The role of surface-based representations of shape in visual object recognition

This study contrasted the role of surfaces and volumetric shape primitives in three-dimensional object recognition. Observers (N?=?50) matched subsets of closed contour fragments, surfaces, or volumetric parts to whole novel objects during a whole–part matching task. Three factors were further manipulated: part viewpoint (either same or different between component parts and whole objects), surface occlusion (comparison parts contained either visible surfaces only, or a surface that was fully or partially occluded in the whole object), and target–distractor similarity. Similarity was varied in terms of systematic variation in nonaccidental (NAP) or metric (MP) properties of individual parts. Analysis of sensitivity (d′) showed a whole–part matching advantage for surface-based parts and volumes over closed contour fragments—but no benefit for volumetric parts over surfaces. We also found a performance cost in matching volumetric parts to wholes when the volumes showed surfaces that were occluded in the whole object. The same pattern was found for both same and different viewpoints, and regardless of target–distractor similarity. These findings challenge models in which recognition is mediated by volumetric part-based shape representations. Instead, we argue that the results are consistent with a surface-based model of high-level shape representation for recognition.     

Editorial to the special issue Neuronus

Did you visit the Neuronus conferences in the years 2012 and 2013 in Kraków? If not, then you certainly should have a close examination of this special issue including this introduction to at least have a glimpse of an idea of the highly interesting topics in the field of cognitive neuroscience that were presented at these conferences. If you were there, it is for sure a good choice to focus on this special issue as well, first to refresh your minds (we know our memories are far from perfect), but especially to see what happened with research of the presenters at these conferences.     

Associative priming and orthographic choice in nonword spelling

Abstract

An experiment is reported in which adult English-speaking subjects wrote nonwords to dictation in a free (unprimed) condition and in a primed condition in which the nonword was preceded by a word that was an associate of a word that rhymed with the nonword target (e.g. vatican—(pope)→ bope vs detergent—(soap)→boap). Choice of orthographic patterns in nonword spelling was additively influenced by the associative priming and by sound-spelling contingency (the proportion of words in the lexicon containing the critical pattern). However, an analysis of unprimed spellings suggested that contingency was no more than a partial determinant of orthographic choice. Some implications for models of spelling storage and retrieval are discussed.     

The power of representation and interpretation: Doubling statistical reasoning performance with icons and frequentist interpretations of ambiguous numbers

Abstract

Six highly familiar melodies were submitted to three transformations: reduction and two rhythmic group transformations. These three transformations offered the opportunity to compare the role of various means of melody recognition: melodic contour, harmonic structure, local surface cues. If melody recognition relies on melodic contour, an original melody would be easier to recognise after rhythmic group transformation than after reduction; the rhythmic group transformation, but not the reduction, preserves the melodic contour. If melody recognition depends on the harmonic structure, an original melody would be easier to recognise after reduction than after a rhythmic group transformation; the reduction, but not the rhythmic group transformation, respects the underlying harmonic structure. The results of two experiments, one with children and one with adults, showed that recognition was better for rhythmic group transformation but only when local surface cues were preserved, a result that could neither be predicted by the melodic contour hypothesis nor by the harmonic structure hypothesis. The results give support to the cue abstraction hypothesis, which suggests that melody recognition relies on the recognition of certain surface cues abstracted while hearing and which are then memorised. Recognition performances and speed of recognition served as dependent variables.     

Action representation across ages and cultures: Recognition of action means–end change in German and Chinese children and adults

Actions can be represented as a hierarchy of goals and means, whereas the granularity of the top level depends on the action's complexity. So far, most evidence comes from imitation studies. We explored this issue by evaluating the detection of means and end changes in a recognition paradigm across ages and cultures. German and Chinese preschoolers (n = 53) and adults (n = 58) studied videos of tool-use actions differing in complexity and familiarity. In the test phase, participants judged identical, means-changed and end-changed actions as same or different. Changes of the actions' end were generally identified more accurately independent of age and culture. Means' changes, but not ends' changes, were detected more frequently for complex than for simple actions. Changes in familiar actions were recognised better than changes in unfamiliar actions. The data supports a hierarchical model of action representation where the end information is superordinate to means information.     

