Processing Speed

Specific Language Impairment (SLI) and Dyslexia

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Nowadays reading comprehension is the key to be successful in school. Children have difficulties in the early stages of learning to read and the main problem are the phonological skills. Interventions that target phonological skills need to be integrated with the teaching of reading (Hatcher, Hulme, & Ellis, 1994), and it is necessary to understand that a difference exist between dyslexia and maturational delay on reading comprehension. Some studies point out that in countries where children undergo the digital revolution, reading comprehension is worst than other countries. Preschoolers with specific language impairment (SLI) perform worst on tests of reading, spelling and reading comprehension (Snowling, Bishop, & Stothard, 2000), and children with IQ less than 100, have literacy outcomes particularly poor. We can conceptualize a subgroup in the SLI: children with specific SLI-Dyslexiareading impairment.This group shows a substantial drop in reading accuracy between the ages of 8 and 15 years. Another subgroup, over 35%, have reading skills normalized. In the opinion of Bishop, phonological difficulties place children under a literacy failure. Specific reading retardation may account for a poor vocabulary and difficulties in organizing words and syntactic difficulties. Children with problems in phonological route understand words by semantic process. They prefer to use the general meaning of the phrase to understand the word. Another problem that we find in many children with SLI are deficits in verbal working memory. A deficient working memory functioning may account for difficulties in lexical-morphological learning and sentence comprehension (Montgomery, 2003).

Children with dyslexia have a central problem in phonological loop: they have problems in the phonological representation of words and their decodification and also in cognitive processing speed. However, sometimes they have a normal reading comprehension such as dyslexics with high IQ. Dyslexics have difficulties reading pseudowords and this test is the standard for screening dyslexics.

Prevention is one of the keys to help children with SLI. A reading program with highly structured phonic component for 5 years old children is enough to master alphabetic principles and learning to read. In contrast, children at risk of reading delay need an additional training in phoneme awareness (Hatcher, Hulme, & Snowling, 2004).

In 2004 Bishop & Snowling wrote and article about differences between developmental dyslexia and specific language impairment. They explained that dyslexia was reconceptualized as a language disorder with a defficient phonological processing. The authors argued that we need to be aware of semantic and sintactic deficits in SLI. These deficits affect reading comprehension and fluency in adolescents (Bishop & Snowling, 2004).

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Bishop, D. V. M., & Snowling, M. J. (2004). Developmental dyslexia and specific language impairment: same or different? Psychological bulletin, 130(6), 858-886. doi:10.1037/0033-2909.130.6.858

Hatcher, P. J., Hulme, C., & Ellis, A. W. (1994). Ameliorating Early Reading Failure by Integrating the Teaching of Reading and Phonological Skills: The Phonological Linkage Hypothesis. Child Development, 65(1), 41–57. doi:10.1111/j.1467-8624.1994.tb00733.x

Hatcher, P. J., Hulme, C., & Snowling, M. J. (2004). Explicit phoneme training combined with phonic reading instruction helps young children at risk of reading failure. Journal of Child Psychology and Psychiatry, 45(2), 338–358. doi:10.1111/j.1469-7610.2004.00225.x

Montgomery, J. W. (2003). Working memory and comprehension in children with specific language impairment: what we know so far. Journal of Communication Disorders, 36(3), 221-231. doi:10.1016/S0021-9924(03)00021-2

Snowling, M., Bishop, D. V., & Stothard, S. E. (2000). Is preschool language impairment a risk factor for dyslexia in adolescence? Journal of child psychology and psychiatry, and allied disciplines, 41(5), 587-600.

Processing Speed

Posted on Actualizado enn

Processing speed is one of the major factor in general cognition and a fundamental part of the cognitive system (Kail & Salthouse, 1994).

Slow cognitive processing is linked to academic achievement and several clinical disorders. Vulnerability to information processing load is related to attentional problems. Inattentive children perform poorly on measures of information processing speed (Weiler, Bernstein, Bellinger, & Waber, 2000). Some authors talk about the possibility that inattentive subtype of ADHD (ADD), could be a different group from general ADHD characterized by poor cognitive interference control and slow processing (Goth-Owens, Martinez-Torteya, Martel, & Nigg, 2010). Likewise, attention and speed weaknesses coexist in children with Autism and ADHD, an contribute significantly to the Processing Speed_ADHD_Dyslexiaprediction of academic achievement (Mayes & Calhoun, 2007). Deficits in processing speed are a cognitive risk factor for reading disabilities and ADHD (Shanahan et al., 2006). Children with dyslexia, compared with normal performance children, have persistent problems in naming speed for all stimuli regardless the stimulus requires grapheme-phoneme decoding. In the study of Fawcet (Fawcett & Nicolson1994), performance speed of children with dyslexia at the age of seventeen was close to those with eight years old at control group.

