Infants' formation and use of categories to segregate objects

Four- and-a-half-month-old infants' (N = 100) category formation and use was studied in a series of five experiments. For each experiment, the test events featured a display composed of a cylinder and a box. Previous research showed that this display is not clearly parsed as a single unit or as two separate units by infants of this age. Immediately prior to testing, infants were shown a set of category exemplars. Knowledge about this category could help infants disambiguate the test display, which contained a novel exemplar of this category. Clear interpretation of the test display as composed of two separate units (as indicated by infants' longer looking at the move-together than at the move-apart test event) was taken as evidence of category formation and use. In Experiments 1 and 5, infants' prior experience with a set of three different boxes that were similar to the test box facilitated their segregation of the test display. Experiment 2 showed that three different exemplars are necessary: prior experience with any two of the three boxes used in Experiment 1 did not facilitate infants' segregation of the test display. Experiment 3 showed that variability in the exemplar set is necessary: prior experience with three identical boxes did not facilitate infants' segregation of the test display. Experiment 4 showed that under these conditions of very brief prior exposure, similarity between the exemplar set and test box is necessary: prior experience with three different boxes that were not very similar to the test box did not facilitate infants' segregation of the test display. Together, these findings suggest that: (a) number of exemplars, variability, and similarity in the exemplar set are important for infants' category formation, and (b) infants use their category knowledge to determine the boundaries of the objects in a display.     

Figure-background segregation and the formation of illusory figures

Three experiments were carried out to test the relationship between figure-background segregation and illusory contours. Illusory figures are believed to arise as byproducts of figure-background segregation. When, in a scene, part of what should be the background becomes an illusory figure, a mechanism of contour attribution favoring the area in which the illusory figure appears takes place. This mechanism is prevented from operating when the attribution of the contour is inhibited by the presence of "groupable" (connectable) contours. Spatial proximity is one of the factors affecting such grouping: the closer the connectable contours, the more likely is their grouping in a single unit and the less likely is the emergence of an illusory figure. Experimental results showed that the illusory effect was established when contours were prevented from being connected. This outcome is interpreted as evidence that a mechanism of contour attribution is effective in the formation of illusory figures.     

Using census data in the management of religious diversity: an Australian case study

Abstract

Mapping and measuring religious diversity has become critical to the management of interreligious relations in the 21st century. The data about religious identification provided by the Australian census since the formation of Federal Government in Australia, and prior to that in the Colonies, has provided detailed information about the extent of and changes in religious diversity in the nation and in particular cities. Because the census also provides very detailed information about where people of different religions live, it can provide information about the extent to which religious groups are residentially segregated, a factor which affects how people of different religions relate to each other. The methodological issues related to measuring diversity are discussed and the utility in urban contexts of a ‘dissimilarity scale’ is demonstrated. The unique contribution of census data to the mapping and management of religious diversity in Australia is presented.     

Gender Segregation in Childhood: A Test of the Interaction Style Theory

The authors investigated the play/interaction-style theory of gender segregation with a sample of 39 children aged 2 to 5 years (primarily Caucasian). According to this theory, children prefer playmates with styles of play or interaction that are similar to their own. Because such styles are sex differentiated, same-sex playmate preference (i.e., gender segregation) results. The authors observed children during free play to determine preferred playmates and gender segregation level, and they used teacher ratings to derive play/interaction-style scores. The authors used a multiple regression approach to path analysis to analyze effects of sex of participant, participants' play/interaction-style scores, playmates' play/interaction-style scores, and degree of gender segregation to determine their effects on one another. The authors observed significant levels of gender segregation, with highly aggressive or active children displaying less segregation than their peers did. However, gender segregation was not associated with a preference for playmates with similar play or interaction styles.     

Long-term natural ageing of a dissociated dislocation in a Cu-13.43 at.% Al alloy

The nature of impurity-dislocation interactions is one of the key questions governing the strength and plasticity of solid-solution materials. To investigate the influence of impurities on the mechanical properties of intermetallic NiAl, the electronic structure and energy of NiAl with a <100>{010} edge dislocation and transition-metal impurities was calculated using the real-space tight-binding linear muffin-tin orbital method. The localized electronic states, appearing in the core of the dislocation, are found to lead to strong impurity-dislocation interactions via two mechanisms: firstly, chemical locking, due to strong hybridization between impurity electronic states and dislocation localized states; secondly, electrostatic locking, due to long-range charge oscillations caused by the electron localization in the dislocation core. The results obtained explain qualitatively why the solid-solution hardening effect in NiAl correlates with the electronic structure of impurities rather than with size misfit, as expected according to traditional views.     

