Development of egocentric and allocentric spatial representations from childhood to elderly age

Spatial reference frames are fundamental to represent the position of objects or places. Although research has reported changes in spatial memory abilities during childhood and elderly age, no study has assessed reference frames processing during the entire lifespan using the same task. Here, we aimed at providing some preliminary data on the capacity to process reference frames in 283 healthy participants from 6 to 89 years of age. A spatial memory task requiring egocentric/allocentric verbal judgments about objects in peri-/extrapersonal space was used. The main goals were: (1) tracing a baseline of the normal process of development of these spatial components; (2) clarifying if reference frames are differently vulnerable to age-related effects. Results showed a symmetry between children of 6–7 years and older people of 80–89 years who were slower and less accurate than all other age groups. As regards processing time, age had a strong effect on the allocentric component, especially in extrapersonal space, with a longer time in 6- to 7-year-old children and 80- to 89-year-old adults. The egocentric component looked less affected by aging. Regarding the level of spatial ability (accuracy), the allocentric ability appeared less sensitive to age-related variations, whereas the egocentric ability progressively improved from 8 years and declined from 60 years. The symmetry in processing time and level of spatial ability is discussed in relation to the development of executive functions and to the structural and functional changes due to incomplete maturation (in youngest children) and deterioration (in oldest adults) of underlying cerebral areas.     

Egocentric versus Allocentric Spatial Ability in Dentistry and Haptic Virtual Reality Training

The current study investigates the role of egocentric and allocentric spatial abilities in the field of dentistry. Whereas allocentric ability requires spatial transformation from a stationary point of reference, egocentric spatial ability is tied to the sensory‐motor system, and it requires changing one's imagined perspective in space. Experiment 1 investigates the role of different spatial abilities in a tooth preparation exercise. Experiment 2 investigates the interaction of allocentric and egocentric spatial abilities with the effectiveness of haptic virtual reality training. The results show that only egocentric spatial ability was a significant predictor of success in tooth preparation. In addition, an egocentric spatial ability test was the reliable predictor of success in more complex (indirect vision) tasks during haptic virtual reality training. Our results indicate the need for the development of finer measures of the specific spatial skills that might be needed for different dental specializations. Copyright © 2013 John Wiley & Sons, Ltd.     

Left–right coding of past and future in language: The mental timeline during sentence processing

The metaphoric mapping theory suggests that abstract concepts, like time, are represented in terms of concrete dimensions such as space. This theory receives support from several lines of research ranging from psychophysics to linguistics and cultural studies; especially strong support comes from recent response time studies. These studies have reported congruency effects between the dimensions of time and space indicating that time evokes spatial representations that may facilitate or impede responses to words with a temporal connotation. The present paper reports the results of three linguistic experiments that examined this congruency effect when participants processed past- and future-related sentences. Response time was shorter when past-related sentences required a left-hand response and future-related sentences a right-hand response than when this mapping of time onto response hand was reversed (Experiment 1). This result suggests that participants can form time–space associations during the processing of sentences and thus this result is consistent with the view that time is mentally represented from left to right. The activation of these time–space associations, however, appears to be non-automatic as shown by the results of Experiments 2 and 3 when participants were asked to perform a non-temporal meaning discrimination task.     

Lost in space: multisensory conflict yields adaptation in spatial representations across frames of reference

According to embodied cognition, bodily interactions with our environment shape the perception and representation of our body and the surrounding space, that is, peripersonal space. To investigate the adaptive nature of these spatial representations, we introduced a multisensory conflict between vision and proprioception in an immersive virtual reality. During individual bimanual interaction trials, we gradually shifted the visual hand representation. As a result, participants unknowingly shifted their actual hands to compensate for the visual shift. We then measured the adaptation to the invoked multisensory conflict by means of a self-localization and an external localization task. While effects of the conflict were observed in both tasks, the effects systematically interacted with the type of localization task and the available visual information while performing the localization task (i.e., the visibility of the virtual hands). The results imply that the localization of one’s own hands is based on a multisensory integration process, which is modulated by the saliency of the currently most relevant sensory modality and the involved frame of reference. Moreover, the results suggest that our brain strives for consistency between its body and spatial estimates, thereby adapting multiple, related frames of reference, and the spatial estimates within, due to a sensory conflict in one of them.     

