How Navigational Aids Impair Spatial Memory: Evidence for Divided Attention

Abstract

Research has demonstrated navigational aids impair spatial memory, but has not considered important spatial cognitive concepts. For example, impairment may stem from spatial perspective switches between route-based aids and survey-based memory assessments. Further, the verbal format of aid instructions may selectively interfere with verbal working memory (VWM). To address these potential explanations, participants navigated desktop virtual environments in a goal-directed manner. In each within-participants condition, participants either navigated with a verbal or tonal aid that presented mixed spatial perspective instructions or without aid. Both aids yielded slight navigational advantages and steep spatial memory costs despite their mixed perspective instructions. The equivalent impairment between information formats suggests navigational aids impair spatial memory by dividing attention rather than selective interference of VWM.     

Contributing Factors to Temporal and Spatial Associations in Mental Representations of Maps

Abstract

The present work explores an interactive model of spatial and temporal information in map memory. In four experiments, participants learned a map with temporal and spatial information confounded or unconfounded. Attentional and representational levels of information were made apparent through tasks that tap spatial, temporal, or other information. Learning criteria emphasizing sequential order or location imposed differential weighting of the information types in memory. Results indicate that map memory is spatial, but also interacts with the order in which map locations are encountered. Findings show flexibility in allocating attention and information indexing of location and sequential order information in map learning.     

Interactivity in map learning: The effect of cognitive load

The hypothesis that active learning is beneficial relative to passive observation was assessed in the context of spatial knowledge derived from maps. Active and passive participants studied a map either while performing a simultaneous spatial tapping task (high cognitive load) or in the absence of this task (low cognitive load). Active participants controlled how the map was learned, with passive participants observing map learning without exercising control. Spatial recall was assessed in two tests, directional judgements and map drawing. Map drawing and directional judgments showed a similar pattern of results, with performance detrimentally affected by a high load for active participants, but not for passive participants. The results indicate that activity and cognitive load interact, suggesting that active learning can be detrimental to spatial learning in cognitively demanding tasks.     

Timing and sex effects on the “Spatial Orientation Test”: A World War II map reading test

The present study aimed to document the psychometric properties of a recently declassified map reading test used in World War II, known as the Spatial Orientation Test (SOT), which measures mostly the ability to match map and aerial images. We also examined the influence of timing conditions and sex of the participants as correlates of performance. A total of 101 participants (41 males, 60 females) completed the SOT, along with other spatial tests and spatial affect scales (tapping spatial anxiety and confidence). Results showed a significant male advantage on this rediscovered map reading test. Additionally, timing affected overall performance but not the magnitude of sex differences. Finally, significant correlations were found between the SOT and other spatial tests and scales. The processes underlying this test and its potential for future use are discussed.     

Influence of Map Design,Individual Differences,and Environmental Cues on Wayfinding Performance

This exploratory study investigated the effects of map design, individual differences, and environmental cues on wayfinding performance in an outdoor recreational area. Six maps, with three contour representations and two color codes, were used to determine how map design influences wayfinding. Four individual differences: gender, experience in map usage (experience vs. novice), handedness, and cultural difference (local vs. international), were used to predict wayfinding performance. The study area consisted of a trail park with ten junctions, where three of the junctions had signs, as environmental cues to aid users. Multiple regression analyses and logistic regression analysis were performed to predict the total time of completion, time for decision-making, accuracy of decision-making, and total time deviated from route. Results showed that only cultural difference and signage significantly predicted decisionmaking accuracy, and cultural difference was a significant predictor of total time deviated from route. Design implications for use of cues and wayfinding are discussed. In addition, recommendations for maps, trail networks, and environmental design are provided.     

Seeing the Forest or the Trees? Shifting Categorical Effects in Map Memory

People use spatial and nonspatial information to structure memory for an environment. Two experiments explored interactions between spatial and social categories on map memory when mediated by retrieval (Experiment 1) and encoding (Experiment 2) demands. Participants studied a map depicting business locations (including proprietors' race). In Experiment 1, participants completed two memory tasks, one globally focused and the other locally focused. The global task compressed, while the local task expanded, within-category similarity. Furthermore, processing styles carried over to the subsequent task. Experiment 2 emphasized either the spatial or social category during encoding, which increased that category's weighting in memory. These results extend the work of Maddox, Rapp, Brion, and Taylor, suggesting that retrieval and encoding demands can shift how these categories affect spatial memory.     

