Associative learning is one of the basic processes of knowledge acquisition, and one that is generally recognized to be central to the scientific understanding of human memory and cognition. Dr. Wagner's research follows in an approach to characterizing the fundamental mechanisms involved that is shared by a substantial group of investigators, namely the use of a simple, experimentally well-controllable instance of associative learning about which a great deal of supporting behavioral and biological information is available (in this case, Pavlovian-like eyeblink conditioning in the rabbit), and the attempted development of a quantitative, "neural-network" account of the regularities observed. The focus of Dr. Wagner's research at this juncture is on the manner in which associative learning appears to involve distinguishable emotional and non-emotional components that, although experimentally separable, may generally interact, with emotional associations having the effect of modulating the behavioral consequences of non-emotional associations. Studies are aimed at providing a better understanding of the conditions under which such modulation does or does not occur, the consequences it may have for observing related basic phenomena of learning such as "long-term habituation," where in the stimulus- response processing sequence it is effected, and whether it is limited to the modulation of performance, as has been observed, or includes the modulation of associative learning as well. The answers to these questions are very basic to providing a computational neurobiological theory of associative learning.
