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11.
Animal-based theories of Pavlovian conditioning propose that patterning discriminations are solved using unique cues or immediate configuring. Recent studies with humans, however, provided evidence that in positive and negative patterning two different rules are utilized. The present experiment was designed to provide further support for this proposal by tracking the time course of the allocation of cognitive resources. One group was trained in a positive patterning schedule (A−, B−, AB+) and a second in a negative patterning schedule (A+, B+, AB−). Electrodermal responses and secondary task probe reaction time were measured. In negative patterning, reaction times were slower during reinforced stimuli than during nonreinforced stimuli at both probe positions while there were no differences in positive patterning. These results support the assumption that negative patterning is solved using a rule that is more complex and requires more resources than does the rule employed to solve positive patterning.  相似文献   
12.
Marx and Russia     
I present the scope andcharacteristics of Marx's interest in Russiaand review its evolution. Initially, Marx'sattitudes were marked by russophobia,pronounced anti-panslavism, assessments ofRussia as an outpost of European reaction andcounterrevolution, and even as the head of aconspiracy to block the world revolution. Withtime, however, Marx came to consider Russia asthe country in which the outbreak of theRevolution was most likely. In his research forsucessive volumes of Capital, he readRussian theoretical works by, among others, V.Bervi-Flerovskij and A. Koshelev. Marx'sattitudes to the anticipated peasant revolutionin Russia remained ambivalent; to a certaindegree he feared its occurrence suspecting thatit could take on an `asiatic' hue.  相似文献   
13.
自控摄入小剂量酒精影响熟练驾驶行为的实验研究   总被引:1,自引:1,他引:0  
一个小样本受试者内设计实验,受试者在实验允许的酒精剂量范围内自由选择摄入量。实验安排饮酒前,酒后30分钟、110分钟和170分钟四个测试阶段,分别检验受试者在模拟驾驶和实际驾驶两项任务中的认知行为。酒后30分钟实际驾驶的技能与其他三个测试期相比存在有意义的差别显著性;模拟测试任务中酒后对红、黄两种信号灯的认知反应时之间呈现显著性差别,酒后110分钟对黄色信号灯的反应明显延迟。研究提示:受试对酒精感受性的估计是不可靠的,小剂量酒精也能对驾驶行为构成伤害。  相似文献   
14.
This study assessed the performance of the PC-PTSD in diagnosing postdeployment posttraumatic stress disorder (PTSD) in a cohort of Air Force Medical Services personnel (N = 18,530). The prevalence of PTSD in the cohort was 5.18% based on medical record data. The area under the receiver operating characteristic curve was 0.69, indicating poor classification accuracy. Sensitivity was 47.55%, specificity was 90.68%, positive predictive value was 21.79%, and negative predictive value was 96.94%. The positive and negative likelihood ratios were 5.10 and 0.58, respectively. Several risk factors were found to be associated with a diagnosis of postdeployment PTSD: being a nurse, being enlisted in the medical service career field, being enlisted in the mental health service career field, those over age 30, being a member of the Active Duty service component, and having one’s first deployment be to Iraq. Being an officer was found to be a protective characteristic. These factors could potentially improve screening for PTSD among Air Force healthcare personnel.  相似文献   
15.
词语后情绪环境对其中的事件记忆产生影响,但是事件后情绪环境如何影响记忆加工仍不清楚。不同的情绪环境理论—“唤醒偏向竞争理论”,“拓宽-建构理论”,“记忆中心的积极情绪促进理论”支持情绪促进的不同本质。已有的研究表明,注意在情绪记忆中有重要作用。实验一、实验二分别探讨词语后情绪环境对其语义加工与内源源加工和外源源加工的影响。与中性环境相比,积极与消极情绪环境阻碍了外源源特征的加工; 与中性环境和积极情绪环境相比,消极情绪环境阻碍了内源源特征的加工。实验结果支持“唤醒偏向竞争理论”,同时表明“评估”和“注意放置”在情绪环境影响中的重要作用。  相似文献   
16.

Objective

To describe an immobility reaction (IR) that was not previously reported at or immediately after birth in human newborns.

Method

We analyzed 31 videos of normal term vaginal deliveries recorded from Time 0 of birth defined as the as the moment that lies between the birth of the thorax and the pelvis of the infant. We searched for perinatal factors associated with newborn's IR.

Results

IR at birth was observed in 8 of the 31 newborns. The main features of their behavior were immobilization, frozen face, shallow breathing and bradycardia. One of the 8 newborns had sudden collapse 2 h after birth. We found significant relationships between maternal prenatal stress (PS) and IR (p = .037), and a close to significant one between infants’ lividness at Time 0 and IR (p = .053). The first breath of the 31 newborns occurred before and was not associated with the first cry (p < .001).

