"Salience": A factor which can override temporal contiguity in taste-aversion learning.
01 May 1970-Journal of Comparative and Physiological Psychology (American Psychological Association)-Vol. 71, pp 192-197
About: This article is published in Journal of Comparative and Physiological Psychology.The article was published on 1970-05-01. It has received 134 citations till now. The article focuses on the topics: Salience (neuroscience) & Taste aversion.
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TL;DR: This specialized conditioning mechanism, which specifically adjusts gustatory hedonic values through delayed visceral feedback, is widespread among animals, including man and rat, and is based on the animals' having similar gustatory systems, similar convergence of gustatory and internal afferents to the nucleus solitarius, and similar midbrain regulatory mechanisms.
Abstract: In regulating the internal homeostatic environment mammals, by necessity, employ behavioral strategies that differ from the tactics used in coping with contingencies in the external environment. When an animal consumes a meal, the palatability of that meal is automatically adjusted in accordance with the ultimate internal effects of that meal. If the meal causes toxicosis, the animal acquires an aversion for the taste of the meal; conversely, if recuperation follows ingestion of the meal, the taste of that meal is enhanced. Unlike the learning that occurs when externally referred visual and auditory signals are followed by punishment in the form of peripheral pain or reward in the form of food in the mouth, conditioning to the homeostatic effects of food can occur in a single trial and rarely requires more than three to five trials, even though the ultimate effects of the meal are delayed for hours. Paradoxically, the animal need not be aware of the ultimate internal effect in the same sense that it is aware of external contingencies. For example, an aversion can be acquired even if the animal is unconscious when the agent of illness is administered. Thus, the way in which food-effects are stored in memory may be fundamentally different from the way in which memories of specific time-space strategies devised for external contingencies are stored. This separation of function is indicated by limbic lesions which disrupt conditioning to a buzzer that is followed by shock and facilitate conditioning to a taste that is followed by illness. Operationally speaking, one can describe both aversion conditioning and buzzer-shock conditioning in the spacetime associationistic terms of classical conditioning. However, psychologically speaking, one must realize that in aversion conditioning the animal does not act as if it were acquiring an "if-then" strategy. It acts as if a hedonic shift, or a change in the incentive value of the flavor were taking place. Such hedonic shifts are critical in regulation of the internal milieu. When an animal is in need of calories, food tends to be more palatable; as the caloric deficit is restored, food becomes less palatable. If the animal's body temperature is below optimum, a warm stimulus applied to the skin is pleasant. When body temperature is too high, the converse is true. In this way, homeostatic states monitored by internal receptors produce changes in the incentive values of external stimuli sensed by the peripheral receptors, and guide feeding behavior. In mammals at least, the gustatory system, which provides sensory control of feeding, sends fibers to the nucleus solitarius. This brainstem relay station also receives fibers from the viscera and the internal monitors of the area postrema. Ascending fibers bifurcate at the level of the pons and project toward the feeding areas of the hypothalamus and the cortex. The olfactory system which primarily projects to the limbic system does not play a primary role in adjusting food incentives. Rather, it plays a secondary role in the activation of feeding, as do other external sensory systems. This specialized conditioning mechanism, which specifically adjusts gustatory hedonic values through delayed visceral feedback, is widespread among animals, including man and rat. These two species are remarkably similar in their thresholds and preferences for gustatory stimuli. The behavioral similarities are based on the animals' having similar gustatory systems, similar convergence of gustatory and internal afferents to the nucleus solitarius, and similar midbrain regulatory mechanisms. Thus, it is not surprising that the feeding of obese rats with internal hypothalamic damage resembles the feeding of obese human beings insensitive to the internal signs of this caloric state. Obviously, man has a highly specialized form of symbolic communication and the rat does not, yet man's cognitive specialization does not prevent him from developing aversions to food consumed before illness even when he knows that his illness was not caused by food (43).
