Human Spatial Orientation Research Articles

Memory effects of visual and olfactory landmark information in human wayfinding

Non-human animals are exceptionally good at using smell to find their way through the environment. However, the use of olfactory cues for human navigation is often underestimated. Although the sense of smell is well-known for its distinct connection to memory and emotion, memory effects in human navigation using olfactory landmarks have not been studied yet. Therefore, this article compares wayfinding and recognition performance for visual and olfactory landmarks learned by 52 participants in a virtual maze. Furthermore, it is one of the first empirical studies investigating differences in memory effects on human navigation by using two separate test situations 1 month apart. The experimental task was to find the way through a maze-like virtual environment with either olfactory or visual cues at the intersections that served as decision points. Our descriptive results show that performance was above chance level for both conditions (visual and olfactory landmarks). Wayfinding performance did not decrease 1 month later when using olfactory landmarks. In contrast, when using visual landmarks wayfinding performance decreased significantly, while visual landmarks overall lead to better recognition than olfactory landmarks at both times of testing. The results demonstrate the unique character of human odor memory and support the conclusion that olfactory cues may be used in human spatial orientation. Furthermore, the present study expands the research field of human wayfinding by providing a study that investigates memory for landmark knowledge and route decisions for the visual and olfactory modality. However, more studies are required to put this important research strand forward.

Examination of Human Spatial Reasoning Capability and Simulated Autonomous Rendezvous and Docking Monitoring Performance

Autonomous rendezvous and docking (ARD) maneuvers are challenging tasks that require collaboration between a human and a spacecraft to be successful. As automation becomes more integrated into ARD systems, it is important to consider when and why a human may take control. Intrinsic human characteristics can influence these decisions. We consider how human spatial orientation capacity affects participants when monitoring a simulated ARD maneuver and initiating takeover when the system is perceived to be failing. Participants’ spatial reasoning capability was assessed and compared to performance in the monitoring task and perceived mental workload. While participants showed high rates of success in the task, they showed a wide range in spatial reasoning capacity and perceived mental demand. Spatial reasoning capacity did not indicate participants’ mental workload, which has implications for the human as the supervisor. These results inform future work on augmentative displays that may incorporate exocentric and egocentric views.

Flying enhances viewing from above bias on ambiguous visual stimuli.

The human spatial orientation system is well designed on the ground but is imperfect in the aeronautical three-dimensional (3D) environment. However, human perception systems perform Bayesian statistics based on encountered environments and form shortcuts to improve perceptual efficiency. It is unknown whether our perception of spatial orientation is modified by flying experience and forms perceptual biases. The current study tested pilot perceptual biases on ambiguous visual stimuli, the bistable point-light walkers, and found that flying experiences increased the pilot's tendency to perceive himself as higher than the target and the target as farther away from them. Such perceptual effects due to flight are likely to be attributed to experience of variable vestibular state in a higher position in 3D space, rather than the experience of a higher viewpoint. Our findings suggest that flying experience will modifies our visual perceptual biases, and that more attention should be paid to the enhanced viewing from above bias when flying to avoid overestimating altitude or viewing angle when the visual conditions are ambiguous.

Towards a flexible and generalizable computational model-based framework for mitigation of spatial disorientation in sensory-deprived environments

