SPATIAL KNOWLEDGE ACQUISITION AND THE BLIND:  THE EFFECT OF ENVIRONMENTAL AUDITORY CUES ON SPATIAL AWARENESS

 

James R. Marston

 

Department of Geography

University of California Santa Barbara

Santa Barbara, CA U.S.A.93101

Tel: +1 805-893-7274 Email: marstonj@geog.ucsn.edu

 

 

 

 

Abstract:  This paper reports on an experiment that used auditory cues (Talking Signs® Remote Infrared Audible Signage) to increase environmental awareness in a multi-modal urban transit station.  One group of participants used their regular methods of orientation and travel while the others used the additional auditory cues.  Two types of tests were conducted to measure spatial knowledge acquisition.  Participants were given two opportunities to make a shortcut, if they were aware of its presence.  In both instances, those that used the auditory cues were vastly superior in their ability to make distance-saving shortcuts.  In addition, a set of spatial relationship questions was examined.  Those that used the auditory cues answered these questions much more accurately than those that used their regular methods.  These additional auditory cues gave information that is not normally available and it appears that poor spatial awareness (a major problem of blind navigation) is the lack of accessible cues, not an inherent cognitive processing flaw of these individuals.

 

Keywords:  Accessibility, blind, vision-impaired, spatial knowledge acquit ion, cognitive maps, environmental cues, blind navigation

 

 

 

1.  Introduction

 

The ability of blind people, especially those born without sight (congenitally blind), to understand spatial relationships or build an accurate cognitive map is a topic on which there is little agreement.  Some research has shown that those without sight are not easily able to encode and integrate spatial relationships (Rieser, Lockman et al. 1980), while other research shows no such effect  (Loomis, Klatzky et al. 1993)..  The normative belief is that there is a processing problem when a blind person deals with spatial thinking.  There are three major theories: deficiency, inefficiency, and difference (Fletcher 1980).  For a review of experiments on this topic, see (Thinus-Blanc and Gaunet 1997)

 

There is a fourth possibility, that of an amodal representation (Carreiras and Codina 1992) which postulates that the blind are able to store and process spatial relationships in a manner similar to the sighted, but that it might take them longer. Current work has shown that when performing navigation tasks in a real environment, and with the availability of cues that are accessible to the user, blind people exhibit little or no difference from sighted people (Jacobson, Kitchin et al. 1998; Golledge, Blades et al. 1999; Marston 2002).  This paper reports that with additional auditory cues blind travelers can learn these necessary spatial relationships very quickly. 

 

A field test that used Talking Signs® Remote Infrared Audible Signage (RIAS) in a large urban transit terminal was conducted.  The experiment design, methods, and participants are reported elsewhere (Marston 2002; Marston and Golledge 2003; Marston and Church In Publication).  The ability to understand the environment when using regular navigation skills and when using RIAS was tested with a group of blind participants.  Twenty of those participants had no useful vision and, to reduce moise and variance , only those data are reported here.

 

 

2.  Spatial Knowledge Revealed by Navigation and Wayfinding Tasks

 

In the field test, two of the search and find tasks allowed participants to take any route they chose to locate the next task destination.  From one starting point (cabstand), participants were told to find the water fountain in the terminal.  No additional path information was given.  The terminal had side doors facing Townsend Street that led into the station, and these doors were labeled with RIAS transmitters (see Figure 1).  No mention had been made of these doors.

 

Air currents and crowd noise might have been available as cues for the blind to enable them to notice or locate the doors to the street.  For the 11 blind participants that used their regular methods first, only three (27%) made the shortcut through the side doors.  The rest retraced the longer path they had previously taken to the cabstand.  In contrast, all nine (100%) of the blind participants using RIAS on their first trial used the shortcut.  Although they had not been looking for the door, they appear to have learned about it while scanning around during the previous or current tasks.  No formal data was collected, but the researcher noticed that some participants heard the side door message while they were looking for Track #2 (in the previous sub-task) after leaving the track door on the guided walk, or from the outside while going to the cabstand.  It was also possible to hear the message while starting to retrace the original path if they were scanning in that direction.

