Right-hemisphere language: Familial and nonfamilial sinistrals,cognitive deficits and writing hand position in sinistrals,and concrete-abstract,imageable-nonimageable dimensions in word recognition. A review of interrelated issues

While left-hemisphere language dominance is more general than dextrality, and reversed dominance is less frequent than sinistrality, there are disputes in both the clinical and the experimental literature on a number of related issues which pertain to a possible language contribution from the minor hemisphere. These issues include the nature and extent of bilaterality in sinistrals, whether this is more pronounced in the strongly or weakly sinistral, and in those with or without other sinistral close relatives, whether sinistrality is largely or at all a consequence of birth stress, whether sinistrals differ from dextrals in visuospatial or even verbal skills, Levy's (1978) hypothesis that a knowledge of the hand position employed in writing (hooked or noninverted) may accurately predict language lateralization in sinistrals, and the possible extent of a minor hemisphere contribution to the recognition of high frequency, concrete, or imageable nouns. Findings relating to the above issues are reviewed, and it is concluded that much of the current confusion stems from poor control of subject factors such as sex, strength and family history of handedness, and nature of stimuli and their mode of presentation.