PurposeSpatial disorientation (SD), an incorrect perception of one's orientation, position or motion, jeopardizes the safety and performance of aviators, astronauts, and professionals in other domains such as SCUBA and firefighting. Active countermeasures can assist navigators in real-time with maintaining orientation – and may mitigate the deleterious impacts of SD. A necessary component of such a system, however, is a method by which to estimate possible SD being experienced, and detect when intervention is warranted. Computational tools utilizing models of human spatial orientation perception provides an unobtrusive means to estimate the spatial awareness of the navigator. Previously proposed computational detection methods, however, have been designed to capture specific SD events that are commonly experienced by fixed-wing aircraft pilots. We propose a generalizable computational framework that can be adapted to different environments, vehicles (e.g., spacecraft) and operating theatres. ProposalWe leverage the state-of-the-art Observer model to compute spatial orientation perception in sequence with an integrative algorithm to capture the severity of orientation misperception over time. A Bayesian likelihood model is used for system and parameter identification of the proposed algorithm candidates we have developed. A novel two-part experimental methodology is proposed to first gather necessary data for informing likelihood estimators (e.g., estimates of SD), and then assess the potential system benefits (e.g., safety, control performance) while using a well-tuned computational detection tool in real-time. ImplementationSimulated motion stimuli were used in the development of algorithm candidates and optimization techniques. Our simulation results and application of the generalized framework to various navigation environments demonstrate the utility of capturing all state parameters related to orientation perception (e.g., acceleration, angular velocity, zenith etc.) which enables the system to capture the continuum of SD involving a variety of different stimuli. As a proof-of-concept effort, we have developed an experimental paradigm representing a helicopter piloting scenario in the presence of mission-related distractions. ConclusionThe proposed computational tool, when appropriately fitted for the environment of relevance, may be used to trigger real-time countermeasure interventions for the goal of mitigating adverse impacts of SD events in operational environments. SD can manifest in drastically different ways given the sensory environment, such as an absence of a tonic loading of gravity during spaceflight. The integrative and generalizable nature of this framework may facilitate translatable progress in SD mitigation research across the many domains which it plagues.

Visual space orientation and representational gravity: Contextual orientation visual cues modulate the perceptual extrapolation of motion.

The perceived offset of a moving target is usually displaced forward, in the direction of motion (representational momentum), and downward, in the direction of gravity (representational gravity). In what refers to the latter, the meaning of "downward in the direction of gravity" is ill-defined, for it is known that the perceived direction of gravity ("downward") results from the interaction of vestibular signals, sensitive to the gravito-inertial vector, an aprioristic tendency to assume that it aligns with the body's main axis (idiotropic vector) and visual cues. The present work aims to disclose what effects visual cues have on representational gravity. Participants performed a spatial localization task as well as a subjective visual vertical (SVV) and an oriented character recognition task (OCHART), with stimuli superimposed on a realistic background either aligned with earth's vertical or tilted rightward or leftward. Outcomes disclosed significant and lawful effects of the orientation of the visual context on spatial localization judgements. Specifically, forward displacement along the target's motion direction was bigger for targets moving along the "horizontal" direction implied by the background scene. These trends were furthermore found to be correlated, at an individual level, with the magnitude of SVV, but not with the perceptual upright (as measured with OCHART). These findings show that features of the spatial localization judgements specifically index the visually induced spatial orientation, thus offering the prospect to expand available tools for inquiries concerning human spatial orientation, besides clarifying the multisensorial nature and significantly expanding the notion of representational gravity. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Evaluation of APOE ɛ2/ɛ3/ɛ4 Alleles in a Cohort of Individuals Affected by Developmental Topographical Disorientation.

The three common alleles of the APOE gene, ɛ2/ɛ3/ɛ4, have been linked to human spatial orientation. We investigated the genetic role of APOE in developmental topographical disorientation (DTD), a lifelong condition that results in topographical disorientation. We genotyped the APOE ɛ2/ɛ3/ɛ4 alleles in a cohort of 20 unrelated DTD probands, and found allele frequencies not statistically different from the those seen in the population as a whole. Therefore, we found no evidence that DTD occurs preferentially on a genetic background containing any particular APOE allele, making it unlikely that these APOE alleles are contributing to the development of DTD.

Spatial orientation in virtual environment compared to real-world

Virtual reality (VR) is popular across many disciplines and has been increasingly used in sports as a training tool lately. However, it is not clear whether the spatial orientation of humans works equally within VR and in the real-world. In this paper, two studies are presented, in which natural body movements were allowed and demanded. Firstly, a series of verbal and walking distance estimation tests were conducted in both the virtual and the real environment. The non-parametric Friedman test with pairwise comparisons showed no significant differences neither in verbal nor in walking distance estimations between the conditions (all p > 0.05). However, shorter distances (0.9-1.5 m) were estimated more precisely than larger distances (2.6-2.8 m) in both environments. Secondly, a self-developed route recall test to examine the spatial orientation was performed in the virtual and the real environment. The participants visually perceived the predefined route and were instructed to follow these routes with their eyes blindfolded and afterward to return to their starting position. Between the ending and the starting position, no difference between the two environments was observed (p > 0.05). Based on these two studies, the performance of the human spatial orientation preliminarily verified the same in a virtual and real environment.

