Abstract: Visuo-spatial impairments are common following brain injury. The impairments differ in severity, involving symptoms such as partial vision loss, unawareness of one side of space, and topographic disorientation. In this exploratory study we investigated wayfinding difficulties experienced by four community-dwelling individuals with visuo-spatial impairments due to brain injury. Semi-structured interviews were conducted to elicit information about the type of travel the informants undertook independently, the environments they frequented, and the strategies they used to compensate for disability.

One informant had a moderate visual field cut resulting from stroke, and was able to travel and work independently. Two informants had visual field deficits in addition to topographic disorientation. They used very systematic strategies based on landmarks and path learning to master navigating in a variety of settings. The fourth informant had diffuse brain injury resulting in topographic disorientation and short-term memory impairment. He relied on his spouse for transportation needs.

The interactions of these informants with the environment provide information that may be useful for enhancing independence and quality of life following brain injury, and for identifying future directions for research on wayfinding with visuo-spatial impairment. Simple environmental modifications in the home may improve orientation. Travel outside the home presents considerable challenges related in part to environmental design.

Keywords: visuo-spatial impairment, wayfinding, brain injury

INTRODUCTION

Wayfinding is necessary for independent living, and is essential for maintaining and developing life activity space. Wayfinding is comprised of activities such as navigating, orienting oneself in geographic space, and finding one's way about. In many cases, visuo-spatial ability is affected following stroke or traumatic brain injury (Barrash et al., 2000; Bernspang et al., 1987; Edmans & Lincoln, 1987; Halligan & Marshall, 1998; Sunderland, Wade & Hewer, 1987), and this may result in difficulty wayfinding. People with visuo-spatial impairment (VSI) may be unaware of one side of space, have difficulty determining the relationship of their bodiesy to the environment surrounding them, have partial vision loss that results in perception of fractured images of the environment, or have profound topographic disorientation, among other conditions (Bottini et al., 1990; Robertson & Halligan, 1998; Stone et al., 1998). These conditions may be associated with difficulty finding objects, navigating in familiar and unfamiliar locations, traveling outside the home, and orienting in small-scale as well as large-scale space. As compared with the general population, people with VSI from brain injury lack independence in activities of daily living (Edmans & Lincoln, 1990) and have poor functional outcomes with respect to independent living (Denes, et al., 1982; Jesshope, Clark & Smith, 1991). Although wayfinding is grounded in visuo-spatial functioning, wayfinding is not the focus of existing studies of visuo-spatial disability. Discussions of the effects of wayfinding difficulties on life activity space – both environmental and social dimensions (Dyck, 1995; Thapar, Bhardwaj & Bhardwaj, 2001) – are absent from the literature on visuo-spatial impairment from brain injury.

This study was designed to address the need for information about wayfinding behavior among people with VSI from stroke and brain injury, in everyday environments. The primary aims were to learn about navigation strategies used by individuals with VSI, to gain insights about visuo-spatial function through semi-structured tests and open-ended discussions of wayfinding, and to investigate how environments support or fail to support individuals with VSI. To address these aims, we investigated the wayfinding difficulties experienced by study informants with visuo-spatial impairment from brain injury, and collected information about the strategies the informants used to wayfind within and outside the home.

LITERATURE REVIEW

Perspectives on Visuo-Spatial Function

Behavioral Geography and Environmental Psychology

Wayfinding and environmental cognition have been studied extensively in behavioral geography (Garling & Golledge, 1993; Golledge, 1999; Tversky, 1993) and environmental psychology (Appleyard, 1970; Kaplan & Kaplan, 1982; Lynch, 1960). Studies of children have identified elements of environmental knowledge including landmarks, paths, and configurational knowledge, suggesting a multidimensional approach to wayfinding (McDonald & Pellegrino, 1993). Golledge (1994) has identified spatial hierarchies and spatial association, among other factors, as important elements of spatial cognition in human populations. Though theories of spatial cognition are advancing through this work, few studies of wayfinding in people with disabilities have been conducted. These studies have focused on Alzheimer's disease (Passini et al., 1998; Passini et al., 2000), vision-impairment and blindness (Jacobson, 1998; Liu, Gauthier & Gauthier, 1991; Golledge, 1999), and physical disability (Herman & Bruce, 1981; Taylor & Taylor, 1996). To our knowledge, studies of wayfinding in geography and psychology have not included people with visual or spatial impairments due to brain injury.

