Coherent motion detection in illiterate, literate and dyslexic readers in Papua New Guinea

Abstract

Individuals with dyslexia have often been found to have deficits in coherent motion processing, an index of global dorsal stream functioning. In studies involving pre-literate children it has been demonstrated that there could be a relationship between dorsal stream functioning and poor reading ability, lending weight to the claim that dorsal stream deficits may contribute to reading failure. This research looks at coherent motion sensitivity in adult illiterate readers and matched literate and dyslexic readers. The coherent motion sensitivity of lliterate and literate adult readers from Papua New Guinea, and dyslexic readers from Australia were examined to see if research in adults could likewise illuminate the discussion on the role of dorsal stream functioning in reading ability. The results of this analysis will be discussed as well as possible areas for further investigating the relationship between dorsal stream function and reading ability.

A Temporal Sampling Basis for Visual Processing in Developmental Dyslexia

“…Dyslexic readers have significantly higher spatial and temporal threshold to the FD illusion presented at 18 Hz (Gori et al, 2014), 25 Hz (Pammer and Wheatley, 2001), and 50 Hz (Kevan and Pammer, 2008) compared to non-dyslexic readers, indicating that a specific magnocellular oscillatory synchronization deficit may exist as early as the retina. Pre-readers at risk of dyslexia show the same threshold differences to the FD illusion presented at 50 Hz (Kevan and Pammer, 2008) and illiterate, semi-literate, and literate adults are all equally sensitive to the illusion presented at 50 Hz (Flint and Pammer, 2011). This suggests that sensitivity to the FD illusion is not dependant on magnocellular development as a child learns to read and is therefore not a consequence of failing to learn to read (Kevan and Pammer, 2008;Flint and Pammer, 2019).…”