A Novel Training Program to Improve Human Spatial Orientation: Preliminary Findings.

The ability to form a mental representation of the surroundings is a critical skill for spatial navigation and orientation in humans. Such a mental representation is known as a “cognitive map” and is formed as individuals familiarize themselves with the surrounding, providing detailed information about salient environmental landmarks and their spatial relationships. Despite evidence of the malleability and potential for training spatial orientation skills in humans, it remains unknown if the specific ability to form cognitive maps can be improved by an appositely developed training program. Here, we present a newly developed computerized 12-days training program in a virtual environment designed specifically to stimulate the acquisition of this important skill. We asked 15 healthy volunteers to complete the training program and perform a comprehensive spatial behavioral assessment before and after the training. We asked participants to become familiar with the environment by navigating a small area before slowly building them up to navigate within the larger and more complex environment; we asked them to travel back and forth between environmental landmarks until they had built an understanding of where those landmarks resided with respect to one another. This process repeated until participants had visited every landmark in the virtual town and had learned where each landmark resided with respect to the others. The results of this study confirmed the feasibility of the training program and suggested an improvement in the ability of participants to form mental representations of the spatial surrounding. This study provides preliminary findings on the feasibility of a 12-days program in training spatial orientation skills. We discuss the utility and potential impact of this training program in the lives of the many individuals affected by topographical disorientation as a result of an acquired or developmental condition.

Facial nerve palsy in acute otitis media – case study

The hearing and balance organ maintains human spatial orientation as well as the ability to localize and discriminate individual sounds. Without properly functioning hearing organ, it would be impossible to develop speech, which is a mean of communication and social interaction. Therefore, it is important to observe the condition of particular senses, including hearing, and in case of disturbing symptoms or accidents causing damage, contact a specialist. This will enable early diagnosis and intervention. Sound is received by human organism through the conductive and receiving parts of the hearing organ. It is important to determine which part of hearing organ is impaired, since the procedure for receiving and conductive hearing loss is different. Precise diagnosis may determine the location of hearing damage. The basic element of diagnostics is case history. Further, a complex laryngological examination is conducted. The next step is the examination of the patient with appropriate subjective tests (Weber tests, distraction test, whispered voice test) and objective tests (OAE, tympanometry, brainstem auditory evoked potentials). These tests indicate the location and extent of hearing damage and also suggest the appropriate treatment for the individual patient. Acute otitis media is a condition that mainly affects children, but it also occurs in adults – more often men. It is usually caused by viral and bacterial infections of the upper respiratory tract. Characteristic is the sudden onset of discomfort, exudation in the tympanic cavity, along with ear pain and inflammation. Acute otitis media may lead to complications such as facial nerve palsy, tympanosclerosis, labyrinthitis, mastoiditis, and brain abscess.

Ventral-Dorsal Functional Contribution of the Posterior Cingulate Cortex in Human Spatial Orientation: A Meta-Analysis.

The retrosplenial cortex has long been implicated in human spatial orientation and navigation. However, neural activity peaks labeled “retrosplenial cortex” in human neuroimaging studies investigating spatial orientation often lie significantly outside of the retrosplenial cortex proper. This has led to a large and anatomically heterogenous region being ascribed numerous roles in spatial orientation and navigation. Here, we performed a meta-analysis of functional Magnetic Resonance Imaging (fMRI) investigations of spatial orientation and navigation and have identified a ventral-dorsal functional specialization within the posterior cingulate for spatial encoding vs. spatial recall. Generally, ventral portions of the posterior cingulate cortex were more likely to be activated by spatial encoding, i.e., passive viewing of scenes or active navigation without a demand to respond, perform a spatial computation, or localize oneself in the environment. Conversely, dorsal portions of the posterior cingulate cortex were more likely to be activated by cognitive demands to recall spatial information or to produce judgments of distance or direction to non-visible locations or landmarks. The greatly varying resting-state functional connectivity profiles of the ventral (centroids at MNI −22, −60, 6 and 20, −56, 6) and dorsal (centroid at MNI 4, −60, 28) posterior cingulate regions identified in the meta-analysis supported the conclusion that these regions, which would commonly be labeled as “retrosplenial cortex,” should be more appropriately referred to as distinct subregions of the posterior cingulate cortex. We suggest that future studies investigating the role of the retrosplenial and posterior cingulate cortex in spatial tasks carefully localize activity in the context of these identifiable subregions.

