Describes how a behavioral system in Aplysia (marine snail) can be used to examine mechanisms of several forms of learning at different levels of analysis: behavioral, cell-physiological, ultrastructural, and molecular. Focusing on short-term sensitization, suggests how molecular mechanisms can be extended to explain long-term memory and classical…

By studying forgetfulness in humans and monkeys, scientists are learning about the anatomy of normal memory. Results of amnesia studies, indicating that memory collapse occurs in a selective fashion depending on the cause, may help resolve a fundamental dispute among learning theorists. (JN)