Dyslexia symptoms and biological dysfunction According to some internationally recognized diagnostic manuals, dyslexia is a condition in which the normal ways of skills’ acquisition are blocked in the early stages of development. This is not a consequence of absent opportunities for learning or some form of brain injury or disease. It is considered that the causes of dyslexia are rooted in cognitive functioning abnormalities resulting from some type of biological dysfunction. That is why, dyslexia is defined as problematic learning which limits the ability of students to have a full command over information processing, motor skills, and the working memory. In individuals with the disorder, difficulties in recognizing, identifying, and discovering stimuli have been reported. In turn, these lead to difficulties in mastering some or all skills associated with speech, reading, spelling, writing, and arithmetic.