共查询到20条相似文献，搜索用时 31 毫秒
1.
Carlo Ambrogi Lorenzini Corrado Bucherelli Aldo Giachetti Giovanna Tassoni 《Learning & behavior》1990,18(2):191-198
The effect of tail-handling on exploratory behavior of the rat, measured as step-through latency in a well-lighted, two-box apparatus, was investigated. Male adult Wistar rats, aged 60 days, were employed in all three experiments. Experiment 1, in which the subjects were handled at different times after entering the goal chamber (0, 10, 30, 60, 300, and 600 sec), showed that immediate handling, relative to detention in the goal chamber (delay of handling) had an inhibitory effect on exploration. Experiment 2 showed that groups handled immediately after entering the goal chamber but then detained there for different durations all showed the same progressive inhibition of exploration. Experiment 3 showed that the inhibition of exploration (very long step-through latencies) due to tail-handling immediately after entering the goal chamber could be significantly decreased by further trials in which handling was delayed for a sufficient duration (30 sec or more). Handling is discussed as a stimulus that is aversive enough to elicit conditioned passive-avoidance responses (inhibition of exploratory behavior), although it is subject to rapid extinction. 相似文献
2.
When children are placed into foster care the caseworker must give preference to an adult relative, many of whom are grandparents, over an unrelated caregiver. This kinship preference is based in evolutionary biology, which suggests that the imperative to care for a child should be greater for kin versus non-kin. However, not all kin are related to a child in the same way, and level of paternity uncertainty may influence level of care provided. For instance, maternal grandparents can be assured that they share genetic material with their grandchild, while paternal grandparents may not have the same level of certainty. Owing to the possibility of paternity uncertainty, we hypothesize that out-of-home placements with paternal grandparents will be at a greater risk of subsequent investigations than placements with maternal grandparents or with foster parents. We secured data on placements n = 560 of children ages 1.5 to 17 following a maltreatment investigation from a merger of the National Survey of Child and Adolescent Well-Being NSCAW II and the National Child Abuse and Neglect Data System NCANDS. Kaplan-Meier and multivariate Cox regression were used to examine the difference in time to the first new investigation by type of out-of-home placement while controlling for covariates. Consistent with our hypothesis, placements with paternal grandparents were at a higher risk of a subsequent investigations than placements with maternal grandparents or non-kin foster parents. Results suggest a need for further considerations of child safety in foster care based on genetic relatedness of caregivers. 相似文献
3.
To determine whether observing components of periparturitional behavior affects the manifestation of those behaviors in virgin rats, virgins selected for nonplacentophagia and for the absence of spontaneous maternal behavior toward pups were exposed to stimulus rats that were giving birth, eating donor placenta, or eating lab chow. During observations, subjects could either eat donor placenta or just see and smell it. The subjects were tested subsequently for placentophagia and for the rate of onset of pup-induced maternal behavior. The results indicated that: (1) access to placenta in the presence of other rats led to placentophagia; (2) when such placentophagia occurred in conjunction with exposure to other rats that were giving birth or eating donor placenta, the subjects became permanent placentophages (otherwise, the subjects reverted and did not eat on subsequent placentophagia tests); (3) none of the observation conditions, regardless of the availability of placenta during observation, affected the maternal sensitization latency. The results are discussed in terms of social facilitation, exposure learning, and desensitization to exteroceptive stimuli. 相似文献
4.
Tiffany M. Field 《Child development》1991,62(3):539-547
80 infants, toddlers, and preschoolers were observed before, during, and after separations from their mothers, who were attending conferences (M duration = 4 days). Half the sample was separated only once and the other half experienced 3 separations across a 6-month period. The study was designed: (a) to determine how separations affect children's behavior when there are no changes in the family constellation as there typically are during other separations, such as the birth of a new child, and (b) to determine the effects of repeated separations. Fewer changes in sleep and play behaviors suggested that this type of separation was less stressful than separations for the birth of another child. Nonetheless, the separations were still stressful, but principally for the single-separation group. In that group, changes were noted in both play and sleep behaviors. Following reunion, their sleep behaviors and more sophisticated play behaviors returned to baseline. However, activity level and the more insecure behaviors, such as wandering aimlessly, watching other children play, and interacting with their teachers, remained elevated following the mother's return. The multiple-separation group, in contrast, showed only 1 behavior change during their third separation, i.e., reduced interactions with their peers during the separation period, which returned to baseline following reunion. Repeated-measures analyses of the first and third separations of the multiple-separations group suggested that only the first separation was stressful. Thus, the infants and children in this study seemed to adapt to repeated separations. 相似文献
5.
