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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thirsty rats were trained to press a lever for either a sucrose solution or saline before performance was tested in extinction while the animals were either hungry alone or experiencing both hunger and a sodium appetite. Reinforcer-specific motivational control was observed in that the animals trained with the sucrose solution pressed more than those trained with the saline when they were tested hungry, but not when they were tested under combined hunger and sodium appetite. In order to assess the role of a Pavlovian incentive process in this effect, thirsty animals received non-contingent pairings of one stimulus with the sucrose solution and another with saline in the second experiment. In an extinction test the sucrose stimulus augmented lever pressing relative to the saline stimulus when the animals were hungry, but not when they were thirsty. In the subsequent experiments the contribution of the Pavlovian process was equated by giving concurrent training with both incentives. Lever pressing and chain pulling were reinforced concurrently, one with the sucrose solution and the other with saline, while the animals were thirsty. Once again, the animals pressed more in extinction if this action had been trained with the sucrose solution rather than the saline, but only if they were hungry rather than thirsty. Thus, instrumental performance across a thirst-to-hunger shift can also be controlled by an instrumental incentive process. The direct engagement of the instrumental process by this motivational shift contrasts to the absence of such control following a hunger-to-thirst transition (Dickinson & Dawson, 1987a), a fact attributed to the asymmetrical motivational interactions produced by water and food deprivation.
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PMID:Motivational control of instrumental performance following a shift from thirst to hunger. 228 40

The synergistic interaction between odor and taste in flavor-toxicosis conditioning was tested in two experiments. The temporal interval between a 2-min odor and a 2-min taste was varied for thirsty rats licking at a water spout. In the first experiment, taste was presented at time zero, and odor was presented at -10, -1, 0, 1 and 10 min to independent groups in a simple compartment. In the second experiment, taste was presented at 0, and odor was presented at -5, -2, and 0 min in a "wind tunnel" apparatus. The results indicated that odor alone is an ineffective conditioned stimulus for a toxic unconditioned stimulus under our conditions, simultaneous (0-min) presentation of odor with taste potentiates the odor component so that it becomes more effective than the taste component, a 2-min interval between odor and taste attenuates potentiation, and a 5-min interval disrupts the effect, and the interaction in asymmetrical, that is, odor has no such systematic effect on the conditioning of taste.
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PMID:Taste potentiation of poisoned odor by temporal contiguity. 648 15

Nonconserving children may fail to conserve because of difficulties in verbally expressing nonlinguistic knowledge of equivalence relationships. This may be partly due to an inability of the right hemisphere, which mediates the performance of internal reversals and conservation, to communicate with the speaking left hemisphere because of the immaturity of the corpus callosum. This relationship presumably results in the asymmetrical activation of the left hemisphere when verbal responses are required. To assess the possibility that nonconservers have an awareness of the reversibility of these operations, three groups of nonconserving children (N = 42) were either asked which of two containers (one of which appeared to contain more liquid, but had previously been shown to contain less) had more in it, or which (pretending they were very thirsty and it was their favorite drink) they would prefer. To assess whether nonconservers respond primarily with left hemisphere activation, patterns of lateral eye movement in response to verbal-analytic or spatial-emotional stimuli were obtained in a fourth group (N = 37). Both hypotheses were supported.
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PMID:Nonlinguistic Knowledge, Hemispheric Laterality, and the Conservation of Inequality in Nonconserving Children. 2814 70