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1.
Previous experiments have shown that the negative contrast effect in consummatory behavior that occurs when rats are shifted from 32% to 4% sucrose is alleviated by the tranquilizer chlordiazepoxide (CDP). However, in these experiments, CDP was effective on the second postshift day but not on the first postshift day. The three experiments described in this paper suggest that this differential effectiveness of CDP is not due to the difference in preshift-postshift retention intervals on Day 1 (24 h) and Day 2 (48 h), but is due instead to the necessity of some degree of experience (about 5 min) with the postshift solution. These results, combined with those of an earlier study which showed elevated corticosterone in shifted animals on the second postshift day but not on the first postshift day, suggest that negative contrast may be a dynamic process, involving sequential processes of detection, evaluation, and conflict over the postshift period. It was further suggested that CDP becomes effective in moderating contrast only when the conflict stage is reached. 相似文献
2.
In three experiments, rats shifted from 32% to 4% sucrose consumed less of the 4% sucrose than did rats that had received only the 4% solution. Experiment 1 showed that this negative contrast effect was not accompanied by a corticosterone elevation on the first day subsequent to the shift. Experiments 2 and 2a showed that corticosterone levels were substantially elevated on the 2nd postshift day and that there was a tendency for degree of elevation in corticosterone to be related to degree of lick suppression. These results are discussed in terms of other data suggesting that anxiolytic drugs and disinhibitory stimuli are more effective in alleviating contrast on the 2nd postshift day than on the 1st postshift day. It is suggested that, in the present paradigm, reaction to stimulus change may be the primary determinant of contrast on the 1st postshift day, but emotional processes related to reward loss and/or conflict develop by the 2nd postshift day. 相似文献
3.
In three experiments, we studied the consequences of ejaculation upon the frustrative or contrast response of male rats exposed
to reward downshift situations (i.e., surprising changes from 32% to 4% sucrose solutions). Similar to what has been found
after treatment with anxiolytic agents, consummatory suppression was partially reversed by previous ejaculations in a second
postshift trial (Experiments 2 and 3), such a result not having been obtained in a first postshift trial (Experiment 1). Moreover,
the effect of ejaculations upon males' behavior during a second postshift trial was transitory, disappearing when assessed
during the third and fourth postshift trials (Experiment 3). These results are in accordance with both Amsel's (1958, 1992)
frustration theory and Flaherty's (1996) multistage hypothesis of successive negative contrast; the diverse factors that are
known to modulate contrast effects are considered, including an interpretation of the present data in terms of the anxiolytic-like
effect of the ejaculation. 相似文献
4.
In a series of three experiments, rats shifted from a 32% to a 4% sucrose solution, after 10 days’ exposure to the 32% solution, exhibited a negative contrast effect in lick rate. In each experiment, shifted rats that received a novel stimulus (tone) during the postshift period exhibited a higher lick rate (smaller contrast effect) than shifted subjects not receiving the tone. This increase in lick rate resembles Pavlovian disinhibition and is interpreted as supporting an inhibitory view of successive negative contrast effects. Control conditions included in Experiments 2 and 3 favored the disinhibition interpretation of the effect of the tone, as opposed to a rate-dependency hypothesis or to the nonspecific energization of behavior. In Experiments 4–6, the tone was introduced coincident with the occurrence of a simultaneous negative contrast effect. Rather than disinhibition, a decrease in licking occurred. These results were discussed in terms of differences between successive and simultaneous contrast. 相似文献
5.
Rats shifted from 32% sucrose to 4% sucrose lick less than rats that experience oniy the 4% solution. Previous experiments have found this negative contrast effect to be reduced (“disinhibited”) by the addition of a novel tone in the postshift period. In Experiment 1 of this paper, the negative contrast effect was enhanced when a novel flavor was added to the sucrose solution in the postshift period. In Experiments 2–4, changes in the ambient context, even changes sufficient to produce disruptions in licking, did not alter the degree of negative contrast. Tiese results suggest that (1) rats compare rewards across substantially different contexts, (2) contrast may serve to enhance taste neophobia, and (3) a disinhibitory effect may be confined to the presentation of punctate, nontaste, novel stimuli within a familiar context. 相似文献
6.
