Biased attention and the fused dichotic words test

This study examines the effect of biased attention on the fused dichotic words test (FDWT) and the CV syllables dichotic listening test (CVT). Eight males and eight females were given both tests with two different instructions: to direct attention to the left ear (DL), or to the right ear (DR). These instructions led to highly significant differences in response on the CVT, but only a marginal shift in performance on the FDWT. While the FDWT is not completely unaffected by attentional manipulations, it is far less influenced by such effects than the CVT. This indicates that subject-initiated shifts of attention are much less likely to affect performance on the FDWT than on other dichotic rests and makes it a more valuable task to assess cerebral speech lateralization.