ABSTRACT

Spatial frequency refers to the number of cycles per degree of visual angle in a pattern. When low spatial frequency gratings are moving quickly, we see flicker at lower contrasts than we see pattern but we experience the reverse at high spatial frequencies. The possibility of a visual deficit in dyslexics has recently been investigated within the theoretical framework of spatial frequency analysis. Visible persistence is one measure of temporal processing in spatial frequency channels and refers to the continued perception of a stimulus after it has been physically removed. Lovegrove and colleagues attempted to predict from Breitmeyer's theory the effect that different types of spatial context may have on reading accuracy in dyslexics and controls. The results with different modes of visual presentation and with the effects of wavelength on reading in dyslexics and controls will be further investigated in our laboratory and are encouraging.