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Impaired Visual Attention in Children with Dyslexia.

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Title: Impaired Visual Attention in Children with Dyslexia.
Language: English
Authors: Heiervang, Einar, Hugdahl, Kenneth
Source: Journal of Learning Disabilities. Jan-Feb 2003 36(1):68-73.
Peer Reviewed: Y
Page Count: 6
Publication Date: 2003
Document Type: Journal Articles
Reports - Research
Descriptors: Attention Control, Attention Deficit Disorders, Attention Span, Computer Assisted Testing, Dyslexia, Elementary Education, Reaction Time, Student Characteristics, Symptoms (Individual Disorders), Visual Learning, Visual Stimuli
ISSN: 0022-2194
Abstract: A cue-target visual attention task was administered to 25 children (ages 10-12) with dyslexia. Results showed a general pattern of slower responses in the children with dyslexia compared to controls. Subjects also had longer reaction times in the short and long cue-target interval conditions (covert and overt shift of attention). (Contains references.) (Author/CR)
Notes: Special Issue: IQ-Discrepancy Definitions and the Diagnosis of LD.
Journal Code: CIJJUN2003
Entry Date: 2003
Accession Number: EJ660994
Database: ERIC
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  Value: <anid>AN0008844469;led01jan.03;2003Mar07.10:50;v1.9</anid> <title id="AN0008844469-1">Impaired Visual Attention in Children with Dyslexia </title> <sbt id="AN0008844469-2">Abstract</sbt> <p>Reading involves the correct and rapid identification of visual stimuli with letters and words. The processing of visual stimuli depends not only on the integrity of the peripheral and central visual system but also on the attentional systems involved. In the present study, a cue-target visual attention task was administered to a population-based sample of 25 children with dyslexia from 10 to 12 years of age. A control group matched for group size, age, and gender was obtained from the same general population. A two-stage screening process involved a spelling task of regular words followed by a battery of five single-word reading tasks. The cue-target task involved both a computer-controlled stimulus presentation and a computer-controlled measurement of reaction time. The data were analyzed by visual field, cue condition (valid, invalid, and no cue), and cue-target interval (CTI). The results showed a general pattern of slower responses in the dyslexia group compared to the control group. The dyslexia group also had longer reaction times in the short CTI condition (covert shift of attention) and in the long CTI condition (overt shift of attention). The findings may reflect a general attentional deficit to visual stimuli in dyslexia, possibly related to problems with the recruitment of necessary cognitive resources for the performance of complex reaction time tasks and for fluent reading.</p> <p>Dyslexia is characterized by impaired single-word reading, frequently involving deficits in phonological decoding (Shaywitz, 1998). Other aspects of written and oral language may also be affected. Parents and teachers often report attention problems in children with dyslexia (Hinshaw, 1992), but few studies have looked specifically at the cognitive mechanisms behind these attention deficits.</p> <p>We have studied shifts of attention, which occur, for example, when shifting focus from word to word during reading. One established way of studying shifts of attention in the visual domain is the cue-target paradigm (Posner, 1980, 1988). In this task, a target (e.g., an asterisk) is presented on a computer screen, and a motor response is required (e.g., pressing a key on a computer keyboard). Reaction time (RT) is automatically recorded by computer. The target stimulus is presented randomly in either the left or the right visual field (LVF or RVF). The target is preceded by a visual cue in 80% of the trials, either in the same or in the opposite visual field (valid or invalid cue). In 20% of the trials, there is no preceding cue. The shortest RT is typically