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Visual & Auditory Tests Link to Academic Learning
- An Evidence Base
Visual spatial attention and speech segmentation are both impaired in preschoolers at
familial risk for developmental dyslexia.
Facoetti A, Trussardi AN, Ruffino M, Gori S, Zorzi M. Dyslexia 2010, 16(3):226-3.
Phonological skills are foundational of reading acquisition and impaired phonological processing is widely assumed to
characterize dyslexic individuals. However, reading by phonological decoding also requires rapid selection of sublexical
orthographic units through serial attentional orienting, and recent studies have shown that visual spatial attention is
impaired in dyslexic children. Our study investigated these different neurocognitive dysfunctions, before reading
acquisition, in a sample of preschoolers including children with (N=20) and without (N=67) familial risk for
developmental dyslexia. Children were tested on phonological skills, rapid automatized naming, and visual spatial
attention. At-risk children presented deficits in both visual spatial attention and syllabic segmentation at the group
level. Moreover, the combination of visual spatial attention and syllabic segmentation scores was more reliable than
either single measure for the identification of at-risk children. These findings suggest that both visuo-attentional and
perisylvian-auditory dysfunctions might adversely affect reading acquisition, and may offer a new approach for early
identification and remediation of developmental dyslexia.
Dyslexia: a deficit in visuo-spatial attention, not in phonological processing.
Vidyasagar TR, Pammer K. Trends Cogn Sci. 2010, Feb;14(2):57-63.
Developmental dyslexia affects up to 10 per cent of the population and it is important to understand its causes. It is
widely assumed that phonological deficits, that is, deficits in how words are sounded out, cause the reading difficulties
in dyslexia. However, there is emerging evidence that phonological problems and the reading impairment both arise
from poor visual (i.e., orthographic) coding. We argue that attentional mechanisms controlled by the dorsal visual
stream help in serial scanning of letters and any deficits in this process will cause a cascade of effects, including
impairments in visual processing of graphemes, their translation into phonemes and the development of phonemic
awareness. This view of dyslexia localizes the core deficit within the visual system and paves the way for new strategies
for early diagnosis and treatment.
Influence of the visual attention span on child reading performance: a cross sectional study.
Bosse M, Vladois S. Journal of Research in Reading 2009, 32(2):230-253.
The visual attention (VA) span deficit hypothesis was found successfully to account for variability in developmental
dyslexia (Bosse, Tainturier & Valdois, 2007). We conducted a cross-sectional study on 417 typically developing children
from first, third and fifth grades examining the role of VA span on the development of reading skills. A battery including
reading, phoneme awareness and VA span tasks was administered. Results show that VA span predicts variations in
learning to read independent of the influence of phoneme awareness. Moreover, whereas the specific influence of VA
span on pseudoword reading declines from first to third grade, VA span has a significant and sustained influence across
grades for the irregular words. In addition to phoneme awareness, the VA span contributes to reading performance
from the beginning of literacy instruction, suggesting that it might have a long-term influence on specific orthographic
Developmental dyslexia: the visual attention span deficit hypothesis.
Bosse ML, Tainturier MJ, Valdois S. Cognition. 2007, Aug;104(2):198-230.
The visual attention (VA) span is defined as the amount of distinct visual elements which can be processed in parallel in
a multi-element array. Both recent empirical data and theoretical accounts suggest that a VA span deficit might
contribute to developmental dyslexia, independently of a phonological disorder. In this study, this hypothesis was
assessed in two large samples of French and British dyslexic children whose performance was compared to that of
chronological-age matched control children. Results of the French study show that the VA span capacities account for a
substantial amount of unique variance in reading, as do phonological skills. The British study replicates this finding and
further reveals that the contribution of the VA span to reading performance remains even after controlling IQ, verbal
fluency, vocabulary and single letter identification skills, in addition to phoneme awareness. In both studies, most
dyslexic children exhibit a selective phonological or VA span disorder. Overall, these findings support a multi-factorial
view of developmental dyslexia. In many cases, developmental reading disorders do not seem to be phonological
disorders. We propose that a VA span deficit is a likely alternative underlying cognitive deficit in dyslexia.