 

The second route where a shortcut was possible occurred after participants visited Track Door #11 at the far end of the terminal (Figure 2).  From that door, they were told to go to the street corner that had first been visited.  Again, no directions were given.  There was a series of doors across from the track doors that led to a plaza opening up to the street.  This is the kind of situation where, even if a blind person knew there were doors available, they would not know what was outside the doors, or whether they could get to the corner without barriers or obstacles in the way.  Only two (18%) of the eleven blind participants without RIAS used the shortcut through the doors leading to the outside plaza; the others all walked back down the hall in the opposite direction and went out the main exit that they had learned in the first task.  For the nine blind participants that used RIAS first, eight (89%) used the door opposite the track door to directly access the corner.  The RIAS transmitter above the door had the message, “Exit to 4th and King plaza.”  They must have found this message while scanning around the environment (either while walking to Track #11 or when starting the trip to the corner). The message giving the direction and identity of the doors appeared to provide them with enough information to attempt navigation in a totally new area of the environment (the plaza area).

 

For the two shortcut tests, blind people using their regular method on their first attempt had 22 chances to make a shortcut, and participants were only able to take full advantage of the potential accessibility in the environment and use the shortest path five times (23%).  When using RIAS, first time participants had 18 chances to use a shorter path, and all but one (95%) did so.  As an objective measure of accuracy in navigation, the ability to reduce distance by making correct (optimal) spatial decisions is fundamental.  RIAS demonstrated its ability to save distance and time for participants in new environments, making it easier to gain access to more activities.

 

The propensity to make shortcuts and the spatial knowledge awareness exhibited here is a true measure of the utility of their cognitive map information.  Being able to make shortcuts shows an understanding of the object-to-object spatial arrangement and the ability to make efficient route choices, which is the goal or utility of a good mental representation of an environment.  Many blind people would rather stay with a known environment than risk obstacles and barriers in a new environment, thus avoiding apprehension and stress.  This inability to access the “best” or optimal path is a major restriction to access in new environments and limits independent travel and efficient learning of spatial arrangements.  Instead of being taught a new path by a friend, stranger, or instructor, blind people using RIAS appear to learn an environment on their own and access the environment in the way that it was designed.

 

 

3.  Spatial Knowledge Revealed Through Verbal Statements

 

Another way to measure cognitive map knowledge is to examine spatial products revealed by verbal or written descriptions.  A type of sentence framing technique was used where participants were asked to give the answers to a series of 20 questions that dealt with both spatial arrangements and knowledge of the environment.  Questions that dealt directly with spatial relationships between concession stands and the ticket window and with relationships between amenities in the waiting room area were used.  Other questions dealt with the spatial arrangement of the track doors, information about the traffic lane configuration of the streets they crossed, names of the streets, and other more general spatial relationships in the terminal environment.  To reduce variance and increase validity, only the participants who had no useful vision are examined.

 

The spatial questions were asked after five transfer tasks were completed, in the No RIAS and RIAS conditions.  Participants had not been told that any spatial questions would be asked and so had no way to cognitively prepare for a spatial test.  The questions were given in such an order that no previous question could give the answer to any further question.  Of the 20 questions asked of the 11 participants with no useful vision using their regular method (No RIAS) on the first trial, 44% were answered correctly.  In comparison, the nine participants who used RIAS for their first attempt in the field test got 88% correct.  The use of RIAS was highly significant; the difference between the blind group using their regular method and the group using RIAS was (p<.0002).

 

3.1  Frequency Distribution of Spatial Knowledge Performance

 

The frequency distribution of each person’s correct scores between the two groups was highly skewed in favor of those using RIAS.  Figure 3 shows the frequency distribution of each subject’s correct answers on their first trial, a measure of their spatial awareness.

