Response competition and target word detection during shadowing in a dichotic listening task.

College students (N = 24) served as subjects in a within-subjects study of auditory attention in which four tasks were performed. In the easiest task, a single passage was presented and shadowed while target word detections were indicated by pressing a key. The other three tasks also required target word detection, but a second passage was presented simultaneously. One task had no target words in the unshadowed passage; the other two tasks required a key-pressing response to the target words in both passages, either with one hand or with each hand. We expected performance to decrease as task complexity increased; this was partially confirmed. The task of shadowing and detecting target words is too difficult to be used to test perception or response limitations of attention.