Is there a common linkage among reading comprehension, visual attention, and
Solan HA, Shelley-Tremblay JF, Hansen PC, Larson S. J Learn Disabil. 2007, 40(3):270-8.
The authors examined the relationships between reading comprehension, visual attention, and magnocellular
processing in 42 Grade 7 students. The goal was to quantify the sensitivity of visual attention and magnocellular visual
processing as concomitants of poor reading comprehension in the absence of either vision therapy or cognitive
intervention. Nineteen good readers (M = grade equivalent of 11.2) and 23 poor readers (M = grade equivalent of 3.5)
were identified. Participants were tested for visual attention skills (Cognitive Assessment System: CAS) and
magnocellular integrity (Coherent Motion Threshold: CM). Individual and combined correlations of dependent variables
with reading were significant at the 0.01 level. When combined, the two tests (CAS + CM) accounted for 61% of the
variance in reading comprehension. Logistic regression analysis measured sensitivity of the two diagnostic tests.
Attention tests correctly classified 95.7% of poor readers, and coherent motion correctly classified 78.3% of poor
readers. When the data were combined, 91.3% of poor readers were correctly classified. The research reinforces the
notion that a common linkage exists between reading comprehension, visual attention, and magnocellular processing.
Diagnostic test batteries for students who have been identified as reading disabled should include magnocellular and
visual attention tests. Procedures to diagnose and ameliorate these disabilities are discussed.
Vision, Visual-Information Processing, and Academic Performance Among Seventh-Grade
Schoolchildren: A More Significant Relationship Than We Thought?
Goldstand S, Koslowe K, Parush S. American Journal of Occupational Therapy, 2005, 59 (4): 377-389.
Objective: To compare visual and visual-information processing skills between children with and without mild reading
and academic problems and examine the incidence of visual deficits among them.
Method: Seventy-one seventh graders classified as proficient (n = 46) and nonproficient (n = 25) readers were
compared with respect to scores on an accepted vision screening, on tests of visual-perception, visual-motor
integration, and academic performance. Further, academic performance and visual-information processing were
compared between children who failed and passed the vision screening.
Results: Visual deficits were found in 68% of the participants, and among significantly more boys than girls.
Nonproficient readers had significantly poorer academic performance and vision-screening scores than the proficient
readers. Participants who passed the visual screening performed significantly better in visual perception than those
Conclusion: Visual function significantly distinguishes between children with and without mild academic problems, as
well as on visual-perception scores. The high occurrence of visual deficits among participants warrants consideration of
vision deficits among schoolchildren with academic performance difficulties.
Does a visual-orthographic deficit contribute to reading disability?
Badian N. Annals of Dyslexia 2005,55(1):28-52.
In this study, visual-orthographic skills were defined as the ability to recognize whether letters and numerals are
correctly oriented. Aims were to investigate whether visual-orthographic skills would contribute independent variance
to reading, and whether children with a visual-orthographic deficit would be more impaired readers than similar
children without this deficit. Participants were 207 children, aged 8 to 10 years, who attended school in a small
suburban community. Because of the evidence that phonological awareness and naming speed are strongly related to
reading, visual-orthographic skills were entered into hierarchical regression analyses following these variables. With
age, verbal IQ, and verbal short-term memory also controlled, visual-orthographic skills accounted for significant
independent variance in all reading measures. When children with a visual- orthographic deficit (29% of the sample)
were compared with those without this deficit, they were significantly lower on all reading variables. At 8 to 10 years of
age, reading progress of some children continues to be hampered by a problem in orthographic memory for the
orientation of letters and numerals. Such children will require special attention, but their problems may be overlooked.
As recommended by Willows and Terepocki (1993), there is need for further research on the phenomenon of letter
reversals when they occur among children beyond first grade.
Smooth pursuit eye movements are associated with phonological awareness in preschool
Callu D, Giannopulu I, Escolano S, Cusin F, Jacquier-Roux M, Dellatolas G. Brain and Cognition 200, 58:217-225.
