Visual backward masking is frequently used to study the temporal dynamics of
visual perception. These dynamics may include the temporal features of conscious
percepts, as suggested, for instance, by the asynchronous–updating model (Neumann, 1982) and perceptual–retouch
theory ((Bachmann, 1994). These models
predict that the perceptual latency of a visual backward mask is shorter than
that of a like reference stimulus that was not preceded by a masked stimulus.
The prediction has been confirmed by studies using temporal–order judgments: For
certain asynchronies between mask and reference stimulus, temporal–order
reversals are quite frequent (e.g. Scharlau,
& Neumann, 2003a). However, it may be argued that these
reversals were due to a response bias in favour of the mask rather than true
temporal-perceptual effects. I introduce two measures for assessing latency
effects that (1) are not prone to such a response bias, (2) allow to quantify
the latency gain, and (3) extend the perceptual evidence from order reversals to
duration/interval perception, that is, demonstrate that the perceived interval
between a mask and a reference stimulus may be shortened as well as prolonged by
the presence of a masked stimulus. Consequences for theories of visual masking
such as asynchronous–updating, perceptual–retouch, and reentrant models are
discussed