Everyday Navigation Research Articles

Muslim American University Students’ Perceptions of Islam and Democracy: Deconstructing the Dichotomy

The aftermath of 9/11 and the current surge of revolutions in North Africa and the Middle East have caused Muslim Americans to be either demonized or forgotten altogether, despite the significance of their everyday navigation of both Islamic and democratic values and unique efforts toward identity construction. The neglect of the Muslim American individual experience in the dominant discourse on Islam and democracy has stifled the voices of members of this marginalized population, thereby limiting their self-representation. Through the use of a phenomenological framework and Critical Discourse Analysis, this study complicates the dominant discourses on Islam and democracy by shedding light on the lived experiences of seven Muslim American university students and providing supplemental perspectives from their university professors. These participants constructed an alternative discourse that positioned the Islamic and democratic values of equality, respect, freedom, and education as compatible, albeit with some complications. The article concludes with suggestions toward better understanding and enactment of Islamic and democratic values, including attaining education and engaging in civic participation.

What verbal orientation information do blind and partially sighted people need to find their way around? A study of everyday navigation strategies in people with impaired vision

For wayfinding at museums, galleries, and heritage sites, the majority of people who are blind or partially sighted favour verbal directions over tactile maps. Those who provide such directions are usually fully sighted. Can we assume that details considered important by those with vision are equally helpful to those without? This article presents a study comparing descriptions of familiar routes recalled by fully sighted, partially sighted, and blind participants, highlighting the differences in navigation strategies. All participants cited landmarks, but those with impaired vision also detailed significantly more objects, or ‘milestones’, en route. In the absence of such milestones, they relied on metrics that were often environmental or body-based. Distances were precisely specified, rather than ‘vague’. Landmarks and milestones were accessed multimodally by blind and partially sighted participants, or a combination of landmarks and milestones were sought for corroboration. In contrast, fully sighted participants reported predominantly unimodal information, that is, visual. The findings may have practical implications for improving the type of verbal orientation information provided to assist blind or partially sighted people.

Systematic Biases in Human Heading Estimation

Heading estimation is vital to everyday navigation and locomotion. Despite extensive behavioral and physiological research on both visual and vestibular heading estimation over more than two decades, the accuracy of heading estimation has not yet been systematically evaluated. Therefore human visual and vestibular heading estimation was assessed in the horizontal plane using a motion platform and stereo visual display. Heading angle was overestimated during forward movements and underestimated during backward movements in response to both visual and vestibular stimuli, indicating an overall multimodal bias toward lateral directions. Lateral biases are consistent with the overrepresentation of lateral preferred directions observed in neural populations that carry visual and vestibular heading information, including MSTd and otolith afferent populations. Due to this overrepresentation, population vector decoding yields patterns of bias remarkably similar to those observed behaviorally. Lateral biases are inconsistent with standard Bayesian accounts which predict that estimates should be biased toward the most common straight forward heading direction. Nevertheless, lateral biases may be functionally relevant. They effectively constitute a perceptual scale expansion around straight ahead which could allow for more precise estimation and provide a high gain feedback signal to facilitate maintenance of straight-forward heading during everyday navigation and locomotion.

Executive and memory correlates of age-related differences in wayfinding performances using a virtual reality application

ABSTRACT The aim of this study was to evaluate in large-scale spaces wayfinding and spatial learning difficulties for older adults in relation to the executive and memory decline associated with aging. We compared virtual reality (VR)-based wayfinding and spatial memory performances between young and older adults. Wayfinding and spatial memory performances were correlated with classical measures of executive and visuo-spatial memory functions, but also with self-reported estimates of wayfinding difficulties. We obtained a significant effect of age on wayfinding performances but not on spatial memory performances. The overall correlations showed significant correlations between the wayfinding performances and the classical measures of both executive and visuo-spatial memory, but only when the age factor was not partialled out. Also, older adults underestimated their wayfinding difficulties. A significant relationship between the wayfinding performances and self-reported wayfinding difficulty estimates is found, but only when the age effect was partialled out. These results show that, even when older adults have an equivalent spatial knowledge to young adults, they had greater difficulties with the wayfinding task, supporting an executive decline view in age-related wayfinding difficulties. However, the correlation results are in favor of both the memory and executive decline views as mediators of age-related differences in wayfinding performances. This is discussed in terms of the relationships between memory and executive functioning in wayfinding task orchestration. Our results also favor the use of objective assessments of everyday navigation difficulties in virtual applications, instead of self-reported questionnaires, since older adults showed difficulties in estimating their everyday wayfinding problems.