The distorted hand metric representation serves both perception and action

ABSTRACT

The representation of our body location is achieved by integrating sensorimotor inputs with information about our body size. Previous studies have shown that the metric representation of our hand, also called the body model, is distorted, namely overestimated in width and underestimated in length, although we are able to perform accurate fine movements. Considering the known dissociation between action-oriented and perception-oriented body representations, we asked whether the body model mainly serves body perception or whether it is also involved in movements. Twenty-one healthy adults were administered with the Localization Task (LT) which required the participants to localise the perceived position of their unseen hand by means of a stick held by their other hand, and the Proprioceptive Matching Task (PMT) which required the participants to match their perceived hand position with a visual target. LT and PMT maps were compared with the actual hand sizes. We found that the PMT map exhibited similar body model distortions, confirming that the body model is involved in motor programming. Furthermore, we observed that a partial adjustment of the distortions occurs in a motor condition.     

Body image distortions in healthy adults

Distortions of body image have often been investigated in clinical disorders. Much of this literature implicitly assumes healthy adults maintain an accurate body image. We recently developed a novel, implicit, and quantitative measure of body image — the Body Image Task (BIT). Here, we report a large-scale analysis of performance on this task by healthy adults. In both an in-person and an online version of the BIT, participants were presented with an image of a head as an anchoring stimulus on a computer screen, and told to imagine that the head was part of a mirror image of themselves in a standing position. They were then instructed to judge where, relative to the head, each of several parts of their body would be located. The relative positions of each landmark can be used to construct an implicit perceptual map of bodily structure. We could thus measure the internally-stored body image, although we cannot exclude contributions from other representations. Our results show several distortions of body image. First, we found a large and systematic over-estimation of width relative to height. These distortions were similar for both males and females, and did not closely track the idiosyncrasies of individual participant's own bodies. Comparisons of individual body parts showed that participants overestimated the width of their shoulders and the length of their upper arms, relative to their height, while underestimating the lengths of their lower arms and legs. Principal components analysis showed a clear spatial structure to the distortions, suggesting spatial organisation and segmentation of the body image into upper and lower limb components that are bilaterally integrated. These results provide new insight into the body image of healthy adults, and have implications for the study and rehabilitation of clinical populations.     

Developing number–space associations: SNARC effects using a color discrimination task in 5-year-olds

Human adults’ numerical representation is spatially oriented; consequently, participants are faster to respond to small/large numerals with their left/right hand, respectively, when doing a binary classification judgment on numbers, known as the SNARC (spatial–numerical association of response codes) effect. Studies on the emergence and development of the SNARC effect remain scarce. The current study introduces an innovative new paradigm based on a simple color judgment of Arabic digits. Using this task, we found a SNARC effect in children as young as 5.5 years. In contrast, when preschool children needed to perform a magnitude judgment task necessitating exact number knowledge, the SNARC effect started to emerge only at 5.8 years. Moreover, the emergence of a magnitude SNARC but not a color SNARC was linked to proficiency with Arabic digits. Our results suggest that access to a spatially oriented approximate magnitude representation from symbolic digits emerges early in ontogenetic development. Exact magnitude judgments, on the other hand, rely on experience with Arabic digits and, thus, necessitate formal or informal schooling to give access to a spatially oriented numerical representation.     

非数量视觉特征对数量感知的影响

以往许多研究探讨了各种视觉特征对数量判断任务的影响,但得出了不一致的结论.本研究依据信号检测论原理对刺激特征影响数量判断的方式进行考察.结果发现:刺激大小、形状和分布均匀度等因素可影响数量判断的反应标准,但不会影响辨别力;刺激聚集或组块会直接对数量判断的辨别力产生影响.结果表明,不同刺激特征对数量判断的影响方式存在差异.一方面,人类具有从刺激特征中直接抽取数量信息进行认知比较的能力;另一方面,刺激点聚集或组块可以直接影响被试的数量感知.此外,我们还推测,组块是通过改变客体表征的方式来影响数量感知的.     

情绪对注意功能网络的调制

情绪性注意是一种对具有情绪意义的刺激进行选择和加工的注意.由于刺激的情绪效价能调制人脑的感知和注意系统,因而,与对中性刺激的注意相比,情绪性注意的神经机制更加复杂.较早的研究显示,杏仁核对感知皮层的调制对情绪性注意起关键作用.近期的证据表明,杏仁核对注意功能网络的调制可能是其重要的神经机制.本文梳理了相关领域的研究证据,主要强调情绪性刺激对注意的警觉、定向和执行控制网络的调制,发现情绪性注意加工的认知神经机制可能涉及一个以杏仁核为核心的多重功能网络.