Attention and the crossmodal construction of space

Traditional studies of spatial attention consider only a single sensory modality at a time (e.g. just vision, or just audition). In daily life, however, our spatial attention often has to be coordinated across several modalities. This is a non-trivial problem, given that each modality initially codes space in entirely different ways. In the last five years, there has been a spate of studies on crossmodal attention. These have demonstrated numerous crossmodal links in spatial attention, such that attending to a particular location in one modality tends to produce corresponding shifts of attention in other modalities. The spatial coordinates of these crossmodal links illustrate that the internal representation of external space depends on extensive crossmodal integration. Recent neuroscience studies are discussed that suggest possible brain mechanisms for the crossmodal links in spatial attention.     

视觉和言语空间信息共同作用下SNARC效应的空间参照特点

已有研究显示,SNARC效应存在多个灵活的空间参照系统,可在不同的实验条件下激活。心理数字线理论对于SNARC效应空间编码的理解仅局限于物理空间层面,并不能很好地甄别SNARC效应空间参照系统的激活条件。研究以视觉空间和言语空间双编码理论为基础,考查在视觉空间信息与言语空间信息共同作用下,单手（左手或右手）与双手反应下SNARC效应的空间参照特点。结果显示,在视觉空间信息与言语空间信息共同作用下,左手、右手和双手反应下均出现了典型SNARC效应,且左手、右手和双手反应下的数字空间映射模式相似。研究结果证实,在视觉-空间与言语空间信息共同作用下仅激活SNARC效应多个灵活的空间参照系统中的身体中心为基础的参照系统,说明言语空间信息的参与有助于激活该效应中身体中心为基础的空间参照系统。     

时空干扰效应：基于贝叶斯模型的解释

时空干扰效应是指时间知觉受空间信息干扰或空间知觉受时间信息干扰而出现错觉的现象。部分研究认为时空干扰是不对称的,空间对时间的干扰总是更大;还有研究认为时间和空间相互干扰的强度受实验因素影响,一般来说,空间对时间的干扰更大,但时间也能对空间产生同等程度甚至更大的干扰。在回顾隐喻理论和量值理论的主要观点之后,重点分析贝叶斯模型对时空干扰效应的解释,最后提出未来研究应关注的三个问题,即拓展贝叶斯模型对时空干扰效应的解释范围,探明基于贝叶斯推断的时空干扰神经机制和探索时空干扰的调控方法。     

听障和听力正常人群空间主导性和空间参照框架的交互作用

通过要求被试分别在近处空间和远处空间完成空间参照框架的判断任务, 考察了听障和听力正常人群空间主导性和空间参照框架的交互作用。结果表明：(1)相对于听力正常人群, 听障人群完成自我参照框架判断任务的反应时更长, 而在完成环境参照框架判断任务无显著差异; (2)听障人群和听力正常人群空间主导性和空间参照框架交互作用呈现出相反模式。研究表明, 听障人群在听力功能受损后, 其空间主导性和空间参照框架的交互作用也产生了变化。     

Müller-Lyer图形中长度加工与时距估计的关系

采用复制法,考察Müller-Lyer错觉条件下,长度加工与时距估计的关系。实验1和实验2分别采用实线段和空线段,结果发现,图形的客观长度越长,估计的时距越长;箭头朝向造成的主观长度错觉对时距估计无影响;时距对长度判断的影响较小。实验3进一步操作线段长度和箭杆方向,发现长度错觉不影响时距估计与错觉量的大小无关。研究表明刺激的客观长度与时间在心理表征上存在自动化的联结,也受到刺激、实验方法和时距等因素的影响。     

Haptic parallelity perception on the frontoparallel plane: the involvement of reference frames

It has been established that spatial representation in the haptic modality is subject to systematic distortions. In this study, the haptic perception of parallelity on the frontoparallel plane was investigated in a bimanual matching paradigm. Eight reference orientations and 23 combinations of stimulus locations were used. The current hypothesis from studies conducted on the horizontal and midsagittal planes presupposes that what is haptically perceived as parallel is a product of weighted contributions from both egocentric and allocentric reference frames. In our study, we assessed a correlation between deviations from the veridical and hand/arm postures and found support for the role of an intermediate frame of reference in modulating haptic parallelity on the frontoparallel plane as well. Moreover, a subject-dependent biasing influence of the egocentric reference frame determines both the reversal of the oblique effect and a scaling effect in deviations as a function of bar position.     

