2.5 Masking and attention
Before I summarise the material in this section, and we move on to consider attentional processes with clearly-seen displays, it would be appropriate to consider the relevance of the masking studies to the issue of attention. We began the whole subject by enquiring about the fate of material which was, in principle, available for processing, but happened not to be at the focus of attention. Somehow we have moved into a different enquiry, concerning the fate of material that a participant was trying to attend to, but did not have time to process. This seemed a natural progression as the course unfolded, but are the two issues really related? Merikle and Joordens (1997) addressed this very question; they characterised it as a distinction between perception without awareness (such as in masking studies) and perception without attention (as with dichotic listening). They carried out a number of studies, in which processing was rendered difficult either by masking, or by giving the participants two tasks, so that they could not focus on the target. They concluded that the results were entirely comparable, and that the same underlying processes are at work in both kinds of study.