Previous experiments have shown that the intake of a 0.15% saccharin solution is suppressed if saccharin access is followed by access to 32 % sucrose in brief daily pairings. The present experiments found that: (1) the degree of suppression was not altered when no time elapsed between presentation of the two solutions each day (15 sec had been the minimum in previous experiments and was used as the control in this experiment); (2) the degree of suppression was not altered by chlordiazepoxide (6, 12, or 20 mg/kg), although the drug had large appetite-stimulating effects; (3) suppression was not influenced by amphetamine (0.25 or 0.50 mg/kg); and (4) contrast could be established or eliminated, even after extended training, by manipulating the sequences of solutions presented (saccharin-saccharin or saccharin-sucrose). The results were interpreted in terms of a contrast effect based on the learned anticipation of a preferred substance. The chlordiazepoxide data suggest that this contrast is different from successive negative contrast, and the intersolution interval data suggest that the occurrence of contrast rather than a reinforcement effect is not due to a time gap between presentations of the two solutions. 相似文献
7.
In a consummatory experiment patterned after previous work with rats and goldfish, successive negative incentive contrast was sought in didelphid marsupials of two species (Lutreolina crassicaudata andDidelphis albiventris). Half of the subjects of each species were trained from the outset with a 32% sucrose solution and shifted occasionally to a 4% sucrose solution; the rest, which served as controls, were trained only with the 4% solution. The positive results obtained (less response to the 4% solution in the shifted subjects than in the controls) fit the hypothesis, based on comparative work with descendants of older vertebrate lines, that the mechanism of successive negative incentive contrast evolved in a common reptilian ancestor of birds and mammals. 相似文献
8.
Charles F. Flaherty 《Learning & behavior》1982,10(4):409-440
The literature relevant to incentive contrast effects is reviewed, with emphasis on the data published since the reviews by Black (1968) and Dunham (1968). Contrary to the evidence available for the earlier reviews, the current literature indicates that positive contrast is a reliable phenomenon. Its occurrence is facilitated by use of a constant delay of reward, use of a long runway, or possibly by a shift while a negative contrast effect, resulting from a previous shift, is still present in the animals’ behavior. Positive contrast also occurs in consummatory behavior when sucrose or saccharin solutions are shifted. Conditions that are ineffective in producing positive contrast are reviewed, as are the effects of numerous variables on both successive and simultaneous contrast. In addition, positive and negative contrast effects resulting from shifts in delay or percentage of reward, contrast resulting from shifts in sucrose, saccharin, or ethanol solutions, contrast in choice behavior, and transsituational contrast are reviewed. The relationship of the data to several theoretical interpretations of contrast is also considered. 相似文献
9.
In Experiment I, rats showed no evidence of a successive negative contrast effect (NCE) when shifted from immediate reward to a 15-sec delay of reward. Experiment II provided a direct comparison of NCE in both successive and simultaneous paradigms. As in Experiment I, there was no evidence of a successive NCE, but a reliable simultaneous NCE was observed. These results add support for the view that simultaneous and successive NCEs are not due to a single, common process. 相似文献
10.
Contrast in consummatory behavior was investigated following repeated shifts from 32% to 4% sucrose. In Experiment 1, contrast in licking and in open-field measures of activity occurred following the second and third downshifts. In Experiments 2a and 2b, equivalent contrast effects occurred following the first and second downshifts in sucrose. In Experiment 3, negative contrast remained unabated following nine downshifts in animals shifted between 32% and 4% sucrose on alternate days. Similar results were found for five downshifts in animals shifted every 2 days. In both of these latter conditions, positive contrast occurred over the first few shifts and was then lost as the 32% control group reached asymptote. These data show that repeated negative contrast effects in consummatory behavior are robust and enduring and occur under several different sets of experimental parameters. The results are discussed in terms of reinforcement level and emotional interpretations of contrast effects, and the possibility was suggested that the causal mechanism of contrast changes with repeated shifts. 相似文献
11.
