Stimulus localization interferes with stimulus recognition: evidence from an attentional blink paradigm.

Recognition of a second target (T2) can be impaired if presented within 500 ms after a first target (T1): This interference phenomenon is called the attentional blink (AB; e.g., Raymond, Shapiro, & Arnell, 1992) and can be viewed as emerging from limitations in the allocation of visual attention (VA) over time. AB tasks typically require participants to detect or identify targets based on their visual properties, i.e., pattern recognition. However, no study so far has investigated whether an AB for pattern recognition of T2 can be elicited if T1 implies a second major function of the visual system, i.e., spatial computations. Therefore, we tested in two experiments whether localization of a peripherally presented dot (T1) interferes with the identification of a trailing centrally presented letter T2. For Experiment 1, T2 performance increased with onset asynchrony of both targets in single-task (only report letter) and dual-task conditions. Besides this task-independent T2 deficit, task-dependent interference (difference between single- and dual-task conditions) was observed in Experiment 2, when T1 was followed by location distractors. Overall, our results indicate that limitations in the allocation of VA over time (i.e., an AB) can also be found if T1 requires localization while T2 requires the standard pattern recognition task. The results are interpreted on the basis of a common temporal attentional mechanism for pattern recognition and spatial computations.