Combined expectancy effects: An accumulator model.

When participants use cues to prepare for a likely stimulus or a likely response, reaction times are facilitated by valid cues but prolonged by invalid cues. In studies on combined expectancy effects, two cues give information regarding two dimensions of the forthcoming task. When the two cues consist of two separable stimuli their effects are approximately additive. When cues are presented as an integrated stimulus, cueing effects interact. A model is presented that simulates effects like these. The model assumes that cues affect different processing stages. When implicit information suggests that expectancies are unrelated, as for instance with separated cues, cueing effects at early and late levels of processing remain independent. When implicit information suggests that expectancies are related, as with integrated cues, however, a mechanism that is sensitive to the validity of the early stage cue, leads to an adjustment of the cueing effect at the late stage. The model is based on neurophysiologically plausible assumptions, it is given explicitly in mathematical terms, and it provides a good fit to a large body of empirical data. (PsycINFO Database Record (c) 2016 APA, all rights reserved)

Accession Number: 2005-14639-002. PMID: 16154124 Partial author list: First Author & Affiliation: Mattler, Uwe; Department of Neurology II, Center for Advanced Imaging, Otto-von-Guericke University, Magdeburg, Germany. Release Date: 20060103. Publication Type: Journal (0100), Peer Reviewed Journal (0110). Format Covered: Print. Document Type: Journal Article. Language: English. Major Descriptor: Cues; Expectations; Motor Processes; Reaction Time. Minor Descriptor: Mathematical Modeling. Classification: Human Experimental Psychology (2300). Population: Human (10); Animal (20). Methodology: Mathematical Model. References Available: Y. Page Count: 42. Issue Publication Date: Nov, 2005.