recorded for targets in the visual field of the left hemisphere for right-handed people when targets are preceded by a valid cue, and when there is a long cue-target interval (CTI; Hugdahl & Nordby, 1994; Posner, Early, Reiman, Pardo, & Dhawan, 1988). The facilitation of responses by valid cues occurs within 100 to 150 ms after the cue, and before any movement of the eyes. According to Posner and Peterson (1990), this covert shift of attention depends on the dorsal (magnocellular) visual system. This rapid, motion-sensitive pathway projects to the visual areas V1, V2, and parietal areas, whereas a slower, pattern-sensitive, ventral (parvocellular) pathway projects to other sublayers of V1 and V2 and to temporal visual areas.</p> <p>With regard to reading, skilled single-word reading has been found to require little visual attention (Posner, Sandson, Dhawan, & Shulman, 1989). However, this may not be the situation for unskilled or impaired reading (Treisman & Gormican, 1988). In a small group of poor readers, Brannan and Williams (1987) found lower accuracy on the cue-target task compared to good readers, especially for short CTI trials. This was interpreted as a possible deficit in the rapid dorsal visual system, supporting the temporal processing hypothesis for dyslexia. This hypothesis claims that there are deficits not only in the dorsal visual system but in all neural systems responsible for the processing of rapid sensory stimuli, resulting in reading impairment and oral language problems (Anderson, Brown, & Tallal, 1993; Stein & Walsh, 1997). A larger and more recent study measured reaction time, not accuracy, on the cue-target task in children with dyslexia and control children (Jonkman, Licht, Bakker, & Van den Broek-Sandmann, 1992). Children with dyslexia were found to have longer overall RTs but no specific deviations in the different cue conditions. However, a single, relatively long cue-target interval was used in their study, and the effect of CTI was therefore not evaluated.</p> <p>The aim of the present study was to examine if the pattern observed in the two previous studies on the cue-target task in children with reading impairment who were recruited from clinical settings (Brannan & Williams, 1987; Jonkman et al., 1992) could be confirmed in children with dyslexia who were screened from the general population. Specifically, we wanted to see if the group with dyslexia had particular problems processing rapidly appearing, short CTI targets.</p> <hd id="AN0008844469-3">Method</hd> <hd1 id="AN0008844469-4"> Sample </hd1> <p>Children with dyslexia were recruited from 12 primary schools in the Bergen area of Norway by a two-stage screening procedure. In the first stage of the screening, schoolteachers administered a spelling task with 40 regular Norwegian words to 950 children in the 4th grade (Johnsen, 1985). In the second stage of the screening, 83 children scoring in the lower 10th percentile on the spelling test were given a battery of reading tasks from the KOAS test (see Note; Høien & Lundberg, 1989). This is a computerized test with five reading tasks, tapping both phonological decoding and orthographic coding abilities. To be included in the dyslexia group, a mean reading score at least 2 SD below the mean age level was required. Children with an IQ below 85, with major visual or hearing impairments, with neurological disease or damage, or who did not speak Norwegian as their first language were excluded. The final dyslexia group consisted of 25 children from 10 to 12 years of age. There were 20 boys and 5 girls. One boy and one girl were not right-handed. IQ was assessed by the Wechsler Intelligence Scale for Children-Revised (WISC-R; Wechsler, 1974), by an estimation from four Verbal subscales (Information, Similarities, Arithmetic, and Vocabulary) and four Performance subscales (Picture Completion, Picture Arrangement, Block Design, and Coding). Handedness was assessed with Annett's questionnaire (Annett, 1967). A child was classified as right-handed if the right hand was preferred for at least 9 of the 12 tasks. None of the children had been diagnosed with attention-deficit/hyperactivity disorder (ADHD) or scored above the 90th percentile on attention problems according to parent and teacher ratings (Achenbach, 1991). A control group matched for age, gender, and handedness was recruited from the same school forms. All control children scored at or above the age mean on reading and spelling, otherwise meeting the same criteria as the children with dyslexia. Table 1 presents group characteristics.