Linked Life Data

11769867

Source:http://linkedlifedata.com/resource/pubmed/id/11769867

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2001-12-24
pubmed:abstractText
Developmental reading disability (dyslexia) has traditionally been attributed to impaired linguistic skills. Recent psychophysical data suggest that dyslexia may be related to a visual perceptual deficit. A few visual evoked potential (VEP) studies have addressed this hypothesis, but their results are far from consistent. We submitted 9 dyslexic subjects and 9 age- and sex-matched normal controls to checkerboard pattern reversal VEPs. The main experimental variables were: large (0.5 cycles per degree; cpd) and small (2 cpd) checks and two reversal frequencies (2.1 Hz and 8 Hz); mean luminance and contrast (60 cd/m2 and 50%, respectively) were kept constant in all four conditions. Transient VEP (2.1 Hz) parameters did not differ between controls and dyslexics at 2 cpd. At 0.5 cpd, N70 amplitude was significantly smaller and N70 latency significantly shorter in dyslexics. Amplitudes for the fundamental frequency (8 Hz), as well as for the second and third harmonics of the steady-state VEPs were smaller in dyslexics for both stimulus sizes. A discriminant analysis correctly classified each subject. Our data confirm the hypothesis of a perceptual deficit in dyslexic subjects. The abnormalities are related to spatial and temporal stimulus frequencies: they appear when large stimuli are presented, or when the stimulation frequency is high. These data support the hypothesis of selective magnocellular dysfunction in dyslexia.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:issn
0393-5264
pubmed:author
pubmed:issnType
Print
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
219-29
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:articleTitle
Visual evoked potential abnormalities in dyslexic children.
pubmed:affiliation
Department of Neurology, IRCCS C. Mondino Institute of Neurology, Pavia, Italy. aromani@mondino.it
pubmed:publicationType
Journal Article, Clinical Trial