Electronic Thesis and Dissertation Repository


Master of Science




Dr. Stefan Köhler


We investigated the sensitivity of ERP components implicated in recognition memory to degree of experimentally controlled and lifetime cumulative exposures during explicit memory judgements. A parietally distributed ERP component spanning both the FN400/N400 and the LPC time windows tracked both types of judgements. This effect appears to be an LPC effect with an early onset, and differs from previously reported effects of repetition linked to implicit memory. Based on recent evidence, we interpreted it as response-related evidence accumulation processes that are in line with both single-process models and continuous dual-process models. We also observed more positive ERPs in the left ROIs for frequency judgements as compared to lifetime familiarity judgements. This effect could be linked to encoding differences in the perirhinal cortex. Our findings provided new evidence concerning the memory of cumulative exposures, and demonstrated the possibility of studying certain aspects of lifetime cumulative familiarity in a laboratory environment.