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M Domjan

Publications and source records attributed to M Domjan.

At least 19 recordsLinked to original sources
PubMed1992

Increased responding to female stimuli as a result of sexual experience: tests of mechanisms of learning.

Sexual experience increases the response of males to stimuli provided by female conspecifics in a variety of species. The mechanisms of learning involved in this type of phenomenon were explored in two experiments with Japanese quail. The results indicated that instrumental conditioning with copulatory opportunity is not necessary for the acquisition of responding to female cues, and responding is not facilitated by learning about the location of the female. However, the response of males to female stimuli (as well as to arbitrary stimuli associated with access to a female) was enhanced by the presence of sexually conditioned contextual cues. Substantial levels of responding also occurred to female stimuli in a context where the subjects never encountered a female quail before. This latter outcome is consistent with the possibility that stimuli from a female become directly associated with sexual reinforcement during the course of sexual experience. Similar forms of learning may be involved in the effects of sexual experience on the response of mammalian species to female odours.

Animals↗
PubMed1991

Learning to discriminate the sex of conspecifics in male Japanese quail (Coturnix coturnix japonica): tests of "biological constraints".

Male Japanese quail learn to approach and remain near female, but not male, quail if they are allowed to copulate with female quail and receive noncopulatory exposures to males. The generality of the mechanisms involved in this type of discrimination learning was investigated in the present study. In Experiment 1, Ss learned to spend more time near initially unfamiliar blonde quail than familiar brown female or male quail as a result of being allowed to copulate with the blonde, but not the brown, quail. In Experiment 2, Ss learned to respond more to nonreproductive male as compared with female quail as a result of being allowed to copulate with the males, but not with the females. The experiments provided some evidence of a bias favoring responding to females independent of copulatory reinforcement contingencies. However, the results also indicated remarkable plasticity of discrimination learning about species-specific sexual stimuli.

Animals↗
PubMed1991

Discriminating the sex of conspecifics by male Japanese quail (Coturnix coturnix japonica).

How male Japanese quail (Coturnix coturnix japonica) discriminate the sex of conspecifics at a distance was investigated by testing subjects with male and female stimulus birds on the other side of a small window after opportunities to copulate with females and again after repeated exposures to males in the absence of copulatory opportunity. Time spent near the window, frequency of window approaches, duration of window visits, rate of walking near the window, line crossings outside the window area, pecking the window, and crowing were measured. Subjects responded similarly in the presence of male and female stimulus birds during the first test block but discriminated the sex of conspecifics after noncopulatory exposures to males. The discrimination was evident in less locomotion and less crowing in the presence of females as compared with males and, as predicted by a discrimination learning hypothesis, developed largely through a change in responding to males.

Animals↗
PubMed1989

Sexual-discrimination learning in male Japanese quail (Coturnix coturnix japonica).

We investigated how male Japanese quail (Coturnix coturnix japonica) learn through extensive social and sexual experience to discriminate between male and female conspecifics. Opportunity for heterosexual copulation was important for this learning, but even extensive copulatory opportunity was not sufficient to produce a sexual discrimination; subjects also required exposure to other males. Exposure to females after copulatory opportunity did not produce a sexual discrimination but facilitated its acquisition. Time or exposure to only the visual features of male birds (provided by taxidermic models) after copulatory opportunity did not result in differential responding to male and female conspecifics. Finally, presenting stimulus birds one at a time proved to be a more sensitive test of sexual-discrimination learning than presenting two stimulus birds at the same time. The results indicate that sexual-discrimination learning is similar to conventional associative learning.

Animals↗
PubMed1989

Contextual conditioning and the control of copulatory behavior by species-specific sign stimuli in male Japanese quail.

Three experiments were conducted to identify species-specific sign stimuli sufficient to elicit copulatory behavior in male Japanese quail and to determine how learning is involved in the control of behavior by these sign stimuli. In Experiment 1, sexually experienced subjects were tested for copulatory behavior with a live female quail and with a model consisting of a female quail's head and neck mounted in front of a foam pad. Comparable levels of copulatory behavior were observed in the two tests, indicating that static visual cues provided by a female quail's head and neck are sufficient to elicit copulatory behavior in this species. Experiment 2 showed that male birds that previously received numerous opportunities to copulate with a live female quail in the test situation were significantly more likely to copulate with the head + neck model than were sexually inexperienced subjects. Experiment 3 showed that prior sexual experience with live quail facilitated responding to the head + neck model only if the sexual experience was provided in the same place where subjects were later tested with the model. This last finding suggests that sexual experience facilitates control of copulatory behavior by species-specific sign stimuli through contextual conditioning. Contextual conditioning may lower the threshold for sexual behavior with the result that a stimulus as impoverished as an immobile model containing only the head and neck of a female quail becomes sufficient to elicit normal levels of copulatory behavior. The results are also discussed as an example of conditioned stimulus facilitation of responding to an unconditioned stimulus.

