One reason why music features temporal regularities is that they elicit expectancies about when an event will occur, focusing a listener�s attention around certain points in time. Evidence comes from phoneme monitoring tasks (using reaction times, J. G. Martin, 1979) and pitch and time judgment tasks (using accuracy measures, M. R. Jones, H. Moynihan, N. MacKenzie,& J. Puente, 2002; E. W. Large & M. R. Jones, 1999). Reaction times were faster and accuracy was higher for rhythmically expected elements than for unexpected elements. By contrast, A. Penel and M. R. Jones (2004) recently reported an inversely related finding: faster reaction times for rhythmically unexpected tones, which they labeled a temporal capture effect. The present research examines expectancy versus capture phenomena by using a speeded detection task in which listeners must respond to a lower pitched target located within monotone and isochronous sequences. One interonset interval was shortened or lengthened independently of the target�s position. Temporal irregularities tended to trigger false alarms, suggesting capture effects. Patterns of reaction times showed expectancy effects when the temporally perturbed event preceded the target, but these effects seemed to decrease with time in the sequence. When the target itself was temporally perturbed, some capture was observed, but only when the target came early in the sequence. We conclude that Martin�s (1979) expectancy effects in phoneme monitoring were coarticulatory rather than rhythmical.
- ©© 2005 by the Regents of the University of California All rights reserved.