 

 

Figure 3: Frequency Distribution of Answers to Spatial Questions

 

 

3.2  Cognitive Map Knowledge And Spatial Awareness In A New Environment

 

Of the 20 questions, 14 dealt directly with various types of spatial relationships (Table I), and the next section will discuss these various groups of spatial questions.  It is difficult to use externalized spatial products to accurately measure the internal cognitive map.  The main interest here is how that map’s spatial data has real utility for blind travelers, which information is the hardest to learn without vision, and how these gaps in the cognitive map can affect independent travel and accessibility. 

Spatial Questions

Regular Methods

Using

RIAS

 

Percent Correct

BUILDING INFORMATION

 

 

Which track # did we first start at?

9

78

Where do the doors across from tracks 9-12 lead?

18

78

How many train tracks serve the Caltrain station?

27

100

LOCATION OF TRAIN TRACKS

 

 

Which tracks are closest to the waiting room?

27

67

Which tracks are closest to the main entrance?

36

67

ARRANGEMENT OF TRAIN TRACKS

 

 

Which track door # is closest to track door 7?

45

100

Which track door # is closest to track door 6?

55

100

ARRANGEMENT OF CONCESSION STANDS

 

 

What concession counter is closest to the train area?

55

89

Which concession counter is closest to or across from the ticket window?

55

100

Which concession counter is closest to the front street?

73

89

What concession counter is closest to the Candy counter?

82

100

ARRANGEMENT OF AMENITIES

 

 

What amenity is furthest from the phone?

55

89

What amenity is closest to the phone?

55

100

Which amenity is closest to the water fountain?

73

89

 

Table I Spatial Relationship Data

 

3.2.1  Building Information:  These three questions asked about information that was not directly needed to complete the field test, and the results show that this information was not learned by most of the regular method (No RIAS) participants.  Those using RIAS picked up this information quite well, even though it was not critical to the task and participants were not required to navigate to those locations.  This ability to pick up information about locations while doing other tasks is often impossible without sight, unless an active and physical search is undertaken.  To be able to learn about the environment while simply walking through it is what vision allows, and this ability to easily gather spatial information helps make sighted navigation much more efficient.

 

Only one blind subject answered the hardest question using regular methods of orientation.  Participants were walked to the beginning location of the test with their eyes closed and started with their back to the door.  There was little utility in knowing where they started from, and few cues available to gain this knowledge.  With RIAS, participants got this question right 78% of the time.  The next hardest question asked about the doors across from tracks 9-12 and where they led.  Only two (18%) participants knew the answer without RIAS.  Since most of the regular method participants did not even use these doors (for the shortcut), they probably did not know that the doors even existed.  With RIAS, 78% knew the correct answer.  The other question put in this Building Information group asked for the total number of tracks at the station.  The highest track door actually visited was #11 and, without knowledge of the track layout and extent of the hallway, it was difficult to know the correct answer.  For the regular orientation group, three people (27%) knew there were actually 12 track doors.  All participants using RIAS got that question correct.

 

2.2.2  Location of Train Tracks:  Two questions asked about the relationship between track doors and other locations in the terminal building.  Again, this knowledge was relevant but not critical for the navigation task.  The higher scores with RIAS show that the use of auditory cues gave better spatial knowledge of the environment.  It is quite difficult for blind people to get enough distal cues to understand the relationships between locations in a large open space.  With no visual cues to spatial arrangements, blind travelers must often go to a wall and search along it until they find a location.  Later, they might be at the opposite wall to find other locations.  If the open space between these two locations is an area that is too large to comprehend without vision, they might have little or no knowledge of the spatial relationship between the two locations.  The two locations might even be directly across from each other, but this knowledge can be hard or impossible to acquire, at least without a great deal of physical activity.

 

Of those using their regular orientation skills of navigation (No RIAS), only three (27%) knew which tracks were across from the waiting room, and four (36%) knew which tracks were closest to the main entrance hallway.  When using RIAS, participants got both of those questions right 67% of the time.