J. L. Smart 《Learning & behavior》1976,4(3):313-316
The development of the hippocampus in rats may be vulnerable to undernutrition during the fetal and suckling periods. Hence the behavioral effects of early growth restriction may resemble those of hippocampal lesions. This suggestion was investigated by testing previously undernourished rats for reversal learning, an ability badly affected in hippocampectomized rats. Developing rats were undernourished by feeding their mothers a restricted quantity of a good quality diet during pregnancy and lactation. All rats were fed ad lib from weaning. Reversal of spatial discrimination learning was tested in adult animals using a water T-maze. Previously undernourished rats learned the initial spatial discrimination more quickly than controls. However, there was no effect of early treatment on serial reversal learning in Experiment I or on performance of a single reversal after prolonged initial training in Experiment II. 相似文献
6.
Jon L. Williams 《Learning & behavior》1984,12(2):209-216
Responses of mother rats were observed 24 h before and 24 and 72 h after exposure to one of three 8-day postpartum treatments: shock escape training, yoked inescapable shock, or restrained with no shock. In contrast to those in the other two groups, the dams given inescapable shock showed slower speed to approach the nest, shorter durations of being on the nest, and lower frequency and shorter total duration of oral contact with their pups. These dams also retrieved their pups less frequently, but this measure, as well as the frequency of leaving the nest, did not result in significant differences between groups. Since the traditional interpretations of the learned-helplessness effect were not entirely able to account for these findings, the observed uncontrollable-stress-produced changes in maternal behavior were examined from an ethological perspective. 相似文献
7.
Experiment I demonstrated shuttlebox avoidance conditioning using intense white noise as a UCS. Ten rats were given 25 trials a day for 6 days. Escape latencies declined and avoidance responses increased over trial blocks. Experiment II provided support for a functional similarity between shock as a UCS and intense noise as a UCS by demonstrating the Kamin effect following incomplete shuttlebox training to noise. Separate groups of rats were given 25 trials followed by an additional 25 trials either 0, 1, 4, or 24 h later. The U-shaped Kamin effect was evident in the avoidance measure. A similar but inverted U-shaped function was obtained for the escape latency measure. Escape latencies were longer on retraining than on original training at 1 h but not at 0, 4, or 24 h after original training. 相似文献
8.
Latency measures of starting to drink and of consummatory behavior were used to investigate ingestional neophobia to novel visual and novel taste cues in chicks. In Experiment 1 (N = 36), latencies to start drinking were reliably shorter to ingesta that appeared familiar from previous rearing or preexposure procedures. After drinking started, consummatory responding occurred reliably more rapidly to familiar taste cues than to novel ones. However, the presence of familiar visual cues reliably facilitated consumption of a novel taste. Experiments 2 and 3 (Ns = 144 and 180) were performed to evaluate, respectively, whether the ingestional effects of taste stimulus intensity, 0%–6% vinegar, and of visual stimulus intensity, 0%–1.0% concentrations of red food-coloring in water, changed during ontogeny for chicks 3, 5, and 7 days old. In Experiment 2, reliable direct effects of taste concentration on consummatory response latencies occurred immediately in 7-day-olds but were delayed in 3-day-olds. In Experiment 3, each age group immediately showed reliably slower starting and consummatory response times, the higher the concentration of red food-coloring. Intake performance in both experiments was consistent with the latency data. Experiments 1–3 showed that visual and taste cues of ingesta separately influenced approach and consummatory behaviors of the ingestive response sequence and that these influences depend on ontogenetic events. 相似文献
9.
The effects of flavor preexposure and retention interval were assessed in 6- and 12-day-old rats. Conditioned aversions to a flavor appeared at both ages. The conditioning of the younger pups was unaffected by conditioned stimulus (CS) preexposure and was not evident after a 10-day retention interval. For the 12-day-old rats, preexposure to either the flavor CS or a different flavor attenuated aversion strength when the rats were tested soon after conditioning. Other 12-day-old rats that were tested 10 days after conditioning also expressed substantial aversions, but with a retention interval of this length, the aversions were equivalent for animals preexposed to the CS and those not preexposed before conditioning. This loss of the CS-preexposure effect over a long interval, which has also been observed in adult rats, identifies the locus of this effect as postacquisition and perhaps at the stage of memory retrieval. 相似文献
10.
Bruce L. Brown Nancy S. Hemmes Soledad Cabeza De Vaca Concettina Pagano 《Learning & behavior》1993,21(4):360-368
In two experiments, pigeons were exposed to an autoshaping procedure in which a keylight was followed by food under delay or trace conditions, while measures were taken of keypecking and time spent near the key. In Experiment 1, the birds in the trace group spent less time near the key than did the delay birds. Moreover, the trace birds exhibited a pattern of withdrawal from the key during the trial. In Experiment 2, visual observations of the birds’ location and latencies to eat both indicated that the trace birds’ withdrawal from the conditioned stimulus was accompanied by goal tracking. The difference in performance between the delay and trace conditions was taken as evidence that a trace stimulus may exert control over behavior as an occasion setter. 相似文献
11.
