Multimodal integration for the representation of space in the posterior parietal cortex.

The posterior parietal cortex has long been considered an ''association'' area that combines information from different sensory modalities to form a cognitive representation of space. However, until recently little has been known about the neural mechanisms responsible for this important cognitive process. Recent experiments from the author''s laboratory indicate that visual, somatosensory, auditory and vestibular signals are combined in areas LIP and 7a of the posterior parietal cortex. The integration of these signals can represent the locations of stimuli with respect to the observer and within the environment. Area MSTd combines visual motion signals, similar to those generated during an observer''s movement through the environment, with eye-movement and vestibular signals. This integration appears to play a role in specifying the path on which the observer is moving. All three cortical areas combine different modalities into common spatial frames by using a gain-field mechanism. The spatial representations in areas LIP and 7a appear to be important for specifying the locations of targets for actions such as eye movements or reaching; the spatial representation within area MSTd appears to be important for navigation and the perceptual stability of motion signals.     

Know Thy Neighbor: Costly Information Can Hurt Cooperation in Dynamic Networks

People need to rely on cooperation with other individuals in many aspects of everyday life, such as teamwork and economic exchange in anonymous markets. We study whether and how the ability to make or break links in social networks fosters cooperate, paying particular attention to whether information on an individual''s actions is freely available to potential partners. Studying the role of information is relevant as information on other people''s actions is often not available for free: a recruiting firm may need to call a job candidate''s references, a bank may need to find out about the credit history of a new client, etc. We find that people cooperate almost fully when information on their actions is freely available to their potential partners. Cooperation is less likely, however, if people have to pay about half of what they gain from cooperating with a cooperator. Cooperation declines even further if people have to pay a cost that is almost equivalent to the gain from cooperating with a cooperator. Thus, costly information on potential neighbors'' actions can undermine the incentive to cooperate in fluid networks.     

Augmented Reality for the Assessment of Children's Spatial Memory in Real Settings

Short-term memory can be defined as the capacity for holding a small amount of information in mind in an active state for a short period of time. Although some instruments have been developed to study spatial short-term memory in real environments, there are no instruments that are specifically designed to assess visuospatial short-term memory in an attractive way to children. In this paper, we present the ARSM (Augmented Reality Spatial Memory) task, the first Augmented Reality task that involves a user''s movement to assess spatial short-term memory in healthy children. The experimental procedure of the ARSM task was designed to assess the children''s skill to retain visuospatial information. They were individually asked to remember the real place where augmented reality objects were located. The children (N = 76) were divided into two groups: preschool (5–6 year olds) and primary school (7–8 year olds). We found a significant improvement in ARSM task performance in the older group. The correlations between scores for the ARSM task and traditional procedures were significant. These traditional procedures were the Dot Matrix subtest for the assessment of visuospatial short-term memory of the computerized AWMA-2 battery and a parent''s questionnaire about a child''s everyday spatial memory. Hence, we suggest that the ARSM task has high verisimilitude with spatial short-term memory skills in real life. In addition, we evaluated the ARSM task''s usability and perceived satisfaction. The study revealed that the younger children were more satisfied with the ARSM task. This novel instrument could be useful in detecting visuospatial short-term difficulties that affect specific developmental navigational disorders and/or school academic achievement.     

Place,scale and the racial claims made for multiracial children in the 1990 US Census

Multiracial children embody ambiguities inherent in racial categorization and expose fictions of discrete races. Nevertheless, parents of multiracial children were asked for the 1990 US Census to report a single race for their offspring. Using confidential 1990 Census micro-data, we investigate the choices parents made for the three most common racially mixed household types (Asian-white, black-white and Latino-white) in twelve large metropolitan areas. We find that context affects the reporting of children's racial identity. We examine these effects with models that incorporate three spatial scales: households, neighbourhoods and metropolitan areas. Model estimates reveal that racial claims made by parents of Latino- and Asian-white (but not black-white) children varied significantly across metropolitan area. A neighbourhood's proportion white increased the probability that parents reported their children as white, while a neighbourhood's racial diversity increased the probability that black-white parents claimed a non-white race (black or ‘other’) for their children.     

