Recent work has shown that adapting to a visual or auditory stimulus of a
particular duration leads to a repulsive distortion of the perceived duration of
a subsequently presented test stimulus. This distortion seems to be
modality-specific and manifests itself as an expansion or contraction of
perceived duration dependent upon whether the test stimulus is longer or shorter
than the adapted duration. It has been shown (Berger et al 2003, Journal
of Vision
3, 406–412) that perceived events can be as effective as actual
events in inducing improvements in performance. In light of this, we
investigated whether an illusory visual duration was capable of inducing a
duration after-effect in a visual test stimulus that was actually no different
in duration from the adaptor. Pairing a visual stimulus with a concurrent
auditory stimulus of subtly longer or shorter duration expands or contracts the
duration of the visual stimulus. We mapped out this effect and then chose two
auditory durations (one long, one short) that produced the maximum distortion in
the perceived duration of the visual stimulus. After adapting to this bimodal
stimulus, our participants were asked to reproduce a visual duration. Group data
showed that participants, on average, reproduced the physical duration of the
visual test stimulus accurately; in other words, there was no consistent effect
of adaptation to an illusory duration.