</p> <hd1 id="AN0008844469-5"> Test Procedure </hd1> <p>The visual cue-target paradigm was presented on an IBM PS/2 computer with a 17-inch SVGA screen. The Micro Experimental Laboratory software (MEL 2; Psychological Software Tools, 1990) was used to control stimulus presentation and to measure reaction time. A central fixation cross and two boxes at 5 degrees of visual angle from the cross remained on the screen for the whole experiment. The target consisted of an asterisk presented either in the left or in the right box. The room was darkened, and the children were seated 70 cm from the computer screen. The children were instructed to maintain visual fixation at the central cross and to quickly press the space bar when an asterisk appeared. The index finger of the dominant hand was used for the response. Reaction time (RT) was measured from the onset of the target to the onset of the key press. RTs shorter than 100 ms and longer than 2,500 ms were discarded as anticipation and omission errors, respectively. The frequency of anticipation and omission errors was low in both groups (0.85% vs. 0.62%, ns).</p> <p>Trials were randomly presented in five blocks of 48 trials each, allowing for a brief pause between each block. For half of the trials, the target was presented in the right visual field, and for the other half in the left visual field. In 200 of the 240 trials (83%), a cue consisting of a second border around the box was presented before the target (this appeared on screen as a brightening of the box). In 160 trials (67% of all), the target appeared in the same physical location as the cue (valid cue). That is, the target asterisk appeared inside the box that was lit up. In 40 trials (17%), the target appeared in the location opposite to the cue (invalid cue). That is, the target appeared inside the box that was not lit up. Finally, in 40 trials (17%) there was no cue before the target was presented. For cued trials, the cue was presented 1,000 ms after the onset of the response. The cue-target interval was 100 ms in half of the trials and 800 ms in the other half. The order of presentation was randomized. On no-cue trials, the target was presented either 1,100 ms or 1,800 ms after the previous response, in order to match the temporal characteristics of the cued trials.</p> <p>For each child, mean RT for trials with correct responses was calculated for each of the 12 within-subject conditions; cue (valid, no cue, and invalid), interval (100 ms and 800 ms), and visual field (RVF and LVF). RT scores from the within-subject conditions were subject to an analysis of variance (ANOVA) with group (dyslexia, control) as the between-subjects factor.</p> <hd id="AN0008844469-6">Results</hd> <p>There was a significant main effect of group, F (<reflink idref="bib1" id="ref1">1</reflink>, 48) = 7.48, p < .01, with longer mean RT for the dyslexia group (630 ms) than for the control group (555 ms). There was also a significant main effect of cue, F (<reflink idref="bib2" id="ref2">2</reflink>, 96) = 39.33, p < .001, with shorter mean RT for valid-cue trials (554 ms) than for no-cue trials (610 ms) and invalid-cue trials (612 ms). The main effect of CTI was also significant, F (<reflink idref="bib1" id="ref3">1</reflink>, 48) = 123.92, p < .001, with shorter mean RT for the 800-ms CTI trials (540 ms) than for the 100-ms CTI trials (644 ms). Finally, the ANOVA showed a significant main effect of visual field, F (<reflink idref="bib1" id="ref4">1</reflink>, 48) = 4.91, p = .035, with shorter mean RT for RVF trials (586 ms) than for LVF trials (598 ms).