Increases in rewards promote flexible behavior

Offering reward for performance can motivate people to perform a task better, but better preparation for one task usually means decreased flexibility to perform different tasks. In six experiments in which reward varied between low and high levels, we found that reward can encourage people to prepare more flexibly for different tasks, but only as it increased from the level on the previous trial. When the same high rewards were offered continuously trial after trial, people were more inclined to simply stick with doing what had worked previously. We demonstrated such enhancements in flexibility in task switching, a difficult visual search task, and an easier priming of pop-out search task, which shows that this effect generalizes from executive tasks to perceptual processes that require relatively little executive control. These findings suggest that relative, transient changes in reward can exert more potent effects on behavioral flexibility than can the absolute amount of reward, whether it consists of money or points in a social competition.     

Hippocampal CA1 kindling but not long-term potentiation disrupts spatial memory performance

Long-term synaptic enhancement in the hippocampus has been suggested to cause deficits in spatial performance. Synaptic enhancement has been reported after hippocampal kindling that induced repeated electrographic seizures or afterdischarges (ADs) and after long-term potentiation (LTP) defined as synaptic enhancement without ADs. We studied whether repeated stimulations that gave LTP or ADs resulted in spatial performance deficits on the radial arm maze (RAM) and investigated the minimal number of ADs required for such deficits. Three experimental groups were run as follows: (1) 5 hippocampal ADs in 1 d (5-AD group), (2) 10 hippocampal ADs in 2 d (10-AD group), and (3) 12 -frequency primed-burst stimulations (PBSs) in 2 d in order to induce LTP without ADs (LTP group). Each experimental group was run together with a control group during the same time period. Rats were first trained in a spatial task on a radial arm maze with four of the eight arms baited, then given control or experimental treatment, and maze performance was tested in the first week (1-4 d) and fourth week (22-25 d) after treatment. Basal dendritic population excitatory postsynaptic potentials (pEPSPs) and medial perforant path (MPP)-evoked dentate gyrus population spike and polysynaptic CA1 excitation were recorded before and after experimental and control treatment. Spatial memory errors, in particular reference memory errors, were significantly higher in the 10-AD kindled group than any other group on the first and fourth week after treatment. Spatial memory errors were not significantly different in the 5-AD and LTP groups as compared with any control groups at any time. Basal dendritic pEPSP in CA1 was enhanced for about 1 wk after 12 PBSs, 10 ADs, or 5 ADs, while the dentate gyrus population spike and CA1 polysynaptic excitation evoked by MPP was increased for up to 4 wk after 10 ADs, but not 12 PBSs. Thus, distributed alteration of multiple synaptic transmission in the entorhinal-hippocampal circuit, but not LTP at the basal dendritic synapses in CA1, may disrupt spatial performance after 10 hippocampal ADs.     

Black, Hispanic, and White American mothers of adolescents: construction of a national standard

Black, Hispanic, and White American mothers (n = 739) and adolescents (n = 806) completed the Parent Success Indicator to rate maternal performance on subscales of Communication, Use of Time, Teaching, Frustration, Satisfaction, and Information Needs. A weighted method corresponding to ethnic proportions in the American population was applied to construct a national standard for comparative reference. In general, both generations perceived mother performance as favorable. Teaching received the highest rating followed by Satisfaction levels. Mothers felt that Information Needs were their greatest limitation while adolescents reported that their mothers were prone to frustration. The amount of time mothers and adolescents spent together was the most significant independent variable influencing parent performance. Other variables such as income and marital status had limited impact.     

Stimulated release of tissue plasminogen activator from artery wall sympathetic nerves: implications for stress-associated wall damage

