Human Spatial Navigation Research Articles

Spatial Navigation: Spatial Learning in Real and Virtual Environments

Humans and many non-human animals need to accurately and efficiently navigate from one place to the next in their environment. Over 3,000 years ago the volcanic islands of the Pacific were settled by the people of Polynesia (Gibbons, 2001). These navigators sailed in craft from Samoa to Hawaii covering an area extending some 4,500 km without the benefits of modern navigational equipment. Errors in the es timation of direction or position during trips to and from the islands in this region could have dire consequences. Some 2,400 years later, European sailors had started mastering oceanic navigation and were probably surprised to discover that people had already traveled to, and were living on, these remote Pacific islands. Today, few humans make such long trips without the benefits of modern navigational tools. Traditionally investigations of human and nonhuman place learning have used very different approaches to understand the underlying mechanisms involved in spatial learning. Although these approaches and associated techniques have provided each respective research area with valuable information about spatial processing, one important problem has been the minimal communication between the two disciplines which share such a common interest. Our review examines the two main theories of place learning—the associative approach and the cognitive mapping theory—through the examination of current research using three main behavioral techniques that were developed for the study of spatial navigation in animals but modified for the study of human spatial navigation. Although the focus of our review is at a behavioral level, we consider how these approaches have strengthened our understanding of the neurological mechanisms of place learning in animals and discuss how future research, comparative in nature, will allow for an excellent opportunity for future comparative studies of spatial place learning. Many non-human animals were engaging in impressive feats of navigation long before people were navigating across oceans. Desert ants (Cataglyphis fortis) live in subterranean nests that insulate them from arid conditions above ground. During the course of the day foraging ants depart their nest in search of food, in this case other insects that have succumbed to the desert heat. The foraging desert ant may be required to take a rather long (several hundred meters) and circuitous route before it finds a food item, since the loca tion of food items vary dramatically from day to day. Once the foraging ant has found food, it takes a direct route back to the entrance of the subterranean nest (Wehner, 2003). Errors in the estimation of the nest location could easily prove fatal. Notably, like an early human navigator on the ocean, the ant’s impressive feat of navigation is accomplished in a relatively homogeneous environment lacking surfaces that could be used as landmarks to help indicate the position of the nest.

Human spatial navigation deficits after traumatic brain injury shown in the arena maze, a virtual Morris water maze

Objective: Survivors of traumatic brain injury (TBI) often have spatial navigation deficits. This study examined such deficits and conducted a detailed analysis of navigational behaviour in a virtual environment.Design: TBI survivors were tested in a computer simulation of the Morris water maze task that required them to find and remember the location of an invisible platform that was always in the same location. A follow-up questionnaire assessed everyday spatial ability.Method: Fourteen survivors of moderate-to-severe TBI were compared to 12 non-injured participants. Results: TBI survivors navigated to a visible platform but could not learn the location of the invisible platform. The difference between TBI survivors and uninjured participants was best indicated by two new dependent variables, path efficacy and spatial scores.Conclusion: This study confirms the capacity of virtual environments to reveal spatial navigation deficits after TBI and establishes the best way to identify such deficits.

Neurosurgical Recordings Reveal Cellular Networks Underlying Human Spatial Navigation

Neurosurgery: March 2004 - Volume 54 - Issue 3 - doi: 10.1227/01.NEU.0000309603.15208.48

Cellular networks underlying human spatial navigation.

Place cells of the rodent hippocampus constitute one of the most striking examples of a correlation between neuronal activity and complex behaviour in mammals. These cells increase their firing rates when the animal traverses specific regions of its surroundings, providing a context-dependent map of the environment. Neuroimaging studies implicate the hippocampus and the parahippocampal region in human navigation. However, these regions also respond selectively to visual stimuli. It thus remains unclear whether rodent place coding has a homologue in humans or whether human navigation is driven by a different, visually based neural mechanism. We directly recorded from 317 neurons in the human medial temporal and frontal lobes while subjects explored and navigated a virtual town. Here we present evidence for a neural code of human spatial navigation based on cells that respond at specific spatial locations and cells that respond to views of landmarks. The former are present primarily in the hippocampus, and the latter in the parahippocampal region. Cells throughout the frontal and temporal lobes responded to the subjects' navigational goals and to conjunctions of place, goal and view.

