title: Response-level probability effects on reaction time: now you see them, now you don't.
abstract: Many reaction time (RT) experiments have tested for response-level probability effects. Their results have been mixed, which is surprising because psychophysiological studies provide clear evidence of motor-level changes associated with an anticipated response. A survey of the designs used in the RT studies reveals many potential problems that could conceal the effects of response probability. We report five new RT experiments testing for response-level probability effects with the most promising of the previous designs-that of Blackman ( 1972 )-and with new designs. Some of these experiments yield evidence of response-level probability effects, but others do not. It appears that response-level probability effects are present primarily in simple tasks with a strong emphasis on response preparation, possibly because participants only expend effort on response preparation in these tasks.
authors.affiliation: CIN-Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany. steffen.katzner@uni-tuebingen.de
authors.forename: Steffen
authors.initials: S
authors.lastname: Katzner
authors.forename: Jeff
authors.initials: J
authors.lastname: Miller
mesh_terms: D001288:Attention / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D011336:Probability; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D055815:Young Adult