急性脑梗塞患者CD_18、CD_54与CD_62p、CD_63表达变化的临床研究

为探讨粘附分子CD18、CD54和血小板CD62、CD63表达变化与急性脑梗塞（ACI）发病之间的关系,本文应用流式细胞仪（FCM）检测了52例ACI患者治疗前后CD18、CD54与CD62p、CD63两者的表达水平,并与30例正常人作对照。结果显示,脑梗塞组治疗前两者的表达水平均明显上调,与正常对照组比较均有显著差异...     

Two hands are better than one: a new assessment method and a new interpretation of the non-visual illusion of self-touch

A simple experimental paradigm creates the powerful illusion that one is touching one’s own hand even when the two hands are separated by 15 cm. The participant uses her right hand to administer stimulation to a prosthetic hand while the Examiner provides identical stimulation to the participant’s receptive left hand. Change in felt position of the receptive hand toward the prosthetic hand has previously led to the interpretation that the participant experiences self-touch at the location of the prosthetic hand, and experiences a sense of ownership of the prosthetic hand. Our results argue against this interpretation. We assessed change in felt position of the participant’s receptive hand but we also assessed change in felt position of the participant’s administering hand. Change in felt position of the administering hand was significantly greater than change in felt position of the receptive hand. Implications for theories of ownership are discussed.     

Do people treat missing information adaptively when making inferences?

When making inferences, people are often confronted with situations with incomplete information. Previous research has led to a mixed picture about how people react to missing information. Options include ignoring missing information, treating it as either positive or negative, using the average of past observations for replacement, or using the most frequent observation of the available information as a placeholder. The accuracy of these inference mechanisms depends on characteristics of the environment. When missing information is uniformly distributed, it is most accurate to treat it as the average, whereas when it is negatively correlated with the criterion to be judged, treating missing information as if it were negative is most accurate. Whether people treat missing information adaptively according to the environment was tested in two studies. The results show that participants were sensitive to how missing information was distributed in an environment and most frequently selected the mechanism that was most adaptive. From these results the authors conclude that reacting to missing information in different ways is an adaptive response to environmental characteristics.     

Rethinking volitional control over task choice in multitask environments: Use of a stimulus set selection strategy in voluntary task switching

Under conditions of volitional control in multitask environments, subjects may engage in a variety of strategies to guide task selection. The current research examines whether subjects may sometimes use a top-down control strategy of selecting a task-irrelevant stimulus dimension, such as location, to guide task selection. We term this approach a stimulus set selection strategy. Using a voluntary task switching procedure, subjects voluntarily switched between categorizing letter and number stimuli that appeared in two, four, or eight possible target locations. Effects of stimulus availability, manipulated by varying the stimulus onset asynchrony between the two target stimuli, and location repetition were analysed to assess the use of a stimulus set selection strategy. Considered across position condition, Experiment 1 showed effects of both stimulus availability and location repetition on task choice suggesting that only in the 2-position condition, where selection based on location always results in a target at the selected location, subjects may have been using a stimulus set selection strategy on some trials. Experiment 2 replicated and extended these findings in a visually more cluttered environment. These results indicate that, contrary to current models of task selection in voluntary task switching, the top-down control of task selection may occur in the absence of the formation of an intention to perform a particular task.     

Risk aversion in information seeking

The information gain model argues that participants select alternatives with a larger expected value of information gain. The present study investigated risk aversion in information seeking to examine whether the expected value always determines information-seeking behaviour. For this investigation, we used a scale method selection task in which participants were required to select one of two scales for weighing coins in order to find an underweight coin. Two experiments showed that participants more frequently selected the alternative that provided information gain without risk, although its expected information gain was smaller. This finding indicates the presence of risk aversion in information seeking, suggesting that information-seeking behaviour is affected by risk associated with obtaining information gain.     

Potential Effects of Faking on the NEO-PI-R: Willingness and Ability to Fake Changes Who Gets Hired in Simulated Selection Decisions

The impact of response distortion (faking) on selection decisions was investigated. Participants (N = 224) completed the NEO-PI-R under instructions to “make the most favorable impression” and/or “answer honestly.” Those instructed to fake were often over-represented at the top of the score distributions as instructions to fake resulted in higher scores both between and within groups in a test–retest situation. There was significantly lower correspondence between participants’ honest scores and their faked scores as well as multiple instances where participants with unfavorable honest scores subsequently produced the most favorable scores when faking. Response distortion may remain a serious threat to the use of personality test scores in selection.

The enhanced Simon effect for older adults is reduced when the irrelevant location information is conveyed by an accessory stimulus

The Simon effect, better performance when irrelevant stimulus location corresponds with the response location than when it does not, typically is larger for older than younger adults. However, Simon and Pouraghabagher [Simon, R. J., & Pouraghabagher, A. R. (1978). The effect of aging on the stages of processing in a choice reaction time task. Journal of Gerontology, 33, 553-561] found no age difference using an accessory-stimulus Simon task in which the relevant dimension was the color of a visual stimulus and the irrelevant dimension the location of a tone. Experiment 1 confirmed that older adults show a larger Simon effect than younger adults for the visual Simon task and that this age-related deficit is reduced or eliminated for the auditory-accessory task. Experiment 2 provided evidence suggesting that a small part of the age-related deficit in the visual Simon task is due to having to code the location of the relevant stimulus, but Experiment 3 showed that the majority of the deficit is due to the relevant and irrelevant information being conveyed by the same stimulus. Reaction-time distribution analyses show similar functions for younger and older adults, suggesting that the time course of activation is similar for both age groups.     

达尔文医学的哲学启示

达尔文医学从本源上阐明队类疾病产生的偶然性与必然性的对立统一。其对进化论的重新反思和认识,具有重要的人文价值和现实意义。