in a semantic-categorization task, children had more trouble rejecting pseudohomophone misspellings as a member of a designated category than rejecting control misspellings. Differences between more and less advanced readers occurred, but they need not be attributed to differential use of phonology in word recognition. Instead, they were explained in terms of a difference between reader groups in spelling-verification efficiency. The results of the present studies on beginning reading parallel studies on skilled reading by Van Orden et al. (1992). The main conclusion was that assembled phonology plays an important role in word recognition in beginning readers.     

Cross-cultural differences in processes underlying sequential cognitive activity

Abstract: Similarities and differences in the processes underlying performance on the Stroop Color-Word Test (Card A, 100 color words/black ink; Card B, 100 color patches; Card C, 100 color words/incongruous ink color) were investigated with Japanese ( N = 96) and Americans ( N = 96) with stimulus items read: (a) vertically, top to bottom; and (b) horizontally, left to right. Total time as well as errors, namely, those involved with the underlying processes of identification and sequential organization, were significantly longer or more frequent on Card C than on Cards A and B for both nationalities and spatial arrangements. Further, greater frequency of serial organization errors in females than in males was obtained for the Japanese group, and the opposite for the American group. The implications and directions for future research are discussed.