Recurrent stress is clinically associated with early onset hypertension and coronary artery disease. A mechanism linking emotion to pathogenic remodeling of the artery wall has not been identified. Stress stimulates acute regulated release of tissue plasminogen activator (t-PA) into the circulation, which is presently attributed to the vascular endothelium. Sympathetic neurons also synthesize t-PA and axonally transport it to the arterial smooth muscle. Unlike release by the endothelium, a stress-stimulated sympathetic discharge would potentially accelerate degradation of the wall matrix by plasmin. To assess whether sympathetic axons are the principal source of acute stress-induced arterial release of t-PA, we compared the output from small densely innervated and large sparsely innervated isolated artery segments before and after sympathetic stimulation, and after ablations. Following phenylephrine infusion densely-innervated microvessels in uveal eyecups were released over 60-fold greater amounts of active t-PA per milligram than the sparsely innervated aorta; and ten-fold more than carotid artery segments. Mesenteric artery release was 4.8-fold greater than release by the carotid artery. In vivo, uveal release of t-PA increased more than three-fold within one minute following superior cervical sympathetic ganglion electrical stimulation, and after phenylephrine, or nicotine infusions of the anterior chamber. Circulating levels of t-PA fell 70% following chemical sympathectomy. We propose that sympathetic nerves are the primary source of stress-induced release of t-PA into and from the densely innervated resistance arteries and arterioles, where dysregulated plasmin-induced proteolysis could damage the wall matrix.     

Antipsychotic medication adherence, cocaine use, and recidivism among a parolee sample

This study examined the independent and interactive associations between cocaine use and antipsychotic medication adherence in predicting 12 month criminal recidivism among a sample of mentally ill parolees (N = 200). Consistent with prior research, cocaine use (based on hair assays) was associated with more than a threefold increase (relative to non-cocaine users) in the likelihood of a parolee being returned to custody during the follow-up period. Although medication adherence (based on urine specimens) was not independently associated with a significant reduction in recidivism risk, the interaction between cocaine use and medication adherence was significant, revealing a disproportionate impact of medication adherence specific to cocaine users. Prediction models of recidivism based on self-reported measures of medication adherence and cocaine use revealed only marginally significant trends for cocaine use, no effect for adherence, and no significant interaction between these two predictors.     

动觉监督早期介入对动作技能形成的影响

通过人工动作技能项目和典型职业操作技能项目的训练活动,研究了动觉监督早期介入对动作技能形成的影响,结果表明早期进行动觉监督训练可以更为充分、有效地发挥动觉监督的作用,提高动作技能形成的成绩和效率。据此讨论了“视觉为主转化为动觉为主”监督机制观点的局限性,认为自觉的职业操作技能训练活动无须遵循这一结论;提出了含有动觉训练的职业操作技能训练模式。     

内省的心理学新探─—自我观察与心理调适

本文对内省作为一种心理学的基本方法作了历史回顾。作者还把内省看作人的某种个性倾向或心理特征尝试进行实证研究。调查结果表明,内省在被试看来,是自我概念形成与发展所必不可少的。结果还使作者确信,对内省联系个体心理与行为的调适作实证研究,不仅可行,而且有益。     

合体汉字字形识别过程探索

该研究用微观发生范式探索了合体汉字和假字的字形识别过程 ,结果发现 :(1 )部件字、真字和假字的正确提取率随呈现时间增长而提高 ,字形刺激的特征加工是一个有序的发展过程 ,对字形的识别加工过程受字形熟悉性和字形结构方式的影响 ;(2 )在左右型字刺激和上下型字刺激中 ,经常首先从右部件或下部件中提取笔画或笔画组合 (称首特征 ) ,而且首特征的提取不受字形熟悉性影响。根据以上结果可以推测 ,字形结构属性在字形识别加工的最初阶段先于特征获加工 ,字形熟悉性则对首特征提取后的特征或部件加工过程产生影响。     

学业不良学生类型与特点的聚类分析

该研究运用Ｑ聚类分析对上海市区１４８０名初中预备班学生的能力和个性特征进行分类研究。结果发现１４８０名被试中存有心理发展水平不同的六个主要类别,这些类别与学生学业成绩的优劣关系密切。同时,３５３名差生可分为四个主要类型：即,暂时性困难学生、能力型困难学生、动力型困难学生和整体性困难学生,不同类型的差生具有不同的特点。这为针对不同类型学生的特点制定有效的教育措施提供了依据。     

铁路灯光信号显示的一些研究

铁路色灯信号不论在白天或夜间都指挥着列车的运行,其显示好坏直接关系到列车的安全和效率。影响色灯信号显示的因素很多,如光源参数,光系统结构,灯光散角,天气好坏等。而色灯信号的颜色,观察距离(或视张角)以及亮对比度是人对信号识别的三个较重要因素,所以我们想从这三个方面来讨论信号灯光显示问题。