Place learning in humans: The role of distance and direction information

Although the process of establishing a memoryof a location is necessary for navigation,relatively little is known about theinformation that humans use when forming placememories. We examined the relative importanceof distance and angular information aboutlandmarks in place learning. Participantsrepeatedly learned a target location inrelation to three distinct landmarks in animmersive computer-generated (virtual)environment. Later, during testing, theyattempted to return to that location. Theconfigurations of landmarks used during testingwere altered from those participants learned inorder to separate the effects of metricdistance information and information aboutinter-landmark angles. In general,participants showed greater reliance ondistance information than angular information. This reliance was affected by nonmetricrelationships present during learning, as wellas by the degree to which the learnedenvironment contained right or straightangles.     

晃动基座下正向-正向回溯初始对准方法

针对传统方式需要对准时间长的问题,提出一种晃动基座下正向-正向回溯初始对准方法,实现了快速初始对准的目的。首先,给出了导航惯性系粗对准的基本原理,分析了导航惯性系粗对准在回溯过程中的作用。其次,对捷联惯导系统初始对准过程进行了深入的研究,利用导航惯性系建立精对准系统误差模型,将晃动基座时变姿态误差角估计问题转换为时不变姿态误差角估计问题,进而为正向-正向回溯对准奠定了理论基础。在此基础上,详细分析了正向-正向回溯对准的基本原理和设计方法。最后,通过设计仿真实验,验证了本文设计的对准方法可以在303 s内实现晃动基座上航向误差优于0.1°的对准精度。试验结果表明,本文提出的方法具有计算效率高、对准时间短、对准精度高的优点。     

基于天文角度观测的机载惯性/天文组合滤波算法研究

针对采用天文/惯性位置组合时对导航选星有特殊要求,提出了基于天文角度观测信息的机载惯性/天文组合滤波方案及算法.对基于天文角度观测的INS/CNS组合导航系统的原理进行了充分阐述,分析并建立了基于单星或多星观测条件下的组合导航系统线性化量测方程,并针对角度观测时高度通道不可观的特点,增加了气压高度输出为系统的观测量,并在此基础上设计了组合滤波器算法.最后进行了组合导航系统仿真,并通过协方差分析的方法对比分析了单星和双星观测条件下的滤波性能.仿真结果表明,即使是在单星观测条件下,组合导航系统也能获得较好的定位精度;若观测星数增多,则可以大大提高系统性能,表明该组合导航系统设计方案是成功可行的.     

Spatial Influence of Environmental Axes in a Baseball Field

Abstract

We investigated the influence of environmental axes in a baseball field. In Experiment 1, participants walked either a path in the prototypical orientation (home plate to second base) or one which was rotated 225°. Recall for object locations was best when participants imagined themselves aligned with axes salient from the experienced orientation. In Experiment 2, when learning was through a route text, there was less of an influence of environmental axes. In Experiment 3, when participants walked both paths, memories were good for the atypical orientation, suggesting that task-specific spatial cues can be more influential than a prior conceptual north.     

Route generation and description using the notions of object's influence area and spatial conceptual map

In the GRAAD Project we aimed at creatinga system which could generate route directions thatare comparable to route directions created by humanparticipants. With this goal in mind, we started froma linguistic and cognitive study of route directionsproduced by people and the study of cognitive modelsof mental maps. We proposed a new qualitative spatialmodel that can support the spatial properties of humanroute directions. This model is based on the notion ofobject's influence area which is used to modelneighborhood, orientation and distance. The proposedapproach relies on the manipulation of spatialentities in a spatial conceptual map (SCM) which isthe computarized analog of a mental map used bypeople. We developped the GRAAD System, software thatgenerates routes in a SCM and describes them innatural language. Finally, we conducted an experimentin order to compare GRAAD's route directions androutes described by human participants in similarexperimental conditions. GRAAD's output was notdistinguishable from route directions created by humanparticipants. In this paper we present the mainresults obtained during all phases of the GRAADProject.     

