| |
Abstract:
We investigated whether the ease with which distracting
sounds can be ignored depends on their distance from fixation, and
from attended visual events. In Experiment 1, participants shadowed
an auditory stream of words presented behind their head, while
simultaneously fixating visual lip-read information consistent with
the relevant auditory stream, or meaningless 'chewing'
lip-movements. An irrelevant auditory stream of words was presented
from either the same side as the fixated visual stream or from the
opposite side. Selective shadowing was less accurate in the former
condition, implying that distracting sounds are harder to ignore
when fixated. Furthermore, the impairment when fixating distractor
sounds was greater when speaking rather than chewing lips were
fixated, suggesting that people find it particularly difficult to
ignore sounds at locations actively attended for visual
lip-reading, rather than merely passively fixated. Further
experiments tested whether these results are specific to crossmodal
links in speech perception, by replacing the visual lip-movements
with a rapidly changing stream of meaningless visual shapes. The
auditory task was still shadowing, but the active visual task was
now monitoring for visual targets at one location. A decrement in
shadowing was again observed when passively fixating toward the
irrelevant auditory stream. This decrement was larger when
performing a difficult active visual task there versus fixating,
but not for a less demanding visual task versus fixating.
71A
|