Slaves of the environment: the movement of herbivorous insects in relation to their ecology and genotype

The majority of insect species do not show an innate behavioural migration, but rather populations expand into favourable new habitats or contract away from unfavourable ones by random changes of spatial scale. Over the past 50 years, the scientific fascination with dramatic long-distance and directed mass migratory events has overshadowed the more universal mode of population movement, involving much smaller stochastic displacement during the lifetime of the insects concerned. This may be limiting our understanding of insect population dynamics. In the following synthesis, we provide an overview of how herbivorous insect movement is governed by both abiotic and biotic factors, making these animals essentially ''slaves of their environment''. No displaced insect or insect population can leave a resource patch, migrate and flourish, leaving descendants, unless suitable habitat and/or resources are reached during movement. This must have constrained insects over geological time, bringing about species-specific adaptation in behaviour and movements in relation to their environment at a micro- and macrogeographical scale. With insects that undergo long-range spatial displacements, e.g. aphids and locusts, there is presumably a selection against movement unless overruled by factors, such as density-dependent triggering, which cause certain genotypes within the population to migrate. However, for most insect species, spatial changes of scale and range expansion are much slower and may occur over a much longer time-scale, and are not innate (nor directed). Ecologists may say that all animals and plants are figuratively speaking ''slaves of their environments'', in the sense that their distribution is defined by their ecology and genotype. But in the case of insects, a vast number must perish daily, either out at sea or over other hostile habitats, having failed to find suitable resources and/or a habitat on which to feed and reproduce. Since many are blown by the vagaries of the wind, their chances of success are serendipitous in the extreme, especially over large distances. Hence, the strategies adopted by mass migratory species (innate pre-programmed flight behaviour, large population sizes and/or fast reproduction), which improve the chances that some of these individuals will succeed. We also emphasize the dearth of knowledge in the various interactions of insect movement and their environment, and describe how molecular markers (protein and DNA) may be used to examine the details of spatial scale over which movement occurs in relation to insect ecology and genotype.     

The television and the shrine: Towards a theoretical model for the study of mass communications in Nigeria 1

The context in which the new mass media are produced, distributed, and consumed in Nigeria differs as radically from the everyday world of the “developed” nations as it does from traditional Nigerian societies of a century ago. Many sociologists of mass communication have failed to address the issue of cultural difference in their accounts of media and their role in the third world. It is suggested that Weber's concepts of “enchantment” and “rationalization” should both be re‐examined if one wishes to better understand a world in which television and the ancestral shrine exist in both spatial and ideological proximity to one another.     

Hippocampal synaptic plasticity: role in spatial learning or the automatic recording of attended experience?

Allocentric spatial learning can sometimes occur in one trial. The incorporation of information into a spatial representation may, therefore, obey a one-trial correlational learning rule rather than a multi-trial error-correcting rule. It has been suggested that physiological implementation of such a rule could be mediated by N-methyl-D-aspartate (NMDA) receptor-dependent long-term potentiation (LTP) in the hippocampus, as its induction obeys a correlational type of synaptic learning rule. Support for this idea came originally from the finding that intracerebral infusion of the NMDA antagonist AP5 impairs spatial learning, but studies summarized in the first part of this paper have called it into question. First, rats previously given experience of spatial learning in a watermaze can learn a new spatial reference memory task at a normal rate despite an appreciable NMDA receptor blockade. Second, the classical phenomenon of ''blocking'' occurs in spatial learning. The latter finding implies that spatial learning can also be sensitive to an animal''s expectations about reward and so depend on more than the detection of simple spatial correlations. In this paper a new hypothesis is proposed about the function of hippocampal LTP. This hypothesis retains the idea that LTP subserves rapid one-trial memory, but abandons the notion that it serves any specific role in the geometric aspects of spatial learning. It is suggested that LTP participates in the automatic recording of attended experience'': a subsystem of episodic memory in which events are temporarily remembered in association with the contexts in which they occur. An automatic correlational form of synaptic plasticity is ideally suited to the online registration of context event associations. In support, it is reported that the ability of rats to remember the most recent place they have visited in a familiar environment is exquisitely sensitive to AP5 in a delay-dependent manner. Moreover, new studies of the lasting persistence of NMDA-dependent LTP, known to require protein synthesis, point to intracellular mechanisms that enable transient synaptic changes to be stabilized if they occur in close temporal proximity to important events. This new property of hippocampal LTP is a desirable characteristic of an event memory system.     

