Abstract
Multitasking often causes human errors, traffic accidents, and lowered productivity. Yet increasing attention to one task does not always distract: sometimes, it enhances concurrent task processing. In the attentional boost effect (ABE), detecting and responding to attentionally demanding targets yields better memory for background images, relative to baseline or distractor trials. Theoretical accounts have attributed the ABE to a temporal orienting response upon the detection of a behaviorally relevant event. But what triggers the ABE? Here we tested the roles of visual template matching, target classification, and response. Participants in Experiments 1 and 2 encoded objects to memory while simultaneously monitoring a stream of letters and digits. They pressed a button for letters and made no response to digits. In different blocks, the targets were either a specific letter, allowing visual template matching for its detection, or a broader category of eight letters. The ABE was robust in both conditions but was significantly stronger in the specific-letter condition. Experiments 3 and 4 examined whether the ABE could be found when participants delayed response to the trial following the target. When the target was a specific letter, memory enhancement occurred for the objects paired with the target, but not for the next object (response-paired). In contrast, when the target was a broader category of letters, the ABE was abolished for both the target-paired and the response-paired objects. Visual template matching to a specific target may have sharpened the temporal orienting response, yielding a larger or more robust ABE. These findings show that visual template matching, a key component of the biased competition theory of attention, not only increases attention to the target stimuli but also broadly facilitates concurrent task processing.