Predictive testing and oncogenes

Case vignette: sharing unanticipated genetic information. The Questor family has experienced an unusual number of malignancies in the past two generations and has been advised by an oncologist that the p53 oncogene known as Li-Fraumeni Syndrome may be present in the family genome. The option of predictive genetic testing has been raised and several branches of the family have chosen to undergo screening to determine whether they are at risk for cancer because of the gene. Roger and Liz Questor have arranged for screening of themselves and their three children, ages 12, 10, and 7. The couple has, by all appearances, been happily married for 14 years. None of the family members are found to carry the oncogene; however, the geneticist conducting the analyses has made an interesting incidental discovery. The 10-year-old child is not the biological progeny of Roger Questor. Although the 12- and 7-year-olds are clearly the biological children of the couple, it is evident that the 10-year-old born to Liz Questor was fathered by a person other than Roger. What are the ethical obligations of the geneticist with respect to any sharing or disclosure of the information that has been discovered incidentally? What course of action, if any, do you recommend?     

与年龄相关的认知速度减慢及学习改善过程

该工作应用人机对话方式完成心算、符号数字、数字鉴别和计数四项作业认知速度年老减慢及学习改善过程的研究,被试３５０人,４６—７５岁。研究结果表明：四项认知作业速度随年老进行性减慢;然而,老年人经学习训练认知作业速度可明显改善。上述变化程度与作业所需时间有密切关系,提示年老过程中枢信息加工过程速度的减慢快于外周感觉─运动过程速度的减慢,学习改善作用也可能主要是中枢过程速度的提高。     

Adaptation effects and reversible figures: A comment on Horlitz and O’Leary

In a recent article, Horlitz and O’Leary (1993) offer a reinterpretation of the results of several studies over the past 40 years that have employed the prolonged-inspection technique in the investigation of reversible figures. Specifically, they contend that, contrary to the favored interpretation of neural adaptation effects, the results of these studies reveal the combined influence of such topdown processes as attention and perceptual learning as well as such methodological difficulties as unwanted demand characteristics. In this note, we examine their analysis of the literature, their alternative theoretical model, and the supporting conclusions they draw from their two experiments. We argue that there is considerable evidence from a variety of studies for the joint role of bottom-up and top-down processes in reversible figures. Moreover, we propose that Horlitz and O’Leary’s own research, rather than eliminating the possibility of neural-adaptation effects, is best conceptualized as providing additional evidence for the role of higher-order processes in these phenomena.     

AUGMENTING SIMPLIFIED HABIT REVERSAL WITH AN AWARENESS ENHANCEMENT DEVICE: PRELIMINARY FINDINGS

The chronic hair pulling of a 36-year-old woman with moderate mental retardation was initially treated with a simplified habit-reversal (SHR) procedure that consisted of awareness training, competing response training, and social support. When SHR did not produce large and sustained reductions in hair pulling, an awareness enhancement device was added, and it reduced hair pulling to near-zero levels in two settings. The results are discussed, and directions for future research with this device are provided.     

The temporal structure of spoken sentence comprehension in Chinese

Three experiments with 60 native Chinese speakers were conducted to examine the temporal structure of spoken sentence comprehension in Chinese. In the two sentence-gating experiments, listeners heard sentence fragments of various sizes, either successively or individually, and decided on the agent role of the sentence. In the agent-naming experiment, listeners repeated aloud the sentence agent upon hearing the sentence. Converging evidence was derived from these experiments indicating the usefulness of sentence gating in tapping into the temporal structure of comprehension and in evaluating listeners’ comprehension on the basis of partial information. Results from these experiments show that partial sentence information plays a very important role in Chinese sentence comprehension, and that Chinese listeners integrate incomplete and ungrammatical sentence fragments by reference to complete and grammatical models in the language. It is argued that these processing characteristics reflect properties of the Chinese language in which few morphological, grammatical, and syntactic constraints are placed on the relationships between sentence constituents.     