Topography of rodent whisking--I. Two-dimensional monitoring of whisker movements

During 'active touch' the rodent whiskers scan the environment in a series of repetitive movements ('whisks') generating afferent signals which transform the spatial properties of objects into spatio-temporal patterns of neural activity. Based upon analyses carried out in a single movement plane, it has been generally assumed that these trajectories are essentially uni-dimensional, although more complex movements have been described in some rodents. The present study was designed to examine this assumption and to more precisely characterize whisking topography by monitoring whisking trajectories along both the antero-posterior and dorso-ventral axes. Using optoelectronic monitoring techniques with high-spatio-temporal resolution, movement data were obtained from a population of vibrissae sampled at different locations on the mystacial pad in head-fixed rats isolated from the perturbing effects of contact. For a substantial proportion of the population of whisking movements sampled, the trajectories generated by a single whisker is most accurately described as occupying an expended two-dimensional space in which the A-P component predominates. However, the whisker system exhibits a considerable range of trajectory types, suggesting a high degree of movement flexibility. For each vibrissa position, it was possible to delineate a 'trajectory' domain -- that portion of the animal's whisking space which is scanned by the movements of that vibrissa during whisking. Since the 'domains' of adjacent whiskers in the same row tend to overlap, synchronized movements of a subset of whiskers could generate a set of overlapping somatosensory fields analogous to overlapping retinal receptive fields. The organization of such trajectory domains within the rats' whisking space could provide the spatial component of the spatio-temporal integration process required to extract information about environmental features from the inputs generated by its recursive whisking movements.     

A Simple Iterative Model Accurately Captures Complex Trapline Formation by Bumblebees Across Spatial Scales and Flower Arrangements

Pollinating bees develop foraging circuits (traplines) to visit multiple flowers in a manner that minimizes overall travel distance, a task analogous to the travelling salesman problem. We report on an in-depth exploration of an iterative improvement heuristic model of bumblebee traplining previously found to accurately replicate the establishment of stable routes by bees between flowers distributed over several hectares. The critical test for a model is its predictive power for empirical data for which the model has not been specifically developed, and here the model is shown to be consistent with observations from different research groups made at several spatial scales and using multiple configurations of flowers. We refine the model to account for the spatial search strategy of bees exploring their environment, and test several previously unexplored predictions. We find that the model predicts accurately 1) the increasing propensity of bees to optimize their foraging routes with increasing spatial scale; 2) that bees cannot establish stable optimal traplines for all spatial configurations of rewarding flowers; 3) the observed trade-off between travel distance and prioritization of high-reward sites (with a slight modification of the model); 4) the temporal pattern with which bees acquire approximate solutions to travelling salesman-like problems over several dozen foraging bouts; 5) the instability of visitation schedules in some spatial configurations of flowers; 6) the observation that in some flower arrays, bees'' visitation schedules are highly individually different; 7) the searching behaviour that leads to efficient location of flowers and routes between them. Our model constitutes a robust theoretical platform to generate novel hypotheses and refine our understanding about how small-brained insects develop a representation of space and use it to navigate in complex and dynamic environments.     

城市绿地与居民健康福祉相关性研究进展——基于生态系统服务供需匹配视角

城市绿地耦合了生态系统服务与人类福祉,兼顾公平与效率的城市绿地空间格局,是提升人居环境和改善民生的重要途径。在厘清相关概念内涵的基础上,基于Citespace软件对城市绿地生态系统服务与健康福祉及其相近概念进行关键词共现图谱与聚类分析,可以发现：研究集聚性强、各集群下研究领域重叠度高,研究尺度逐渐精细化,城市绿地与建成环境、休闲性体力活动与健康空间分异成为近几年研究热点。从供给侧：城市绿地绿地生态系统服务类型以及其估与测度方法,需求侧：居民健康福祉需求测度方法及时空表达,供需匹配：城市绿地生态系统服务供需匹配方法与空间公平,提升与调控：城市绿地时空结构优化与高效服务4个方面系统地综述了绿地生态系统服务与居民健康相关性研究,并指出目前城市绿地生态系统服务供需研究在研究内容、研究逻辑、研究方法及研究结果等方面还需进一步深化与提升。未来研究应重点关注城市绿地生态系统服务空间特征关系与居民健康需求层级的供需匹配程度,通过耦合新数据环境下精细化、规范性居民健康时空行为空间研究,总结供需平衡状态下多维度城市绿地高效服务的空间形态、功能结构与要素组织,并将其应用到城市绿地空间格局研究与绿地系统规划实践中,拓展人居环境优化提质的理论与方法。     

What do children think happens to the food they eat?

