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The ability of two species of tits to remember the location and/or features of an object was tested in a delayed-matching-to-sample procedure. Three values of retention interval between presentation of the sample stimulus and the choice--30 sec, 5 min, and 15 min--were used. Both species performed at above-chance level at all retention intervals, and there was no significant decline in accuracy with increasing interval. A pool of 100 stimulus objects was used, but the results of control trials indicated that the birds responded primarily to location rather than stimulus features of the object itseif. Although the food-storing marsh tit tended to perform at a higher level than the non-storing great tit, the only significant difference between the species was in the first 50 trials of the first treatment, when the birds were acquiring the task. The results are discussed in relation to the hypothesized special memory capacity of food-storing birds.  相似文献   
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Three experiments, each using a single group of pigeons, are reported. In Experiment 1 subjects were initially trained with two stimuli, one of which was always followed by food, the other being reinforced according to a 50% partial reinforcement schedule. Subsequently a serial procedure was adopted in which an additional stimulus, C, was consistently followed by the partially reinforced CS. A second additional stimulus, A, was followed on half of its occurrences by the continuously reinforced CS, its remaining presentations being followed by nothing. The rate of autoshaped keypecking was substantially greater during A than during C. In the remaining experiments subjects received first-order conditioning with a single stimulus that was either partially (Experiment 2) or continuously (Experiment 3) reinforced. The stimuli A and C were then again introduced for serial autoshaping. Stimulus A was occasionally paired with the CS and occasionally followed by nothing, whereas stimulus C was always followed by the CS. As in Experiment 1, the rate of responding during A was greater than during C. It is proposed that one influence on the rate of autoshaped keypecking during a CS is the accuracy with which the immediate consequences of that CS are predicted.  相似文献   
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A child's adjustment to wartime stress is reliant not only on individual responses and qualities, but very significantly on the availability of support that they may receive from their parent or caregivers and quality of relationships. Strengthening parental support has the potential to be valuable. A pilot two-arm randomised controlled trial investigated the feasibility of delivering and evaluating the “Caring for Children Through Conflict and Displacement” intervention with caregivers in the West Bank. Feasibility to recruit and train non-specialist staff on-the-ground to screen families for eligibility, collect outcome data, deliver the intervention and to recruit and retain families in the study were examined. Research staff and intervention facilitators were successfully appointed in the field, screened participants and delivered the intervention to 120 caregivers, collecting outcome measures pre-and post-delivery. All families completed the outcome measures, with very little missing data. This indicated that the intervention can be delivered feasibly and evaluated with families in this humanitarian context. Preliminary outcome data showed promise that the intervention may have the potential to both improve family functioning and reduce children's problem behaviour. Implications of family-focused initiatives, particularly within a conflict/post-conflict context for the prevention of several negative health and social outcomes directions, are discussed.  相似文献   
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