Phonological awareness is strongly related to reading ability, but reports are more conflicting concerning the
association of high level oculomotor skills with reading. Here, we show that phonological awareness is specifically
associated with the ability to perform smooth pursuit eye movements in preschool children. Two large independent
samples of preschool children (n=838 and n=732) aged 5-6.4 years, without history of neurological disorder, were
examined by school medical doctors for visual and oculomotor problems. Nineteen percent of the children in the first
sample and 14% in the second failed at the clinical evaluation of smooth pursuit eye movements, and 17 and 15%,
respectively, presented another visual or oculomotor problem. Ten short cognitive tests were performed by the same
children. Visual and oculomotor problems other than a failure on smooth pursuit were not consistently related to the
cognitive tasks, with one exception, the visual recognition of letters. Children who failed at smooth pursuit obtained
lower scores at a number of cognitive tasks, and especially phonological awareness tasks and copy of visually presented
trajectories. Poor working memory and/or failure of anticipation during the tracking of a visual or auditory stimulus
related to frontal cortex immaturity may explain these associations in preschool children.
Voluntary control of saccadic and smooth-pursuit eye movements in children with learning
Fukushima J, Tanaka S, Williams JD, Fukushima K. Brain and Development 2005, 27(8): 579-588.
Eye movement is crucial to humans in allowing them to aim the foveae at objects of interest. We examined the
voluntary control of saccadic and smooth-pursuit eye movements in 18 subjects with learning disorders (LDs) (aged 816) and 22 normal controls (aged 7-15). The subjects were assigned visually guided, memory-guided, and anti-saccade
tasks, and smooth-pursuit eye movements (SPEM). Although, the LD subjects showed normal results in the visually
guided saccade task, they showed more errors in the memory-guided saccade task (e.g. they were unable to stop
themselves reflexively looking at the cue) and longer latencies, even when they performed correctly. They also showed
longer latencies than the controls in the anti-saccade task. These results suggest that they find it difficult to voluntarily
suppress reflexive saccades and initiate voluntary saccades when a target is invisible. In SPEM using step-ramp stimuli,
the LD subjects showed lower open- and closed-loop gains. These results suggest disturbances of both acceleration of
eye movement in the initial state and maintenance of velocity in minimizing retinal slip in the steady state. Recent
anatomical studies in LD subjects have suggested abnormalities in the structure of certain brain areas such as the
frontal cortex. Frontal eye movement-related areas such as the frontal eye fields and supplementary eye fields may be
involved in these disturbances of voluntary control of eye movement in LDs.
Spatial load factor in prediction of reading performance.
Larter SC, Herse PR, Naduvilath TJ, Dain SJ. Ophthalmic Physiol Opt 2004, 24(5):440-449.
This study investigated whether there is a relationship between reading age and clinical optometric tests that have
varying degrees of spatial loading in their design. Spatial loading in this context is the demand on the visual system to
process information about the relative position and orientation of stimuli. A total of 112 children aged 8-11 years were
assessed using saccadic eye movement and rapid naming tasks with varying spatial loads. All were subtests of Garzia's
Developmental Eye Movement test and Liubinas' SeeRite Reading Diagnostic Programme. Variability in load was
achieved by comparing rapid naming of numerals vs the spatially loaded letters p, d, b, q; and by comparing the speed
of reading numerals presented in increasingly complex arrays. Reading Age was assessed independently and results
were analysed by multiple logistic regression. Spatially loaded naming tasks performed at speed exposed a Spatial
Loading Factor which clearly differentiates children at risk with reading.
Deficient saccadic inhibition in Asperger’s disorder and the social-emotional processing
Manoach DS, Lindgren KA, Barton JJS. Journal of Neurology and Neurosurgery and Psychiatry 2004, 75:1719-1726.
Background: Both Asperger's disorder and the social-emotional processing disorder (SEPD), a form of non-verbal
learning disability, are associated with executive function deficits. SEPD has been shown to be associated with deficient
Objective: To study two executive functions in Asperger's disorder and SEPD, inhibition and task switching, using a
single saccadic paradigm.
Methods: 22 control subjects and 27 subjects with developmental social processing disorders-SEPD, Asperger's
disorder, or both syndromes-performed random sequences of prosaccades and antisaccades. This design resulted in
four trial types, prosaccades and antisaccades, that were either repeated or switched. The design allowed the
performance costs of inhibition and task switching to be isolated.
