移植免疫中微嵌合现象给我们的思考

随着移植免疫学研究的不断深入发展,诱导免疫耐受克服移植排斥反应已成为器官移植的主要研究目标。Starzl提出“双向移植排斥理论”并阐述临床使用免疫抑制药物下移植排斥反应的特点,突破了原有单向移植排斥理论的框架。“双向移植排斥理论”及理论内存在的问题给予我们众多有益的思考,在移植免疫学研究中,只有坚持用系统原则动态的看待事物间的联系与矛盾,进行科学实践,才能获得正确的理论,从而进一步推动移植免疫学的发展。     

Short-term visual memory for contour curvature in a delayed discrimination task

Abstract: A two-interval forced-choice of constant stimuli was used to measure the point of subjective equality (PSE) and discrimination threshold for standard contour curvature (1.91, 3.24 deg⁻¹) held in short-term visual memory (STVM). At both standard curvatures, the PSE for remembered curvature was nearly constant for standard curvature from 2 s to 16 s retention intervals, while the discrimination threshold increased as a linear function of retention interval. These results show that the decay in STVM for contour curvature is due to the noisy representation of curvature, neither to fading of the represented curvature nor to converging to the constant curvature. Furthermore, the Weber fraction was nearly constant for both standard curvatures at any delay from 2 to 16 s.     

Revising Process Metaphysics in Response to Ian Barbour's Critique

In Religion in an Age of Science , Ian Barbour concludes that the contemporary evolutionary worldview with its emphasis on the interplay of law and chance, relationality and autonomy, can be properly accounted for only by something like the process-relational metaphysics of Alfred North Whitehead. At the same time, he expresses serious reservations about certain features of Whitehead's scheme, notably, his perceived inability to account for the ongoing identity of the human self and for the fact of multilevel organization within organisms and in the world of inanimate compounds. In this article, I suggest that both of these difficulties can be resolved if one adopts a revisionist understanding of the Whiteheadian category of society according to which democratically organized societies possess an ontological unity and exercise a corporate agency proper to their own level of existence and activity. Furthermore, if one applies this revisionist understanding of societies to the Whiteheadian doctrine of God, a Trinitarian understanding of God becomes possible within the overall parameters of process-relational metaphysics. In this way, traditional belief in the doctrine of the Trinity can be reconciled with a scientifically credible worldview.     

Visual analysis of data in a multielement design

Ninety Board Certified Behavior Analysts (BCBAs) and 19 editorial board members evaluated hypothetical data presented in a multielement design. We manipulated the variability, trend, and mean shift of the data and asked the participants to determine if the data demonstrated experimental control. The results showed that variability, trend, and mean shift interacted to affect the participants’ ratings of experimental control. The level of agreement between participants was variable, but was generally lower than in previous research.     

The modality effect of ego depletion: Auditory task modality reduces ego depletion

An initial act of self‐control that impairs subsequent acts of self‐control is called ego depletion. The ego depletion phenomenon has been observed consistently. The modality effect refers to the effect of the presentation modality on the processing of stimuli. The modality effect was also robustly found in a large body of research. However, no study to date has examined the modality effects of ego depletion. This issue was addressed in the current study. In Experiment 1, after all participants completed a handgrip task, one group's participants completed a visual attention regulation task and the other group's participants completed an auditory attention regulation task, and then all participants again completed a handgrip task. The ego depletion phenomenon was observed in both the visual and the auditory attention regulation task. Moreover, participants who completed the visual task performed worse on the handgrip task than participants who completed the auditory task, which indicated that there was high ego depletion in the visual task condition. In Experiment 2, participants completed an initial task that either did or did not deplete self‐control resources, and then they completed a second visual or auditory attention control task. The results indicated that depleted participants performed better on the auditory attention control task than the visual attention control task. These findings suggest that altering task modality may reduce ego depletion.     

Simple actions influence pop-out search

Recent research has revealed that a simple action (pressing a computer key) produced in response to a visual object prioritizes features of that object in subsequent visual search. The effects of simple action, however, have only been studied with search displays that required serial search. Here we explored whether simple actions have an effect when the target in visual search is always a salient singleton. Participants viewed a coloured shape at the beginning of each trial, and sometimes they acted (pressed the space bar) in response to it. In the subsequent search task, after acting (but not after viewing), the previously-seen colour affected search performance even though the target was always a salient singleton and the colour was uninformative. The results reveal that prior action can interact with bottom-up salience during search. Implications for our understanding of both visual search and repetition priming are discussed.     

Modelling individual difference in visual categorization

Recent years has seen growing interest in understanding, characterizing, and explaining individual differences in visual cognition. We focus here on individual differences in visual categorization. Categorization is the fundamental visual ability to group different objects together as the same kind of thing. Research on visual categorization and category learning has been significantly informed by computational modelling, so our review will focus both on how formal models of visual categorization have captured individual differences and how individual difference have informed the development of formal models. We first examine the potential sources of individual differences in leading models of visual categorization, providing a brief review of a range of different models. We then describe several examples of how computational models have captured individual differences in visual categorization. This review also provides a bit of an historical perspective, starting with models that predicted no individual differences, to those that captured group differences, to those that predict true individual differences, and to more recent hierarchical approaches that can simultaneously capture both group and individual differences in visual categorization. Via this selective review, we see how considerations of individual differences can lead to important theoretical insights into how people visually categorize objects in the world around them. We also consider new directions for work examining individual differences in visual categorization.     

Mothers' Attention‐getting Utterances During Shared Book Reading: Links to Low‐income Preschoolers' Verbal Engagement,Visual Attention,and Early Literacy

This study examined associations among low‐income mothers' use of attention‐getting utterances during shared book reading, preschoolers' verbal engagement and visual attention to reading, and their early literacy skills (N = 51). Mother–child shared book reading sessions were videotaped and coded for each utterance, including attention talk, contextualized talk, de‐contextualized talk, and print talk. Preschoolers' attention during book reading was assessed using two measures: verbal engagement by using a rating scale of preschoolers' involvement in book reading discussion and visual attention by coding visual gaze. Findings indicated that mothers' attention talk was positively associated with children's verbal engagement, while maternal print talk was associated with children's visual attention. Further, low‐level maternal print talk was associated with higher early decoding scores of children when it was accompanied with high‐level maternal attention talk. Copyright © 2015 John Wiley & Sons, Ltd.     

汉语双字词在心理词典中的表征方式:来自fNIRS的证据

以汉语双字构成的真词与假词为实验材料,22名大学生为被试,采用功能性近红外脑成像技术(f NIRS)和事件相关设计,考察被试在完成词汇判断任务时的大脑激活模式,探索汉语双字词在心理词典中的表征方式。结果发现:(1)在完成真假词判断任务时,被试大脑左侧额叶和左侧颞叶均被激活;(2)与判断假词相比,被试在判断真词时显著地激活左额上回和左额中回。这一结果说明汉语双字词在心理词典中是混合表征的。