In this study we examined whether event-related
potentials (ERPs) associated with stimulus repetition and
recognition in a serial-probe recognition task were comparable
to ERPs in other tasks that are more typically used to
investigate old/new ERP effects. The experiment consisted
of 320 trials in which a recognition probe followed a four-item
memory set; 160 trials consisted of images depicting common
objects that were easy to label (EL task), and 160 trials
consisted of images depicting abstract patterns that were
difficult to label (DL task). Nineteen participants indicated
whether a probe that followed each memory set was or was
not presented in the memory set. Half of the probes matched,
and half did not match, an item in the preceding memory
set. ERPs appeared to reflect two processes—one that
differentiated between recently presented stimuli and other
stimuli and another that distinguished between repeated
stimuli and new stimuli. ERPs to recent probes were more
positive than ERPs to other probes in the EL and DL tasks.
ERPs to match (old) probes were more positive than ERPs
to nonmatch (new) probes only in the EL task.