Why does a double dissociation study effectively localize distinct cognitive functions after brain damage?

💡 Explanation

Double dissociation uses selective impairment. If damage A impairs process X but not Y, while damage B impairs process Y but not X, it suggests separate mechanisms. This is because selective impairment is observed; therefore, the functions are likely localized rather than being diffusely represented, because widespread diaschisis would affect multiple processes.

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