Neuroscience

Neuroscience studies of visuo-spatial cognition focus on brain function. Visuo-spatial cognition is broken down into smaller functions such as object recognition and the location of objects relative to self and other objects. Kosslyn (1992) explained "spatiotropic mapping," or locating objects in space, as positioning an object in space relative to oneself and to other objects. The task of spatiotropic mapping involves visual stimuli, mental mapping, and associative memory as elements; in other words, what we see, how we locate what we see in space, and our mental representations of the world around us. Amorim (1998) has adapted this model to wayfinding, adding egocentric (person-centered) and allocentric (object-centered) reference frames. Yet these theories of spatial cognition and visuo-spatial function are not well integrated into research on visuo-spatial disability.

Visuo-Spatial Impairment

Visuo-spatial impairments differ in nature and severity. Low order visual and spatial impairments include the inability to recognize or identify size, form and color (Bernspang et al., 1987). Higher order impairments – the focus of this study – include hemianopia (partial vision loss), unilateral neglect (unawareness of or inattentiveness to one side of space), topographic disorientation (lack of configurational knowledge of the environment), and disturbances of body awareness (Robertson & Halligan, 1998).

Visuo-spatial deficits have been reported in approximately 70% of patients with right or left hemisphere brain damage due to stroke (Stone, Halligan, & Greenwood, 1993). Bernspang et al. (1987) found high order visuo-spatial deficits in 60% of a sample of 109 stroke patients within two weeks following acute stroke. Visuo-spatial neglect has been reported in 40% to 44% of patients at two months post-stroke (Robertson & Halligan, 1998). Friedman and Leong (1992) reported persistence of perceptual impairment in 64% of a group of 70 informants at three months post-stroke.

People with visuo-spatial disorders are often described and classified in the literature but little explanation of visuo-spatial dysfunction is presented. Experts have recognized this emphasis on description and lack of cohesive theory in studies of unilateral neglect, a specific manifestation of visuo-spatial impairment:

If language and language disorders can yield to theoretical understanding, there is no reason why spatial cognition and its disorders should not likewise be intelligible. Our worries on this latter score are concerned with the fact that few current 'explanations' of 'neglect' are anything more than a description of the phenomena phrased in terms that insinuate understanding without actually delivering." (Robertson & Marshall, 1993, pp. 321-323)

Halligan and Marshall (1994) have suggested that unilateral neglect may be related to an inability to integrate local and global visual phenomena. This perspective seems parallel to theories of spatial cognition in geography and psychology, which emphasize spatial imagery and spatial association as key elements of wayfinding (Golledge, 1994; Tversky, 1993).

Medical Rehabilitation

Patients with visuo-spatial disorders following stroke have been found to lack independence in activities of daily living as compared with the general population (Denes et al., 1982; Edmans & Lincoln, 1990; Jesshope, Clark & Smith, 1991; Kotila, Niemi & Laaksonen, 1986). Perhaps for this reason rehabilitation studies have focused on compensation for disability through behavioral changes such as visual scanning (Edmans & Lincoln, 1989). Some studies have reported attempts to use technical devices as interventions to improve visuo-spatial function, such as special corrective lenses to enhance vision (Butter & Kirsch, 1992) or special computer displays intended to correct attention deficits (Butter & Kirsch, 1995). But these studies have been largely unsuccessful with respect to enhancing visuo-spatial function (Bowen, Lincoln & Dewey, 2002).

Warren (1993) presented a hierarchy of visual skills, including components such as oculomotor control, visual acuity, scanning, pattern recognition, and visuo-cognition, as a guide to evaluating and treating visuo-spatial disability; but the model does not incorporate perspectives on visuo-spatial cognition from diverse disciplines and does not provide insights regarding the relationship of impaired individuals to the environment. It seems essential to integrate theory of visuo-spatial function with knowledge about an individual's impairment and observations of that individual in familiar environments in order to enhance understanding of visuo-spatial impairment and develop effective rehabilitation strategies. Yet studies of community-dwelling individuals with visuo-spatial impairments with such topographic disorientation, are rare (Alsaadi et al, 2000; Takahashi et al., 1997).

METHOD

This study was designed with consideration of the various disciplinary perspectives on visuo-spatial function. The principal investigator interviewed four community-dwelling individuals with visuo-spatial disorders due to brain injury. This sample included two men and two women ranging in age from 43 to 64 years. The informants were recruited for the interviews through formal and informal contacts with individuals in health care settings. Informants included in the study were able to communicate clearly, able to ambulate independently, and were not in fragile health. We focused on individuals at least one year post-injury, because these individuals would have acquired some experience living and coping with VSI by that time.

