Age-related differences in the retrieval of phonologically similar words during sentence processing: Evidence from ERPs

We investigated how phonologically similar words are encoded and retrieved from memory during sentence processing across younger and older adults. Critical sentences included two phonologically similar or dissimilar noun phrases (henceforth NPs) followed by a pronoun. We examined brain activity time-locked to the onsets of the second NP, and the pronoun to investigate the encoding and retrieval of the NPs, respectively. Encoding the second NP resulted in smaller N400 amplitudes when the preceding NP was phonologically similar, for both younger and older adults, suggesting age-invariant encoding facilitation with increasing phonological similarity. However, when processing the pronoun, younger adults exhibited greater negativity following phonologically similar NPs, suggesting retrieval difficulty, whereas older adults showed greater negativity for pronouns following dissimilar NPs, suggesting an apparent retrieval facilitation. A post-hoc behavioral experiment suggested that older adults perform shallow processing during retrieval. The results suggest age-related decline in retrieval, but not encoding, of phonological information.