Dyslexia and a transient/magnocellular pathway deficit: The current situation and future directions

Lexical learning and dysgraphia in a group of adults with developmental dyslexia

“…The hypothesis of a second visual factor in dyslexia has a long history (for a review, see Lovegrove, 1996). However, our results point specifically to impairments of visuo sequential memory rather than to more general impairments of visual memory.…”

Does Dyslexia Develop from Learning the Alphabet in the Wrong Hemisphere? A Cognitive Neuroscience Analysis

“…Indeed, although temporal processing deficits are common in dyslexia (see Farmer & Klein, 1995, for a review), many dyslexics are not impaired in this respect either auditorily (Reed, 1989;Tallal, 1980;Tallal & Stark, 1982) or visually (Høien, 1982;Riding & Pugh, 1977-in the latter studies demonstrating even less visual persistence than good readers. Furthermore, the deficit in the temporally sensitive transient/magnocellular pathway that has been identified in many studies of dyslexia (see Lovegrove, 1996, for an overview) is not found in dyslexics manifesting dyseidetic (LL) characteristics (Borsting et al, 1996;Ridder, Borsting, Cooper, McNeel, & Huang, 1997;Slaghius & Ryan, 1999;Spinelli et al, 1997).…”

Visual information processing in dyslexic children

“…It seems to be associated with reduced phonological awareness and multisensory deficits. One of these lacks has been suggested to result from abnormal visual pathways: Most dyslexic studies (Lovegrove, 1996) indicate a defect in the magnocellular components of the visual processing streams (Livingstone et al, 1991;Brannan et al, 1998). The magnocellular system is, in addition to the parvocellular system, one of the two interactive subsystems for visual processing, arising from cells widely distributed across the retina and projecting to the visual cortex via the ventral lateral geniculate nucleus.…”