Human subjects' reviews of the study protocols and consent documents were conducted and approved by two hospitals. The principal investigator obtained informed consent from each participant prior to conducting the interview. The interviews were conducted in familiar locations (home, work, rehabilitation center). They were audio taped and transcribed at a later time by the principal investigator. Study informants received a payment of $25 as compensation for participation.

Three of the informants had suffered right brain injury due to stroke, and one had suffered diffuse traumatic brain injury in a car accident. Information from the informant with traumatic brain injury provides contrast and reveals the importance of memory in compensatory strategies used by other study participants.

A mix of qualitative and quantitative methods was used to collect data. Open-ended discussions enabled the principal investigator to obtain information on topics for which there are no formalized instruments or tests, while structured, pre-existing tests provided more standard information about the nature of the informants' impairments. The informants provided information about the severity of their disability, the type of travel they undertook independently, and characteristics of the environments they frequented (in the home and outside of the home), through discussion. Information about environmental characteristics was obtained from the informants' descriptions of the places they frequented, and/or by the principal investigator in photographs. Open-ended discussions were used to gather information about wayfinding strategies the informants had developed in familiar spaces. The focus on open-ended discussion of wayfinding strategies was intended to provide insights regarding compensation strategies within particular settings that might prove useful to individuals with similar impairments.

Two structured tests from the Behavioural Inattention Battery (Wilson, Cochburn & Halligan, 1987) were included in the study protocol to identify unilateral neglect. The tests required (1) canceling small stars on a page containing both large and small stars, and (2) copying three figures, such as a 3-dimensional line-drawing of a cube. These tests are helpful for identifying individuals who lack awareness of the left side of space. These tests were not timed, so the results are not standardized and are used only for descriptive purposes in this paper. A semi-structured object location task was also used to determine whether an informant could search effectively for an object in a familiar setting, and for the purpose of observing searching strategies used by the informant. This test was not standardized since the environments from individual to individual varied greatly, so results of the test are not presented in this paper. However, information about searching strategies obtained through open-ended discussion is presented qualitatively in the following section. Notes from open-ended discussion, and information transcribed from the audiotapes were organized according to sections in the interview guide. The themes of wayfinding in the home and out of home emerged as categories suitable for distinguishing important aspects of coping behavior.

INDIVIDUAL COPING STRATEGIES

Mr. P. was a 65-year-old man with left hemianopia (left peripheral vision loss). He was one year and four months post-stroke at the time of the interview. He lived and worked at the edge of a large city, near a riverfront. In the district where he worked, there were many small, older storefronts along a two-lane, commercialized street. He ran a small business and traveled by car independently within the community. Regarding wayfinding in the home, Mr. P. said: "Home is not a problem."

When asked to provide directions to the freeway from his business location, Mr. P. drew a simple, correct map on a plain piece of paper. However, he failed to connect two lines at the upper left corner of a box he drew to represent a store. This omission in his drawing was consistent with a left-side vision cut. His ability to draw a map suggested that he could associate places in a mental representation (spatial association), and that he was able to use an abstract representation of space (the map) as a wayfinding aid.

Strategies for Wayfinding Outside of the Home: Mr. P. described strategies he used to compensate for his disability, including: turning his head frequently, looking around from left to right, exercising care when crossing a street, moving through crowds with his wife at his left side (to avoid bumping into people or objects in his left visual field), and driving with caution in familiar areas. He also expressed a preference for roads with traffic lights at intersections since traffic flow is regulated, reducing the need for vigilant scanning to see traffic coming from all directions.

In Mr. P.'s case, it is possible that his perception of only partial images of the environment due to left hemianopia made it difficult to construct a complete or useful mental representation of the environment. Kosslyn's (1992) concept of spatiotropic mapping provides insights on this point. Spatiotropic mapping involves integrating the location of an object on the retina with eye position, to form a visual representation of space. Mr. P. is particularly troubled in crowded settings where people ("objects") are changing position rapidly. Thus, it is possible that, given the blind spots in his perceived images of the environment, it is necessary for him to change eye position frequently in order to construct an accurate view of the environment. This would make the task of determining the position of objects, especially moving objects, extraordinarily complex.