1,074 citations
TL;DR: The proposed theoretical scheme represents a shift away from hypothetical "laws of learning" toward an interpretation of behavioral change in terms of interaction and competition among tendencies to action according to principles evolved in phylogeny.
Abstract: Replication and extension of Skinner's "superstition" experiment showed the development of two kinds of behavior at asymptote: interim activities (related to adjunctive behavior) occurred just after food delivery; the terminal response (a discriminated operant) occurred toward the end of the interval and continued until food delivery. These data suggest a view of operant conditioning (the terminal response) in terms of two sets of principles: principles of behavioral variation that describe the origins of behavior "appropriate" to a situation, in advance of reinforcement; and principles of reinforcement that describe the selective elimination of behavior so produced. This approach was supported by (a) an account of the parallels between the Law of Effect and evolution by means of natural selection, (fc) its ability to shed light on persistent problems in learning (e.g., continuity vs. noncontinuity, variability associated with extinction, the relationship between classical and instrumental conditioning, the controversy between behaviorist and cognitive approaches to learning), and (c) its ability to deal with a number of recent anomalies in the learning literature ("instinctive drift," auto-shaping, and auto-maintenance). The interim activities were interpreted in terms of interactions among motivational systems, and this view was supported by a review of the literature on adjunctive behavior and by comparison with similar phenomena in ethology (displacement, redirection, and "vacuum" activities). The proposed theoretical scheme represents a shift away from hypothetical "laws of learning" toward an interpretation of behavioral change in terms of interaction and competition among tendencies to action according to principles evolved in phylogeny.
1,063 citations
TL;DR: From an evolutionary standpoint, mechanisms that enable animals to experience feedback, sensations such as satiety and malaise, should be highly correlated with nutritional well being, toxicosis, and nutritional deficiencies, which are directly related with survival and reproduction.
Abstract: Ruminants select nutritious diets from a diverse array of plant species that vary in kinds and concentrations of nutrients and toxins, and meet their nutritional requirements that vary with age, physiological state. and environmental conditions. Thus, ruminants possess a degree of nutritional wisdom in the sense that they generally select foods that meet nutritional needs and avoid foods that cause toxicosis. There is little reason to believe that nutritional wisdom occurs because animals can directly taste or smell either nutrients or toxins in foods. Instead, there is increasing evidence that neurally mediated interactions between the senses (i.e., taste and smell) and the viscera enable ruminants to sense the consequences of food ingestion, and these interactions operate in subtle but profound ways to affect food selection and intake, as well as the hedonic value of food. The sensation of being satisfied to the full (i.e., satiety) occurs when animals ingest adequate kinds and amounts of nutritious foods, and animals acquire preferences (mild to strong) for foods that cause satiety. Unpleasant feelings of physical discomfort (i.e., malaise) are caused by excesses of nutrients and toxins and by nutrient deficits, and animals acquire aversions (mild to strong) to foods that cause malaise. What constitutes excesses and deficits depends on each animal's morphology, physiology, and nutritional requirements. This does not mean that ruminants must maximize (optimize) intake of any particular nutrient or mix of nutrients within each meal or even on a daily basis, given that they can withstand departures from the normal average intake of nutrients (i.e., energy-rich substances, nitrogen, various minerals, and vitamins). Rather, hemostatic regulation needs only some increasing tendency, as a result of a gradually worsening deficit of some nutrient or of an excess of toxins or nutrients, to generate behavior to correct the disorder. Extreme states should cause herbivores to increase diet breadth and to acquire preferences for foods that rectify maladies. From an evolutionary standpoint, mechanisms that enable animals to experience feedback, sensations such as satiety and malaise, should be highly correlated with nutritional well being, toxicosis, and nutritional deficiencies, which are directly related with survival and reproduction.
879 citations
Cites background from ""Salience": A factor which can over..."
...Finally, salient flavors affect the relationship (Kalat and Rozin 1970, 1971): For example, lambs with an aversion to cinnamon-flavored wheat also avoided cinnamon-flavored rice (Launchbaugh and Provenza 1993)....