HEATHER ELISE MURPHY 《Psychology in the schools》2012,49(9):883-891
Lesbian, gay, bisexual, and transgender (LGBT) students face many risk factors every day when they enter their school's door. These students often fear for their safety at school, are victimized, have academic difficulties, suffer from issues with their identity development, and are at risk for suicide. School‐based Gay‐Straight Alliances (GSAs) have been shown to reduce the risk for LGBT students in these areas. School psychologists are in a unique position to be instrumental in alleviating many of the problems LGBT students face every day by being a GSA advisor. This article reviews the literature on LGBT student risk in terms of the benefits of a GSA and guides school psychologists on how to start and advise a GSA in their schools. 相似文献
12.
Handling of preweanlings (Days 2–15) had substantial effects on the open-field behavior of rats when tested as adults. In general, handled rats reared more, ambulated more, and defecated less than nonhandled rats. However, the handling manipulation had no effect on the degree of negative contrast that occurred when rats were shifted from 32% to 4% sucrose. Experiments 2 and 3 showed that preweaning handling did not influence sucrose neophobia in two different test situations. These data, in conjunction with those of other studies, suggest that preweaning handling may have powerful but limited effects on adult behavior, and that these effects are probably not best characterized in terms of global concepts such as emotionality. 相似文献
13.
辩证法认为发展的实质是新事物的产生和旧事物的灭亡,辩证否定是发展的决定性环节。中国远程教育发展的历史说明,只有否定才能将各个依次更替的发展阶段联系起来,开放大学是广播电视大学自身否定的结果。开放大学要高于并强于电大,需要加强自我意识,从电大波浪式前进的印迹中领悟到否定的根本原因在于事物的内部;要加强特色课程建设,开放的课程要有社会影响力。 相似文献
14.
Reactivity to a reward is affected by prior experience with the different reinforcer values of that reward, a phenomenon known as incentive relativity, which can be studied using the consummatory succesive negative contrast (cSNC) paradigm, in which the performance of animals that receive a 4 % sucrose solution after trials on which they were exposed to 32 % sucrose is compared with that of subjects that always receive the 4 % sucrose solution. The exploration of a novel open field can enhance or block the acquisition of associative and nonassociative memories. The effect of open field on cSNC has not yet been explored. The main result of the present study was that open-field exposure significantly modified the expression of cSNC. Exposure to an open field 1 h but not immediately before the downshift interfered with the expression of cSNC. These animals drank more of the downshifted reward than did controls that were not exposed to the apparatus, and this behavior persisted for up to three recovery trials. This phenomenon was observed even when the animals were given a more protracted preshift phase and when the discrepancy between the preshift and shift incentive values of sucrose were increased. An open field also interfered with incentive downshift when open-field exposure occurred 6 h before the downshift, and repeated exposure to the apparatus did not deteriorate this effect. The present study adds to a growing body of literature that indicates that open-field exploration can interfere with memory formation. 相似文献
15.
The effects of age on the forgetting of stimulus attributes in a differential fear-conditioning paradigm were examined with
18- and 70-day-old rats tested in either the original conditions or shifted stimulating conditions at one of three retention
intervals (1, 48, and 120 h). Adults displayed significant shifts at each retention interval, with those tested in the original
context displaying greater fear than those tested in the shifted conditions. By contrast, by 48 h the 18-day-olds had forgotten
the specific attributes of the training situation and began treating the two stimulating conditions as functionally equivalent
(Experiment 1). In Experiment 2, we tracked the ontogenetic emergence of adult-like memory for stimulus attributes and found
a dramatic increase in memory capability by 25 days of age. Experiment 3 illustrated that the forgotten memory attributes
of infants may be retrieved by administering a 90-sec cuing treatment 10 min prior to the 48-h test. Implications for the
phenomenon of infantile amnesia are discussed. 相似文献
16.