</p> <p>The only significant three-way interaction was between group, cue and interval, F (<reflink idref="bib2" id="ref5">2</reflink>, 96) = 3.72, p = .028, which is illustrated in Figure 1.</p> <p>Figure 1 shows particularly long RTs in the dyslexia group compared to the control group in the no-cue, 100-ms CTI condition (712 ms vs. 606 ms). This resulted in longer RTs on no-cue trials than on invalid-cue trials, a pattern observed only for short CTI trials in the dyslexia group. The distribution of scores for the no-cue, short CTI condition shows that 11 children with dyslexia (44%) had longer mean RTs than the slowest control child for either RVF or LVF targets (see Figure 2).</p> <hd id="AN0008844469-7">Discussion</hd> <p>The dyslexia group showed longer RTs than the control group in all conditions of this cue-target visual attention experiment. Thus, the pattern of an overall reduced performance on this task that was observed in two previous studies of children with reading impairments from clinical settings (Brannan & Williams, 1987; Jonkman et al., 1992) was confirmed in this population-based sample of children with dyslexia. Thus, unlike those of previous studies, the results cannot be attributed to possible selection biases, such as an overrepresentation of children with co-occurring ADHD or other emotional or behavioral problems.</p> <p>The dyslexia and control groups were carefully matched for age, gender, and handedness and had a similar social and educational background, coming from the same school class forms and living areas. The robustness of the present results is supported by the typical findings of the effects of cue and CTI on performance in nondisabled individuals, with shorter RT for valid-cue, long CTI trials (Posner, Early, et al., 1988; Hugdahl & Nordby, 1994). The effect of visual field seen in this and other studies, with shorter RTs for RVF targets, has not been interpreted as an indication of a lateralized deficit. Rather, it is thought to result from the fact that RVF stimuli project to the left hemisphere, which controls the responding hand in right-handed individuals (Bryden, 1964; Posner, Early, et al., 1988). Twenty-three of the 25 children in each group were right-handed in the present study.</p> <p>Children with ADHD have also been found to have slower responses on this type of task (Swanson et al., 1991; Carter, Krener, Chaderjian, Northcutt, & Wolfe, 1995; Øie, Rund, & Sundet, 1998). However, whereas children with ADHD show particular impairment on long CTI trials, children with dyslexia show impairment on short CTI trials as well. In fact, Brannan and Williams (1987) found the lowest accuracy for children with dyslexia in short CTI trials, and in the present study, the groups likewise differed most on no-cue, short CTI trials. Thus, whereas children with dyslexia seem to show most impairment in conditions demanding a covert shift of attention, which depends on the posterior attention system, children with ADHD show more impairment in conditions involving overt attentional shifts, a process that depends more on the anterior attention system (Posner, 1988).</p> <p>Although the children were instructed to hold visual fixation on a central cross on the computer screen, there was no monitoring of eye movements. However, previous studies have shown that participants are unlikely to move their eyes under these conditions, where acuity is not necessary to make the response (Posner & Presti, 1987). Other studies involving brief stimuli presented in the left and right visual half-fields with central fixation have also shown that participants do not move their eyes (McKeever, 1986).</p> <p>In some versions of the Posner task, a neutral cue condition has been included. However, previous studies in our laboratory (e.g., Stormark, Field, Hugdahl, & Horowitz, 1997) have shown that performance with a neutral cue resembles performance on a no-cue condition in that it falls between the performance on the valid and the invalid cues in the short interval condition.