Genome-wide mediation analysis of psychiatric and cognitive traits through imaging phenotypes.

Heritability is well documented for psychiatric disorders and cognitive abilities which are, however, complex, involving both genetic and environmental factors. Hence, it remains challenging to discover which and how genetic variations contribute to such complex traits. In this article, they propose to use mediation analysis to bridge this gap, where neuroimaging phenotypes were utilized as intermediate variables. The Philadelphia Neurodevelopmental Cohort was investigated using genome-wide association studies (GWAS) and mediation analyses. Specifically, 951 participants were included with age ranging from 8 to 21 years. Two hundred and four neuroimaging measures were extracted from structural magnetic resonance imaging scans. GWAS were conducted for each measure to evaluate the SNP-based heritability. Furthermore, mediation analyses were employed to understand the mechanisms in which genetic variants have influence on pathological behaviors implicitly through neuroimaging phenotypes, and identified SNPs that would not be detected otherwise. Our analyses found that rs10494561, located in the intron region within NMNAT2, was associated with the severity of the prodromal symptoms of psychosis implicitly, mediated through the volume of the left hemisphere of the superior frontal region ( P=2.38×10-8). The gene NMNAT2 is known to be associated with brainstem degeneration, and produce cytoplasmic enzyme which is mainly expressed in the brain. Another SNP rs2285351 was found in the intron region of gene IFT122 which may be potentially associated with human spatial orientation ability through the area of the left hemisphere of the isthmuscingulate region ( P=3.70×10-8). Hum Brain Mapp 38:4088-4097, 2017. © 2017 Wiley Periodicals, Inc.

Perception of rotation, path, and heading in circular trajectories.

When in darkness, humans can perceive the direction and magnitude of rotations and of linear translations in the horizontal plane. The current paper addresses the integrated perception of combined translational and rotational motion, as it occurs when moving along a curved trajectory. We questioned whether the perceived motion through the environment follows the predictions of a self-motion perception model (e.g., Merfeld et al. in J Vestib Res 3:141–161, 1993; Newman in A multisensory observer model for human spatial orientation perception, 2009), which assume linear addition of rotational and translational components. For curved motion in darkness, such models predict a non-veridical motion percept, consisting of an underestimation of the perceived rotation, a distortion of the perceived travelled path, and a bias in the perceived heading (i.e., the perceived instantaneous direction of motion with respect to the body). These model predictions were evaluated in two experiments. In Experiment 1, seven participants were moved along a circular trajectory in darkness while facing the motion direction. They indicated perceived yaw rotation using an online tracking task, and perceived travelled path by drawings. In Experiment 2, the heading was systematically varied, and six participants indicated, in a 2-alternative forced-choice task, whether they perceived facing inward or outward of the circular path. Overall, we found no evidence for the heading bias predicted by the model. This suggests that the sum of the perceived rotational and translational components alone cannot adequately explain the overall perceived motion through the environment. Possibly, knowledge about motion dynamics and familiar stimuli combinations may play an important additional role in shaping the percept.

Human Spatial Orientation Perception During Simulated Lunar Landing Motions

Safe and precise piloted lunar landings require control inputs that depend on an accurate perception of vehicle orientation and motion. However, the unique environment and motions experienced during a lunar landing trajectory may lead to misperceptions in vehicle state. Eight subjects participated in a human subject experiment in the NASA Ames vertical motion simulator, where self-reports of perceptions of vehicle tilt angle and horizontal velocity were made during lunar-landing-like motions. Three cases of sensory cues were studied: Subjects were blindfolded and given no visual cues; subjects were provided a simulated dynamic view of the lunar terrain out a forward-looking window; and subjects were provided dynamic instrument displays showing current vehicle states. Subjects’ perception indications differed substantially from the motions being simulated in the blindfolded and out-the-window conditions, but were better matched when viewing instrument displays. Subject perceptions were also compared with predictions from a numerical model of orientation perception, and qualitatively matched in the blindfolded case, but were less well aligned in the out-the-window case. These types of misperceptions may impact astronaut control inputs and degrade vehicle performance and safety.

