Practicing simple visual tasks induces substantial improvement. We investigated whether increased efficiency is accompanied by automaticity and immunity to across-task interference. We found that although practice speeds orientation feature detection, it does not abolish susceptibility to interference from introduction of concurrent central-letter identification, which takes priority. Yet following training with each task, observers successfully managed to perform the tasks concurrently. The effectiveness of separate training implies that the role of improved intertask coordination in achieving concurrent performance was minor. Indeed, even when initial training was concurrent, improvement on the two tasks was sequential, and the higher-priority (central) task was learned first. However, automatic processing was not accomplished either, because increasing the difficulty of the higher-priority task interfered with performance of both tasks. What appears to be orchestrated posttraining performance is actually mainly an emergent property of speeded initial processes rather than either eliminated bottlenecks or improved central executive management.
Bibliographical noteFunding Information:
We thank Anne Treisman, Ken Nakayama, Harold Pashler, Julian Joseph, Jochen Braun, Howard Hock, Asher Cohen, Ehud Zohary, and Ehud Ahissar for helpful discussions and comments. We thank anonymous reviewers for helpful criticism of an earlier draft of this article. This study was supported by grants from the Israel Science Foundation of the Israel Academy of Sciences and Humanities, the U.S.-Israel Binational Science Foundation (BSF), and The National Institute for Psychobiology in Israel.