In this study, the explanations of two classes of 10-year old children about what happens to the food that they eat were explored, particularly in the context of theories about the development of children's concepts of the human body. These ideas were investigated in a number of ways: obtaining children's own writing and drawings; semi-structured individual interviews; and examining choices made between alternative explanations. The results suggested that children applied their knowledge of everyday materials to understand the initial stages of what happens to food, but their ideas about later stages were more tentative and within the group there was a range of different kinds of explanation preferred. The limitations and achievements of the children's thinking are considered in the context of the school curriculum.     

Thermodynamic Costs of Information Processing in Sensory Adaptation

Biological sensory systems react to changes in their surroundings. They are characterized by fast response and slow adaptation to varying environmental cues. Insofar as sensory adaptive systems map environmental changes to changes of their internal degrees of freedom, they can be regarded as computational devices manipulating information. Landauer established that information is ultimately physical, and its manipulation subject to the entropic and energetic bounds of thermodynamics. Thus the fundamental costs of biological sensory adaptation can be elucidated by tracking how the information the system has about its environment is altered. These bounds are particularly relevant for small organisms, which unlike everyday computers, operate at very low energies. In this paper, we establish a general framework for the thermodynamics of information processing in sensing. With it, we quantify how during sensory adaptation information about the past is erased, while information about the present is gathered. This process produces entropy larger than the amount of old information erased and has an energetic cost bounded by the amount of new information written to memory. We apply these principles to the E. coli''s chemotaxis pathway during binary ligand concentration changes. In this regime, we quantify the amount of information stored by each methyl group and show that receptors consume energy in the range of the information-theoretic minimum. Our work provides a basis for further inquiries into more complex phenomena, such as gradient sensing and frequency response.     

Law and ‘race’ in the citizenship spaces of Myanmar: spatial strategies and the political subjectivity of the Burmese Chinese

As Myanmar undergoes political and societal transition, observers are asking questions about citizenship and ethnic identity. How does one think about citizenship and people's negotiations with law in political-legal regimes that do not subscribe to liberal democratic norms? This paper investigates how law marginalizes the Burmese Chinese minority in Myanmar and the nature of their legal participation. Since law asserts cultural power impacting the way people think and behave, we engage with the concept of legal consciousness to understand how perceptions of legal vulnerability shape political subjectivity ambivalently. The paper highlights the spatial strategies and everyday practices that the Burmese Chinese deploy to navigate oppressive laws, but signals that internal social divisions and geopolitical considerations deter collective action towards rights assertion. It argues that studying the multiple sites and scales through which law is engaged contributes towards recovering citizenship aspirations where engagement with power and authority are articulated differently from Western norms.     

Putting flesh to the bone: looking for solidarity in diversity,here and now

In many Western European countries, concern rises that both formal mechanisms of redistribution and informal acts of charity, reciprocity and support are challenged by ethnic and cultural diversity. Against such gloomy perspectives, this paper draws on insights from sociology, geography, pedagogy and political science to argue that four traditional sources of solidarity (interdependence, shared norms and values, struggle and encounter) remain relevant, but require a rethinking of their spatial and temporal framing to capture today's intricate engagements of solidarity. More specifically, we draw on theories from the aforementioned disciplines to claim that our understanding of solidarities grounded in the spatial boundedness of territorial states and the intergenerational continuity of supposedly culturally homogeneous nations should be complemented and enriched with an in-depth knowledge of solidarities developing in an entirely different spatio-temporal register, namely that of the everyday places and practices in which people engage across ethnic and cultural boundaries.     