Results: Subjects with both Asperger's disorder and SEPD showed deficient inhibition, as indicated by increased
antisaccade errors and a disproportionate increase in latency for antisaccades relative to prosaccades. In contrast, task
switching error and latency costs were normal and unrelated to the costs of inhibition.
Conclusion: This study replicates the finding of deficient saccadic inhibition in SEPD, extends it to Asperger's disorder,
and implicates prefrontal cortex dysfunction in these syndromes. The finding of intact task switching shows that
executive function deficits in Asperger's disorder and SEPD are selective and suggests that inhibition and task switching
are mediated by distinct neural networks.
Clock drawing in developmental dyslexia.
Eden GF, Wood FB, Stein JF. Journal of Learning Disabilities 2003, 36(3):216-228.
Although developmental dyslexia is often defined as a language-based reading impairment not attributable to low
intelligence or educational or socioeconomic limitations, the behavioral manifestations of dyslexia are not restricted to
the realm of language. Functional brain imaging studies have shed light on physiological differences associated with
poor reading both inside and outside the classical language areas of the brain. Concurrently, clinically useful tests that
elicit these nonlinguistic deficits are few. Specifically, the integrity of the dorsal visual pathway, which predominantly
projects to the parietal cortex, remains underinvestigated, lacking easily administered tests. Here we present the Clock
Drawing Test (CDT), used to test the visuoconstructive ability of children with and without dyslexia and garden-variety
poor readers. Compared to typically reading children, many children with dyslexia and some garden-variety poor
readers showed significant left neglect, as measured by the distribution of figures drawn on the left clock face. In the
poor readers with dyslexia, we observed spatial construction deficits like those of patients with acquired righthemisphere lesions. The results suggest that in some children with dyslexia, right-hemisphere dysfunction may
compound the phonological processing deficits attributed to the left hemisphere. The CDT provides an easy
opportunity to assess skills known to be associated with right-hemisphere parietal function. This test can be easily
administered to children for both clinical and research purposes.
Altered control of visual fixation and saccadic eye movements in attention-deficit
Munoz DP, Armstrong IT, Hampton KA, Moore KD. Neurophyisol 2003, 10:1152.
Attention-deficit hyperactivity disorder (ADHD) is characterized by the overt symptoms of impulsiveness, hyperactivity,
and inattention. A frontostriatal pathophysiology has been hypothesized to produce these symptoms and lead to
reduced ability to inhibit unnecessary or inappropriate behavioral responses. Oculomotor tasks can be designed to
probe the ability of subjects to generate or inhibit reflexive and voluntary responses. Because regions of the frontal
cortex and basal ganglia have been identified in the control of voluntary responses and saccadic suppression, we
hypothesized that children and adults diagnosed with ADHD may have specific difficulties in oculomotor tasks requiring
the suppression of reflexive or unwanted saccadic eye movements. To test this hypothesis, we measured eye
movement performance in pro- and anti-saccade tasks of 114 ADHD and 180 control participants ranging in age from 6
to 59 yr. In the pro-saccade task, participants were instructed to look from a central fixation point toward an eccentric
visual target. In the anti-saccade task, stimulus presentation was identical, but participants were instructed to suppress
the saccade to the stimulus and instead look from the central fixation point to the side opposite the target. The state of
fixation was manipulated by presenting the target either when the central fixation point was illuminated (overlap
condition) or at some time after it disappeared (gap condition). In the pro-saccade task, ADHD participants had longer
reaction times, greater intra-subject variance, and their saccades had reduced peak velocities and increased durations.
In the anti-saccade task, ADHD participants had greater difficulty suppressing reflexive pro-saccades toward the
eccentric target, increased reaction times for correct anti-saccades, and greater intra-subject variance. In a third task
requiring prolonged fixation, ADHD participants generated more intrusive saccades during periods when they were
required to maintain steady fixation. The results suggest that ADHD participants have reduced ability to suppress
unwanted saccades and control their fixation behavior voluntarily, a finding that is consistent with a fronto-striatal
pathophysiology. The findings are discussed in the context of recent neurophysiological data from nonhuman primates
that have identified important control signals for saccade suppression that emanate from frontostriatal circuits.
On the relationship between dynamic visual and auditory processing and literacy skills;
results from a large primary-school study.