Human spatial orientation in non-stationary environments: relation between self-turning perception and detection of surround motion

We investigated the relative weighting of vestibular, optokinetic and podokinetic (foot and leg proprioceptive) cues for the perception of self-turning in an environment which was either stationary (concordant stimulation) or moving (discordant stimulation) and asked whether cue weighting changes if subjects (Ss) detect a discordance. Ss (N = 18) stood on a turntable inside an optokinetic drum and turned either passively (turntable rotating) or actively in space at constant velocities of 15, 30, or 60°/s. Sensory discordance was introduced by simultaneous rotations of the environment (drum and/or turntable) at ±{5, 10, 20, 40, 80}% of self-turning velocity. In one experiment, Ss were to detect these rotations (i.e. the sensory discordance), and in a second experiment they reported perceived angular self-displacement. Discordant optokinetic cues were better detected, and more heavily weighted for self-turning perception, than discordant podokinetic cues. Within Ss, weights did not depend on whether a discordance was detected or not. Across Ss, optokinetic weights varied over a large range and were negatively correlated with the detection scores: the more perception was influenced by discordant optokinetic cues, the poorer was the detection score; no such correlation was found among the podokinetic results. These results are interpreted in terms of a "self-referential" model that makes the following assumptions: (1) a weighted average of the available sensory cues both determines turning perception and serves as a reference to which the optokinetic cue is compared; (2) a discordance is detected if the difference between reference and optokinetic cue exceeds some threshold; (3) the threshold value corresponds to about the same multiple of sensory uncertainty in all Ss. With these assumptions the model explains the observed relation between optokinetic weight and detection score.

Numerical simulation of human orientation perception during lunar landing

In lunar landing it is necessary to select a suitable landing point and then control a stable descent to the surface. In manned landings, astronauts will play a critical role in monitoring systems and adjusting the descent trajectory through either supervisory control and landing point designations, or by direct manual control. For the astronauts to ensure vehicle performance and safety, they will have to accurately perceive vehicle orientation. A numerical model for human spatial orientation perception was simulated using input motions from lunar landing trajectories to predict the potential for misperceptions. Three representative trajectories were studied: an automated trajectory, a landing point designation trajectory, and a challenging manual control trajectory. These trajectories were studied under three cases with different cues activated in the model to study the importance of vestibular cues, visual cues, and the effect of the descent engine thruster creating dust blowback. The model predicts that spatial misperceptions are likely to occur as a result of the lunar landing motions, particularly with limited or incomplete visual cues. The powered descent acceleration profile creates a somatogravic illusion causing the astronauts to falsely perceive themselves and the vehicle as upright, even when the vehicle has a large pitch or roll angle. When visual pathways were activated within the model these illusions were mostly suppressed. Dust blowback, obscuring the visual scene out the window, was also found to create disorientation. These orientation illusions are likely to interfere with the astronauts' ability to effectively control the vehicle, potentially degrading performance and safety. Therefore suitable countermeasures, including disorientation training and advanced displays, are recommended.

Optimal estimator models for spatial orientation and vestibular nystagmus

Mathematical models have played an important role in research on the vestibular system over the past century, from the torsion pendulum analogies of the semicircular canal to the optimal estimator "observer" models of multisensory interaction and adaptation. This short review is limited to our own contributions in bringing the technology of feedback control theory to bear on the understanding of human spatial orientation, eye movements, and nystagmus, both on Earth and in space. It points to the importance of the "internal model" concept for treatment of the manner in which the brain constantly makes predictions about future sensory feedback, adjusts the weightings of sensors according to their signal-to-noise ratios, and adapts control according to the motion environment, and availability of sensory cues.