The naive theory of the infant and other maternal attitudes in two subgroups in Israel 总被引：2，自引：0，他引：2
A Ninio 《Child development》1979,50(4):976-980
104 mothers of 1- and 3-year-old children were interviewed. Half of the mothers were of high and half of low SES. Low SES mothers believed that infants acquire basic cognitive skills, such as vision, hearing, and comprehending speech, at a later age than high SES mothers. Low SES mothers also believed that the introduction of cognitively stimulating activities during the first years, such as buying the first book or starting to feed the self, should occur later than did high SES mothers. No status group differences were observed in the favored timetable of physical caregiving, such as toilet training or weaning. Nor were there status group differences on the strictness/leniency dimension or in the unwillingness to put pressure on infants for accelerated development. The naive theory of the infant as a cognitive being and the timing of cognitively enriching activities were found to belong to a common cluster, separated out from the rest of the maternal attitudes, in an analysis of the intercorrelation matrixes obtained in the two samples. 相似文献
12.
A series of eight experiments was run to characterize the potentiation of the transport response reported with tactile stimulation. Experiments 1A–C were designed to investigate the types of tactile stimulation that could potentiate an initially weak transport response. Experiments 2A–C were designed to assess the effect of maternal/littermate deprivation on responsiveness to external stimuli in 9- and 16-day-old rat pups. Experiments 3A and 3B were designed to investigate, pharmacologically, underlying mechanisms for the transport response potentiation effect. It was found that if the initial stimulus in producing a strong transport response is inadequate, additional tactile stimulation can potentiate the response. The additional stimuli work best if they are diffuse, if discrete inputs can summate over areas, or if they encompass the snout area. It also was found that isolation could lead to increased responsiveness to stimuli normally eliciting or potentiating the response in 9- and 16-day-old rats. Finally, results indicate that both dopaminergic and beta-noradrenergic systems are important in the response potentiation seen with maternal/littermate deprivation. 相似文献
13.
In 2 experiments we asked whether training in multiple contexts could eliminate context-dependent memory retrieval at 6 months as it does for adults. We found that 24-hour retention was disrupted when infants were trained in one context and tested in another but not when they were trained in multiple contexts prior to testing in a novel context (Experiment 1). After a long delay, however, training in multiple contexts did not facilitate memory retrieval in a novel context: An otherwise effective retrieval cue (the training mobile) did not alleviate forgetting 3 weeks later when it was presented in a novel context (Experiment 2). These findings demonstrate that multiple learning contexts can override the debilitating effects of an altered context on memory retrieval at 6 months, but only over the short term. The resistance of older memories to retrieval in novel contexts after long periods of disuse may be adaptive, insuring that potentially inappropriate or irrelevant memories will not be expressed. 相似文献
14.
Growth and development following prenatal stress exposure in primates: an examination of ontogenetic vulnerability 总被引：6，自引：0，他引：6
Previous studies have found that stressful events during pregnancy can influence the developing fetus, resulting in attentional and neuromotor problems. This prospective study examined whether periods of vulnerability exist for neurobehavioral impairments associated with prenatal stress, using a nonhuman primate model. Twenty-eight rhesus monkey infants were born to mothers in 3 groups: (1) early gestation stress involving mild psychological stress from gestational days 45-90, (2) mid-late gestation stress from days 90-145, and (3) undisturbed controls. Infants were separated from their mothers on days 4, 9, 15, and 22 (+/- 1) postpartum for growth and neurobehavioral assessments. Results indicated that infants from the early gestation stress condition weighed less than infants from mothers stressed during mid-late gestation. Moreover, whereas both groups scored lower than controls on measures of attention and neuromotor maturity, early gestation stress was associated with more pronounced and more pervasive motor impairments than mid-late gestation stress. These results suggest sensitivity to prenatal stress effects peaks during early gestation, tapering off during mid-late gestation. Clarifying the period of greatest vulnerability to prenatal stress moves toward elucidating the underlying mechanism for prenatal stress effects and may lead to more successful intervention and/or prevention. 相似文献
15.
David Chiszar Santford Wellborn Mary Ann Wand Kent M. Scudder Hobart M. Smith 《Learning & behavior》1980,8(3):505-510
In Experiment 1, boid and colubrid snakes defecated with shorter latencies after their home cages were cleaned than did control snakes that received equivalent handling without cage cleaning. Experiment 2 replicated this finding and also showed that snakes exposed to clean cages emit more tongue flicks after reintroduction to the clean home cage than do control snakes. Experiment 3 demonstrated that cage cleaning has similar effects in two species of crotalid snakes. The increase in tongue flicking after cage cleaning is interpreted as investigatory behavior and reflects the fact that snakes respond to the absence of familiar odors. Experiment 4 showed that a clean cage containing odors derived from snake feces produces less tone-flick exploration and fewer defecation responses in rattlesnakes than does a clean cage without such odors. 相似文献
16.
