Matching-stimulus intervals determine P3b amplitudes for both targets and nontargets
It is well established that the amplitude of the Late Positive Complex (LPC) of the event-related potential (ERP) is affected by changes in global target probability, stimulus sequence, and interstimulus interval (ISI). These probability and timing manipulations, however, also alter the target-to-target interval (TTI). Our previous research has systematically shown thatwhen global target probability, stimulus sequence, and ISI are held constant, TTI is a principal determinant of LPC amplitude, with larger LPCs to longer TTIs. Most research in a matching-stimulus interval context has examined changes in LPC amplitudes to targets, rather than nontargets, and all of this research has considered the LPC as a unitary ERP component. The aim of the present study was to explore matching-stimulus interval effects in one of the most widely explored subcomponents of the LPC, the P3b, to both targets (TTI) and nontargets (nontarget-to-nontarget interval; NNI).