Event-related potential (ERP) studies of memory encoding and retrieval: A selective review

Abstract

As event-related brain potential (ERP) researchers have increased the number of recording sites, they have gained further insights into the electrical activity in the neural networks underlying explicit memory. A review of the results of such ERP mapping studies suggests that there is good correspondence between ERP results and those from brain imaging studies that map hemodynamic changes. This concordance is important because the combination of the high temporal resolution of ERPs with the high spatial resolution of hemodynamic imaging methods will provide a greatly increased understanding of the spatio-temporal dynamics of the brain networks that encode and retrieve explicit memories.

The use of neuroimaging to study behavior in patients with epilepsy

“…This reorganization of memory-related processes supports an accumulating body of literature demonstrating interhemispheric reorganization in patients with left TLE (116)(117)(118)(119)(120). However, the study results were based on only two patients and the hippocampal activations were reported between 160-290ms-a time period that is too early to optimally capture cognitive processes (121). To date, no study has used MEG to directly examine memory for verbal and nonverbal material in a well-sized group of patients with epilepsy.…”

The worth of pictures: Using high density event-related potentials to understand the memorial power of pictures and the dynamics of recognition memory

“…Classic ERP studies of recognition memory have shown that studied or "old" items elicit a more positive ERP response than do nonstudied or "new" items (for review, see Friedman and Johnson, 2000). Traditional ERP researchers have broken down this old/new effect into three distinct components, possibly reflecting three distinct cognitive processes.…”

“…Rugg, Curran, and others have dubbed this component the FN400 and posit that attenuation of a frontal negativity peaking around 400 ms is associated with familiarity (Curran, 2000;Friedman & Johnson, 2000;Rugg et al, 1998). For example, Curran (2000) created a high familiarity group of test items by using words that were similar to studied items, and found that familiar words elicited a more positive response at frontal electrode sites than did unstudied words.…”

“…Therefore, this positive deflection has been associated with recollection. According to Friedman and Johnson (2000), this parietal effect increases with study-test repetitions (Johnson et al, 1998a), when items are rated as consciously recollected (Smith, 1993;Smith and Guster, 1993), and when a word is retrieved along with study context (Trott et al, 1999;Wilding et al, 1995;Wilding and Rugg, 1996).…”

Memory for perceived and imagined pictures—an event-related potential study

“…[44,52,74]), which suggests that it indexes neural activity associated with retrieval of information about a prior event rather than with stimulus repetition alone or merely responding "old". It has been suggested that the old/new effect observed during episodic memory may comprise a number of spatio-temporally specific sub-components that reflect different aspects of retrieval [20,40]. Interpreted within the context of dual-process models, an early (300-500 ms post-stimulus) old/new effect has been linked to familiarity and is assumed to evolve from an attenuation of a frontal N400-like component for old items [14,15,39,41,56], whereas the enhancement of a late positive component (400-800 ms), typically, maximal at left parietal regions (but see, e.g.…”