ABSTRACT
For several years, I have been concerned with developing an invertebrate model system that would permit a cellular analysis of a biological causal detection system. Inevitably, this compelled my colleagues and me to consider the roles that associative learning and memory play in causal detection systems and to attempt to elucidate the cellular mechanisms underlying such processes. The system we have chosen is the nudibranch mollusc Hermissenda crassicornis. The goal of the present chapter is to summarize our understanding of the cellular basis of associative learning in Hermissenda and to then extend this perspective to some more interesting and complex causal detection processes. In what follows, I briefly review our current understanding of how associative learning occurs in this animal.
