| Brain event-related potential (ERP) studies of recognition memory have consistently shown that correctly identified old items elicit greater positivity than new items. This is referred to as the old/new effect and is argued to reflect processes related to memory retrieval. To date, there have been no ERP studies of recognition memory that have directly compared the old/new effect in the visual and auditory modalities. In this study, ERPs were recorded from 30 electrode sites while participants (n = 16) were engaged in visual and auditory continuous word recognition memory tasks. The expected old/new effect, with greater late positivity to correctly recognized old words was observed in both modalities, although scalp topography was significantly different. While the visual old/new effect was restricted to midline sites and maximal over the parietal region, the auditory old/new effect involved more lateral sites and was maximal over the occipital region. The timing of the old/new effect was the same across modalities with a peak at 600 ms. In addition, old words elicited greater late negativity (1100--1500 ms) over the left hemisphere than new words, suggesting the activation of verbally mediated post-retrieval processes specific to old responses. Overall, the findings suggest that the old/new effect represents a common cognitive mechanism in the two modalities (i.e., successful retrieval of information from memory), and that a different pattern of neural generators contribute to each. |