Agency and control for the integration of a virtual tool into the peripersonal space

Our representation of the peripersonal space is tied to our representation of our bodies. This representation appears to be flexible and it can be updated to include the space in which tools work, particularly when the tool is actively used. One indicator of this update is the increased efficiency with which sensory events near the tool are processed. In the present study we examined the role of visuomotor control in extending peripersonal space to a common virtual tool-a computer mouse cursor. In particular, after participants were exposed to different spatial mappings between movements of the mouse cursor and movements of their hand, participants' performance in a motion-onset detection task was measured, with the mouse cursor as the stimulus. When participants, during exposure, had the ability to move the cursor efficiently and accurately (familiar hand-cursor mapping), they detected motion-onset targets more quickly than when they could not move the cursor at all during exposure (no hand-cursor mapping). Importantly, reversing the spatial correspondence between the movements of the hand and the cursor (unfamiliar hand-cursor mapping) during exposure, which was thought to preserve the ability to move the cursor (ie agency) while weakening the ability to make the movements efficiently and accurately (ie control), eliminated the detection-facilitation effect. These results provide evidence for the possible extension of peripersonal space to frequently used objects in the virtual domain. Importantly, these extensions seem to depend on the participant's knowledge of the dynamic spatial mapping between the acting limb and the visible virtual tool.     

Observed actions affect body-specific associations between space and valence

Right-handers tend to associate “good” with the right side of space and “bad” with the left. This implicit association appears to arise from the way people perform actions, more or less fluently, with their right and left hands. Here we tested whether observing manual actions performed with greater or lesser fluency can affect observers' space–valence associations. In two experiments, we assigned one participant (the actor) to perform a bimanual fine motor task while another participant (the observer) watched. Actors were assigned to wear a ski glove on either the right or left hand, which made performing the actions on this side of space disfluent. In Experiment 1, observers stood behind the actors, sharing their spatial perspective. After motor training, both actors and observers tended to associate “good” with the side of the actors' free hand and “bad” with the side of the gloved hand. To determine whether observers' space–valence associations were computed from their own perspectives or the actors', in Experiment 2 we asked the observer to stand face-to-face with the actor, reversing their spatial perspectives. After motor training, both actors and observers associated “good” with the side of space where disfluent actions had occurred from their own egocentric spatial perspectives; if “good” was associated with the actor's right-hand side it was likely to be associated with the observer's left-hand side. Results show that vicarious experiences of motor fluency can shape valence judgments, and that observers spontaneously encode the locations of fluent and disfluent actions in egocentric spatial coordinates.     

Differential developmental trajectories for egocentric, environmental and intrinsic frames of reference in spatial memory

We studied the development of spatial frames of reference in children aged 3-6 years, who retrieved hidden toys from an array of identical containers bordered by landmarks under four conditions. By moving the child and/or the array between presentation and test, we varied the consistency of the hidden toy with (i) the body, and (ii) the testing room. The toy's position always remained consistent with (iii) the array and bordering landmarks. We found separate, additive performance advantages for consistency with body and room. These effects were already present at 3 years. A striking finding was that the room effect, which implies allocentric representations of the room and/or egocentric representations updated by self-motion, was much stronger in the youngest children than the body effect, which implies purely egocentric representations. Children as young as 3 years therefore had, and greatly favoured, spatial representations that were not purely egocentric. Viewpoint-independent recall based only on the array and bordering landmarks emerged at 5 years. There was no evidence that this later-developing ability, which implies object-referenced (intrinsic) representations, depended on verbal encodings. These findings indicate that core components of adult spatial competence, including parallel egocentric and nonegocentric representations of space, are present as early as 3 years. These are supplemented by later-developing object-referenced representations.     

自我和物体为参照系的心理旋转分离：内旋效应

采用虚拟的旋转不同角度左、右手模型,构建“左右手判断(Left and right hand judgment: LR)”任务和“相同－不同判断(same and different judgment: SD)”任务,考察这两种实验任务是否都存在内旋效应和角度效应,以此推论被试采用何种旋转策略。结果发现：（1） 两种实验任务结果均表现出显著的角度效应。（2）在LR任务条件下,存在显著的内旋效应,而在SD任务中不存在内旋效应。从而表明当人手图片作为心理旋转材料时,它具有双重角色。被试心理旋转加工时究竟选用何种参照系的旋转策略,与实验材料和实验任务两者都密不可分     

Remembering object position in the absence of vision: egocentric, allocentric, and egocentric decentred frames of reference