Naming speed can also be modified by medication. Children with ADHD taking methylphenidate selectively, can improve color naming speed but not the speed of naming letters or digits. These findings implicate that naming speed deficits are associated with effortful semantic processing in ADHD, and can be improved but not normalized by methylphenidate (Tannock, Martinussen, & Frijters, 2000).

The relationship between learning disabilities and intelligence is not clear. Children with low IQ scores can be good readers. Poor readers at variety of IQ levels show similar reading, spelling, language and memory deficits (Siegel, 1989).

Another important field is the study of neural correlates of processing speed. Children with developmental dyslexia show deficient phonological processing. When we study the functional networks with rapid auditory processing (RAP), we found functional alteration in left hemisphere frontal regions in prereading children at risk for dyslexia (Raschle, Stering, Meissner, & Gaab, 2013).

Finally, studies show a relation between speed processing, rapid naming and phonological awareness, and all three are related to reading achievement. Poor readers are more slow than good readers across response time measures on the rapid object naming task. Catts et al. 2002, suggest that some poor readers have a general deficit in speed processing, and that speed processing may be conceptualized as an “extraphonological” factor. Naming speed explains variance in reading skills independently of measures of phonological awareness (Bowers & Swanson, 1991).

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Bowers, P. G., & Swanson, L. B. (1991). Naming speed deficits in reading disability: Multiple measures of a singular process. Journal of Experimental Child Psychology, 51(2), 195-219. doi:10.1016/0022-0965(91)90032-N

Catts, H. W., Gillispie, M., Leonard, L. B., Kail, R. V., & Miller, C. A. (2002). The Role of Speed of Processing, Rapid Naming, and Phonological Awareness in Reading Achievement. Journal of Learning Disabilities, 35(6), 510-525. doi:10.1177/00222194020350060301

Fawcett, A. J., & Nicolson, R. I. (1994). Naming Speed in Children with Dyslexia. Journal of Learning Disabilities, 27(10), 641-646. doi:10.1177/002221949402701004

Goth-Owens, T. L., Martinez-Torteya, C., Martel, M. M., & Nigg, J. T. (2010). Processing Speed Weakness in Children and Adolescents with Non-Hyperactive but Inattentive ADHD (ADD). Child Neuropsychology, 16(6), 577-591. doi:10.1080/09297049.2010.485126

Kail, R., & Salthouse, T. A. (1994). Processing speed as a mental capacity. Acta Psychologica, 86(2–3), 199-225. doi:10.1016/0001-6918(94)90003-5

Mayes, S. D., & Calhoun, S. L. (2007). Learning, Attention, Writing, and Processing Speed in Typical Children and Children with ADHD, Autism, Anxiety, Depression, and Oppositional-Defiant Disorder. Child Neuropsychology, 13(6), 469-493. doi:10.1080/09297040601112773

Raschle, N. M., Stering, P. L., Meissner, S. N., & Gaab, N. (2013). Altered Neuronal Response During Rapid Auditory Processing and Its Relation to Phonological Processing in Prereading Children at Familial Risk for Dyslexia. Cerebral Cortex, bht104. doi:10.1093/cercor/bht104

Shanahan, M. A., Pennington, B. F., Yerys, B. E., Scott, A., Boada, R., Willcutt, E. G., … DeFries, J. C. (2006). Processing Speed Deficits in Attention Deficit/Hyperactivity Disorder and Reading Disability. Journal of Abnormal Child Psychology, 34(5), 584-601. doi:10.1007/s10802-006-9037-8

Siegel, L. S. (1989). IQ Is Irrelevant to the Definition of Learning Disabilities. Journal of Learning Disabilities, 22(8), 469-478. doi:10.1177/002221948902200803

Tannock, R., Martinussen, R., & Frijters, J. (2000). Naming Speed Performance and Stimulant Effects Indicate Effortful, Semantic Processing Deficits in Attention-Deficit/Hyperactivity Disorder. Journal of Abnormal Child Psychology, 28(3), 237-252. doi:10.1023/A:1005192220001

Weiler, M. D., Bernstein, J. H., Bellinger, D. C., & Waber, D. P. (2000). Processing Speed in Children With Attention Deficit/Hyperactivity Disorder, Inattentive Type. Child Neuropsychology, 6(3), 218-234. doi:10.1076/chin.