| Differences in the semantic priming effect were examined across the life-span. Semantic priming was quantified as the difference between event-related potentials (ERPs) to words that were either semantically related or unrelated to a preceding word. Interest was focused on the processing negativity (PN) component of the ERP. The participants (children, young adults and seniors) performed a semantic category task. The task was designed to minimize the influence of the Late Positive Component (LPC) on the PN, so that the PN latencies and amplitudes could be examined without the influence of the temporal overlap of LPC. The semantic priming effect was evident in both the amplitudes and latencies of PN in all three groups. In addition, all groups exhibited facilitation effects. Inhibition effects, however, were observed only in the young adults and seniors. Hemispheric asymmetry of the priming effect was also examined. Children showed a clear asymmetry favoring the left hemisphere. In young adults, the asymmetry still favored the left hemisphere, but the degree of asymmetry was less robust. In the case of seniors, the priming effect was greater over the right hemisphere. Results are discussed in relation to the observed differences in semantic priming, facilitation, inhibition and hemispheric asymmetry across the lifespan. |