Neurodevelopmental Aspects of Spatial Navigation: A Virtual Reality fMRI Study

Navigation in spatial contexts has been studied in diverse species, yielding insights into underlying neural mechanisms and their phylogenetic progression. Spatial navigation in humans is marked by age-related changes that may carry important implications for understanding cortical development. The emergence of “allocentric” processing, reflecting that ability to use viewer-independent spatial abstractions, represents an important developmental change. We used fMRI to map brain regions engaged during memory-guided navigation in a virtual reality environment in adolescents and adults. Blood oxygen level-dependent (BOLD) signal was monitored in eight adolescents and eight adults in a 1.5-T MRI scanner during three conditions: (1) memory-guided navigation (NAV); (2) arrow-guided navigation (ARROW); and (3) fixation (FIX). We quantified navigation ability during scanning and allocentric memory after scanning, based on subjects' ability to label a previously unseen, aerial view of the town. Adolescents and adults exhibited similar memory-guided navigation ability, but adults exhibited superior allocentric memory ability. Memory-guided navigation ability during scanning correlated with BOLD change between NAV/ARROWS in various regions, including a right frontal and right-anterior medial temporal lobe region. Age group and allocentric memory together explained significant variance in BOLD change in temporoparietal association cortex and the cerebellum, particularly in the left hemisphere. Consistent with developmental models, these findings relate maturation in the coding of spatial information to functional changes in a distributed, left-lateralized neural network.

Age differences in spatial memory in a virtual environment navigation task.

The use of virtual environment (VE) technology to assess spatial navigation in humans has become increasingly common and provides an opportunity to quantify age-related deficits in human spatial navigation and promote a comparative approach to the neuroscience of cognitive aging. The purpose of the present study was to assess age differences in navigational behavior in a VE and to examine the relationship between this navigational measure and other more traditional measures of cognitive aging. Following pre-training, participants were confronted with a VE spatial learning task and completed a battery of cognitive tests. The VE consisted of a richly textured series of interconnected hallways, some leading to dead ends and others leading to a designated goal location in the environment. Compared to younger participants, older volunteers took longer to solve each trial, traversed a longer distance, and made significantly more spatial memory errors. After 5 learning trials, 86% of young and 24% of elderly volunteers were able to locate the goal without error. Performance on the VE navigation task was positively correlated with measures of mental rotation and verbal and visual memory.

Human theta oscillations exhibit task dependence during virtual maze navigation.

Theta oscillations (electroencephalographic activity with a frequency of 4-8 Hz) have long been implicated in spatial navigation in rodents; however, the role of theta oscillators in human spatial navigation has not been explored. Here we describe subdural recordings from epileptic patients learning to navigate computer-generated mazes. Visual inspection of the raw intracranial signal revealed striking episodes of high-amplitude slow-wave oscillations at a number of areas of the cortex, including temporal cortex. Spectral analysis showed that these oscillations were in the theta band. These episodes of theta activity, which typically last several cycles, are dependent on task characteristics. Theta oscillations occur more frequently in more complex mazes; they are also more frequent during recall trials than during learning trials.

Human spatial navigation: cognitive maps, sexual dimorphism, and neural substrates

Recent research on navigation has been particularly notable for the increased understanding of the factors affecting human navigation and the neural networks supporting it. The use of virtual reality environments has made it possible to explore the effect of environment layout and content on way-finding performance, and it has shown that these effects may interact with the sex and age of subjects. Functional brain imaging, combined with the use of virtual environments, has revealed strong parallels between humans and other animals in the neural basis of navigation.

Males and females use different distal cues in a virtual environment navigation task

The study of navigational ability in humans is often limited by the restricted availability and inconvenience of using large novel environments. In the present study we use a computer-generated virtual environment to study sex differences in human spatial navigation. Adult male and female participants navigated through a virtual water maze where both landmarks and room geometry were available as distal cues. Manipulation of environmental characteristics revealed that females rely predominantly on landmark information, while males more readily use both landmark and geometric information. We discuss these results as a possible link between recent human research reporting hippocampal activation in spatial tasks and animal work showing sex differences in both spatial ability and hippocampal development.

Spatial metaphors and disorientation in hypertext browsing

Abstract The spatial metaphor can be used as a framework for explaining and designing tools that alleviate disorientation problems in hypertext systems. The approach based on this metaphor would involve developing tools analogous to navigational aids in physical environments and applying analogous concepts from research on human spatial processing and navigation in physical spaces. Research on hypertext browsing with respect to the spatial metaphor is reviewed and contrasted with the larger task context where users are trying to explore, learn, analyse, and summarize the contents of the hypertext space.