</p> <p>One explanation for the finding of overall longer RTs on the cue-target task could be a general motor slowness in children with dyslexia. Although this may be a contributing factor in some children, Nicolson and Fawcett (1994) have found that children with dyslexia perform normally on simple reaction time tasks that load on the execution of motor responses. The present task involves a more complex cognitive process, where a selective response only to relevant stimuli (targets) is required.</p> <p>The explanation suggested by Brannan and Williams (1987) is related not to the attention systems but rather to the importance of the magnocellular visual system for rapid stimulus processing. Deficits in this system could theoretically impair the facilitation of a response by relevant cues if the processing time for the cue before the target appeared was reduced to a critical limit, and this system has been implicated in the RT facilitation of valid cues (Posner, Early, et al., 1988). However, in the present study, there was a clear facilitation of responses by valid cues in the dyslexia group, even in the short (100 ms) CTI condition (see Figure 1). Moreover, the finding that children with dyslexia show no impairment on simple reaction time tasks (Nicolson & Fawcett, 1994) seems to imply that both sensory processing and motor execution of response are intact.</p> <p>Explanations that are related to the more complex cognitive mechanisms involved in the cue-target task, therefore, seem more plausible. One possible explanation is reduced alertness to visual stimuli, which would reduce processing speed for all conditions of the task (Posner, 1978). Alertness depends on the norepinephrine systems arising from the locus coeruleus in the brain stem, possibly mainly through the right hemisphere (Posner & Peterson, 1990). It has also been suggested that the cerebellum, which is involved in computation for the timing of both motor and sensory tasks, also influences the general performance on the cue-target task (Posner, Petersen, Fox, & Raichle, 1988). However, here also one would have to imply that reduced alertness and cerebellum deficits would have a selective effect on complex RT tasks--like the cue-target task--that is not observed on the simpler RT tasks. An alternative explanation could involve divided attention or a limitation in the recruitment of the cognitive resources necessary for this complex task (Posner & Boies, 1971). This would theoretically result in overall longer RTs as observed in the present study and, possibly, also have a larger effect on short CTI trials, where targets appear more rapidly after the preceding cue (or the preceding response for no-cue trials). An anterior attention system (anterior cingulate and basal ganglia) with a more executive function (attention for action) is thought to be involved in attentional recruitment to perform complex cognitive tasks (Posner & Dehaene, 2000). In the reading process, children have to attend to a complex visual image of letters and words, and it seems plausible that problems in the recruitment of cognitive resources could hamper the speed and fluency of reading.</p> <p>In conclusion, children with dyslexia who were screened from the general population showed a pattern of overall slower responses on this cue-target visual attention task compared to control children. The largest group difference was observed for trials where targets appeared sooner after the preceding response and without a preceding cue. Deficits related to divided attention, with problems in the recruitment of the necessary cognitive resources, could explain the observed results.</p> <hd1 id="AN0008844469-8"> AUTHORS' NOTE </hd1> <p>1. We are grateful to the children, parents, and teachers contributing to this study and to the school authorities of the city of Bergen.</p> <p>2. This work was supported by a grant from the Norwegian Research Council.</p> <hd1 id="AN0008844469-9"> NOTE </hd1> <p>KOAS is an abbreviation for Kartlegging au Ordaukodings Strategiene (examination of word-decoding strategies).