Does a sensory processing deficit explain counting accuracy on rapid visual sequencing tasks in adults with and without dyslexia?
Conlon at al. (2011, Brain and Cognition, 76, 197-205) studied the responses of dyslexic readers and controls to rapidly presented stimuli. They found that the dyslexic readers showed poorer performance than the controls but only when the interstimulus interval (ISI) was short (150 ms), not when it was long (350 ms). This difference they attributed to a magnocellular or dorsal stream deficiency. However, they did not compute the temporal frequency spectra of the two stimuli. This is done here. It is found that it is very difficult to draw any conclusions with regard to the magnocellular system or the dorsal stream using these stimuli.