The principle of aggregation states that the sum of a set of multiple measurements is a more stable and representative estimator than any single measurement. This greater representation occurs because there is inevitably some error associated with measurement. By combining numerous exemplars, such errors of measurement are averaged out, leaving a clearer view of underlying relationships. The present study explored the effect of score aggregation over various time periods on correlations among a number of reliable measures frequently used in open-field testing. Twenty-six male rats were given four open-field tests (4 min in duration) at 48-h intervals. Ambulation, rearing, and defecation responses were measured on a minute-by-minute basis in the open-field tests. Correlation matrices were calculated among the three measures for unaggregated scores (1-min totals) and for scores aggregated over daily tests, and mean correlation coefficients were computed for all three pairwise comparisons of the three response variables. These mean correlations were then compared to those obtained when the open-field measures were aggregated over all 4 test days. The results showed that aggregation produced substantial increases in correlation-coefficient magnitude. The correlation between ambulation and rearing increased from a mean of .39 to a value of .81. Similar increases were observed when defecation scores were correlated with ambulation (?.17 to ?.59) and rearing (?.16 to ?.49). Thus aggregation is an important factor to be considered in the design of psychobiological correlational studies. 相似文献
17.
Fear appeals are messages that focus on avoiding the negative consequences of failure. They are often used by teachers as a motivational tactic prior to high-stakes examinations. In this study, we examined whether 566 secondary school students, from 26 different classes, approaching high-stakes examinations appraised fear appeals as threatening or challenging. Multilevel regression analyses showed that an increased frequency of student-reported (but not teacher-reported) fear appeals were experienced as a threat, when focused on avoiding negative consequences and as a challenge, when focused on the timing of forthcoming examinations. Threat experience was associated with lower student-reported academic self-efficacy, higher attainment value and higher extrinsic value. Challenge experience was associated with higher student-reported attainment value and higher extrinsic value. Results show that students differ in the way that they experience fear appeals. Fear appeals should be conveyed with caution, especially if students have low academic self-efficacy. 相似文献
18.
The cognitive abilities of a group of dysphasic children in a special school in Finland were examined in this study to answer the following questions: Can we categorize their cognitive processing as planning, arousal-attention, simultaneous and successive processing (PASS)? The second question was concerned with detecting subgroups within the dysphasic sample in terms of PASS processes. The subjects were 60 dysphasic children in a special school. Their ages ranged from 7 to 19 years. All subjects were administered tests of planning, arousal-attention as well as simultaneous and successive processing. They were also administered the Wechsler test of intelligence for children and adults according to their ages, two sub-scales of Wechsler memory scale, as well as three ad hoc tests, cancellation task, KS persons and Rey Osterrieth copy task. The results of the factor analysis generally confirmed the emergence of the four PASS factors. As a results of cluster analysis, two subtypes of dysphasics emerged categorized as clearly high and low in the successive factor as well as relatively high and low on the simultaneous factor scores. The low-simultaneous/low-successive group was significantly lower in WISC verbal IQ the Wechsler memory scale for logical memory, and the ad hoc test of KS persons. The results were discussed, in terms of the importance of understanding the language problems typically associated with the two subtypes as well as the remedial program which will take into account their cognitive differences in spite of the fact that both groups had significant language impairment. 相似文献
19.
Whether beginning nursery school, kindergarten, or first grade, many children commonly experience fear at being separated from their parents and at being in a new place for the first time for an extended period. For example, Albert lived across the street from the school where he was to attend first grade. Taken by his brothers and sisters to the school on the first day, Albert was left in a room with a teacher and forty-five other children.Betty Lou Land is an Associate Professor of Reading at Winthrop College and Terry Norton is an Instructor of Reading. 相似文献
20.
Deprivation shifts, using conditions analogous to those which produce strong incentive contrast when reward quantity is changed (extended preshift training, short interval from the last preshift trial to the first postshift trial, large preshift differences in deprivation) resulted in contrast of runway speed and choice behavior. In the first experiment, a downshift of hunger during rats’ runway training produced a slow lessening of speed below that of a group trained continually at low hunger. In the second experiment, rats were trained to traverse a runway to one food-containing goalbox when very hungry and to another, distinctively different food-containing goalbox when not very hungry. The rats were next given a series of choice trials between the two goalboxes. There was a brief preference for the high-hunger goalbox, followed by a preference for the low-hunger goalbox. The results of the second experiment suggest that deprivation affects the strength of conditioning of a cue-reinforcer expectancy, while the slow development of contrast in the first experiment indicates that deprivation also affects the development of either habit strength or a response-reinforcer expectancy. 相似文献