Search

The conscious perception of simple visual stimuli can be modulated by the presence of distractors. In the motion blindness paradigm, the detection of coherent motion is impaired when task-irrelevant motion distractors are presented prior to the target. Aim of this study was to examine the feature specificity of the distractor effect. For this reason, targets were either defined by motion coherence (“motion blindness”) or orientation changes (“orientation blindness”). In a series of three experiments we show that distractors have to share the feature characteristics of the target in order to reduce its detectability. However, independent inhibition sets for visual features can be activated if the targets’ characteristics are ambiguous.

There is growing evidence that motion perception is modulated by visual selective attention. In the ‘attention-induced motion blindness’ paradigm the detection of coherent motion in a random dot kinematogram (RDK) is impaired in a rapid serial presentation task [Sahraie, A., Milders, M., & Niedeggen, M. (2001). Attention induced motion blindness. Vision Research, 41, 1613–1617]. The effect depends on irrelevant motion episodes (distractors) prior to the target. In this study, we show that both the number and timing of distractors affect detection performance, allowing for implications on the build-up and release of inhibition. Furthermore, we rule out the possibility that subjects falsely classify targets as distractors due to uncertainty of temporal order.

Recent studies have shown evidence for modulation of cortical activity by attention in visual areas involved in motion processing. Behavioural effects of this modulation have only been reported for high-order, but not for luminance-based motion. We show that attentional load can even affect the perception of a first-order motion inducing a short-termed motion blindness. The detection of transient coherent motion embedded in a rapid serial visual presentation was severely impaired if colour features were to be processed simultaneously. The findings reported here show attentional requirements can affect motion perception. This effect can not be explained by motion adaptation or priming and may instead arise from the suppression of irrelevant stimuli.