Changes in recognition memory over time: an ERP investigation into vocabulary learning

Although it seems intuitive to assume that recognition memory fades over time when information is not reinforced, some aspects of word learning may benefit from a period of consolidation. In the present study, event-related potentials (ERP) were used to examine changes in recognition memory responses to familiar and newly learned (novel) words over time. Native English speakers were taught novel words associated with English translations, and subsequently performed a Recognition Memory task in which they made old/new decisions in response to both words (trained word vs. untrained word), and novel words (trained novel word vs. untrained novel word). The Recognition task was performed 45 minutes after training (Day 1) and then repeated the following day (Day 2) with no additional training session in between. For familiar words, the late parietal old/new effect distinguished old from new items on both Day 1 and Day 2, although response to trained items was significantly weaker on Day 2. For novel words, the LPC again distinguished old from new items on both days, but the effect became significantly larger on Day 2. These data suggest that while recognition memory for familiar items may fade over time, recognition of novel items, conscious recollection in particular may benefit from a period of consolidation

T-test maps showing the distribution of old/new effects for words and novel words on day 1 and day 2.

<p>T-test maps showing the distribution of old/new effects for words and novel words on day 1 and day 2.</p

Mean percentage of errors on Day 1 and Day 2 of the Episodic Memory task (standard deviations in parenthesis).

<p>Mean percentage of errors on Day 1 and Day 2 of the Episodic Memory task (standard deviations in parenthesis).</p

a Familiarity: Mean amplitude in the Familiarity (300–450 ms) time window collapsed across electrode sites (F3, Fz, F4, C3, Cz, C4, P3, Pz, P4).

<p><b>b</b> Recollection: Mean amplitude in the Recollection (450–750 ms) time window collapsed across electrode sites (F3, Fz, F4, C3, Cz C4, P3, Pz, P4).</p

English Words: ERP responses to trained and untrained English words on day 1 and day 2.

<p>English Words: ERP responses to trained and untrained English words on day 1 and day 2.</p

Novel Words: ERP responses to trained and untrained novel words on day 1 and day 2.

<p>Novel Words: ERP responses to trained and untrained novel words on day 1 and day 2.</p