Talcott JB, Witton C, Hebb GS, Stoodley CJ, Westwood EA, France SJ, Hansen PC, Stein JF. Dyslexia. 2002, 8(4): 204-25.
Three hundred and fifty randomly selected primary school children completed a psychometric and psychophysical test
battery to ascertain relationships between reading ability and sensitivity to dynamic visual and auditory stimuli. The
first analysis examined whether sensitivity to visual coherent motion and auditory frequency resolution differed
between groups of children with different literacy and cognitive skills. For both tasks, a main effect of literacy group
was found in the absence of a main effect for intelligence or an interaction between these factors. To assess the
potential confounding effects of attention, a second analysis of the frequency discrimination data was conducted with
performance on catch trials entered as a covariate. Significant effects for both the covariate and literacy skill was
found, but again there was no main effect of intelligence, nor was there an interaction between intelligence and
literacy skill. Regression analyses were conducted to determine the magnitude of the relationship between sensory and
literacy skills in the entire sample. Both visual motion sensitivity and auditory sensitivity to frequency differences were
robust predictors of children's literacy skills and their orthographic and phonological skills.
The incidence and nature of letter orientation errors in reading disability.
Terepocki M, Kruk RS, Willows DM. J Learn Disabil 2002, 35(3):214-233.
Letter orientation confusions (reversals) in the reading and writing of 10-year-old children with and without reading
disability were investigated to determine whether reading disability is associated with letter orientation errors and to
identify the nature of the errors. In a variety of tasks measuring letter orientation confusions in reception (reversal
detection and recognition) and production (controlled writing, copying), individuals with reading disability made more
orientation confusions than average readers. Orientation errors were more frequent for reversible than for
nonreversible items in tasks involving long-term memory processes. The results did not appear to be related to group
differences in attention or speed of motor responding. Possible sources of orientation confusions, including deficient
magnocellular system processing, mislabeling, and overreliance on visual strategies, are discussed.
Oculomotor abnormalities in attention deficit hyperactivity disorder. A preliminary study.
Mostofsky SH, Lasker AG, Cutting LE, Denckla MB, Zee DS. Neurology 2001, 57:423-430.
Background: Prevailing hypotheses suggest that attention deficit hyperactivity disorder (ADHD) is secondary to
dysfunction of motor intentional systems mediated by prefrontal circuitry. Oculomotor paradigms provide a
mechanism for examining and localizing dysfunction at the interface between movement and cognition.
Objective: Three different saccade tasks (reflexive or prosaccades, antisaccades, and memory-guided saccades) were
used to examine functions necessary for the planning and the execution of eye movements, including motor response
preparation, response inhibition, and working memory.
Methods: The study included 19 children with ADHD, divided into two groups: a group of 8 children on
methylphenidate at the time of testing and a group of 11 children not taking any psychoactive medication. Results from
the two groups were compared with those from 25 age- and gender-matched normal control children.
Results: Both groups of children with ADHD made significantly more directional errors than did controls on the
antisaccade task and significantly more anticipatory errors than did controls on the memory-guided saccade task,
findings that are consistent with deficits in response inhibition. There were no significant differences in prosaccade
latency, although unmedicated children with ADHD showed significantly greater variability in latency on the prosaccade
task than did controls. On the memory-guided saccade task there were no significant differences in saccade accuracy;
however, unmedicated children with ADHD showed longer saccade latency than did either controls or medicated
children with ADHD.
Conclusion: Oculomotor findings suggest that deficits in prefrontal functions, in particular response inhibition,
contribute to behavioral abnormalities observed in ADHD. Findings also suggest that the administration of
methylphenidate is associated with improvements in the consistency of motor response. Although there were no
observed improvements in response inhibition with methylphenidate, conclusions await a design in which subjects
complete testing both on and off medication.
Voluntary saccadic control in dyslexia.
Biscaldi M, Fischer B, Hartnegg K. Perception 2000, 29:509-521.
