The effects of total sleep deprivation on recognition memory processes: A study of event-related potential

This study examined the memorization of information after a night of normal sleep and total sleep deprivation (TSD) by means of event-related potentials (ERPs). We expected a disfacilitatory effect of TSD on memory processing. Eighteen subjects were tested twice in a counterbalanced fashion. During the study session, subjects were presented with unfamiliar face stimuli and asked to memorize them for a subsequent memory test. At the test session, the subjects were presented with the studied faces intermixed with “new” faces and asked to indicate the previously presented stimuli. The N100 was used as a covariate to control for the differences in level of vigilance between the two sessions. Sleep deprivation decreased subjects’ ability to discriminate new from previously studied stimuli and decreased the peak amplitude of the early component (N200) to the decrement of performance. In addition, following TSD the amplitude of the late frontal component (LFC), which is thought to reflect contextual processing, was decreased in covariance with the N100 vigilance component. The amplitude of the late posterior component (LPC/P600) was also reduced but was unrelated to the vigilance component of the ERP. Based on prior studies, this LPC reduction can be interpreted to indicate a decrease in information retrieved after TSD. In summary, a night of TSD decreased the amplitude of the ERPs associated with complex episodic memory task stimuli, affected the frontal cortex during episodic retrieval, and prevented the elaboration process. Furthermore, there was an inability to discriminate what is and what is not in memory, possibly due to less local processing of details.     

眼睛运动如何与记忆相关？

很久以来,人们一直在致力于研究人的眼动与心理活动之间的关系,从而揭示其间的奥妙。众多研究表明,睡眠时的快速眼动（RapidEyeMovements,REM）及其周期对记忆的形成与巩固有重要作用。在清醒状态下,人的眼动就是为了获得视觉信息,如果涉及记忆任务,这就是编码阶段的具体行动。另外,问题解决过程也有眼动参与。总体看来,眼动和记忆之间是一种双向的关系,适当的眼动训练或许能够提高记忆成绩。     

亲子间科技干扰与青少年网络人际关系成瘾：有调节的中介模型

对1353名高中生进行问卷调查,探究亲子间科技干扰与青少年网络人际关系成瘾之间的关系,相对剥夺感的中介作用及内在觉知的调节作用,结果表明：（1）亲子间科技干扰正向预测青少年网络人际关系成瘾;（2）相对剥夺感是亲子间科技干扰与网络人际关系成瘾之间的中介变量;（3）亲子间科技干扰与网络人际关系成瘾的间接效应前半段受到内在觉知的调节。因此,亲子间科技干扰和网络人际关系成瘾之间存在有调节的中介效应。     

早期剥夺所致大鼠抑郁样行为与海马BDNF mRNA表达变化

为探讨早期剥夺对大鼠行为与海马脑源性神经营养因子(BDNF)mRNA表达的影响,将新生的SD大鼠随机分为正常对照组与早期剥夺组,早期剥夺组在出生后1～14d每天孤养4h。监测体重,在出生后36?64天进行液体消耗试验,每周一次。12w龄时,进行穿梭箱试验,酶联免疫法检测海马BDNF含量,原位杂交法观察海马BDNF mRNA的表达。早期剥夺组大鼠体重显著低于正常对照组(p0.01),糖水摄入量与糖水偏爱显著低于正常对照组(p0.05或p0.01)。穿梭箱试验中,早期剥夺组大鼠在训练时的穿梭反应次数显著少于正常对照组(p0.05),在测试时,两组大鼠的被动逃避行为、主动逃避行为与逃避错误次数无显著差异。早期剥夺组大鼠海马BDNF含量、CA1区和CA3区BDNF mRNA表达显著低于正常对照组(p=0.05或p0.05)。提示早期剥夺可导致大鼠生长减慢,表现出快感缺失的抑郁样行为,但未诱导成年大鼠表现出明显的习得性无助倾向,早期剥夺能下调成年大鼠海马BDNFmRNA的表达。     

Optimism and Revolt of the Oppressed: A Comparison of Two Polish Jewish Ghettos of World War II

One World War II Jewish ghetto that revolted, the Warsaw Ghetto, is compared to one that did not, the Lodz Ghetto, in order to examine the causes of violent resistance. This structured focused comparative method (George, 1979) illuminates problems with previous explanations for revolt and nonrevolt in Jewish ghettos and suggest psychological variables that might have led to or precluded organized violence. Specifically, it appears that these two ghettos differed in their perceptions about their future. The residents of the Warsaw Ghetto believed they had no hope of survival while residents of the Lodz Ghetto remained optimistic. These differing perceptions seem to have led to the different outcomes. Possible causes of these percetpions are also discussed.     

The Holte Sleeping Technique: An experimental study

The Holte Sleeping Technique is an alternative to medication to facilitate sleep onset in situations of normal stress. The technique is based on a combination of conditioning within the theory of learning, simulation of natural bodily processes, and manipulation of naturally available sleep-releasing stimuli. The author describes the technique and reports on experimental testing of its efficacy. Fifty-six female subjects were selected according to criteria based on questionnaires and sleep logs. The subjects were randomly assigned to a treatment group, a placebo group, and a no-treatment group. A pre-test-post-test design was used. The author questions the generalizability of findings from modern electronic sleep laboratories to the bedrooms of everyday life. In order to optimize the combination of normal stress, objective criteria and generalizability, sleep onset was measured by behavioural criteria based on the "fog-horn procedure" developed by the author. At post-test 67% of the treatment group fell asleep, while only 17% of the placebo group and 25% of the no-treatment group fell asleep. The differences were significant. It is concluded that the Holte Sleeping Technique is highly effective. In a discussion of placebo trials the author argues that traditional medical trials do not take into consideration the differentiating psychological attribution effects occurring by giving the same experimental instruction under different experimental conditions. As a consequence the active treatment is given better conditions than the placebo in traditional clinical trials.     

Lean and mean rats: Some effects of acute changes in the food supply upon territorial aggression

In experiment 1, individually housed rats subjected to short-term food restriction displayed more territorial aggression toward conspecific intruders than controls maintained on a free-feeding diet. In experiment 2, small groups of three adult male rats had access to either a standard laboratory diet or the standard diet plus sucrose. Groups with the sucrose supplement were significantly less aggressive toward intruders than controls. Sucrose availability did not produce appreciable gains in body weight but it did reliably decrease within-colony weight variation. The results suggest the existence of an effective dietary mechanism that enables a social species such as Rattus norvegicus to tolerate each other in dense feeding aggregations when food is abundant. Conversely, when food is limited, social intolerance increases and serves to limit the development of large feeding groups.     

Thinking about complex decisions: How sleep and time-of-day influence complex choices

In this study, we systematically manipulate a person’s state of sleep; Sleep-deprived and Well-rested along with Matching or Mismatching the decision time-of-day to their circadian preferred time-of-day. We assessed how these conditions influenced performance on an incentivized complex decision task. In the overall analysis of these variables no differences emerged. However, a comparison of the more cognitively depleting Sleep-deprivation/Circadian-mismatch condition to the cognitively enhancing Well-rested/Circadian-match condition showed improved performance in the Well-rested/Circadian matched group for one complex decision task but not for the other. These findings build upon the existing literature on sleep and circadian rhythm effects while uniquely observing the combined effects of these variables on complex decision making.