On language laterality in normal dextrals and sinistrals: results from the bilateral object naming latency task

Neuropsychologia. 1995 Dec;33(12):1627-35. doi: 10.1016/0028-3932(95)00042-9.

Abstract

Rasmussen and Milner [N.Y.Acad. Sci. Vol. 299, pp. 355-379, 1977] published data on late-lesioned (after age 6) epileptic patients who had suffered left hemisphere lesions. They estimated that left hemisphere dominance occurred in 96% of dextrals and 70% of sinistrals. These figures have been regarded as valid estimates for normal dextrals and sinistrals. We administered the Bilateral Object Naming Latency Task, a verbal tachistoscopic task with very good psychometric properties, to 188 dextral and 72 sinistral normals. Results showed that 93.6% of the dextrals and 80.3% of the sinistrals were left hemisphere dominant. A consideration of results from a number of carefully conducted dichotic listening studies suggests, as do present results, that the 70% left-dominance estimate of Rasmussen and Milner for normal sinistrals may be too low by about 10%. It is suggested that 'bilateral dominance', present in 15% of the epileptic sinistrals of Rasmussen and Milner, may be much less common in normal sinistrals.

Publication types

  • Comparative Study

MeSH terms

  • Brain / physiology*
  • Dichotic Listening Tests
  • Dominance, Cerebral / physiology*
  • Female
  • Functional Laterality*
  • Humans
  • Language*
  • Male
  • Reaction Time
  • Visual Fields