The role of eye-movement control in dyslexia is still unclear. Recent studies, however, confirmed that dyslexics show
poor saccadic control in single and sequential target tasks. In the present study we investigated whether dyslexic
subjects are impaired on an antisaccade task requiring saccades against the direction of a stimulus. Altogether, 620
subjects between the ages of 7 and 17 years were classified as dyslexics (N = 506) or control subjects (N = 114) on the
grounds of the discrepancy between their intellectual abilities and reading/spelling achievements. All subjects
performed an overlap prosaccade and a gap antisaccade task with 100 trials to each side of stimulation in random
order. Variables analysed were the overall saccadic reaction time of both tasks; and from the antisaccade task the
number of errors (prosaccades), the number of corrected errors, and the number of trials in which the subjects still
failed to reach the side opposite the stimulus even after two saccades. An analysis of variance was carried out taking
into account the development of saccadic behaviour with age and the differences between the groups. The results
confirm development of saccade control with age, especially in the voluntary component (a frontal-lobe function) for
both groups, but indicate that the antisaccade task performance, as measured by the error and the correction rate, is
significantly worse in the dyslexic group at ages above 8 years. Up to 50% of the dyslexics performed the antisaccade
task 1.5 standard deviations below the mean of the controls.
Magnocellular visual function and children's single word reading.
Cornelissen PL, Hansen PC, Hutton JL, Evangelinou V, Stein JF. Vision Res. 1998, 38(3):471-82.
Recent research has shown that reading disabled children find it unusually difficult to detect flickering or moving visual
stimuli, consistent with impaired processing in the magnocellular visual stream. Yet, it remains controversial to suggest
that reduced visual sensitivity of this kind might affect children's reading. Here we suggest that when children read,
impaired magnocellular function may degrade information about where letters are positioned with respect to each
other, leading to reading errors which contain sounds not represented in the printed word. We call these
orthographically inconsistent nonsense errors "letter" errors. To test this idea we assessed magnocellular function in a
sample of 58 unselected children by using a coherent motion detection task. We then gave these children a single word
reading task and found that their "letter" errors were best explained by independent contributions from motion
detection (i.e., magnocellular function) and phonological awareness (assessed by a spoonerism task). This result held
even when chronological age, reading ability, and IQ were controlled for. These findings suggest that impaired
magnocellular visual function, as well as phonological deficits may affect how children read.
Effect of oculomotor and other visual skills on reading performance: A literature review.
Taylor Kulp M, Schmidt P. Optometry and Vision Science 1996, 73 (4): 283-292.
Reading disability is a multifaceted problem, which requires an interdisciplinary approach. Many visual difficulties have
been shown to be related to reading ability. Efficient reading requires accurate eye movements and continuous
integration of the information obtained from each fixation by the brain. A relation between oculomotor efficiency and
reading skill has been shown in the literature. Frequently, these visual difficulties can be treated successfully with vision
The Vision Screening of Academically & Behaviorally At-Risk Pupils
Johnson R, Nottingham D, Stratton R, Zaba J. Journal of Behavioral Optometry 1996, 7(2):39.
The New York State Optometric Association Vision Screening Battery (NYSOA) was administered to 81 at-risk
elementary, middle school, and high school students in order to rule out vision difficulties as contributing to academic
difficulties and/or as to various determinations of attention deficit disorder (ADD), attention deficit hyperactivity
disorder (ADHD), dyslexia or dyslexic, or oppositional-defiant behavior, etc. Thirty-three were classified as both
academically and behaviorally at-risk. Ninety-seven percent of the students with behavioral problems failed at least one
of the NYSOA subtests. A chi-square statistical analysis revealed that students who were academically at risk or
behaviorally at risk scored significantly lower on the tracking, stereopsis, hyperopia, and color vision subtests. The
results of this screening were also compared to several measures of academic achievement and subjective visual and
academic assessment questionnaires.
Verbal and visual problems in reading disability.
Eden G, Stein J, Wood M, Wood F. Journal of Learning Disabilities 1995, 28 (5): 272-290.
In a preliminary study (Eden, Stein & Wood 1993), we showed that visuospatial and oculomotor tests can be used to
differentiate children with reading disabilities from nondisabled children. In the present study, we investigated a larger
sample of children to see if these findings held true. Using 93 children from the Bowman Gray Learning Disability
Project (mean age = 11.3 years: 54 boys, 39 girls), we compared the phonological and visuospatial abilities of
nondisabled children (children whose reading at fifth grade rated a Woodcock-Johnson reading standardized score
between 85 and 115), and children with reading disability (whose reading standardized score was below 85 on the
Woodcock-Johnson). In addition to performing poorly on verbal tests, the children with reading disability were
significantly worse than nondisabled children at many visual and eye movement tasks. A high proportion of the
variance (68%) in reading ability of both the nondisabled children and those with reading disability could be predicted 3
by combining visual and phonological scores in a multiple regression. These results provide further support for the
hypothesis that reading disability may, to some extent, result from dysfunction of the visual and oculomotor systems.
