A dichotic listening study of differences in cerebral organization in dextral and sinistral subjects

The purpose of the present study was to compare immediate recall of paired dichotic presentation of CV-syllables in a dextral and a sinistral group when considering both gender, familial sinistrality, and hand-posture during writing. Forty subjects (20 dextrals and 20 sinistrals) were given 306 presentations of the six Swedish stop-consonants paired with the vowels a, i, and u in a dichotic-listening test. The results showed significant differences between the two groups with fewer consonant-errors observed for the right ear input in the dextral group, and fewer consonant-errors in the left ear input in the sinistral group. Thus, a REA was demonstrated for the dextral group, and a LEA was demonstrated for the sinistral group. The results were most clear-cut for the consonants whereas vowels yielded insignificant differences. It is concluded that the present design allows for the separation of left- and right-hemisphere language dominance for right- and left-handed subjects.