Mrs. B., a 46 year-old woman, was interviewed one year post-stroke. She was diagnosed with left hemianopia and topographic disorientation due to right hemisphere stroke. At the time of the interview, she was unable to travel independently outside the home. She lived with her husband and two children in a house in a rural area, in a small, private subdivision.

Strategies for Wayfinding in the Home: Mrs. B. had lived in her house for seven years prior to her stroke. She said she did not have any trouble wayfinding in the house, but did have difficulty wayfinding in unfamiliar settings. Within Mrs. B.'s home, an open floor plan and "radial" arrangement of rooms around the staircase made it possible for her to look around and see most of the rooms on each floor. This design is quite different from a nursing home described by Passini et al. (2000), where the linear arrangement of rooms along a corridor made it difficult for residents to find their rooms. Mrs. B. said she sometimes lost track of objects in the home, but she used a systematic method of "searching surfaces" to find things, or asked family members for help. She had reorganized all of the drawers in the kitchen after her stroke, in an effort to learn the locations of kitchen items.

Strategies for Wayfinding Outside of the Home: The road leading away from Mrs. B.'s subdivision was a dirt road bordered by trees, with few houses or other landmarks to use as navigation aids. At the time of the interview, Mrs. B. was unable to drive independently though she expressed hope that she would drive again someday. When others drove her places, Mrs. B. said she became disoriented. Given that she was unable to orient herself in large-scale space (such as a neighborhood, community or other large geographic area), Mrs. B. developed the strategy of memorizing which way to turn at intersections.

Shopping at a local grocery store was a challenge that Mrs. B. embraced as a means to develop her wayfinding ability. She expressed her frustration in trying to master the layout of the store, and used an aisle-by-aisle grocery list prepared before she went shopping to locate items in the store. Each time sections of the store were rearranged, this created a new challenge for her. She expressed her thankfulness for her husband's support and patience in allowing her to locate items independently.

Ms. C., a 43 year-old woman who has diabetes and is insulin-dependent, was interviewed three years post stroke. She lived alone and traveled outside the home to shopping malls and medical offices. Ms. C. had left hemianopia, left unilateral neglect, and topographic disorientation such as that of a patient described by Bottini et al. (1990). Unilateral neglect was evident in the copying task she completed, where details of the figures copied were omitted or copied with errors.

Ms. C. was aware of her own location based on visual cues around her ("at home" or "at the grocery store"), but was unable to determine the relative locations of places such as the bathroom relative to the kitchen, or the grocery store relative to her home. She stated at one point in the interview: "I study maps. I read them all the time. They don't help me. There are no maps in my head....I used to be able to find my way around -- on campus, from the parking lot, into some building, up the stairs, down a different way to get back to my car. Now I can't do that anymore." The complex configuration of Ms. C.'s deficits makes it difficult to say whether one or another of her visuo-spatial impairments had a more profound impact on the difficulties she faced when traveling.

Strategies for Wayfinding in the Home: Within her home, Ms. C. was able to function well despite persistent disorientation. She minimized clutter to make object location easier, and kept lights on as orientation aids. She placed the couch in her living room at an angle toward the wall, apparently to minimize input to her left visual field. This level of functioning represented quite an improvement compared to the first year post-stroke. At that time, Ms. C. said she used, for instance, the hum of the refrigerator motor as a clue to where the kitchen was located. From that level, she advanced to paying attention to minute visual details in the environment, such as the deadbolt lock above the doorknob on the front door, for orientation and wayfinding.

When asked to describe the first object she noticed when she walked in the front door of the home, from memory, Ms. C. said: "I can't remember. I go kind of straight back, but then I have to look. When I come in and have a bunch of groceries, I have to go past that treadmill. I see the chair and computer furniture and know not to go that way. The window with Venetian blinds is significant because of the pattern, the light coming through."

Strategies for Wayfinding Outside of the Home: When traveling in the community, Ms. C. used visual scanning, landmarks and detailed directions to find her way around. Friends helped her to find new locations. As they drove, she wrote very detailed directions (both to and from the location) to follow later. This method of keeping and relying on detailed directions, seemed to enable her to categorize and analyze information about the environment, as might a person in an unfamiliar setting. She openly stated that she relied on landmarks and the arrangements of landmarks in sequences (path learning) – elements of the multidimensional system of wayfinding that are fundamental for wayfinding in young children (McDonald & Pellegrino, 1993).