Differences in eye movements and reading problems in dyslexic and normal children.
Eden G, Stein JF, Wood HM, Wood FB. Vision Research 1994, 34 (10): 1345-1358.
It has been suggested that eye movement abnormalities seen in dyslexics are attributable to their language problems.
In order to investigate this claim, we studied eye movements in dyslexic children during several non-reading tasks.
Dyslexic children were compared to normal and backward readers on measures of fixation, vergence amplitude,
saccade and smooth pursuit. The results were compared to the children’s phonological ability. Dyslexic children (n = 26)
had significantly worse eye movement stability during fixation of small targets than normal children (n = 30). Vergence
amplitudes were lower for dyslexics than for controls. A qualitative assessment of saccadic eye movements revealed
that dyslexics exhibit fixation instability at the end of saccades. Assessment of smooth pursuit revealed poor smooth
pursuit in the dyslexic group, particularly when pursuing a target moving from left to right. Dyslexic children also
performed significantly worse than normal children on a test of phonological awareness (Pig Latin). Eye movement
results were studied in the light of the findings on phonological awareness: dyslexics with small vergence amplitudes
also always have poor phonemic awareness. However, poor fixation control is found in dyslexics with or without poor
phonological ability. The backward reading children performed similar to the dyslexics on all tests, suggesting that the
deficiencies observed in this study are not specific to children with dyslexia. The problems experienced by the children
(revealed by a questionnaire) are in agreement with those measured in terms of eye movement recording sand
phonemic awareness. Sex, handedness, IQ or the presence of attention deficit disorder (ADD) did not appear to
influence the children’s performances on any of the eye movement tasks. The presence of oculomotor abnormalities in
a nonreading task strongly suggest that the underlying deficit in the control of eye movements seen in dyslexics is not
caused by language problems alone.
Visuo-spatial discrimination and mirror image letter reversals in reading.
McMonnies CW. J Am Optom Assoc 1992, 63(10):698-704.
This review compares visuo-spatial and linguistic mechanisms for discriminating between mirror image letters. The
conclusion is drawn that both processes play a role in efficient reading, their relative contributions varying with reading
experience and ability. It is shown that arguments used to reject visuo-spatial theories in mirror image letter reversals
are flawed. Attention is drawn to the importance of visuo-spatial discrimination of mirror image letters, based on
confident left/right body awareness, for beginning readers and for older children who are deficient in compensatory
linguistic skills. When confused left/right body awareness is found in association with reversal problems, there is an
indication to provide remediation that includes the promotion of mirror image letter discrimination based on confident
left/right body awareness. Early intervention (pre-school and infants class) programs that teach left/right body
awareness as a pre-reading skill are justified when the progress of beginning readers is facilitated and the need for
remedial intervention is reduced in later years.
Jordan Left-Right Reversal Test: An analysis of visual reversals in children and significance
for reading problems.
Jordan BT, Jordan SG. Child Psychiatry Hum Dev. 1990, 21(1):65-73.
The Jordan Left-Right Reversal Test (JLRRT) was first published in 1974 (1) as a convenient measure of symbol reversals
in children. A current revision of the test, based on 3,000 children, showed error scores to be inversely related to age
and sex. Learning disabled children and a group of below average readers made significantly more errors, indicating
that visual reversals are dysfunctional for reading skills.
Basic auditory processing and developmental dyslexia in Chinese.
Wang H, Huss M, Hamalainen J, Goswami U. Reading & Writing 2010, 25(2):509-536.
