Historically, sensory systems have been largely ignored as potential loci of information storage in the neurobiology of learning and memory. They continued to be relegated to the role of "sensory analyzers" despite consistent findings of associatively induced enhancement of responses in primary sensory cortices to behaviorally important signal…

Notes that a minimum list of criteria for the engram would include an eventual high correlation with learned changes in behavior, lack of necessary correlation with the stimuli, and absence of necessary correlation with the motor response (Performance). (Author/AM)