Animals↗
PubMed1979

Effects of distribution of the drug unconditioned stimulus on taste-aversion learning.

Rats injected with lithium chloride after exposure to a taste or olfactory stimulus learn stronger aversions to these cues if the drug is administered in two small injections 35 min apart than if all of the drug is given in a single injection. This facilitation of conditioning produced by distribution of the drug unconditioned stimulus occurs with both low and high lithium doses (Experiments 1 and 2), is more evident in male than in female rats (Experiment 1), and is directly related to the amount of the flavored solution consumed prior to drug treatment (Experiment 4). Increasing the interval between two small drug injections beyond an optimal value results in a progressive loss of the facilitation of conditioning (Experiments 2 and 3), and the optimal drug distribution interval may be shorter for olfactory cues (Experiment 3) than for taste stimuli (Experiments 1 and 2). Control observations (Experiments 5A and 5B) showed that the drug distribution effect is not due to handling or other non-drug factors involved in giving two rather than only one injection. The phenomenon is consistent with recently-proposed models of conditioning and suggests that the differential effectiveness of various drugs in taste aversion conditioning may be related to differences in the time course of the unconditioned drug effects.

Animals↗
PubMed1978

Ingestional aversion learning in preweanling rats.

Ingestional aversions were conditioned in 12- and 15-day-old rats by infusing a .5% solution of saccharin into the oral cavity and following this oral infusion by the injection of lithium chloride. At both ages, subjects for which the saccharin exposure was followed by lithium injection within 2-3 min drank less when the saccharin solution was again presented by oral infusion 12 hr later; such suppressions of intake were not observed in subjects that previously received the saccharin and lithium in an unpaired fashion (Experiments 1 and 3). Ingestional aversions were also learned by 12-day-olds when a 30-min interval was introduced between saccharin exposure and lithium toxicosis but not when toxicosis was delayed by 120 min (Experiment 2). In contrast, 15-day-olds learned aversions with both the 30- and 120-min-delay intervals (Experiment 3). Despite the absence of long-delay learning in 12 day olds, ingestional aversions conditioned at 12 days of age were retained for 2 wk (Experiment 4). These results provide further evidence of the associative abilities of neonatal rats and illustrate a developmental aspect of long-delay learning.

Age Factors↗
PubMed1977

Early environmental influences on conditioned and unconditioned ingestional and locomotor behaviors.

For 34-44 days after weaning one group of rats was raised in a socially enriched environment, whereas another group was raised in isolated individual cages without handling. Following this differential rearing subjects were tested for ingestional neophobia and its attenuation, enhancement of ingestional neophobia by aversive drug administration, taste-aversion learning and extinction, open-field activity, and passive shock-avoidance learning. Although the differential rearing influenced open-field activity and shock-avoidance this manipulation did not have a significant effect on the various measures of conditioned and unconditioned ingestional behaviors. The results provide further evidence for the distinctiveness of gustatory-visceral and telereceptor-cutaneous sensory systems.

Animals↗
PubMed1977

Selective suppression of drinking during a limited period following aversive drug treatment in rats.

Administration of lithium chloride disrupted the intake of flavored solutions but not water in rats. This intake suppression was directly related to the amount of lithium administered (Experiment 1), occurred with both palatable and unpalatable novel saccharin solutions (Experiment 2), but was only observed if subjects were tested starting less than 75 min. after lithium treatment (Experiment 3). Twenty-five daily exposures to saccharin did not attenuate the effect (Experiment 4). However, in saccharin-reared and vinegar-reared rats, lithium did not disrupt consumption of the solutions these subjects had access to throughout life, even though suppressions of intake were observed when these subjects were tested with novel flavors (Experiment 5). The selective disruption of drinking is interpreted as a novelty-dependent sensitization reaction to the discomfort of aversive drug administration.

Animals↗
PubMed1977

Taste aversions conditioned by the aversiveness of insulin and formalin: role of CS specificity.