</p> <hd id="AN0008844469-10">TABLE 1 Means and Standard Deviations of Demographic Characteristics by Group</hd> <ct id="AN0008844469-11"> Legend for Chart: A - Variable B - Dyslexia(a) M C - Dyslexia(a) SD D - Control(a) M E - Control(a) SD A B C D E Age (years) 11.8 0.5 11.8 0.5 Verbal IQ 102.3(*) 9.1 111.8 13.0 Performance IQ 104.2 9.5 110.5 14.4 Reading (%) 69.0(**) 9.9 96.3 1.6 Handedness(b) 10.5 2.9 11.1 2.5 Note. IQ scores from the Wechsler Intelligence Scale for Children-Revised (Wechsler, 1974); reading scores from the KOAS test (Høien & Lundberg, 1989). (a) n = 25. (b) right hand preferred for n out of 12 tasks (Annett, 1967). (*) p < 01. (**) p < .001, Student's t test.</ct> <p>GRAPH: FIGURE 1. Mean reaction times of both groups, for the three different cue conditions in short (100 ms) and long (800 ms) cue-target interval (CTI) trials.</p> <p>GRAPH: FIGURE 2. Distribution of reaction times for both groups in no cue, 100 ms cue-target interval trials (target presented 1,100 ms after previous response).</p> <ref id="AN0008844469-12"> <title> REFERENCES </title> <blist> <bibl id="bib1" idref="ref1" type="bt"></bibl> <bibtext>Achenbach, T. M. (1991). Integrative guide for the 1991 CBCL/4-18, YSR, and TRF profiles. Burlington: University of Vermont, Department of Psychiatry.</bibtext> </blist> <blist> <bibl id="bib2" idref="ref2" type="bt"></bibl> <bibtext>Anderson, K. C., Brown, C. P., & Tallal, P. (1993). Developmental language disorders: Evidence for a basic processing deficit. Current Opinion in Neurology and Neurosurgery, 6, 98-106.</bibtext> </blist> <blist> <bibl id="bib3" type="bt"></bibl> <bibtext>Annett, M. J. (1967). The bimodal distribution of right, mixed and left handedness. Quarterly Journal of Experimental Psychology, 19, 327-333.</bibtext> </blist> <blist> <bibl id="bib4" type="bt"></bibl> <bibtext>Brannan, J. R., & Williams, M. C. (1987). Allocation of visual attention in good and poor readers. Perception & Psychophysics, 41, 23-28.</bibtext> </blist> <blist> <bibl id="bib5" type="bt"></bibl> <bibtext>Bryden, M. P. (1964). Tachistoscopic recognition and cerebral dominance. Perceptual and Motor Skills, 19, 686-672.</bibtext> </blist> <blist> <bibl id="bib6" type="bt"></bibl> <bibtext>Carter, C. S., Krener, P., Chaderjian, M. R., Northcutt, C., & Wolfe, V. (1995). Asymmetrical visual-spatial attentional performance in ADHD: Evidence for a right hemisphere deficit. Biological Psychiatry, 18, 661-683.</bibtext> </blist> <blist> <bibl id="bib7" type="bt"></bibl> <bibtext>Hinshaw, S. P. (1992). Externalizing behaviour problems and academic underachievement in childhood and adolescence: Causal relationships and underlying mechanisms. Psychological Bulletin, 111, 127-155.</bibtext> </blist> <blist> <bibl id="bib8" type="bt"></bibl> <bibtext>Høien, T., & Lundberg, I. A. (1989). A strategy for assessing problems in word recognition among dyslexics. Scandinavian Journal of Educational Research, 33, 185201.</bibtext> </blist> <blist> <bibl id="bib9" type="bt"></bibl> <bibtext>Hugdahl, K., & Nordby, H. (1994). Electrophysiological correlates to cued attentional shifts in the visual and auditory modalities. Behavioral and Neural Biology, 62, 21-32.</bibtext> </blist> <blist> <bibl id="bib10" type="bt"></bibl> <bibtext>Johnsen, K. (1985). Ord-diktater 1.-6. klasse [Spelling tests Grade 1-6]. Oslo: Universitetsforlaget.</bibtext> </blist> <blist> <bibl id="bib11" type="bt"></bibl> <bibtext>Jonkman, I., Licht, R., Bakker, D. J., & Van den Broek-Sandmann, T.M. (1992). Shifting of attention in subtyped dyslexic children: An event-related potential study. Developmental Neuropsychology, 8, 243259.</bibtext> </blist> <blist> <bibl id="bib12" type="bt"></bibl> <bibtext>McKeever, W. F. (1986). Tachistoscopic methods in neuropsychology. In H. J. Hannay (Ed.), Experimental techniques in human neuropsychology (pp. 167-211). New York: Oxford University Press.</bibtext> </blist> <blist> <bibl id="bib13" type="bt"></bibl> <bibtext>Nicolson, R. I., & Fawcett, A. J. (1994). Reaction times and dyslexia. Quarterly Journal of Experimental Psychology, 47, 29-48.