The contribution of visual persistence to the perceived duration of brief targets

Two experiments were conducted to examine the role of sensory persistence on tasks of perceived duration employing very brief visual stimuli. Using a standard temporal judgment task, the first experiment replicated both the “size effect” and “empty-filled” illusion reported by previous investigators. However, entirely comparable results were also found with a probematching task, which theoretically assesses the degree of persistence exhibited by a stimulus. The second experiment examined the effect of target luminance on perceived duration. Consistent with a sensory persistence interpretation, judgments of duration increased with increasing luminance. The results from the two experiments were discussed in terms of varying degrees of retinal persistence produced by different stimuli. This view was contrasted with currently dominant interpretations that postulate changes in perceived duration to reflect different information-processing requirements across stimulus conditions.     

The effects of spatial frequency and target type on perceived duration

Two experiments are reported that attempt to demonstrate a critical role played by sensory persistence on a standard perceived-duration task employing brief visual stimuli. Experiment 1 examined the effect on perceived duration of varying the spatial frequency of a target. For both 40- and 70-msec flashes, increased spatial frequency resulted in reduced estimates of perceived duration. These results were contrasted with predictions derived from cognitive processing models of duration perception. In Experiment 2, three typical types of target employed in current research (an outlined circle, a “noise”-filled circle, and a completely filled circle) were shown to differ significantly in their perceived duration and in their sensitivity to increases in physical duration. The results were discussed in terms of variable degrees of retinal persistence produced by the three types of targets. The possible implications for specific discrepancies in the literature and across-study comparisons in general were enumerated.     

快速眼动相(REM)睡眠剥夺对大鼠记忆巩固的影响

本实验应用小站台水环境技术剥夺大鼠快速眼动相(REM)睡眠,比较了在学习后不同时间剥夺REM睡眠对记忆巩固的影响异同,结果证明:大鼠在学习后,立即剥夺REM睡眠24小时对记忆巩固明显不利;如在立即剥夺REM睡眠24小时后再让其恢复自由睡眠24小时,记忆成绩无明显改善;学习后允许自由睡眠24小时对记忆巩固明显有利;如在自由睡眠24小时后再行REM睡眠剥夺24小时,记忆成绩仍保持良好。说明学习后一段时间自由睡眠对于记忆的巩固是重要的,剥夺REM睡眠对于记忆的巩固明显不利。     

5—13岁儿童空间认知发展的研究——判别相等面积的再探

本实验是《5—11岁儿童两种空间关系认知发展的实验研究》的继续,但将内部被占面积改为圆形。结果表明:儿童判别面积从直觉判断发展到推理判断之间经历一种过渡形态。表现为,在同一判别中直觉和推理活动交错;能将被占面积各部分整合成整体,但对剩余面积部分的判别受直觉因素束缚;理解等量减等量所余相等原理,但不能用来解决面临的课题等四种形式。完成这种过渡需要解决三个相互联系的问题。也再次证明儿童判别面积这种空间认知发展,在一定年龄范围存在着阶段性特点,同时儿童这种认知能力的显露程度又以课题条件难易为转移。     

Aerobic conditioning and stress reduction: Participation or conditioning?

The efficiency of an aerobic conditioning program (jogging) is compared to cognitive therapy (stress inoculation) and a waiting list control in modifying self-reported chronic stress. The participants were community residents; 48 were females and 25 were males. Treatment sessions were conducted over a 10-week period with subjects meeting in small groups for 1$\text{1}\text{2}$ hours per week. The State/Trait Inventories, a Tension Thermometer and a submaximal bicycle ergometer test were administered pre, post and follow-up. Repeated measures, multivariate analysis of variance indicated that both treatments were effective in reducing stress compared to the waiting list control and that these changes were maintained at 3-month follow-up. Multivariate analysis indicated that participants with higher initial levels of aerobic fitness did not report less stress, while participants who obtained higher levels of fitness during the conditioning program fared no better in reducing stress than their counterparts who obtained lower levels of aerobic fitness. These findings are of interest because they suggest that the psychosocial components of the fitness program were active ingredients of treatment rathee than the effects of improved cardiovascular functioning.