ABSTRACT
This conclusion chapter summarizes the author’s personal research findings concerning functional hemispheric asymmetries in children suffering from the most common developmental disorders – developmental stuttering, developmental dyslexia, non-syndromic intellectual disability and autism spectrum disorder, which provide clear evidence that the disorders are not unitary regarding cerebral lateralization of function and show how the study of populations with developmental disorders as homogeneous groups could mask the real status of the studied phenomena and lead to misleading interpretations of the results.
Two main assumptions that need future research in verification are made based on these series of studies using uniform research methods: first, each population of persons with developmental speech, language or literacy disorders contains a subgroup for which the aberrant cerebral lateralization is causally related to the emergence of the disorder and second, each population of persons with developmental disorders that are not linguistic in nature contains a subgroup with comorbid language impairment that might be caused by the aberrant cerebral lateralization.
