Research data for paper ‘Proactive and retroactive interference with associative memory consolidation is time and circuit dependent'.
Interference-based forgetting occurs when new information acquired either before or after a learning event attenuates memory expression (proactive and retroactive interference, respectively). Often multiple learning events occur in rapid succession, leading to competition between consolidating memory traces. In such cases however it is unknown what factors determine which memory is remembered or forgotten. By subjecting Lymnaea to either two similar or two different types of consecutive single-trial classical conditioning trials, we show that the effect of interference depends both on the timing of new learning and the underlying neuronal mechanisms. When two consolidating memories engage neuronal mechanisms in the same circuit, new learning during a lapse period of the original memory promotes retroactive interference whereas new learning outside lapses promotes proactive interference. When different circuits are involved, retroactive interference still occurs during lapses but new learning during a non-lapse period is not affected by proactive interference and both memories survive.