Human cognitive neuroscience seminar

Speaker: Elva Peng (University of Edinburgh)

Title: The effect of levels-of-processing on the rates of forgetting

Abstract: The levels-of-processing framework, proposing that deep processing yields superior retention, has provided an important paradigm for memory research and a practical means of improving learning. However, the available levels-of-processing literature mainly focuses on immediate memory performance, and it is still unclear whether the initial level of processing affects the forgetting slopes. The present experiments are designed to explore whether words encoded at qualitatively different levels are forgotten at different rates. In the first two experiments, depth of processing was manipulated within-participant at encoding under deep and shallow conditions (semantic vs rhyme judgement in Experiment 1; semantic vs. consonant-vowel pattern decision in Experiment 2). Recognition accuracy (hit rate and d prime) was measured between-participants immediately after learning and at 30-minute, 2-hour, and 24-hour delays. The third experiment employed a between-participant design, contrasting the rates of forgetting following semantic and phonological (rhyme) processing at immediate, 30-minute, 2-hour, and 6-hour delays. The results from three experiments consistently demonstrated a large-sized effect of levels of processing on immediate performance and a medium-to-large-sized level effect on delayed recognition but no level × time interaction. The retention curves presented parallel declines between deep and shallow processing with the passage of time. It suggests that the rates of forgetting are independent of the qualitatively distinct encoding operations manipulated by levels of processing.