| Abstract: | Examined 2 response bias parameters in a spatial cueing paradigm: (1) "cued location (CL) bias," the relative probability with which a signal is incorrectly assigned to the CL; and (2) "likelihood ratio (beta)," the amount of evidence required to decide that a signal appeared at a particular CL or un-CL. The 2 parameters were found to be differentially sensitive to stimulus onset asynchrony (SOA) between peripheral cue and target. CL bias was strongly affected by SOA, decreasing within 300 msec after peripheral cue onset. In contrast, the difference in beta between CLs and un-CLs was independent of SOA. This suggests that CL bias reflects strong but transitory pathway preactivation following a peripheral cue. In contrast, beta effects predominantly reflect "late" decision-making processes that differentially weight the sensory evidence from CLs and un-CLs according to their a priori signal probabilities. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
