Generalisation between motor and declarative memory sequences: A conceptual replication of Mosha & Robertson (2016)

Motor and declarative memory systems have been traditionally considered distinct. However, a study by Mosha and Robertson (2016) reported striking evidence of "generalization" between motor and declarative learning. Specifically, learning improved if the current task (e.g., motor sequence) shared the same high-level ordinal structure as an earlier task (e.g., word list), demonstrating cross-domain transfer of unstable memories. This finding has significant implications for our understanding and conceptualization of memory taxonomies but has not been replicated. Here, healthy adult participants (N = 125) completed a word list and motor sequence task in counterbalanced order with either a shared or distinct sequence structure. In contrast to Mosha and Robertson (2016), we found that a shared ordinal structure between the declarative and motor sequence tasks did not facilitate performance. Overall, our results challenge the robustness of cross-domain generalization, and underscore the complexity of cross-memory interactions.