His research has investigated basic psychological processes and the application of that understanding to the relief of emotional disorders. (mbct.com)
It includes disorders in which one or more basic psychological processes involved in the comprehension and / or use of language (spoken or written) cause an impairment in a student's ability to listen, think, read, write, spell, and or complete mathematical calculations. (blog.edmentum.com)
According to the National Center of Learning Disabilities, a learning disability is «a disorder in one or more of the basic psychological processes involved in understanding or in using language, spoken or written, which disorder may manifest itself in the imperfect ability to listen, think, speak, read, write, spell, or do mathematical calculations». (elearningindustry.com)