Microsaccadic modulation of response times in spatial attention tasks
- 366 Downloads
Covert shifts of attention are usually reflected in RT differences between responses to valid and invalid cues in the Posner spatial attention task. Such inferences about covert shifts of attention do not control for microsaccades in the cue-target interval. We analyzed the effects of microsaccade orientation on RTs in four conditions, crossing peripheral visual and auditory cues with peripheral visual and auditory discrimination targets. Reaction time was generally faster on trials without microsaccades in the cue-target interval. If microsaccades occurred, the target-location congruency of the last microsaccade in the cue-target interval interacted in a complex way with cue validity. For valid visual cues, irrespective of whether the discrimination target was visual or auditory, target-congruent microsaccades delayed RT. For invalid cues, target-incongruent microsaccades facilitated RTs for visual target discrimination but delayed RT for auditory target discrimination. No reliable effects on RT were associated with auditory cues or with the first microsaccade in the cue-target interval. We discuss theoretical implications on the relation about spatial attention and oculomotor processes.
KeywordsVisual Target Spatial Attention Auditory Target Covert Shift Spatial Attention Task
This research was supported by Deutsche Forschungsgemeinschaft (grants KL-955/3 and KL/955-6). Data and R-scripts are available upon request. We thank Erich Schröger and a reviewer for helpful comments.
- Baayen, R. H. (2008). Practical data analysis for the language sciences with R. Cambridge: Cambridge University Press.Google Scholar
- Bates, D. (2008). lme4: Linear mixed-effect models using S4 classes. R package version 0.999375–1 [Software]. Vienna: R Foundation for Statistical Computing.Google Scholar
- Clowes, M. B. (1962). A note on colour discrimination under conditions of retinal image constraint. Optica Acta, 9, 65–68.Google Scholar
- Ditchburn, R. W. (1955). Eye-movements in relation to retinal action. Optica Acta, 1, 171–176.Google Scholar
- Krummenacher, J., Müller, H.J., & Geyer, T. (2008). RT performance in visual search is affected by dimension- and space-based intertribal contingencies. Psychological Research.Google Scholar
- Pinheiro, J., & Bates, D. (2000). Mixed-effects models in S and S-Plus. New York: Springer.Google Scholar
- Posner, M. I. (1980). Orientation of attention. The VIIth Sir Frederic Bartlett lecture. Quarterly Journal of Experimental Psychology, 32A, 3–25.Google Scholar
- Posner, M. I., & Cohen, Y. (1984). Components of visual orienting. In H. Bouma & D. G. Bouwhuis (Eds.), Attention and Performance, X (pp. 531–556). Hillsdale: Erlbaum.Google Scholar
- R Development Core Team (2007). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. ISBN 3-900051-07-0, URL http://www.R-project.org.
- Rolfs, M., Laubrock, J., & Kliegl, R. (2008). Microsaccade-induced prolongation of saccadic latencies depends on microsaccade amplitude. Journal of Eye Movement Research, 1(3), 1–8.Google Scholar
- Wickham, H. (2007a). Reshaping data with the reshape package. Journal of Statistical Software, 21,1–19. [Software] R package version 0.8.0.Google Scholar
- Wickham, H. (2007b). ggplot2: An implementation of the grammar of graphics. [Software] R package version 0.5.7. http://had.co.nz/ggplot2/.