Effects of modality-dependent cuing and eye movements on
sound localization

Beata TOMORIOVA, Rudolf Andoga, Norbert Kopco

A previous study of visual and auditory hemispheric cuing in
horizontal sound localization found modality-dependent effects of
cuing resulting in biases in responses [Kopco, Tomoriova, Andoga,
J. Acoust. Soc. Am. 121, 3094, 2007]. The previous study also
suggested that some of the effects might be due to eye movements as
eye fixation was not controlled. The goal of the current study was
to isolate the attentional effects from the eye movement
effects. An experiment identical to the previous one was performed,
with the exception that the subjects were fixating the center of
the audiovisual display. Localization performance was measured for
transient auditory stimuli originating in the frontal horizontal
plane. In most runs, a cue preceded the stimulus and indicated
(correctly or incorrectly) the hemisphere (left vs. right) from
which the subsequent target arrived. The cues differed by modality
and the cue-to-target onset asynchrony. The listeners were
instructed to focus their
attention to the cued side. Compared to the previous study, a
reduction in some effects was observed. However, modality-dependent
biases in performance persisted, confirming that auditory spatial
attentional control is modality dependent and operating on time
scale of seconds.

[Supported by the Slovak Science Grant Agency.]