Experimenters in the past have reported that when insulin is used as the unconditioned stimulus (US), rats will learn an aversion to a sodium chloride but not a sucrose solution, whereas with formalin as the US, they will learn an aversion to a sucrose but not a saline solution. The present experiments failed to confirm these findings. Aversions to sucrose were conditioned with insulin and aversions to sodium chloride were conditioned with formalin. The use of a more concentrated sucrose solution in the present study may have been responsible for the successful sucrose-aversion conditioning with insulin. Although the source of the discrepancy in findings concerning aversion conditioning with formalin remains unclear, experiments ruled out numerous possibilities. These experiments also showed that sodium chloride aversion conditioning with formalin is a highly robust phenomenon that occurs with a variety of conditioned stimulus durations and formalin doses, with distributed and massed training, in male and female rats, and even if saline is not the only novel solution presented during conditioning. Furthermore, the aversion can be detected with both single-stimulus and choice test procedures.

Animals↗
PubMed1977

Taste-aversion conditioning with expected versus unexpected drug treatment.

Following differential conditioning in which a drug-predictive taste solution (D) infused into the oral cavity of rats was followed by a lithium injection and a no-drug-predictive solution (ND) was not reinforced, animals received a backward pairing between lithium and a novel saccharin flavor. Subjects infused with either the D solution or tap water immediately before backward conditioning learned weaker saccharin aversions than animals infused with the ND solution and animals given no infusion at this time (Experiments 1 and 3). These latter groups did not differ from each other (Experiment 3). The interference with aversion learning produced by water infusion appeared to be due to conditioned excitation that accrued to sensations of the infusion process. Extinction of the infusion sensations eliminated blocking produced by the infusion of water (Experiments 4 and 5). The blocking of saccharin-aversion learning produced by infusion of the D solution was due, to a large extent, to the conditioned aversiveness of the D taste. Extinction of the aversion to the D taste eliminated the interference with saccharin conditioning (Experiment 2), whereas extinction of the excitatory properties of the infusion process did not prevent the blocking of conditioning by infusion of the D solution (Experiment 5). These results are inconsistent with suggestions that taste-aversion learning is a primitive form of conditioning; rather, they demonstrate the influence of informational variables on conditioned taste aversions.

Administration, Oral↗
PubMed1977

Paradoxical effects of proximal unconditioned stimulus preexposure: interference with and conditioning of a taste aversion.

Taste aversions were conditioned in rats by giving the subjects an injection of lithium following exposure to saccharin. Treatment with lithium shortly (30 to 60 min.) before such a conditioning trial disrupted the taste-aversion learning produced by the postsaccharin drug injection. In Experiment 1, this interference effect was found to be a monotonically decreasing function of the preexposure-to-conditioning interval. The greatest disruption of conditioning was observed with a 30-min. preexposure-to-conditioning interval, and no interference occurred if the preexposure was administered 1 or 2 days before conditioning. These results suggest that in addition to the more durable effects of unconditioned stimulus (US) preexposure emphasized by previous investigators, US preexposure also activates temporary mechanisms that likewise attenuate subsequent conditioning. Experiment 2 demonstrated that lithium given before saccharin exposure disrupts the conditioning produced by a postsaccharin drug injection even if the presaccharin injection would itself otherwise be effective in producing a "backward" conditioned saccharin aversion. This outcome indicates that proximal US preexposure can have two opposite and paradoxical effects: It can interfere with as well as condition a taste aversion.

Animals↗
PubMed1977

Aftereffects of lithium-conditioned stimuli on consummatory behavior.

Exposure to taste or spatial cues previously paired with lithium administration resulted in more drinking during a test session started 15 min. later than did exposure to stimuli previously presented in the absence of drug treatment (Experiments 1, 2, 4, and 5). This outcome reflected an elevation of intake above baseline levels (Experiment 1) and required the presence of the lithium-paired cues rather than merely a history of lithium injections (Experiments 1, 2, 4, and 5). The increased drinking was evident in tests with novel (Experiments 1, 4, and 5) as well as familiar (Experiment 2) palatable solutions and was not attributable to a greater degree of thirst in subjects exposed to the lithium-predictive cues (Experiments 4 and 5). The phenomenon was attenuated by extinction of the lithium-conditioned stimuli (Experiment 3). However, the increased drinking aftereffect probably was not a result of the conditioned aversiveness of lithium-predictive cues, since shock-conditioned stimuli did not elicit enhanced consumption (Experiment 5). Various explanations of the effect are discussed.

Animals↗