Affective loop experiences: designing for interactional embodiment

Involving our corporeal bodies in interaction can create strong affective experiences. Systems that both can be influenced by and influence users corporeally exhibit a use quality we name an affective loop experience. In an affective loop experience, (i) emotions are seen as processes, constructed in the interaction, starting from everyday bodily, cognitive or social experiences; (ii) the system responds in ways that pull the user into the interaction, touching upon end users'' physical experiences; and (iii) throughout the interaction the user is an active, meaning-making individual choosing how to express themselves—the interpretation responsibility does not lie with the system. We have built several systems that attempt to create affective loop experiences with more or less successful results. For example, eMoto lets users send text messages between mobile phones, but in addition to text, the messages also have colourful and animated shapes in the background chosen through emotion-gestures with a sensor-enabled stylus pen. Affective Diary is a digital diary with which users can scribble their notes, but it also allows for bodily memorabilia to be recorded from body sensors mapping to users'' movement and arousal and placed along a timeline. Users can see patterns in their bodily reactions and relate them to various events going on in their lives.The experiences of building and deploying these systems gave us insights into design requirements for addressing affective loop experiences, such as how to design for turn-taking between user and system, how to create for ‘open’ surfaces in the design that can carry users'' own meaning-making processes, how to combine modalities to create for a ‘unity’ of expression, and the importance of mirroring user experience in familiar ways that touch upon their everyday social and corporeal experiences.But a more important lesson gained from deploying the systems is how emotion processes are co-constructed and experienced inseparable from all other aspects of everyday life. Emotion processes are part of our social ways of being in the world; they dye our dreams, hopes and bodily experiences of the world. If we aim to design for affective interaction experiences, we need to place them into this larger picture.     

Evolution of Cooperation in Spatial Traveler's Dilemma Game

Traveler''s dilemma (TD) is one of social dilemmas which has been well studied in the economics community, but it is attracted little attention in the physics community. The TD game is a two-person game. Each player can select an integer value between and () as a pure strategy. If both of them select the same value, the payoff to them will be that value. If the players select different values, say and (), then the payoff to the player who chooses the small value will be and the payoff to the other player will be . We term the player who selects a large value as the cooperator, and the one who chooses a small value as the defector. The reason is that if both of them select large values, it will result in a large total payoff. The Nash equilibrium of the TD game is to choose the smallest value . However, in previous behavioral studies, players in TD game typically select values that are much larger than , and the average selected value exhibits an inverse relationship with . To explain such anomalous behavior, in this paper, we study the evolution of cooperation in spatial traveler''s dilemma game where the players are located on a square lattice and each player plays TD games with his neighbors. Players in our model can adopt their neighbors'' strategies following two standard models of spatial game dynamics. Monte-Carlo simulation is applied to our model, and the results show that the cooperation level of the system, which is proportional to the average value of the strategies, decreases with increasing until is greater than the critical value where cooperation vanishes. Our findings indicate that spatial reciprocity promotes the evolution of cooperation in TD game and the spatial TD game model can interpret the anomalous behavior observed in previous behavioral experiments.     

Weather Effects on the Patterns of People's Everyday Activities: A Study Using GPS Traces of Mobile Phone Users

This study explores the effects that the weather has on people''s everyday activity patterns. Temperature, rainfall, and wind speed were used as weather parameters. People''s daily activity patterns were inferred, such as place visited, the time this took place, the duration of the visit, based on the GPS location traces of their mobile phones overlaid upon Yellow Pages information. Our analysis of 31,855 mobile phone users allowed us to infer that people were more likely to stay longer at eateries or food outlets, and (to a lesser degree) at retail or shopping areas when the weather is very cold or when conditions are calm (non-windy). When compared to people''s regular activity patterns, certain weather conditions affected people''s movements and activities noticeably at different times of the day. On cold days, people''s activities were found to be more diverse especially after 10AM, showing greatest variations between 2PM and 6PM. A similar trend is observed between 10AM and midnight on rainy days, with people''s activities found to be most diverse on days with heaviest rainfalls or on days when the wind speed was stronger than 4 km/h, especially between 10AM–1AM. Finally, we observed that different geographical areas of a large metropolis were impacted differently by the weather. Using data of urban infrastructure to characterize areas, we found strong correlations between weather conditions upon people''s accessibility to trains. This study sheds new light on the influence of weather conditions on human behavior, in particular the choice of daily activities and how mobile phone data can be used to investigate the influence of environmental factors on urban dynamics.     

