Associative learning and sensory integration are two behavioral processes that involve the sensation and processing of stimuli followed by an altered behavioral response to these stimuli, with learning requiring memory formation and retrieval. We found that the cellular and molecular actions of scd-2 dissociate sensory integration and associative learning. This was discovered through investigation of a Caenorhabditis elegans mutation ( lrn-2 ( mm99 )) affecting both processes. After mapping and sequencing, lrn-2 was found to be allelic to the gene, scd-2 . scd-2 -mediated associative learning and sensory integration operate in separate neurons as separate processes. We also find that memories can form from associations that are processed and stored independently from the integration of stimuli preceding an immediate behavioral decision.