 

2.2.3  Arrangement of Train Tracks:  Figure 1 shows the twelve tracks serving the Caltrain terminal.  Tracks 1 and 2 are separated by a wide concrete shared boarding platform, and this pattern is repeated up to the final shared boarding platform for tracks 11 and 12.  There are two sets of double doors that open from the terminal onto each shared platform.  Thus, doors for track 1 and track 2 are directly next to each other, while track 3 is quite a distance away next to the door for track 4).  The spatial arrangement of the doors and tracks is not easily discernable without sight.  Two questions were asked to determine if the participants had learned the spatial arrangement of the track layout.  The two questions asked participants to state which track door # was closest to another.

 

Even after visiting various track doors three times, about half of the No RIAS group still did not show knowledge that the doors were arranged in groups of two (with the odd number door on the right and the even one on the left).  This is critical information needed to make efficient navigation and full use and access of a train terminal.  The people using their regular skills did no better than chance on their answers, getting 45% and 55% of these two questions correct.  With the use of the information provided by the auditory and directional cues, 100% of the participants knew that the doors were arranged in groups of two.  There is a high utility associated with having this type of information.  Since there was no Braille or tactile information on the doors, it could have taken quite a while for a blind person to understand this arrangement and extrapolate this arrangement to all platform doors in the current environment.

 

2.2.4  Arrangement of Concession Stands:  During the field test, participants visited all three concession stands and the ticket window (twice) in the main hallway.  The person-to-object information they acquired while walking to these locations appears to have helped form a better object-to-object understanding than with other types of locations.  For two questions, participants using normal orientation skills got 55% of those questions correct.  In contrast, with RIAS, one of the questions was answered correctly by 100% of the participants, and the other question had one incorrect answer (89%.)  Regular users answered 73% and 82% of the other two questions about the spatial arrangement of the concession stands correctly, and, with RIAS, they scored 89 and 100% respectively.  Clearly, the active search and navigation allowed participants to understand these types of spatial relationships better than some of the other types of locations.  The area between the four locations was quite small and fairly easy to understand.

 

2.2.5  Arrangements of Amenities:  Each of the participants visited three amenities in the waiting room during the field test, during different trips.  They found the “correct” bathroom, the phones, and the water fountain.  This was a very small area; the locations were just a few feet away from each other, although they were on three different  (90 degree separation) walls.  Although these locations were almost touching each other, only 55% of the normal orientation participants were able to identify what was closest to the phone and also what was furthest from the phone.  RIAS users scored 100 and 89% on those 2 questions respectively.  Regular navigation participants scored 73% when asked what was closest to the water fountain, and RIAS users scored 89% on that question.

 

 

2.3  Summary of Spatial questions.

 

Different types of questions about spatial relationships showed a wide range of responses, when participants did not use RIAS auditory cues.  The locations that they did not need to know, or did not visit during the test, showed much lower rates of understanding.  Of those locations that were actually visited during the trials, they scored better, showing that there is increased knowledge of spatial relationships when actively searching and traveling.  However, their spatial knowledge was not close to that exhibited by those who had the additional use of auditory cues.  The lack of accessible cues in the environment is shown to be a major deterrent to acquiring accurate spatial knowledge.  When more accessible cues (RIAS) were provided, blind participants were able to understand the relationships very well, sometimes even better than a sighted person (Marston 2002).

 

 

3.  Summary of Spatial Knowledge Acquisition and Cognitive Maps

 

A researcher using some type of externalized means of measurement must extract the information stored in a person’s cognitive map.  Different spatial products are likely to reveal differing amounts and types of information.  Two methods were used here to gain more convergent validity and concentrated on testing if these observed internalized spatial representations had utility for the user.

