A disorder in one or more fundamental psychological processes involved in understanding or using spoken or written language, i.e. inability to listen, think, spell, write, speak, calculate, and read. Furthermore, specific learning disabilities (SLD) include brain injuries, dyslexia, developmental aphasia, and perceptual disabilities and/or limitations. imperfect ability to listen, think, speak, read, write, spell, or to do mathematical calculations, including conditions such as perceptual disabilities, brain injury, minimal brain dysfunction, dyslexia, and developmental aphasia. SLD does not include learning problems that result from visual, hearing, or motor disabilities due to cognitive disability, emotional disturbance, or environmental, cultural, and economic disadvantage.