A theoretical and experimental case for a visual deficit in specific reading disability

The Familial Incidence of Symptoms of Scotopic Sensitivity/Irlen Syndrome: Comparison of Referred and Mass-Screened Groups

“…Symptoms reported while reading or writing include a blurring and shadowing of letters and words, a doubling, merging, or move-ment of print, eye strain and fatigue, restricted span of focus and problems focussing for an extended period of time (Irlen, 1991a;Whiting, 1985). Similar dstortions have been reported by a number of other investigations (Legein & Bouma, 1982;Lovegrove, Martin, & Slaghuis, 1986;Stein & Fowler, 1985) and are consistent with a sensory afterimaging effect in which images such as words could persist longer for reading disabled than average readers (Riding & Pugh, 1977;Shapiro, Raymond, & Arnell, 1994;Wdows, 1998).…”

The Familial Incidence of Symptoms of Scotopic Sensitivity/Irlen Syndrome: Comparison of Referred and Mass-Screened Groups

“…Symptoms reported while reading or writing include a blurring and shadowing of letters and words, a doubling, merging, or move-ment of print, eye strain and fatigue, restricted span of focus and problems focussing for an extended period of time (Irlen, 1991a;Whiting, 1985). Similar dstortions have been reported by a number of other investigations (Legein & Bouma, 1982;Lovegrove, Martin, & Slaghuis, 1986;Stein & Fowler, 1985) and are consistent with a sensory afterimaging effect in which images such as words could persist longer for reading disabled than average readers (Riding & Pugh, 1977;Shapiro, Raymond, & Arnell, 1994;Wdows, 1998).…”

Duration expansion at low luminance levels

“…They reported that the effect was limited to high temporal frequencies and it was orientation-independent, leading them to suggest that the adaptation occurred at an early site in the magnocellular pathway. This initial observation was further supported by finding that adaptation to a cortically invisible flicker still causes duration compression in normal, but not in dyslexics (Johnston et al, 2008), for whom a magnocellular impairment has been proposed (Lovegrove, Martin, & Slaghuis, 1986;Lovegrove, Bowling, Badcock, & Blackwood, 1980;Lovegrove, Garzia, & Nicholson, 1990;Stein & Walsh, 1997) and that the spatial specificity of the effect is very narrow (Ayhan et al, 2009). We found that adaptation-induced duration compression occurs in a retinocentric frame of reference , but spatiotopic effects have also been reported (Burr et al, 2007, see also Burr, Cicchini, Arrighi, & Morrone, 2011; for further discussion).…”

Spatial frequency processing and the prediction of reading ability: A preliminary investigation

“…The temporal sensitivity experiments show that SRDs are less sensitive than con-trols at all temporal frequencies, but the difference increases with increasing flicker rate. It has been argued in detail elsewhere (Lovegrove, Martin, & Slaghuis, 1986) that all of these results are consistent with a transientsystem deficit in SRDs.…”

The Familial Incidence of Symptoms of Scotopic Sensitivity/Irlen Syndrome: Comparison of Referred and Mass-Screened Groups

“…Symptoms reported while reading or writing include a blurring and shadowing of letters and words, a doubling, merging, or move-ment of print, eye strain and fatigue, restricted span of focus and problems focussing for an extended period of time (Irlen, 1991a;Whiting, 1985). Similar dstortions have been reported by a number of other investigations (Legein & Bouma, 1982;Lovegrove, Martin, & Slaghuis, 1986;Stein & Fowler, 1985) and are consistent with a sensory afterimaging effect in which images such as words could persist longer for reading disabled than average readers (Riding & Pugh, 1977;Shapiro, Raymond, & Arnell, 1994;Wdows, 1998).…”

Duration expansion at low luminance levels

“…They reported that the effect was limited to high temporal frequencies and it was orientation-independent, leading them to suggest that the adaptation occurred at an early site in the magnocellular pathway. This initial observation was further supported by finding that adaptation to a cortically invisible flicker still causes duration compression in normal, but not in dyslexics (Johnston et al, 2008), for whom a magnocellular impairment has been proposed (Lovegrove, Martin, & Slaghuis, 1986;Lovegrove, Bowling, Badcock, & Blackwood, 1980;Lovegrove, Garzia, & Nicholson, 1990;Stein & Walsh, 1997) and that the spatial specificity of the effect is very narrow (Ayhan et al, 2009). We found that adaptation-induced duration compression occurs in a retinocentric frame of reference , but spatiotopic effects have also been reported (Burr et al, 2007, see also Burr, Cicchini, Arrighi, & Morrone, 2011; for further discussion).…”

Spatial frequency processing and the prediction of reading ability: A preliminary investigation

“…The temporal sensitivity experiments show that SRDs are less sensitive than con-trols at all temporal frequencies, but the difference increases with increasing flicker rate. It has been argued in detail elsewhere (Lovegrove, Martin, & Slaghuis, 1986) that all of these results are consistent with a transientsystem deficit in SRDs.…”

The Familial Incidence of Symptoms of Scotopic Sensitivity/Irlen Syndrome: Comparison of Referred and Mass-Screened Groups

“…Symptoms reported while reading or writing include a blurring and shadowing of letters and words, a doubling, merging, or move-ment of print, eye strain and fatigue, restricted span of focus and problems focussing for an extended period of time (Irlen, 1991a;Whiting, 1985). Similar dstortions have been reported by a number of other investigations (Legein & Bouma, 1982;Lovegrove, Martin, & Slaghuis, 1986;Stein & Fowler, 1985) and are consistent with a sensory afterimaging effect in which images such as words could persist longer for reading disabled than average readers (Riding & Pugh, 1977;Shapiro, Raymond, & Arnell, 1994;Wdows, 1998).…”

Duration expansion at low luminance levels

“…They reported that the effect was limited to high temporal frequencies and it was orientation-independent, leading them to suggest that the adaptation occurred at an early site in the magnocellular pathway. This initial observation was further supported by finding that adaptation to a cortically invisible flicker still causes duration compression in normal, but not in dyslexics (Johnston et al, 2008), for whom a magnocellular impairment has been proposed (Lovegrove, Martin, & Slaghuis, 1986;Lovegrove, Bowling, Badcock, & Blackwood, 1980;Lovegrove, Garzia, & Nicholson, 1990;Stein & Walsh, 1997) and that the spatial specificity of the effect is very narrow (Ayhan et al, 2009). We found that adaptation-induced duration compression occurs in a retinocentric frame of reference , but spatiotopic effects have also been reported (Burr et al, 2007, see also Burr, Cicchini, Arrighi, & Morrone, 2011; for further discussion).…”

Spatial frequency processing and the prediction of reading ability: A preliminary investigation

“…The temporal sensitivity experiments show that SRDs are less sensitive than con-trols at all temporal frequencies, but the difference increases with increasing flicker rate. It has been argued in detail elsewhere (Lovegrove, Martin, & Slaghuis, 1986) that all of these results are consistent with a transientsystem deficit in SRDs.…”