Finding the Way

In anthropology, research on human spatial orientation (wayfinding) has centered on two conflicting theories: the "mental map," whereby humans build abstract cognitive representations of the spatial relations between objects, and "practical mastery," which rejects the idea that such abstract representations exist and, in its most developed form, suggests that wayfinding is a process of moving from one recognized visual perspective (vista) to another (transitions between vistas). In this paper we reveal, on the basis of existing psychology and geography research, that both wayfinding theories are in fact complementary: humans rely on mental maps but also memorize vistas while navigating, and an individual's navigation method, ability, and the form of the mental map is likely to depend on a situation as well as on factors such as age, sex, familiarity with the environment, and life history. We demonstrate (using research material obtained during fieldwork carried out among Komi and Nenets reindeer herders) that anthropology can contribute to human spatial cognitive research, which has traditionally been an interdisciplinary endeavor, by identifying differences in spatial representation between different people and peoples. However, future contributions can be achieved only if anthropologists accept that mental maps and route knowledge (as advocated by practical mastery) are part and parcel of spatial cognition.

Time Course and Magnitude of Illusory Translation Perception During Off-Vertical Axis Rotation

Human spatial orientation relies on vision, somatosensory cues, and signals from the semicircular canals and the otoliths. The canals measure rotation, whereas the otoliths are linear accelerometers, sensitive to tilt and translation. To disambiguate the otolith signal, two main hypotheses have been proposed: frequency segregation and canal-otolith interaction. So far these models were based mainly on oculomotor behavior. In this study we investigated their applicability to human self-motion perception. Six subjects were rotated in yaw about an off-vertical axis (OVAR) at various speeds and tilt angles, in darkness. During the rotation, subjects indicated at regular intervals whether a briefly presented dot moved faster or slower than their perceived self-motion. Based on such responses, we determined the time course of the self-motion percept and characterized its steady state by a psychometric function. The psychophysical results were consistent with anecdotal reports. All subjects initially sensed rotation, but then gradually developed a percept of being translated along a cone. The rotation percept could be described by a decaying exponential with a time constant of about 20 s. Translation percept magnitude typically followed a delayed increasing exponential with delays up to 50 s and a time constant of about 15 s. The asymptotic magnitude of perceived translation increased with rotation speed and tilt angle, but never exceeded 14 cm/s. These results were most consistent with predictions of the canal-otolith-interaction model, but required parameter values that differed from the original proposal. We conclude that canal-otolith interaction is an important governing principle for self-motion perception that can be deployed flexibly, dependent on stimulus conditions.

The effect of the configuration and the interior design of a virtual weightless space station on human spatial orientation

In a virtual weightless environment, subjects' orientation skills were studied to examine what kind of cognitive errors people make when they moved through the interior space of virtual space stations and what kind of visual information effectively decreases those errors. Subjects wearing a head-mounted display moved from one end to the other end in space station-like routes constructed of rectangular and cubical modules, and did Pointing and Modeling tasks. In Experiment 1, configurations of the routes were changed with such variables as the number of bends, the number of embedding planes, and the number of planes with respect to the body posture. The results indicated that spatial orientation ability was relevant to the variables and that orientational errors were explained by two causes. One of these was that the place, the direction, and the sequence of turns were incorrect. The other was that subjects did not recognize the rotation of the frame of reference, especially when they turned in pitch direction rather than in yaw. In Experiment 2, the effect of the interior design was examined by testing three design settings. Wall colors that showed the allocentric frame of reference and the different interior design of vertical and horizontal modules were effective; however, there was a limit to the effectiveness in complicated configurations.

A modeling approach to the human spatial orientation system.

The human spatial orientation system is highly complex and nonlinear. It is difficult, therefore, to arrive at an unequivocal model of the underlying processing by merely combining the known elementary mechanisms ("bottom-up" approach); additional "top-down" concepts are required to narrow the choice between several formally equivalent solutions. We here suggest a concept in which sensorimotor control is based on a meta-level that provides an internal representation of the physical stimuli acting upon a subject (e.g., tilt of the support surface), whereas the classic reflex concept essentially proceeds from a direct coupling between physiological stimuli, sensors and actuators. At the hypothesized meta-level, the axial body segments are represented as a stack of superimposed platforms with the lowermost platform (generally the feet) riding on a support surface that acts as the buttress for the subject's active movements. From the sensory point of view, this stack constitutes a system of nested references. This concept explains data from various experiments dealing with self- and object motion perception and body stabilization in a more exhaustive way than does the classic concept. In our view, it provides a robust, flexible, and modular framework for perception and action in space.