</bibtext> </blist> <blist> <bibl id="bib14" type="bt"></bibl> <bibtext>Øie, M., Rund, B. R., & Sundet, K. (1998). Covert visual attention in patients with early-onset schizophrenia. Schizophrenia Research, 34, 195-205.</bibtext> </blist> <blist> <bibl id="bib15" type="bt"></bibl> <bibtext>Posner, M. I. (1978). Chronometric explorations of mind. Hillsdale, NJ: Erlbaum.</bibtext> </blist> <blist> <bibl id="bib16" type="bt"></bibl> <bibtext>Posner, M. I. (1980). Orienting of attention. Quarterly Journal of Experimental Psychology, 32, 3-25.</bibtext> </blist> <blist> <bibl id="bib17" type="bt"></bibl> <bibtext>Posner, M. I. (1988). Structures and functions of selective attention. In T. Boll & D. K. Bryant (Eds.), Clinical neuropsychology and brain function: Research, assessment, and practice (pp. 173-202). Washington, DC: American Psychological Association.</bibtext> </blist> <blist> <bibl id="bib18" type="bt"></bibl> <bibtext>Posner, M. I., & Boies, S. J. (1971). Components of attention. Psychological Review, 78, 391-408.</bibtext> </blist> <blist> <bibl id="bib19" type="bt"></bibl> <bibtext>Posner, M. I., & Dehaene, S. (2000). Attentional networks. In M. S. Gazzaniga (Ed.), Cognitive neuroscience (pp. 155-190). Oxford: Blackwell.</bibtext> </blist> <blist> <bibl id="bib20" type="bt"></bibl> <bibtext>Posner, M. I., Early, T. S., Reiman, E., Pardo, P. J., & Dhawan, M. (1988). Asymmetries in hemispheric control of attention in schizophrenia. Archives of General Psychiatry, 45, 814-821.</bibtext> </blist> <blist> <bibl id="bib21" type="bt"></bibl> <bibtext>Posner, M. I., & Peterson, S. E. (1990). The attention system of the human brain. Annual Review of Neuroscience, 13, 25-42.</bibtext> </blist> <blist> <bibl id="bib22" type="bt"></bibl> <bibtext>Posner, M. I., Peterson, S. E., Fox, P. T., & Raichle, M. E. (1988). Localization of cognitive operations in the human brain. Science, 240, 1627-1631.</bibtext> </blist> <blist> <bibl id="bib23" type="bt"></bibl> <bibtext>Posner, M. I., & Presti, D. (1987). Selective attention and cognitive control. Trends in Neuroscience, 10, 12-17.</bibtext> </blist> <blist> <bibl id="bib24" type="bt"></bibl> <bibtext>Posner, M. I., Sandson, J., Dhawan, M., & Shulman, G. (1989). Is word recognition automatic? A cognitive-anatomical approach. Journal of Cognitive Neuroscience, 1, 50-60.</bibtext> </blist> <blist> <bibl id="bib25" type="bt"></bibl> <bibtext>Shaywitz, S. E. (1998). Dyslexia. The New England Journal of Medicine, 338, 307-312.</bibtext> </blist> <blist> <bibl id="bib26" type="bt"></bibl> <bibtext>Stein, J., & Walsh, V. (1997). To see but not to read: The magnocellular theory of dyslexia. Trends in Neuroscience, 20, 147-152.</bibtext> </blist> <blist> <bibl id="bib27" type="bt"></bibl> <bibtext>Stormark, K. M., Field, N., Hugdahl, K., & Horowitz, M. (1997). Selective attention in alcoholics to visual alcohol cues: An approach-avoidance conflict? Addictive Behaviors, 22, 1-11.</bibtext> </blist> <blist> <bibl id="bib28" type="bt"></bibl> <bibtext>Swanson, J. M., Posner, M. I., Potkin, S., Bonforte, S., Youpa, D., Fiore, C., et al. (1991). Activating tasks for the study of visual-spatial attention in ADHD children: A cognitive anatomic approach. Journal of Child Neurology, 6, 119-127.</bibtext> </blist> <blist> <bibl id="bib29" type="bt"></bibl> <bibtext>Treisman, A.M., & Gormican, S. (1988). Feature analysis in early vision: Evidence from search asymmetries. Psychological Review, 95, 15-48.</bibtext> </blist> <blist> <bibl id="bib30" type="bt"></bibl> <bibtext>Wechsler, D. (1974). Examiner's manual: Wechsler Intelligence Scale for Children-Revised. New York: Psychological Corp.</bibtext> </blist> </ref> <aug> <p>By Einar Heiervang and Kenneth Hugdahl</p> <p></p> <p>Einar Heiervang, MD, is associate professor in child and adolescent psychiatry at the University of Bergen, Norway. His current research interests are childhood developmental disorders, including dyslexia, autism, and ADHD.</p> <p>Kenneth Hugdahl, PhD, is professor of biological psychology at the University of Bergen, Norway. His current research focus is on brain function and dyslexia, attention, and laterality. Address: Einar Heiervang, Department of Psychiatry, University of Bergen, N-5020 Bergen, Norway.</p> </aug>
