Interference asymmetry involving concurrent tasks performed by native American students

Abstract

It is assumed that Native Americans are right‐hemisphere dominant and therefore need special teaching techniques. This study examined the language and spatial lateralization of monolingual English‐speaking Native American students by means of the cognitive‐manual dual‐task model. The results revealed the following asymmetric interference: greater right‐hand disruption while reading, greater left‐hand disruption while solving spatial problems, fewer words read while tapping with the right hand, and fewer spatial problems solved while tapping with the left hand. However, the “good” Native American students had normal (left‐hemisphere language/right‐hemisphere spatial) lateralization, whereas the “poor” students had atypical lateralization for righthanders, primarily involving both left‐hemisphere language and left‐hemisphere spatial function. The neurological consequence of crowding language and spatial processing into the same hemisphere is discussed. Two major conclusions are that the Native American students of this study were not right‐hemisphere dominant, and that nonnormal language/special lateralization resulted in learning problems, possibly suggesting a new subclassification within the special education/handicapping condition of learning disabilities.