It's all in your head: Distractor interference produced by top down expectations.
Yehoshua Tsal, Rotem Avital; It's all in your head: Distractor interference produced by top down expectations.. Journal of Vision 2012;12(9):941. doi: 10.1167/12.9.941.
In several converging paradigms (flanker, attentional blink, negative priming) we investigated the role of top down factors in processing distractors. We presented ambiguous characters that could be perceived as letters or as digits and found that distractor processing was completely determined by context and expectations and not by stimulus identity. For example, in responding to one of two possible targets (S vs. O) in the flanker task, the same ambiguous distractor, i.e., an S-5 hybrid produced substantial interference in responding to an O target when subjects expected letters as distractors but no interference at all when expecting digits as distractors. Since only top-down information was manipulated whereas stimulus-driven data were kept constant, these findings challenge the view that distractor interference reflects primarily bottom up processing where features of incongruent distractors penetrate and automatically activate the representation of the opposite response category. Furthermore, The present results also support the notion that early visual processing is penetrable to higher cognitive processing since obtaining such context effects on unattended stimuli that the perceiver attempts to ignore rather than process represent more genuine perceptual processes that are less susceptible to post perceptual biases. The nature of interaction between top down and bottom up processes in producing unattended perceptual representations and the notion of cognitive penetrability will be discussed.