High-speed traffic on multi-lane roadways and the absence of public transportation made travel outside the home difficult for Ms. C. The area near her home was heavily commercialized, adding to the complexity of the visual landscape. The county she lived in was one of the fastest growing counties in the United States, with new mini-malls and residential areas being built on an on-going basis. She stated that these changes in the landscape undermined her efforts to orient and wayfind. Further, a shade tree ordinance in the area required builders to plant trees to shade commercial parking lots. Ms. C. was very dependent on signage and landmarks for orientation, and she stated that the shade trees hampered her wayfinding by obscuring signage in front of stores and offices.

Mr. D., a 56-year old man, sustained a traumatic brain injury from a car accident five years prior to the time of interview. This brain injury resulted in topographic disorientation and short-term memory loss. He lived with his wife in a small apartment in a town in southeastern Michigan where he had lived most of his adult life. His home was within driving distance of his sister's home.  

Regarding his prior ability to wayfind, the informant said: "Years ago when I was growing up I could find anyplace. Even when I went to a new city the first time, driving across the city just once, it's kind of like you have a map in your head and you know how to go back even though it's not the same street. You know which direction you are going in." The interviewer asked: "Do you feel like you have maps in your head now?" Mr. D. "If we turn a couple of times, I don't know which way we're going. Before, I never had to pay attention. It was easy." Interviewer: "You had a strong sense of orientation. Do you pay attention now to landmarks?" Mr. D.: "Yes I do." Interviewer: "Did you do that in the past?" Mr. D.: "I just knew. Now everything is...I'm not sure what order things are coming in."

Strategies for Wayfinding in the Home: Mr. D. was able to orient himself within the small space of his apartment. He stated, "I can look around and see everything." He described sometimes losing objects such as his eyeglasses. He stated that he tried to place his eyeglasses in a few specific locations, but often could not find them where he thought he last left them. When Mr. D. searched for an object in the office where he was interviewed, he had great difficulty finding it, and seemed to forget the task at hand, with his gaze wandering in an unfocused way around the room.

Strategies for Wayfinding Outside of the Home: In larger spaces outside the home, Mr. D. stated that he became wholly disoriented. He was aware of landmarks, such as a bridge he and his wife crossed while driving to his sister's house, but he said he was unable to concentrate while traveling and could not remember where he was along the path. He said: "If we go somewhere, even if we go there lots of times, I can still not find my way alone. I tell myself I'm going to pay attention...watch where we're going...but it's like I go to sleep along the way. Is it really that I can't remember? I don't seem to pay attention to where we are going. It's like I'm daydreaming or something."

He recalled that when he was young, he hunted in dense pine bogs in southeastern Michigan and although there were no obvious clues for orientation, he never became lost. Yet now, he described his complete lack of orientation by saying, "I never had to pay attention to what was on the road. Now if I'm going from our house to my sister's house, I remember certain things but I kind of get mixed up on which one comes first."

DISCUSSION

During the interviews, the informants described the difficulties they faced coming to terms with their loss of wayfinding ability, in part through explaining their limitations. They described in detail the methods they used to wayfind, and the limitations they experienced related to their disability. They occasionally referred to how they used to find their way, and how different wayfinding felt to them now. All of the informants stated they hoped their condition would improve. Activities they would like to pursue if their impairment diminished were often mentioned. At times, the informants expressed a lack of confidence in their ability to travel independently, even if they were doing so successfully.

All four informants had received some amount of rehabilitation following their injury, yet expressed that they felt it was not effective for regaining independence in living. The rehabilitation was most often of short duration, and occurred early during the recovery phase, perhaps before the individuals had a clear sense of their limitations in conducting activities of daily living. At the time of the interviews, all of the informants had achieved some independence in wayfinding and self-care. One informant stated that at a support group for stroke survivors, he met a woman with a similar impairment who helped him when she shared her strategies for overcoming her visual deficit.

Despite her stroke, diabetes and dependence on insulin, Ms. C. was very independent in travel and everyday life, Her longer experience of visuo-spatial disability may have been reflected in the compensatory strategies she had developed by the time of the interview since she was three years post-stroke at the time of the interview, compared to the other two people who had strokes and who were interviewed almost one year post-stroke. The informant with traumatic brain injury, Mr. D., was wholly different in his trajectory of recovery despite being five years post-TBI, largely because of his memory impairment.

