Fast Mapping (FM) in Adults: A proposed attempt to replicate evidence from implicit memory Poster Number: PT031 Elisa Cooper*1, Andrea Greve1, Richard N. Henson1 1MRC Cognition and Brain Science Unit, University of Cambridge, 15 Chaucer Road, Cambridge, CB2 7EF, UK *elisa.cooper@mrc-cbu.cam.ac.uk Abstract type: Preregistration Poster Abstract theme: Learning & memory 1. Introduction: It has been claimed that adults can learn new knowledge within the same day using a Fast Mapping (FM) procedure, and that this occurs directly in cortex without hippocampal involvement (Cooper et al., 2018). Using an implicit reaction time (RT) measure of lexical competition, Coutanche and Thompson-Schill (2014) reported that non-words were learned (consolidated) as the names of novel objects under FM, but not under standard explicit encoding (EE). We recently failed to replicate this same-day competition effect, and found instead evidence of semantic priming. Here, we preregister a further replication study. 2. Methods: Healthy adults (18-40), tested online, complete one study condition (either FM or EE), and then an implicit (and explicit) memory test after a 10-minute delay. Study involves learning non-words (e.g,"ganaxy") as the names of unknown objects (presented as pictures). One half of objects are natural; the other half man-made. In the FM condition, the name is inferred from a question pertaining to the unknown object and a second, known object; in the EE condition, participants are presented with just the name and unknown object and told to learn. In the implicit test, RTs for a "natural/man-made" decision to probe words (e.g,"galaxy") are contrasted as a function of whether or not a competitor ("ganaxy") was presented at Study. This competition effect is then compared for competitors learned as names of natural vs man-made objects. 3. Approach for statistical analysis: To replicate our previous difference in competition effect for natural versus man-made words in the FM condition, N=30 participants provides 90% power. Coutanche and Thompson-Schill's fast mapping account predicts a slowing of RTs in FM but not EE condition, regardless of natural/man-made category. Our semantic priming account predicts that RTs depend on congruence between probe word category and object category (faster when congruent and slower when incongruent), in both FM and EE conditions. 4. References: Cooper, E., Greve, A., Henson, R.N. (2019). Investigating Fast Mapping (FM) in healthy adults using an implicit memory measure: A replication. OSF registration. https://doi.org/10.17605/OSF.IO/ATKP4 Cooper, E., Greve, A., Henson, R.N. (2019). Investigating Fast Mapping task components: No evidence for the role of semantic referent not semantic inference in healthy adults. Frontiers in Psychology. https://doi.org/10.3389/fpsyg.2019.00394 Cooper, E., Greve, A., Henson, R.N. (2018). Little evidence for Fast Mapping (FM) in adults: A review and discussion, Cognitive Neuroscience. https://doi.org/10.1080/17588928.2018.1542376 Coutanche, M. N., & Thompson-Schill, S. L. (2014). Fast mapping rapidly integrates information into existing memory networks. JEP:G, 143(6), 2296-2303.