Our memories depend on our brain’s ability to form internal representations of relevant aspects of the world that can later be retrieved. The specificity with which past experiences can be remembered varies across the lifespan, possibly due to differences in how precisely information is encoded. This memory formation can be investigated through repetition effects, the common finding that neural activity is altered (suppressed or enhanced) when stimuli are repeated. However, whether differences in this indirect measure of memory formation relate to lifespan age differences in memory specificity has not yet been established. In the present study, we examined repetition effects in event-related potentials and their relation to recognition specificity. During incidental encoding, children (aged 7-9 years), young adults (18-30 years), and older adults (65-76 years) viewed repeated object images from different categories. During subsequent recognition, old, similar, and new objects were presented, allowing for a differentiation of memory for the specific item versus the general category. We identified neural repetition suppression effects in all age groups, and repetition enhancement for adults. Furthermore, individual item recognition performance comprising lure discrimination was positively associated with the magnitude of the neural repetition effects. These brain-behavior associations did not differ between age groups, indicating common neural mechanisms of memory formation. In sum, our findings demonstrate that neural repetition effects reflect encoding mechanisms that facilitate the formation of highly specific memory representations and highlight their significance as a neural indicator of individual differences in episodic memory encoding across the lifespan.
bioRxiv Subject Collection: Neuroscience