Metabolic abnormalities in developmental dyslexia detected by 1H magnetic resonance spectroscopy

Rae, Caroline; Lee, Martin A.; Dixon, Ruth; Blamire, Andrew M.; Thompson, Campbell; Styles, Peter; Talcott, Joel B.; Richardson, Alexandra J.; Stein, John

doi:10.1016/s0140-6736(97)99001-2

Cited by 166 publications

(107 citation statements)

References 23 publications

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“…Dyslexics might also have poor integration of these signals at higher cortical levels. Either or both of these factors would decrease their ability to detect global coherent motion and would be consistent with anatomical evidence of structural impairment in both the retino-cortical M-pathway and within the extrastriate dorsal stream of dyslexics [18,28,44]. However, other studies have suggested that sensory de®cits in dyslexia are associated more with a problem detecting short duration stimuli whether they are dynamic or not ( [19,20] for review see [17]).…”

Section: Introductionmentioning

confidence: 68%

“…How poor motion processing occurs in dyslexia is unknown, although it may result from the impaired development of magnocells in both LGN and cortex that has been suggested by previous studies [18,25,28,44]. Livingstone et al [28] reported a 20% reduction in the area of magnocellular but not parvocellular cells in the lateral geniculate nucleus of dyslexics' brains examined post mortem.…”

Section: Discussionmentioning

confidence: 96%

“…Livingstone et al [28] reported a 20% reduction in the area of magnocellular but not parvocellular cells in the lateral geniculate nucleus of dyslexics' brains examined post mortem. Although no such speci®c dierences are found in the cell layers that receive speci®c inputs from magnocells and parvocells in primary visual cortex [25], Rae et al [44] have demonstrated that dyslexics have lowered cell density relative to controls in an area subsuming the posterior parietal cortex (PPC), an area receiving a predominant input from magnocells [38,39,56]. One hypothesis consistent with both our psychophysical data and these anatomical studies is that dyslexics with visual de®cits have fewer motion detectors, and therefore undersample spatially diuse dynamic stimuli such as coherent RDK motion.…”

Section: Discussionmentioning

confidence: 97%

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Visual motion sensitivity in dyslexia: evidence for temporal and energy integration deficits

et al. 2000

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In addition to poor literacy skills, developmental dyslexia has been associated with multisensory de®cits for dynamic stimulus detection. In vision these de®cits have been suggested to result from impaired sensitivity of cells within the retino-cortical magnocellular pathway and extrastriate areas in the dorsal stream to which they project. One consequence of such selectively reduced sensitivity is a diculty in extracting motion coherence from dynamic noise, a de®cit associated with both developmental dyslexia and persons with extrastriate, dorsal stream lesions. However the precise nature of the mechanism(s) underlying these perceptual de®cits in dyslexia remain unknown. In this study, we obtained motion detection thresholds for 10 dyslexic and 10 control adults while varying the spatial and temporal parameters of the random dot kinematogram (RDK) stimuli. In Experiment 1 stimulus duration was manipulated to test whether dyslexics are speci®cally impaired for detecting short duration, rather than longer stimuli. Dot density was varied in Experiment 2 to examine whether dyslexics' reduced motion sensitivity was aected by the amount of motion energy present in the RDKs. Dyslexics were consistently less sensitive to coherent motion than controls in both experiments. Increasing stimulus duration did not improve dyslexics' performance, whereas increasing dot density did. Thus increasing motion energy assisted the dyslexics, suggesting that their motion detectors have a lower signal to noise ratio, perhaps due to spatial undersampling. 7

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Section: Introductionmentioning

confidence: 68%

Section: Discussionmentioning

confidence: 96%

Section: Discussionmentioning

confidence: 97%

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Visual motion sensitivity in dyslexia: evidence for temporal and energy integration deficits

et al. 2000

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“…Stein's group compared the metabolism of the cerebellum in dyslexics with controls' using magnetic resonance spectroscopy (MRS). They found a lower ratio in the cerebellum of the dyslexics compared with the controls, particularly on the right hand side (Rae et al 1998). More recently, a further study from Rae et al, (2002), used imaging to show cerebellar symmetry in dyslexics but not controls.…”

Section: Wider Research On the Cerebellum And Dyslexiamentioning

confidence: 95%

Dyslexia: The Role of the Cerebellum

Fawcett¹,

Nicolson²

2004

Dyslexia in Context

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“…El grupo de Stein comparó el metabolismo del cerebelo de los disléxicos con el de los controles, utilizando el electroscopio de resonancia magnética. Encontraron una proporción menor en el cerebelo de los disléxicos, comparada con los controles, sobre todo por el lado derecho (Rae et al 1998). …”

Section: Las Investigaciones Más Generales Sobre El Cerebelo Y La Disunclassified

El cerebelo: su implicación en la dislexia

Fawcett

Nicolson

2017

EJREP

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Introducción: En esta revisión exponemos, en líneas generales, el razonamiento y la evidencia que respalda nuestra hipótesis que los problemas sufridos por los disléxicos pueden atribuirse a un deficit cerebelar.Método: Primero, ofrecemos una perspectiva general de la evidencia reciente que propone un papel importante del cerebelo en las habilidades cognitivas, particularmente las que apoyan el lenguaje hablado, además de su papel ya reconocido en las habilidades motrices. Segundo, resumimos la evidencia de nuestro laboratorio a favor de que la función cerebelar sea anormal en la dislexia.Resultados: Consideramos dos líneas concretas de evidencia: la conductual, y la evidencia convergent de la neuroimagen, la cual demuestra diferencias significativas entre los grupos disléxicos y de control. También administramos la misma batería de pruebas conductuales a un grupo de niños que son malos lectores no discrepantes.Discusión: Finalmente, proponemos una cadena causal ontogenético para el desarrollo de la dislexia como déficit cerebelar desde el nacimiento, considerando las implicaciones de este marco para las cuestiones clave en la investigación sobre la dislexia.

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Metabolic abnormalities in developmental dyslexia detected by 1H magnetic resonance spectroscopy

Cited by 166 publications

References 23 publications

Visual motion sensitivity in dyslexia: evidence for temporal and energy integration deficits

Visual motion sensitivity in dyslexia: evidence for temporal and energy integration deficits

Dyslexia: The Role of the Cerebellum

El cerebelo: su implicación en la dislexia

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