Two experiments on visual attention revealed a common finding whereby the addition of an irrelevant distractor increased attention (measured by improved target detection) for the primary task. In an inattentional blindness paradigm, participants tracked visual targets around the screen. Concurrently, participants heard a well-known piece of music, or actively listened to music, or heard no music. In the critical trial participants were significantly more likely to notice an unexpected object moving through the display when they were required to listen to music. This was independent of an increase in cognitive load. Similarly, a separate attentional blink experiment demonstrated significantly enhanced target (T2) detection when the RSVP stream was surrounded by an irrelevant visual distractor. Here the participants were older adults who were either relaxed or showing mild state anxiety. The visual distractor ‘normalised’ blink magnitude in the anxiety condition to be consistent with the low anxiety condition, and younger adults performance. The findings are discussed in terms of an overinvestment theory of visual attention and we speculate that optimal visual attention performance may be U-shaped, where best performance is achieved in the presence of su cient attention to engage the system, but not so much as to increase cognitive load.
34th European Conference on Visual Perception (ECVP), Toulouse, France 28 August - 1 September 2011