An event-related potential investigation of pattern separation and pattern completion processes.

Long-term declarative memory depends on pattern separation and pattern completion to maintain memory specificity. Previous studies aimed at evaluating the underlying neuronal substrates of these computational processes have used a mnemonic discrimination paradigm and functional magnetic resonance imaging (fMRI). An alternative method is electroencephalography and event-related potentials (ERPs), which have a superior time resolution to fMRI. Here, we use ERP analysis to examine neuronal activity during performance of a mnemonic discrimination task. We examined both the late positive component and FN400 components, which have previously been shown to demonstrate an old-new effect. We hypothesized that pattern separation processes would be reflected in correct rejection of similar lures while pattern completion processes would be reflected in falsely categorizing lures as repeated. We did not observe differences between the ERPs associated with these two processes.