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...The concentration of a compound also affects aversions (Kalat and Rozin 1970, Cannon et al. 1985): Sweet (sodium saccharin) or bitter (aluminum sulfate) flavors, regardless of concentration, did not affect lambs’ consumption of barley....
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TL;DR: The chapter discusses the multiple determinants of food selection in man that are divided into biological factors and effects of individual experience, on one hand, and cultural influences, on the other.
Abstract: Publisher Summary This chapter discusses the selection of food by rats, humans, and other animals, and focuses on the complex problems, especially in food recognition and choice, in the omnivores or generalists. Food selection implies food ingestion. Food ingestion implies the presence of food. Therefore, background for the study of food selection includes the food search process: search images and search mechanisms for finding appropriate food stimuli in the environment. Honey bees provide fine examples of a highly developed food search system. Food selection also implies the ability to obtain or capture food, and to assimilate it, for which many often exotic mechanisms have been evolved. Given the presence of potential food, ingestion then usually depends on an internal state or detector indicating a “need” for the particular food or class of foods, and recognition of the potential food as food. Omnivores, such as rats and humans, faced with an enormous number of potential foods, must choose wisely. They are always in danger of eating something harmful or eating too much of a good thing. Although there are some helpful internal mechanisms, such as poison detoxification, nutrient biosynthesis, and nutrient storage, the major share of the burden for maintaining nutritional balance must out of necessity come from incorporation of appropriate nutrients in the environment and, hence, behavior. The most striking parallel between human and rat feeding is in the neophobia seen in both. The chapter discusses the multiple determinants of food selection in man that are divided into biological factors and effects of individual experience, on one hand, and cultural influences, on the other.
456 citations
TL;DR: It is proposed that the CS-US delay gradient is a learning curve: During the delay, a rat gradually learns that a taste is "safe" and a solution which a rat drinks only once becomes safe and resistant to learned aversions for at least 3 wk, suggesting a learned safety mechanism.
Abstract: Rats learn taste aversions with unusually long CS-US delays. This has previously been explained as slow decay of a CS trace or as relative lack of interference. We propose, however, that the CS-US delay gradient is a learning curve: During the delay, a rat gradually learns that a taste is "safe." A solution which a rat drinks only once becomes safe and resistant to learned aversions for at least 3 wk., suggesting a learned safety mechanism. If a rat drinks a solution twice (within the effective CS-US interval) before a single poisoning, it learns less aversion than if it received only the second presentation. The learned-safety theory explains this result; a trace-decay or interference model cannot.
390 citations
References
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01 Dec 1967
TL;DR: The role of attention in Pavlovian conditioning, and use of auditory and visual stimuli to condition rats is discussed in this article, where the authors discuss the use of both visual and auditory stimuli.
Abstract: Role of attention in Pavlovian conditioning, and use of auditory and visual stimuli to condition rats
1,562 citations
TL;DR: In this article, rats were allowed to choose between a novel food and a familiar food and one hour later they were x-irradiated, and their preference for the novel food was less than that exhibited by appropriate controls.
Abstract: Rats were permitted to ingest a novel food and a familiar food. One hour later they were x-irradiated. When they were subsequently allowed to choose between these foods, their preference for the novel food was less than that exhibited by appropriate controls.
369 citations
243 citations
TL;DR: An aversion to saccharin flavored water (.1%) was conditioned in male albino rats using X-rays as the noxious stimulus and it was noted that an aversion could be formed when these stimuli were separated by as much as 12 h.
Abstract: An aversion to saccharin flavored water (.1%) was conditioned in male albino rats using X-rays as the noxious stimulus. The time interval between CS (saccharin) and US (X-ray) was varied for different groups and it was noted that an aversion could be formed when these stimuli were separated by as much as 12 h. Additional groups were run with 4% sucrose as the CS and the maximum effective time interval between CS and US was approximately 6 h.
194 citations
138 citations