Taste-aversion learning has been a popular paradigm for examining associative processes because it often produces outcomes that are different from those observed in other classical conditioning paradigms. One such outcome is taste-mediated odor potentiation in which aversion conditioning with a weak odor and a strong taste results in increased or synergistic conditioning to the odor. Because this strengthened odor aversion was not anticipated by formal models of learning, investigation of taste-mediated odor potentiation was (...) a hot topic in the 1980s. The present manuscript reviews the history of potentiation research with particular focus given to the stimuli that produce potentiation, the conditions that produce potentiation, the possible mechanism of this phenomenon, and possible reasons for the decline of research in this area. Although the number of published reports of potentiation has decreased since the 1980s, recent physiological and behavioral assessments have advanced the field considerably, and the opportunities for future research are bountiful. Recent physiological experiments, for example, have identified the basolateral nucleus of the amygdala as the key brain region to produce taste-mediated odor potentiation (e.g., Hatfield andGallagher, 1995). Also, recent behavioral experiments have extended the generality of synergistic conditioning effects. Studies have shown that odor can potentiate responding to taste (Slotnick, Westbrook and Darling, 1997) and that augmented responding can be produced in the A+/AX+blocking design (e.g., Batsell and Batson, 1999). With the current understanding of where synergistic conditioning may occur in the brain and the new tools to explore synergistic conditioning, we propose various directions for future research to determine whether taste-aversion learning and synergistic conditioning require unique explanations. (shrink)

Taste-aversion learning has been a popular paradigm for examining associative processes because it often produces outcomes that are different from those observed in other classical conditioning paradigms. One such outcome is taste-mediated odor potentiation in which aversion conditioning with a weak odor and a strong taste results in increased or synergistic conditioning to the odor. Because this strengthened odor aversion was not anticipated by formal models of learning, investigation of taste-mediated odor potentiation was (...) a hot topic in the 1980s. The present manuscript reviews the history of potentiation research with particular focus given to the stimuli that produce potentiation, the conditions that produce potentiation, the possible mechanism of this phenomenon, and possible reasons for the decline of research in this area. Although the number of published reports of potentiation has decreased since the 1980s, recent physiological and behavioral assessments have advanced the field considerably, and the opportunities for future research are bountiful. Recent physiological experiments, for example, have identified the basolateral nucleus of the amygdala as the key brain region to produce taste-mediated odor potentiation (e.g., Hatfield andGallagher, 1995). Also, recent behavioral experiments have extended the generality of synergistic conditioning effects. Studies have shown that odor can potentiate responding to taste (Slotnick, Westbrook and Darling, 1997) and that augmented responding can be produced in the A+/AX+blocking design (e.g., Batsell and Batson, 1999). With the current understanding of where synergistic conditioning may occur in the brain and the new tools to explore synergistic conditioning, we propose various directions for future research to determine whether taste-aversion learning and synergistic conditioning require unique explanations. (shrink)

Contrary to the outstanding simplistic view of the taste system, learning studies show a more complex picture. Behavioral data using conditioned taste preference and aversion tasks support the idea that mixtures involve complex interactions between individual taste cues. Evidence from taste conditioned blocking, taste perceptual learning, and taste learned preferences is considered to support such a view. Greater support for research in taste learning and memory is required for a complete (...) understanding of taste recognition. (shrink)

Converging data from different disciplines are showing the role of classical conditioning processes in the elaboration of human and animal behavior to be larger than previously supposed. Restricted views of classically conditioned responses as merely secretory, reflexive, or emotional are giving way to a broader conception that includes problem-solving, and other rule-governed behavior thought to be the exclusive province of either operant conditiońing or cognitive psychology. These new views have been accompanied by changes in the way conditioning is conducted (...) and evaluated. Data from a number of seemingly unrelated phenomena such as relapse to drug abuse by postaddicts, the placebo effect, and the immune response appear to involve classical conditioning processes. Classical conditioning, moreover, has been found to occur in simpler and simpler organisms and recently even demonstrated in brain slices and in utero. This target article will integrate the several research areas that have used the classical conditioning process as an explanatory model; it will challenge teleological interpretations of the classically conditioned CR and offer some basic principles for testing conditioning in diverse areas. (shrink)

Traditional accounts of the role of learning in evolution have concentrated upon its capacity as a source of fitness to individuals. In this paper I use a case study from invasive species biology—the role of conditioned taste aversion in mitigating the impact of cane toads on the native species of Northern Australia—to highlight a role for learning beyond this—as a source of evolvability to populations. This has two benefits. First, it highlights an otherwise under-appreciated role for learning (...) in evolution that does not rely on social learning as an inheritance channel nor “special” evolutionary processes such as genetic accommodation (both of which many are skeptical about). Second, and more significantly, it makes clear important and interesting parallels between learning and exploratory behaviour in development. These parallels motivate the applicability of results from existing research into learning and learning evolution to our understanding of the evolution of evolvability more generally. (shrink)