特征呈现方式对类别知觉表征的影响*

两个实验采用阻碍效应范式探讨了特征的呈现方式对类别知觉表征的影响。研究结果发现在阻碍效应范式中,改变特征的呈现方式引发了不同的类别知觉表征方式;当固定样例特征的呈现位置时,引发了基于样例整体相似性的表征;而随机样例特征的呈现位置时,引发了基于样例特征的解析表征。该结果支持了类别学习的多系统理论。     

注视方向的知觉对注视追随行为的影响

他人的注视线索可诱导观察者将注意自动地转移到该线索所指示的方向上去(注视追随), 但仍不清楚注视方向的知觉在注视追随中起到何种作用。本研究结合注视适应和注视线索提示范式发现：知觉到的注视线索角度越大, 其线索提示效应越强; 知觉适应后被试判断注视方向的准确性下降, 注视线索引起的注意转移量显著减少。可见, 对注视方向的知觉能直接影响注视追随行为, 而注视方向抽取受到刺激显著性(注视角度)和知觉适应等因素的调节。这提示：在意识状态下, 注视知觉与注视追随存在直接联系, 即可能存在从注视知觉系统到注意转移系统的皮层加工通路; 注视追随并非纯粹的反射式加工, 它受自上而下知觉经验的调节。     

图形型归纳推理的神经机制:一项fMRI研究

利用fMRI脑成像技术探讨图形型归纳推理的神经机制。设计了一种由图形形状和条纹方向描述的简单几何图形组成的归纳推理任务,这种图形型任务与以往研究中常用的语句型归纳推理任务是同质的。根据两个图形共享特征数量的不同设计了两种实验任务:共享两个特征(2T)和共享一个特征(1T),以休息基线(Rest)作为控制任务。2T和1T任务均为归纳推理任务,但2T任务包含知觉特征整合成分,而1T任务不包括。结果发现:与控制任务相比,归纳推理任务在前额区(BA6、9、11、46、47)、尾状核、壳核和丘脑等脑区有显著激活,反映了\"前额皮层-纹状体-丘脑\"通路在图形型归纳推理中的重要作用;图形型归纳推理中的知觉信息整合与右侧额下回(BA47)、双侧尾状核头部、壳核等脑区有关。     

Contextual Adaptation of the Unified Protocol for the Transdiagnostic Treatment of Emotional Disorders in Victims of the Armed Conflict in Colombia: A Case Study

The delivery of a contextually adapted version of the Unified Protocol for transdiagnostic treatment of emotional disorders is illustrated through a case study of an internally displaced female victim of armed conflict in Colombia. A detailed account of how her history of continuous traumatic events and her forced displacement resulted in multiple emotional disorders and behaviors which hindered her ability to react to daily stressors illustrates the particular conditions of individuals exposed to extreme violence. Emphasis is placed on how her culture and context required adaptations of evidence-based interventions. The contextually adapted UP (CXA-UP) is described in “slow-motion,” through a session-by-session account of the procedure along with the specific changes in each module. Outcome measures showed four positive diagnoses at pretreatment, but none at posttreatment, 3-month, or 2-year follow-up. Implications for global applications with individuals in similar contexts and for widening access to such interventions are discussed.     

Bistable perception in normal aging: perceptual reversibility and its relation to cognition

The effects of age on the ability to resolve perceptual ambiguity are unknown, though it depends on frontoparietal attentional networks known to change with age. We presented the bistable Necker cube to 24 middle-aged and OAs (older adults; 56–78 years) and 20 YAs (younger adults; 18–24 years) under passive-viewing and volitional control conditions: Hold one cube percept and Switch between cube percepts. During passive viewing, OAs had longer dominance durations (time spent on each percept) than YAs. In the Hold condition, OAs were less able than YAs to increase dominance durations. In the Switch condition, OAs and YAs did not differ in performance. Dominance durations in either condition correlated with performance on tests of executive function mediated by the frontal lobes. Eye movements (fixation deviations) did not differ between groups. These results suggest that OAs’ reduced ability to hold a percept may arise from reduced selective attention. The lack of correlation of performance between Hold and executive-function measures suggests at least a partial segregation of underlying mechanisms.     

Genomic Databases as Global Public Goods?

Recent discussions of genomics and international justice have adopted the concept of 'global public goods' to support both the view of genomics as a benefit and the sharing of genomics knowledge across nations. Such discussion relies on a particular interpretation of the global public goods argument, facilitated by the ambiguity of the concept itself. Our aim in this article is to demonstrate this by a close examination of the concept of global public goods with particular reference to its use in the context of genomic databases. We content that the argument for construing genomics as a global public good depends on seeing it as a natural good by focusing on features intrinsic to genomics knowledge. We shall argue that social and political arrangements are relevant and that recognising this opens the door to construing the use of global public goods language as a strategic one.     

Nature and facts about natural and artifactual categories: Sex differences in the semantic priming paradigm

There is abundant evidence from behavioral and neurophysiological experiments for the distinction of natural versus artifactual categories and a gender-specific difference: women’s performances in cognitive tasks increase when natural categories are used, whereas men’s performances increase with artifactual categories. Here, we used the semantic priming paradigm to study retrieval processes by presenting category labels as primes and exemplars as targets. Overall, in two experiments we found larger priming effects for natural than for artifactual categories. In addition, females showed positive priming effects for natural but negative effects for artifactual categories, whereas males showed positive priming effects for both categories. This pattern matches with that from other tasks and can be interpreted as evidence that the findings from these other tasks are, at least partially, indeed due to different representations or processing modes for males and females and not (exclusively) due to—for example—different familiarity with a category. In a further experiment, we showed that the found pattern for females can be manipulated by focusing on perceptual vs. functional features. The results can be interpreted as first evidence that there are (eventually in addition to different “crystallized” semantic structures) specific default processing modes that differ for males and females.     

15-month-old infants detect violations in pretend scenarios

Are 15-month-old infants able to detect a violation in the consistency of an event sequence that involves pretense? In Experiment 1, infants detected a violation when an actor pretended to pour liquid into one cup and then pretended to drink from another cup. In Experiment 2, infants no longer detected a violation when the cups were replaced with objects not typically used in the context of drinking actions, either shoes or tubes. Experiment 3 showed that infants' difficulty in Experiment 2 was not due to the use of atypical objects per se, but arose from the novelty of seeing an actor appearing to drink from these objects. After receiving a single familiarization trial in which they observed the actor pretend to drink from either a shoe or a tube, infants now detected a violation when the actor pretended to pour into and to drink from different shoes or tubes. Thus, at an age (or just before the age) when infants are beginning to engage in pretend play, they are able to show comprehension of at least one aspect of pretense in a violation-of-expectation task: specifically, they are able to detect violations in the consistency of pretend action sequences.