Conceptual layers and strategies in tour planning

We present an exploratory study of an everyday navigation planning situation, addressing spatial planning strategies as well as cognitive shifts between the visually available map and the conceptualized real-world environment. Participants were asked to plan a diversified holiday route on an island, with the help of a map representing spatial as well as activity information. Following the task proper, they reported in written form about the problem-solving process. Route trajectories were analyzed with respect to their properties, and reports were analyzed with respect to the represented concepts and linguistic patterns. Results reveal that route trajectories tended to be circular rather than random, with relatively few detours or crossing lines. The underlying spatial planning strategies as represented in the written reports resembled earlier findings on the Traveling Salesperson Problem, providing insights into the extent to which this abstract task transfers to a naturalistic scenario. Most crucially, our linguistic analysis provides new results about the representation of conceptual layers when considering the real-world navigation domain of traveling in relation to the actual table-top map planning domain.

Executive Control Deficits as a Prodrome to Falls in Healthy Older Adults: A Prospective Study Linking Thinking, Walking, and Falling

Executive function (EF) deficits may increase fall risk, even among older adults with no overt cognitive impairment. Indeed, the effects of dual tasking (DT) on gait, a challenge to executive control, are more exaggerated in persons with a history of falls. Prospective evidence is, however, lacking. We prospectively evaluated whether EF predicts falls over a 2-year period among 262 community-living, healthy, and well-functioning older adults, focusing on the 201 who reported no falls during the previous year. At baseline, participants completed a computerized cognitive battery that generated an index of EF and other cognitive domains. Gait was assessed using performance-based tests and by quantifying walking during single- and dual-task conditions. The 262 participants (mean age: 76.3 ± 4.3 years, 60.3% women) had intact cognitive function on testing, a low comorbidity index, and good mobility. The EF index predicted future falls. Among those who reported no previous falls, participants in the worst EF quartile were three times more likely to fall during the 2 years of follow-up, and they were more likely to transition from nonfaller to faller sooner. DT gait variability also predicted future falls and multiple falls, whereas other measures of cognitive function, gait, and mobility did not. Among healthy older adults, individuals with poorer EF are more prone to falls. Higher-level cognitive functions such as those regulated by the frontal lobes are apparently needed for safe everyday navigation that demands multitasking. Optimal screening, early detection, and treatment of falls should, apparently, also target this cognitive domain.

Cognitive load of navigating without vision when guided by virtual sound versus spatial language.

A vibrotactile N-back task was used to generate cognitive load while participants were guided along virtual paths without vision. As participants stepped in place, they moved along a virtual path of linear segments. Information was provided en route about the direction of the next turning point, by spatial language ("left," "right," or "straight") or virtual sound (i.e., the perceived azimuth of the sound indicated the target direction). The authors hypothesized that virtual sound, being processed at direct perceptual levels, would have lower load than even simple language commands, which require cognitive mediation. As predicted, whereas the guidance modes did not differ significantly in the no-load condition, participants showed shorter distance traveled and less time to complete a path when performing the N-back task while navigating with virtual sound as guidance. Virtual sound also produced better N-back performance than spatial language. By indicating the superiority of virtual sound for guidance when cognitive load is present, as is characteristic of everyday navigation, these results have implications for guidance systems for the visually impaired and others.

Dissociable Retrosplenial and Hippocampal Contributions to Successful Formation of Survey Representations

During everyday navigation, humans encounter complex environments predominantly from a first-person perspective. Behavioral evidence suggests that these perceptual experiences can be used not only to acquire route knowledge but also to directly assemble map-like survey representations. Most studies of human navigation focus on the retrieval of previously learned environments, and the neural foundations of integrating sequential views into a coherent representation are not yet fully understood. We therefore used our recently introduced virtual-reality paradigm, which provides accuracy and reaction-time measurements precisely indicating the emergence of survey knowledge, and functional magnetic resonance imaging while participants repeatedly encoded a complex environment from a first-person ground-level perspective. Before the experiment, we gave specific instructions to induce survey learning, which, based on the clear evidence for emerging survey knowledge in the behavioral data from 11 participants, proved successful. Neuroimaging data revealed increasing activation across sessions only in bilateral retrosplenial cortices, thus paralleling behavioral measures of map expertise. In contrast, hippocampal activation did not follow absolute performance but rather reflected the amount of knowledge acquired in a given session. In other words, hippocampal activation was most prominent during the initial learning phase and decayed after performance had approached ceiling level. We therefore conclude that, during navigational learning, retrosplenial areas mainly serve to integrate egocentric spatial information with cues about self-motion, whereas the hippocampus is needed to incorporate new information into an emerging memory representation.

SOME APPLICATIONS OF AUTOMATIC NAVIGATION*

In recent years the art of automatic navigation of aircraft has reached its maturity. While it is not yet common for navigators to turn a few dials and then sit back while some machine performs all of the functions of aircraft navigation, the fundamental principles have been studied extensively and experimental models have been used to navigate with acceptable precision over ranges up to several thousands of miles. The next step in the development of these techniques is their exploitation, i.e., they must be developed in their performance and accepted by their users so that they will become a part of everyday aerial navigation.