Mechanisms were examined to clarify relations between maternal depressive symptoms, dysfunctional cognitions, and infant night waking among 45 infants (1-24 months) and their mothers. A mother-driven mediational model was tested in which maternal depressive symptoms and dysfunctional cognitions about infant sleep predicted infant night waking via their impact on mothers' bedtime and nighttime behavior with infants (from video). Two infant-driven mediational models were also examined, in which infant night waking predicted maternal depressive symptoms, or dysfunctional cognitions, via their impact on nighttime maternal behavior. Stronger support for the mother-driven model was obtained, which was further supported by qualitative observations from video-recordings. This study provides important insights about maternal depression's effects on nighttime parenting, and how such parenting affects infant sleep. 相似文献
17.
Children who are separated from their families and usual caregivers in emergencies face a multitude of risks. The humanitarian community lacks methods to systematically capture changes in the frequency and nature of such separations over time. A mobile phone-based community surveillance system was piloted in the Democratic Republic of the Congo. The goal was to identify new cases of unaccompanied and separated children on a weekly basis. Over an 11-week period, community focal points reported 62 cases of separation across 10 communities. The majority of children had been under the care of their parents prior to separation. More than half of the children were unaccompanied, meaning that they were living without an adult relative or customary caregiver. The pilot results suggest that implementing a mobile phone-based surveillance system in a humanitarian setting may be feasible and cost-effective and fills a critical gap in the measurement of separated and unaccompanied children in emergencies. A longer pilot to better understand how the system performs over time is recommended. 相似文献
18.
OBJECTIVE: The heterogeneity within neglecting caregivers has not been explored in an empirical fashion. The current study sought to address this limitation by utilizing archival data in order to explore variability of maternal behavior among neglectful families. METHOD: The current study utilized archival data containing caseworker and self-report information on 100 mothers for whom neglect had been substantiated and was the primary referral concern. Cluster analysis was used to describe patterns of maternal behavior. Subsequent analysis was used to determine differences between the clusters on degree of neglect, maternal depression, perceived social support, and other demographic characteristics (income, education). RESULTS: Five distinct patterns of maternal behavior emerged, each with different ratings of maternal confidence, relatedness, impulse control, and willingness to engage in verbal interactions. The clusters differed on ratings of neglect, life stressors, resource problems and adult problems. The clusters were similar in terms of maternal education, number of children in the home, and monthly income. Additionally, women in all clusters reported similar levels of depression, similar number of children, and a comparable amount of social support. CONCLUSIONS: The five clusters are described and implications for intervention approaches are discussed. 相似文献
19.
Experiment 1 examined male Swiss-Webster, C57, and DBA mice that were housed individually or grouped for 2 weeks and subsequently presented with ovariectomized, estrogenprimed, progesterone-treated females, Within each strain, social isolates showed more mounts, intromissions, and ejaculations and shorter latencies to first mount and intromission, Experiment 2 involved a similar comparison of isolated and grouped male rats, hamsters, and gerbils, Isolation produced no major effect in hamsters but reduced performance in rats and gerbils, The results suggest that facilitation of sexual action patterns by isolation is characteristic of the mouse species, Response decrements with postpubertal isolation in the rat resemble effects of prepubertal isolation in this species, These species differences may parallel differences in physiology and social behavior. 相似文献
20.
Two experiments investigated the importance of visual sensory modality in mediating enriched environmental effects during the preweaning period, and the importance of onset and duration of the enriched experience during the same period. Rat mothers and pups were exposed together in an enriched environment for either 7 or 11 days at different periods from Day 1 to Day 21. Also included was a group of rats which received only handling from Day 11 to Day 21 postpartum and another group in which the mothers were exposed to the enriched environment during the last trimester of pregnancy. Some rats were tested at 27 days of age, and others were tested at 64 days of age in the Hebb-Williams maze test. It was found that exposure in the enriched environment for a period of 7 days before the eyes opened improved rats’ problem-solving behavior above that of control rats and to the level of rats which received such experience after the eyes had opened. Handling of rats did not improve problem-solving behavior, nor did exposure during the gestation period. It was concluded that vision is not the most important factor in mediating effects during the preweaning period, since improvement in problem-solving behavior can occur before the visual system is fully developed. It was suggested that the beneficial enrichment effects might be mediated by the mother, who, in some way, transmits additional stimulation to the infant rat during this early stage of development. 相似文献