The present study explores the relationship between basic auditory processing of sound rise time, frequency, duration
and intensity, phonological skills (onset-rime and tone awareness, sound blending, RAN, and phonological memory) and
reading disability in Chinese. A series of psychometric, literacy, phonological, auditory, and character processing tasks
were given to 73 native speakers of Mandarin with an average age of 9.7 years. Twenty-six children had developmental
dyslexia, 29 were chronological age-matched controls (CA controls) and 18 were reading-matched controls (RL
controls). Chinese children with dyslexia were significantly poorer than CA controls in almost all phonological tasks, in
semantic radical search, and in phonological recoding proficiency. Chinese children with dyslexia also showed
significant impairments in most of the basic auditory processing tasks. Regression analyses demonstrated that different
auditory measures of rise time discrimination were the strongest predictors of individual differences in Chinese
character reading (1 Rise task) and phonological recoding (2 Rise task) respectively, with frequency discrimination also
important for nonsense syllable decoding. Our results support the hypothesis that accurate perception of the
amplitude envelope of speech is critical for phonological development and consequently reading acquisition across
Electrophysiological and behavioural evidence of auditory processing deficits in children
with reading disorders.
Sharma M, Purdy SC, Newall P, Wheldall K, Beaman R, Dillon H. Clinical Neurophysiology 2006 117(5):1130-1144.
Objective: The aim of the research was to investigate auditory processing abilities in children with reading disorders
using electrophysiological and behavioral tasks.
Methods: Differences in auditory processing between control, compensated (age appropriate reading skills with a
history of reading disorder), and reading disordered groups were systematically investigated.
Results: The reading disorder group had significantly lower results than control and compensated reader groups for
most tests in the reading and auditory processing test battery. All children with a reading disorder did not pass at least
one behavioral test of auditory processing, and hence would be diagnosed clinically as having an auditory processing
disorder (APD). The reading disorder group also had significantly smaller /ga/-evoked mismatch negativity (MMN) area
than the control group. Compensated and control groups had similar results for the electrophysiological and behavioral
auditory processing tests. Correlation analyses showed that reading fluency and accuracy and nonword scores
(measured using Castle and Coltheart's word/nonword test) correlated significantly with most APD measures.
Conclusion: The general profile of auditory processing deficits in children with reading disorder was a combination of
deficits on frequency patterns (i.e. frequency pattern test) and absent or small /ga/-evoked MMN. Significant results
from the correlation analyses support the co-morbidity of reading and auditory processing disorders.
Significance: Children with reading disorders are likely to have auditory processing disorders.
On the development of low-level auditory discrimination and deficits in dyslexia.
Fischer B, Hartnegg K. Dyslexia 2004(10):105-118.
Absolute auditory thresholds, frequency resolution and temporal resolution develop with age. It is still discussed
whether low-level auditory performance is of clinical significance--specifically, for delayed maturation of central
auditory processing. Recently, five new auditory tasks were used to study the development of low-level auditory
discrimination. It was found that the development lasts up to the age of 16-18 years (on an average). Very similar tasks
were now used with 432 controls and 250 dyslexic subjects in the age range of 7-22 years. For both groups the
performance in one of the tasks was not related to the performance in another task indicating that the five tasks
challenge independent subfunctions of auditory processing. Surprisingly high numbers of subjects were classified as low
performers (LP), because they could not perform one or the other task at its easiest level and no threshold value could
be assigned. For the dyslexics the incidence of LP was considerably increased in all tasks and age groups as compared
with the age matched controls. The development of dynamic visual and optomotor functions and the corresponding
deficits in dyslexia are discussed in relation to the auditory data presented here.
Auditory temporal perception, phonics and reading disabilities in children.
Tallal P. Brain and Language 1980, (9):182-198.
Reading-impaired and control children were given an experimental battery of nonverbal auditory perceptual tests
which examined discrimination and temporal order perception. Stimulus tones were presented at various rates. There
were no significant differences between groups on tests in which stimuli were presented at slow rates. However, when
the same stimuli were presented more rapidly, the reading-impaired group made significantly more errors than the
controls. The reading-impaired children's ability to use phonics skills (nonsense word reading) was also examined.
There was a high correlation between the number of errors made on the phonics reading test and the number of errors
made in responding to the rapidly presented stimuli in the auditory perceptual tests. The hypothesis that some reading
impairments are related to low-level auditory perceptual dysfunction that affects the ability to learn to use phonics
skills adequately is discussed.