In three experiments we examined whether memory for object locations in the peri-personal space in the absence of vision is affected by the correspondence between encoding and test either of the body position or of the reference point. In particular, the study focuses on the distinction between different spatial representations, by using a paradigm in which participants are asked to relocate objects explored haptically. Three frames of reference were systematically compared. In experiment 1, participants relocated the objects either from the same position of learning by taking as reference their own body (centred egocentric condition) or from a 90 degrees decentred position (allocentric condition). Performance was measured in terms of linear distance errors and angular distance errors. Results revealed that the allocentric condition was more difficult than the centred egocentric condition. In experiment 2, participants performed either the centred egocentric condition or a decentred egocentric condition, in which the body position during the test was the same as at encoding (egocentric) but the frame of reference was based on a point decentred by 90 degrees. The decentred egocentric condition was found to be more difficult than the centred egocentric condition. Finally, in experiment 3, participants performed in the decentred egocentric condition or the allocentric condition. Here, the allocentric condition was found to be more difficult than the decentred egocentric condition. Taken together, the results suggest that also in the peripersonal space and in the absence of vision different frames of reference can be distinguished. In particular, the decentred egocentric condition involves a frame of reference which seems to be neither allocentric nor totally egocentric.     

La perception multisource : une nouvelle approche de la perception de scènes

Research conducted these last years in the field of spatial cognition report empirical findings that are difficult to account for with the traditional visual cognitive model of scene perception. One of the major contributions of these findings has been to invite rethinking scene perception, which would benefit from not being apprehended as centered mainly on the sensory modality considered. On the contrary, the Multisource model of scene perception developed by Intraub et al. offers an alternative theoretical framework considering visual perception as an act of spatial cognition, with spatial information at its core. According to this model, during the initial understanding of a view, the cognitive system would be elaborating a multisource representation, with spatial information constituting an egocentric framework that conveys to the observer a sense of the environment in which he/she is embedded. Scene representation would be organized around an amodal spatial structure combining different sources of information: a bottom-up and external source of information derived from different modalities (e.g., visual, haptic), as well as internal sources of high-level information (i.e., amodal, conceptual and contextual information). These different sources of information would work together to create a simulation of the likely environment, integrating the perceived view into a broader spatial context. Beyond rethinking scene perception, one of the advances of the model is to unify different fields of cognition apprehended until then in isolation. The current paper aims to present this model and some of the results it allows to account for.     

Merging familiar and new senses to perceive and act in space

Our experience of the world seems to unfold seamlessly in a unitary 3D space. For this to be possible, the brain has to merge many disparate cognitive representations and sensory inputs. How does it do so? I discuss work on two key combination problems: coordinating multiple frames of reference (e.g. egocentric and allocentric), and coordinating multiple sensory signals (e.g. visual and proprioceptive). I focus on two populations whose spatial processing we can observe at a crucial stage of being configured and optimised: children, whose spatial abilities are still developing significantly, and naïve adults learning new spatial skills, such as sensing distance using auditory cues. The work uses a model-based approach to compare participants’ behaviour with the predictions of alternative information processing models. This lets us see when and how—during development, and with experience—the perceptual-cognitive computations underpinning our experiences in space change. I discuss progress on understanding the limits of effective spatial computation for perception and action, and how lessons from the developing spatial cognitive system can inform approaches to augmenting human abilities with new sensory signals provided by technology.

     

视时距知觉适应后效的空间选择性

时距知觉适应后效是指长时间适应于某一特定时距会导致个体对后续时距产生知觉偏差。其中对视时距知觉适应后效空间选择性的探讨存在争议,有研究支持位置不变性,也有研究支持位置特异性。这类研究能有效揭示时距编码的认知神经机制,位置不变性可能意味着时距编码位于较高级的脑区,而位置特异性则可能意味着时距编码位于初级视觉皮层。未来还可以探究时距知觉适应后效的视觉坐标表征方式,开展多通道研究以及相应的神经基础研究。     

视觉观点采择中自我中心性偏差的抑制和归因之争

自我中心性偏差是社交失败的重要原因, 但其产生机制还存在争议。以往研究存在抑制性选择模型与流利性错误归因两种理论观点：前者认为对自身观点的抑制失败会导致自我中心性偏差; 后者则认为错误地选择自身更为流畅的信息会导致自我中心性偏差。为整合上述争论, 提出抑制-归因协同作用模型, 认为抑制和归因两种加工或可共同导致自我中心性偏差。未来研究应借助精巧的研究范式和特殊被试群体, 进一步验证该模型。