 

 

 

 

 

 

 

Cognitive mapping research concerned with blind travel provides information on what restrictions exist and what cues are missing.  It allows the testing of assistive devices against known behavior and spatial awareness.  These two experiments, assessing participants’ ability to make shortcuts and assessing their spatial knowledge, provide information about how hard it is to learn spatial information without vision, unless the area is accessed repeatedly.  Blind users trying to navigate unknown spaces can be at a great disadvantage, and that affects their ability to have ready access to many new environments.  Many cannot easily, efficiently, or independently learn new environments without much effort or training.  This incomplete spatial knowledge affects the ability to gain reasonable access and could be a reason why many blind people report very limited travel behavior or never venture out alone.  Even with multiple visits, spatial relationships remain elusive for some.  The ability to increase one’s spatial knowledge with auditory signs, by providing easy access to missing directional and identity cues, allows for independent and dignified wayfinding.  These auditory cues allow blind users to gain some of the critical spatial information that a sighted person can access, and they allow for efficient behavior such as the ability to make shortcuts and learn the layout of an environment.

 

By comparing cognitive mapping results of an assistive aid such as RIAS to the regular method baseline, much needed knowledge is gained about what cues are needed and how to best present these navigation cues to a user.  These two tests provide evidence that, with the availability of additional cues giving direction and location identity, blind people can form an accurate cognitive knowledge of an area just as well as a sighted person.  They can learn locations without visiting them and are able to use this knowledge (utility) to take advantage of the access potential of an environment, something that has previously been denied to them.  This empirical evidence should put to rest the notion that there are inherent flaws in the ability to acquire spatial knowledge without sight.  Blind people appear to have the processing ability required to understand geographic space, and it is the lack of accessible cues that can cause the inferior spatial knowledge often attributed to this group.  RIAS provided essential spatial information that was previously lacking, thus allowing blind travelers to use spatial skills that are otherwise masked or suppressed.

 

References

 

Carreiras, M. and B. Codina (1992). "Spatial cognition of the blind and sighted: Visual and amodel hypotheses." Cahiers de Psychologie Cognitive 12: 51-78.

Fletcher, J. F. (1980). "Spatial representations in blind children. 1. Development compared to sighted children." Journal of Visual Impairment and Blindness 74: 381-385.

Golledge, R. G., M. Blades, et al. (1999). Understanding geographic space without the use of vision. Santa Barbara, CA, Department of Geography, University of California Santa Barbara; Department of Psychology, University of Sheffield, UK; Department of Geography, National University of Ireland, Maynooth, Ireland; and Department of Geography, Queens University, Belfast, Ireland.

Jacobson, R. D., R. Kitchin, M,, et al. (1998). "Learning a complex urban without sight: Comparing naturalistic versus laboratory measures." Presentation made at Mind III: The Annual Conference of the Cognitive Science Society of Ireland.

Loomis, J. M., R. L. Klatzky, et al. (1993). "Non-visual navigation by blind and sighted: Assessment of path integration ability." Journal of Experimental Psychology, General 122(1): 73-91.

Marston, J. R. (2002). Towards an Accessible City: Empirical Measurement and Modeling of Access to Urban Opportunities for those with Vision Impairments, Using Remote Infrared Audible Signage. Unpublished  Dissertation www.geog.ucsb.edu/~marstonj/DIS/OVERVIEW.html. Santa Barbara, University of California: 450.

Marston, J. R. and R. L. Church (In Publication). "A Relative Access Measure to Identify Barriers to Efficient Transit Use by Persons with Visual Impairments." Journal of Disabiltiy and Rehabilitation.

Marston, J. R. and R. G. Golledge (2003). "The Hidden Demand for Activity Participation and Travel by Persons who are Visually Impaired or Blind." Journal of Visual Impairment and Blindness 97(8): 475-488.

Rieser, J. J., J. J. Lockman, et al. (1980). "The role of visual experience in knowledge of spatial layout." Perception & Psychophysics 28(3): 185-190.

Thinus-Blanc, C. and F. Gaunet (1997). "Representation of space in blind persons: Vision as a spatial sense?" Psychological Bulletin 121(1): 20-42.

 

 

 

Figure 1 Path of Travel for Transit Task 3

 

Figure 2 Path of Travel of Transit Task 4