Within the home, the informants emphasized the use of visual scanning, maintaining an organized and clutter-free environment, and rearranging the physical space of the home to support orientation. Ms. C. expressed the most profound difficulty wayfinding within her home, and also had developed the most elaborate coping method, relying on memory, body position, attention to minute details in the environment, methodical visual scanning, organization and lack of clutter.

Mr. P. and Ms. C. planned ahead, traveling at times of day when traffic was low, and choosing routes to avoid busy areas and streets. They tended to avoid driving on the freeway. In addition, Ms. C. used written sequences of landmarks and directions which she reviewed prior to travel outside the home. These two informants seemed to build their travel strategies on a combination of support from friends and family, and reliance on whatever residual elements of residual visual and spatial function they had.

Success in traveling outside the home was accomplished differently for Mrs. B. and Mr. D. who were unable to drive independently at the time of the interviews. They relied solely on friends and family for their travel. Mr. D.'s prior reliance on sense of direction, more than landmarks, for wayfinding and orientation (such as when hunting in the dense pine bog) is consistent with findings that men may rely more on directional sense for wayfinding and less on use of landmarks, as compared with women (Montello et al., 1999). Although he stated that he was aware of landmarks, and seemed to be able to understand the interviewer's suggestion that keeping a list of landmarks between familiar locations might help him to maintain a sense of orientation during travel, it was apparent that his memory loss at the very least, and possibly also his prior reliance on directional sense for orientation, hindered his orientation and eliminated the possibility of independent travel.

Several differences between the informants became obvious through these interviews. Mr. P. was the least impaired of the informants and the most functional of them, evidenced by his ability to continue to run a small business following his stroke. Mr. D. was not the most impaired informant regarding his spatial and visual functioning, but with his loss of short-term memory he became the most dysfunctional informant with respect to travel. Mrs. B. and Ms. C. seemed unable to construct elaborate mental representations of space, yet they were able to retain images of individual places and could memorize sequences of images and directions, which they relied on when wayfinding. Only Ms. C. mentioned using sound in addition to residual visuo-spatial function for wayfinding.

CONCLUSION

Studies of disability in the medical geography literature point up the need to investigate the lives of the people with disabilities in order to understand disability in various physical and social contexts (Thapar, Bhardwaj & Bhardwaj, 2001), and emphasize that geographical and social dimensions of life are integral to the experiences of the people with disabilities (Dyck, 1995). Such information may be used to clarify the problems individuals with VSI face in their attempts to maintain meaningful life activities, and may enhance understanding of the mechanisms underlying normative wayfinding.

The varied nature of visuo-spatial impairments and differences among the informants suggests that a mix of behavioral and environmental accommodations may be needed to improve quality of life for people with visuo-spatial disabilities. The three people whose visuo-spatial impairments were due to stroke remained fairly independent through a combination of developing new wayfinding skills and through support from family and friends . For the man who had TBI, memory played an important role in his ability to navigate and function independently.

Practical, inexpensive methods, such as keeping spaces free from clutter, may improve the interior living spaces of individuals with VSI. Based on Ms. C.'s successful modifications of her home environment, individuals with visuo-spatial impairments may want to make changes in their homes to enhance their independence and orientation. Studies to investigate the usefulness of particular interventions in the home environment are needed.

The outdoor environment poses special challenges because it cannot be controlled and it is constantly changing. It is possible that external support systems in addition to behavioral adaptations will be needed to enable individuals with VSI to wayfind successfully outside the home. For instance, geo-positioning satellite (GPS) devices now on the market might be useful to enhance the orientation and wayfinding of individuals with visuo-spatial impairment.

Future research should focus on determining systematically how different elements of residual visuo-spatial function, and different combinations of residual visuo-spatial function, may be relied upon for wayfinding in different settings. The findings of this study suggest ways to enhance wayfinding ability among individuals with VSI, which should be investigated in further studies with larger samples. Controlled studies in environments that replicate actual living environments, would be useful for identifying various environmental modifications. The potentially important role of the etiology of stroke versus traumatic brain injury in the development of alternative methods of wayfinding may also lead to improvements in wayfinding for people with visuo-spatial impairments. This study suggests the importance of knowledge about everyday activities of individuals with visuo-spatial impairments and the role of wayfinding in their abilities to conduct their everyday activities.

Acknowledgments

The study was supported in part through grants from the University of Michigan Office of the Vice President for Research, School of Nursing and Rackham Graduate School.

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