Discussion

The main features of IR at birth are similar to those of the universal most severe response to severe stress or danger. The relationship with PS suggests that children who had IR at birth might be at risk for similar disorders as those associated with PS. Sudden neonatal collapse of one of the IR newborns needs further research to determine if they are at risk for sudden infant death syndrome.

Conclusion

This first report of an IR reaction at birth in human infants could open up new paths for improving early neonatal care. Further research is needed for maternal PS, stress hormones, umbilical cord blood pH measurements in IR newborns. The challenge of education and support for parents of IR newborns is outlined.  相似文献   
17.

Background

Independent oral feeding requires coordination of suck, swallow and breathe and the lingual musculature plays a significant role in this coordinative action. However, clinical benchmarks of lingual function fundamental to successful feeding have not been explored.

Aims

The present study tests our model for quantifying infant lingual force and size and compares the muscle measures of interest in two cohorts: healthy full-term infants (FT) (N = 5) and healthy preterm infants (PT) (N = 6).

Method

Using an instrumented pacifier and bottle nipple, we determined the resultant compressive forces applied to the nipple by the tongue during nutritive (NS) and nonnutritive sucking (NNS). Muscle size was estimated from measures of posterior tongue thickness using ultrasonography.

Results

After controlling for weight and post menstrual age, statistically significant differences were found between FT and PT infants beginning to feed for NNS frequency and NS tongue force. Clinically significant differences were detected for NNS tongue force and posterior tongue thickness. Additionally, PT infants demonstrated a significant difference in mean tongue force between NS and NNS and FT infants did not. FT infants demonstrated a significant difference in mean frequency between NS and NNS and PT infants did not. Linear regression indicated that mean posterior tongue thickness alone predicted 55% of the variance in NS force.

Conclusions

Results demonstrate the feasibility of our approach and suggest that infant tongue muscle characteristics necessary for successful feeding differ between healthy full term infants and preterm infants who are beginning oral feeding.  相似文献   
18.
研究胰岛素样生长因子结合蛋白2(IGFBP-2)及胰岛素样生长因子结合蛋白6(IGFBP-6)在结直肠癌中的表达及临床意义。采用免疫组织化学法及RT-PCR方法检测结直肠癌、结直肠腺瘤及癌旁正常黏膜组织中IGFBP-2及IGFBP-6的蛋白及mRNA的表达情况,结合临床病理资料进行统计学分析。IGFBP-2及IGFBP-6蛋白的阳性表达及mRNA的表达量在三组组织中均存在异常表达情况,且差异有明显的统计学意义(P〈0.05),在结直肠癌组IGFBP-2、IGFBP-6的阳性表达在肿瘤浸润深度、有无淋巴结转移及Duke's分期存在差异,有明显的统计学差异(P〈0.05)。临床可以把二者作为结直肠癌诊断及预后的早期预测指标。  相似文献   
19.
The role of stimulus presence on spontaneous communication was assessed with 3 participants in a nonconcurrent multiple baseline with embedded reversals design. Participants were taught to request 2 highly preferred items. Once mastery criterion was met, test sessions were conducted with stimuli either visible or absent from the room, and request rate was measured. For 2 participants, training produced requests in both the presence and absence of the stimulus. For one participant, however, the presence of the stimulus was necessary to evoke the response. Results suggest that teaching individuals to request items when they are present may not consistently lead to requests when those items are absent.  相似文献   
20.
While asymmetries have been observed between the dominant and non-dominant legs, it is unclear whether they have different abilities in isometric force control (IFC). The purpose of this study was to compare ankle IFC between the legs. IFC is important for stabilization rather than object manipulation, and people typically use their non-dominant leg for stabilization tasks. Additionally, studies suggested that a limb can better acquire a motor task when the control mechanism of the task is related to what the limb is specialized for. We hypothesized that the non-dominant leg would better (1) control ankle IFC with speed and accuracy, and (2) acquire an ankle IFC skill through direct learning and transfer of learning. Two participant groups practiced an IFC task using either their dominant or non-dominant ankle. In a virtual environment, subjects moved a cursor to hit 24 targets in a maze by adjusting the direction and magnitude of ankle isometric force with speed (measured by the time required to hit all targets or movement time) and accuracy (number of collisions to a maze wall). Both groups demonstrated similar movement time and accuracy between the dominant and non-dominant limbs before practicing the task. After practice, both groups showed improvement in both variables on both the practiced and non-practiced sides (p < .01), but no between-group difference was detected in the degree of improvement on each side. The ability to control and acquire the IFC skill was similar between the legs, which did not support the brain is lateralized for ankle IFC.  相似文献   
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