A Comparison of the effects for sustained versus shifted attention on dichotic listening performance.

We measured the effect of two types of directed attention instructions, sustained bya verbal cue or shifted by a tone cue with different time intervals (150, 450, and 750ms), on a consonant-vowel dichotic listening (C-V DL) test for a large group ofright- and left-handed participants of both sexes. An increasing of the hits and adecreasing of the intrusions from the baseline DL test scores was evident for bothtypes of attentional manipulations, with no differences regarding sex or handedness.Increasing the time from 150 to 450 ms benefited the focusing of attention but thisadvantage was markedly attenuated at the longer 750-ms interval. The improvingeffect was seen for the hits of both the left and right ears and so a right earadvantage was evident for the three time intervals.