Action Possibility Judgments of People with Varying Motor Abilities Due to Spinal Cord Injury

Predictions about one''s own action capabilities as well as the action capabilities of others are thought to be based on a simulation process involving linked perceptual and motor networks. Given the central role of motor experience in the formation of these networks, one''s present motor capabilities are thought to be the basis of their perceptual judgments about actions. However, it remains unknown whether the ability to form these action possibility judgments is affected by performance related changes in the motor system. To determine if judgments of action capabilities are affected by long-term changes in one''s own motor capabilities, participants with different degrees of upper-limb function due to their level (cervical vs. below cervical) of spinal cord injury (SCI) were tested on a perceptual-motor judgment task. Participants observed apparent motion videos of reciprocal aiming movements with varying levels of difficulty. For each movement, participants determined the shortest movement time (MT) at which they themselves and a young adult could perform the task while maintaining accuracy. Participants also performed the task. Analyses of MTs revealed that perceptual judgments for participant''s own movement capabilities were consistent with their actual performance- people with cervical SCI had longer judged and actual MTs than people with below cervical SCI. However, there were no between-group differences in judged MTs for the young adult. Although it is unclear how the judgments were adjusted (altered simulation vs. threshold modification), the data reveal that people with different motor capabilities due to SCI are not completely biased by their present capabilities and can effectively adjust their judgments to estimate the actions of others.     

Joint Entropy for Space and Spatial Frequency Domains Estimated from Psychometric Functions of Achromatic Discrimination

We used psychometric functions to estimate the joint entropy for space discrimination and spatial frequency discrimination. Space discrimination was taken as discrimination of spatial extent. Seven subjects were tested. Gábor functions comprising unidimensionalsinusoidal gratings (0.4, 2, and 10 cpd) and bidimensionalGaussian envelopes (1°) were used as reference stimuli. The experiment comprised the comparison between reference and test stimulithat differed in grating''s spatial frequency or envelope''s standard deviation. We tested 21 different envelope''s standard deviations around the reference standard deviation to study spatial extent discrimination and 19 different grating''s spatial frequencies around the reference spatial frequency to study spatial frequency discrimination. Two series of psychometric functions were obtained for 2%, 5%, 10%, and 100% stimulus contrast. The psychometric function data points for spatial extent discrimination or spatial frequency discrimination were fitted with Gaussian functions using the least square method, and the spatial extent and spatial frequency entropies were estimated from the standard deviation of these Gaussian functions. Then, joint entropy was obtained by multiplying the square root of space extent entropy times the spatial frequency entropy. We compared our results to the theoretical minimum for unidimensional Gábor functions, 1/4π or 0.0796. At low and intermediate spatial frequencies and high contrasts, joint entropy reached levels below the theoretical minimum, suggesting non-linear interactions between two or more visual mechanisms. We concluded that non-linear interactions of visual pathways, such as the M and P pathways, could explain joint entropy values below the theoretical minimum at low and intermediate spatial frequencies and high contrasts. These non-linear interactions might be at work at intermediate and high contrasts at all spatial frequencies once there was a substantial decrease in joint entropy for these stimulus conditions when contrast was raised.     

From Moral Protest to Religious Politics: Ethical Demands and Beur Political Action in France

This paper traces the responses of Muslim youths ('Beurs') to their marginalisation in France. The Beur movement acquired national significance via the politicisation of moral protest in the early 1980s. In spite of early successes, the movement stumbled when the 'politics of austerity' adopted by the French state amplified a social crisis for which migrants became the scapegoats. The Beur movement, like other youth movements of the period, expressed a search for solidarity and a stress on ethical demands. Beurs' disenchantment when their civic elan ran out in the face of everyday difficulties led some to transfer their search for solidarity to the terrain of Islam. Islam, the paper argues, often appears to provide answers to the particular complex of politico-ethical demands for social justice and dignity that the Beur movement expressed. However, the Islamist re-conversion of some Beur militants is to be read as the result of a particular conjunction of multiple power relations which would integrate economic, social, cultural and gender dimensions. It is not necessarily indicative of a failure of the politics of moral protest to promote progressive transformational politics.