Efficacy of temporal processing training to improve phonological awareness among dyslexic and normal reading students.

One of the leading theories for dyslexia suggests that it is the result of a difficulty in auditory temporal processing (ATP). This theory, as well as others, is supported by studies showing group differences and correlation between phonological awareness and ATP. However, these studies do not provide causal relationship. In the current study the authors aimed to test causal relationship between ATP and phonological awareness by comparing the performance of dyslexic and normal reader students in phonological awareness tasks before and after a short-term (5-day) training in either temporal processing (dichotic temporal order judgment; TOJ), nontemporal processing (intensity discrimination), or no training. TOJ training resulted in significant reduction of TOJ threshold and increase in phonological awareness tasks' scores. Intensity discrimination training resulted in a decrease of intensity discrimination threshold, but with no change in phonological awareness tasks. Those who had no training, had no change in TOJ and intensity discrimination thresholds, as well as in the phonological awareness tasks. These results show that (a) a short-term training in temporal processing with no other perceptual cues for adult dyslexic and normal readers can be efficient in improving their phonological awareness; and (b) phonological awareness (dis) ability has causal relationship to ATP.