Monday, February 06, 2012
Making Sense of Sensory Connections: Researchers Identify Mechanism Behind "Associative Memory"
When a person encounters a favorite food or the perfume of a loved one, she will typically experience a recall, usually positive, based on the memories evoked by those smells. Such a recall -- to a smell, sound, taste, or any other sensory stimulus -- is evidence of "associative" learning, says Gilles Laurent, a former professor of biology at Caltech and senior author of the study, as learning often means assigning a value, such as beneficial or not, to inputs that were until then neutral. The original, neutral stimulus acquires significance as a result of being paired, or associated, with a reinforcing reward or punishment -- in this case, the pleasant emotion recalled by a smell. "When we learn that a particular sensory stimulus predicts a reward, there is general agreement that this knowledge is stored by changing the connections between particular neurons," explains Cassenaer. more