Size and orientation cue figure-ground segregation in infants

ABSTRACT

Adult perceivers segregate figure from ground based on image cues such as small size and main axis orientation. The current study examined whether infants can use such cues to perceive figure-ground segregation. Three- to 7-month-olds were familiarized with a pie-shaped stimulus in which some pieces formed a?+?and other pieces formed an x. The infants were then presented with a novelty preference test pairing the?+?and x. The bases for the pieces forming the?+?or x were size and orientation (Experiment 1), size (Experiment 2), and orientation (Experiment 3). In each experiment, infants responded as if they recognized as familiar the shape specified by small size, main axis orientation, or their combination. Control conditions showed that infant performance could not be attributed to spontaneous preference. The findings suggest that infants can achieve figure-ground segregation based on some of the same cues used by adults.     

Rhythmic sensorimotor coordination is resistant but not immune to auditory stream segregation

In a recent study of musicians' sensorimotor synchronization with auditory sequences composed either of beat and subdivision tones differing in pitch or of beat tones only, Repp (2009) found that the phase correction response (PCR) to perturbed beats was inhibited by the presence of subdivisions regardless of whether beats and subdivisions formed integrated or segregated perceptual streams. The present study used a different paradigm in which perturbed subdivisions triggered the PCR. At the slower of two sequence tempi, the PCR was equally large in integrated and segregated conditions, but at the faster tempo stream segregation reduced the PCR substantially. This new finding indicates that although the PCR is strongly resistant to auditory stream segregation, it is not totally immune to it.     

Eating together apart: patterns of segregation in a multi‐ethnic cafeteria

Research on segregation has tended to focus on relations located at a macro‐spatial level of analysis and unfolding in contexts where boundaries to interaction are formally established. This research, by contrast, investigated segregation as a micro‐ecological process by observing patterns of seating in a multi‐ethnic cafeteria. A total of 3114 seating positions were coded over a 2‐week period and the resulting data were analysed using both adapted segregation indices (P and D) and loglinear and logistic regression techniques. The results suggested that ethnic segregation existed both at the level of interactional groups and in the form of broader patterns of racial clustering and dispersal in the cafeteria. Moreover, the magnitude of segregation was predicted by the gender composition of seating groups and by variations in the density of the cafeteria's population over time. Some implications of these results for social psychological research on contact and desegregation are considered. Copyright © 2004 John Wiley & Sons, Ltd.     

预搜索过滤分心物的机制

如果先呈现若干分心物,然后添加靶子与其他分心物,那么就会改善搜索——预搜索效应。对于过滤分心物的潜在机制,研究者相继提出了主动抑制说、突然呈现说与时间分离说等理论。这些理论都有其合理的一面,能解释一些特定的实验现象,但任何单一机制都无法解释所有的实验现象。文章提出,未来的研究应该整合已有的实验现象与理论,系统考察旧客体与新客体的作用,重点整合抑制说与突现说,它们可能是一个连续体的两端     

元音和复合声识别中噪声分离机制的实验研究

该文用配对比较方法,从夫调谐波的数量对谐波筛的影响（实验一）、失调谐波的位置（实验二）以及谐波相位与其失调幅度之间的相互作用（实验三）等三个方面对失调谐波的分离机制进行探讨。研究结果表明：（1）多个谐波同时失调时其失调效应要比单个谐波强,即谐波失调存在累积效应;（2）谐波次数不同,其失调效应也存在差异,这种差异与谐波和共振峰之间的距离有关,谐波越靠近共振峰,其失调效应越明显,但对由等振幅的谐波系列构成的复合声而言,高次谐波的失调效应比低次谐波弱;（3）谐波相位对其失调效应产生间接影响,这种影响与谐波的起始振幅有关,当相位为π／2和3π／2时,失调效应更加明显。