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– Name: Pages
  Label: Page Count
  Group: Src
  Data: 6
– Name: DatePubCY
  Label: Publication Date
  Group: Date
  Data: 2003
– Name: TypeDocument
  Label: Document Type
  Group: TypDoc
  Data: Journal Articles<br />Reports - Research
– Name: Subject
  Label: Descriptors
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22Attention+Control%22">Attention Control</searchLink><br /><searchLink fieldCode="DE" term="%22Attention+Deficit+Disorders%22">Attention Deficit Disorders</searchLink><br /><searchLink fieldCode="DE" term="%22Attention+Span%22">Attention Span</searchLink><br /><searchLink fieldCode="DE" term="%22Computer+Assisted+Testing%22">Computer Assisted Testing</searchLink><br /><searchLink fieldCode="DE" term="%22Dyslexia%22">Dyslexia</searchLink><br /><searchLink fieldCode="DE" term="%22Elementary+Education%22">Elementary Education</searchLink><br /><searchLink fieldCode="DE" term="%22Reaction+Time%22">Reaction Time</searchLink><br /><searchLink fieldCode="DE" term="%22Student+Characteristics%22">Student Characteristics</searchLink><br /><searchLink fieldCode="DE" term="%22Symptoms+%28Individual+Disorders%29%22">Symptoms (Individual Disorders)</searchLink><br /><searchLink fieldCode="DE" term="%22Visual+Learning%22">Visual Learning</searchLink><br /><searchLink fieldCode="DE" term="%22Visual+Stimuli%22">Visual Stimuli</searchLink>
– Name: ISSN
  Label: ISSN
  Group: ISSN
  Data: 0022-2194
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: A cue-target visual attention task was administered to 25 children (ages 10-12) with dyslexia. Results showed a general pattern of slower responses in the children with dyslexia compared to controls. Subjects also had longer reaction times in the short and long cue-target interval conditions (covert and overt shift of attention). (Contains references.) (Author/CR)
– Name: Note
  Label: Notes
  Group: Note
  Data: Special Issue: IQ-Discrepancy Definitions and the Diagnosis of LD.
– Name: CodeSource
  Label: Journal Code
  Group: SrcInfo
  Data: <searchLink fieldCode="JC" term="%22CIJJUN2003%22">CIJJUN2003</searchLink>
– Name: DateEntry
  Label: Entry Date
  Group: Date
  Data: 2003
– Name: AN
  Label: Accession Number
  Group: ID
  Data: EJ660994
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=eric&AN=EJ660994
RecordInfo BibRecord:
  BibEntity:
    Languages:
      – Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 6
        StartPage: 68
    Subjects:
      – SubjectFull: Attention Control
        Type: general
      – SubjectFull: Attention Deficit Disorders
        Type: general
      – SubjectFull: Attention Span
        Type: general
      – SubjectFull: Computer Assisted Testing
        Type: general
      – SubjectFull: Dyslexia
        Type: general
      – SubjectFull: Elementary Education
        Type: general
      – SubjectFull: Reaction Time
        Type: general
      – SubjectFull: Student Characteristics
        Type: general
      – SubjectFull: Symptoms (Individual Disorders)
        Type: general
      – SubjectFull: Visual Learning
        Type: general
      – SubjectFull: Visual Stimuli
        Type: general
    Titles:
      – TitleFull: Impaired Visual Attention in Children with Dyslexia.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Heiervang, Einar
      – PersonEntity:
          Name:
            NameFull: Hugdahl, Kenneth
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 01
              Type: published
              Y: 2003
          Identifiers:
            – Type: issn-print
              Value: 0022-2194
          Numbering:
            – Type: volume
              Value: 36
            – Type: issue
              Value: 1
          Titles:
            – TitleFull: Journal of Learning Disabilities
              Type: main
ResultId 1