The RAN deficit among readers with a selective deficit in reading rate: A domain-specific or a domain-general processing speed deficit?

The RAN deficit among readers with a selective deficit in reading rate: A domain-specific or a domain-general processing speed deficit?

First Author: Michal Shany -- University if Haifa
Additional authors/chairs: 
Or Wiess David Share
Keywords: Dyslexia, rapid automatized naming, processing speed, young readers
Abstract / Summary: 

The present study sought to shed light on the nature of the cognitive deficits among a subgroup of Hebrew-speaking dyslexics who have selective deficits in reading rate and serial naming but not in reading accuracy or phonological awareness. We asked whether the rate deficits in this subgroup are domain-specific or domain-general speed of processing (SOP) deficit. Studies investigating SOP deficits in dyslexia remain inconclusive on the question of domain-generality versus domain-specificity. One reason for the inconclusiveness could be the fact that most dyslexic samples include an unspecified mix of children with either reading accuracy or reading rate deficits, or both. The present study investigated the question of domain-specific or domain-general SOP deficits within the rate-accuracy framework (Shany & Share, 2011), and, specifically, in the selectively reading-rate disabled subgroup. The parent sample included 207 Hebrew-speaking second grade children from eight different schools in the north of Israel. Our screening battery identified 20 children with a selective reading-rate deficit, 20 with a selective reading-accuracy deficit and 20 typical readers. Processing speed measures were organized according to: (1) non-linguistic processing speed (2) linguistic processing speed including (2a) spoken language and (2b) written language and (3) purely alphanumeric RAN tasks. Overall, the results make a strong case for a domain-specific alphanumeric processing speed among in the reading-rate disabled subgroup but not among children with a selective deficit in reading accuracy. The rate-disabled subgroup did not show processing speed deficits on any spoken language task and on 4 out of 5 non-linguistic tasks. This subgroup had reliable and consistent deficits on tasks involving production and recognition of written alphanumeric material. The evidence clearly supported the highly domain-specific nature of serial naming (RAN) deficits among rate-disabled.