星载测控应答机中嵌套环路仿真与优化

建立了星载测控应答机中嵌套环路的仿真模型,对测控应答机中嵌套锁相环路进行了分析和优化。分析发现,存在一个最佳环路带宽,使接收机锁定时间最快;嵌套结构与单环结构相比,可以获得更优的噪声特性。这些结果已用于微小型化星载测控应答机设计中,并得到实验的验证。本文建立的仿真模型可用于测控应答机的设计、调试过程,以寻求最佳设计参数、提高性能指标。     

Dysfunctions of Spatial Cognition in Schizophrenic Patients

ABSTRACT

Twenty outpatients who fulfilled the criteria for a diagnosis of schizophrenia and 28 control participants were invited to learn a route through a complex outdoor environment. They were then tested in tasks intended to explore various aspects of their memorized representation of the navigational episode. Compared to controls, the patients showed significant impairment in both the verbal production of route directions and the drawing of sketch maps. They referred to fewer landmarks and provided fewer directional instructions than the controls, while making a greater number of irrelevant comments. When invited to distinguish between photographs showing views of landmarks encountered along the route and distractors, they performed as well as the controls, and they had similar response times. However, when they were presented with pairs of actual photographs taken along the route, they displayed special difficulty in deciding which of the two landmarks was encountered first along the route. This difficulty in retrieving the sequential structure of the navigational episode suggests that the patients' memories were not accurately linked to one another in their mental representation of the route. These findings are interpreted in the context of current hypotheses about the hippocampal impairment that affects schizophrenic patients.     

Navigation in outdoor environments as an embodied,social, cultural,and situated experience: An empirical study of orienteering

This study investigated novices' “lived experiences” of navigation within the sport of orienteering from an enactive and phenomenological approach. The objective was to qualitatively characterize elements of task-related situations that were meaningful for orienteers. The results showed that the participants continuously made judgments about the reliability of their estimations about whether they were on “the right route” on the course. When the participants judged that they were only approximately on the right route or were unable to locate themselves, elements of the situation other than map and terrain features became meaningful for them. These results demonstrate that, for novice orienteers, navigation activity must extend beyond navigation as a logical, computational way-finding problem to include embodied, social, cultural and situated dimensions.     

Environmental reference systems for large-scale spaces

Human navigation in well-known environments is guided by stored memory representations of spatial information. In three experiments (N = 43) we investigated the role of different spatial reference systems when accessing information about familiar objects at different locations in the city in which the participants lived. Our results indicate that two independent reference systems underly the retrieval of spatial knowledge. Environmental characteristics, e.g., the streets at an intersection, determine which headings are easier to imagine at a given location and lead to differences in accessibility of spatial information (orientation-specific behavior). In addition, access to spatial information depends on the relative direction of a location with respect to the imagined heading, such that information about locations imagined in front of oneself is easier to access than about locations towards the back. This influence of an egocentric reference system was found for environmental knowledge as well as map-based knowledge. In light of these reference system effects, position-dependent models of spatial memory for large-scale environments are discussed. To account for the simultaneous effect of an environmental and an egocentric reference system, we present a 2-level model of spatial memory access.     

基于狄氏先验分布的固体火箭发动机可靠性增长Bayes分析

针对固体火箭发动机研制存在历史信息和专家信息的特点,提出了一种可靠性增长分析的Bayes模型。以狄氏分布作为先验分布,给出了先验分布参数的确定方法。综合利用了先验信息和每一阶段现场试验信息,推导了各阶段可靠性的后验边际分布。给出了当前阶段和后续阶段产品可靠性的Bayes点估计和置信下限,分析了各阶段试验结果对最终产品可靠性估计的影响。最后给出了一个实例,验证了该模型的有效性。     

List of reviewers

Studies of map-learning have suggested that viewing maps from several orientations results in orientation independent encoding. The present investigation examined this claim. Three groups of participants were presented with a map from one orientation, or four orientations, or with the map constantly rotating. Participants' spatial knowledge was then assessed in a pointing task. Response latencies were fastest following presentations of the map from a single orientation. Contrary to earlier results, multiple views led to orientation dependent encoding when account was taken of participants'preferred map orientations. The findings are consistent with the notion that similar mental representations are acquired following single and multiple map views.     

Mental representation of spatial cues in microgravity: Writing and drawing tests

Humans have mental representation of their environment based on sensory information and experience. A series of experiments has been designed to allow the identification of disturbances in the mental representation of three-dimensional space during space flight as a consequence of the absence of the gravitational frame of reference. This NASA/ESA-funded research effort includes motor tests complemented by psychophysics measurements, designed to distinguish the effects of cognitive versus perceptual-motor changes due to microgravity exposure. Preliminary results have been obtained during the microgravity phase of parabolic flight. These results indicate that the vertical height of handwritten characters and drawn objects is reduced in microgravity compared to normal gravity, suggesting that the mental representation of the height of objects and the environment change during short-term microgravity. Identifying lasting abnormalities in the mental representation of spatial cues will establish the scientific and technical foundation for development of preflight and in-flight training and rehabilitative schemes, enhancing astronaut performance of perceptual-motor tasks, for example, interaction with robotic systems during exploration-class missions.