Unique Features Of Guide Dogs:
Backtracking And Homing

by Paul Gabias

Copyright © 1995
National Federation of the Blind

          From the Associate Editor: Dr. Paul Gabias is a professor of psychology at Okanagan College in Kelowna, British Columbia. He is also married to Mary Ellen Reihing Gabias, a long-time Federationist and for several years before her marriage a staff member at the National Center for the Blind in Baltimore. Those who meet Dr. Gabias soon notice how intelligent and well-behaved his guide dogs are. I have known him long enough to have watched him with two animals, both of which he has trained himself. He clearly loves and respects animals, but his guide dogs are not pets; each has been a working partner. What he has to say about using and training dogs as guides is sensible and practical. The following article is reprinted from the December, 1991, issue of Harness Up, the publication of the National Association of Guide Dog Users, the guide dog division of the National Federation of the Blind. Here it is:

          I want to begin by contrasting the guide dog and the cane as two very different mobility methods, each with its own strengths and weaknesses. It is not my intent here impartially to list these. Instead, my purpose is to highlight several specific skills of the dog and the ways they can be integrated into the guide dog's working life. I will do so against the backdrop of contrast with the cane. I call these skills backtracking and homing. The terms mean just what they imply. Backtracking is retracing steps; homing is finding one's way home. Obviously, in a familiar area both activities are easy. However, most exciting travel is done in unfamiliar areas, where by definition the layout changes constantly and homes don't last for more than a few days. It is in these situations that the guide dog, with the skills of homing and backtracking, is at its best. After contrasting the cane and guide dog as useful but different mobility methods, I will describe how to train a guide dog in homing and backtracking.

          First I want to make it clear that, even though the guide dog is my preferred travel aid, I am an experienced cane user and therefore believe that I can make a fair comparison between the two travel methods. I will explain how to teach a guide dog four specific commands: inside, outside, upstairs, and downstairs. The mastery of these commands predisposes the dog to pay attention to the layout of the environment. This attention to layout is what makes the dog ready to learn the strategies of backtracking and homing.

          I will also make a few comparisons between guide dog training and computer programming. The harness handle can be considered a transducer of visual information to proprioceptive information. This transduction from one form of energy to another is not unlike the transduction which goes on inside the nervous system for vision and hearing.

Experience with White Cane and Guide Dog

          At the age of fifteen, while I attended L'Institut Louis Braille, a school for the blind near Montreal, I received cane travel lessons from two blind instructors. I travelled with a cane for three and a half years. Although the cane was too short, it got me where I needed to go safely enough, but much more slowly than necessary. It also brought me into contact with the public. The instructors at the school for the blind did not teach me how I was to deal with the continual pity and amazement of the public generated by my walking around independently with a cane.

          At the age of eighteen I purchased a Labrador retriever puppy I called Rapha. With the help and encouragement of the late Dr. Robert Lambert, who trained his first two guide dogs, I successfully trained Rapha. A few years later John Byfield, a long-time director of training at Guide Dog Foundation and the current director of training at Fidelco Guide Dog Foundation, gave written attestation to my competence as a trainer. Rapha retired at fourteen and a half and was euthanized a year later. During Rapha's lifetime I also successfully trained two other guide dogs. Both were trained and worked in New York City and the surrounding areas. During most of the training of both these dogs, which lasted about four months each, I successfully used a white cane. Then, for approximately a year and a half during Rapha's retirement and the training of my next guide dog--a golden retriever named Viva--I also used a cane.

          The change from dog to cane was difficult for me. Thanks to the NFB, I was now using a long cane, but it took a great deal of work on my part to accept the cane emotionally. The techniques and style were quite different. It seemed to me that the cane made blindness so blatant. I became acutely aware that, through the use of my dog's vision, I had protected myself from strong unresolved negative feelings about blindness. Rapha's retirement and my unwillingness to replace him until he was dead forced me to deal with these feelings. Through the NFB and a very powerful mentor, I was able to deal healthily with these issues.

          After a year and a half of cane use, Viva, my second guide dog, was pretty well trained. Unusual though it may seem, she attended her first National Convention in Kansas City at seven months of age. Those who remember her there will attest to her superb behavior despite her youth. She was a dog in a million. I deeply regretted her death at three and a half years. As we were moving to a new home, she was suddenly stricken with a spinal embolism which left her hindquarters completely paralyzed. Four days later I was again without a guide dog.

          Walking has always been therapeutic to me. The day after Viva's death I took a four-mile walk with my white cane in an unfamiliar area. I repeated this activity for several days.

          That academic year was new for me on many fronts. I had a new job with new students, new surroundings, a new wife who was pregnant, and a new golden retriever puppy named Schubert to train. Thanks to the National Federation of the Blind and my wife, I was now using my cane with confidence and pride. At the end of that year I used my cane on two job interviews, which led to two job offers. One of those interviews resulted in our move to Kelowna, British Columbia, and my appointment as psychology professor at Okanagan College.

          I am a strong advocate of white cane use. Every blind person should know how to use one. But the white cane and guide dog are very different mobility aids. I would like to focus on several of the differences before talking about backtracking and homing.

Contrasts Between the White Cane and Guide Dog

          All the functional differences between using a white cane and a guide dog are derived from one basic difference: the white cane is a tactile aid; the guide dog is a visual aid. In comparing them, it will be useful to begin by examining the kind of information available to the blind pedestrian without either aid.

          Information about the texture of the ground is gathered by the feet and by analyzing the sound that the feet make. Information about the proximity of objects is collected by the ears. Information about the texture and shape of objects and the texture and layout of the ground is picked up by the skin and changes in joint position which occur during exploration with hands and feet. Odors often provide useful information through the nose, and wind direction and sun position, which can both be very useful, are gathered by the skin.

          Therefore, without using either a dog or a cane the blind pedestrian still has access to information about the environment--topography of the ground and the proximity, texture, and shape of nearby objects. In addition, during street crossing, information about the pattern of traffic is picked up by the ears. This traffic pattern is useful in locating the opposite corner.

          What additional information can be provided by the skillful use of the long white cane? The cane is a tactile scanning instrument. It warns the pedestrian of changes in terrain texture and layout, e.g., steps, pathways, and doorways, before the information would be picked up by the feet and the hands. It makes contact with objects before the user's body does, allowing the pedestrian to walk around them. It also augments the auditory information provided by echoes. In short, the cane is mostly a tactile aid, and the range of its information pick-up is very short--that is, distances within a few feet of the user.

          On the other hand, the guide dog is a visual aid. The dog, through its visual system, has access to information at some distance, e.g., the layout of an enclosed space or a large open area like a mall or the lobby of a hotel. At a distance it can perceive the location of significant points in the layout such as staircases, entrances, exits, and elevators. The dog can perceive paths through the gaps in a crowd. The trick is to make the dog's visual information about distance useful to the blind person.

          The dog communicates with its owner through movements of its body, transmitted through the harness handle or, in some circumstances, through the leash. This communication is a transduction of information from vision to touch, called proprioception, which is transfer of information from electromagnetic energy to mechanical energy. Similar kinds of transduction occur within the nervous system. In vision, for example, the receptors of the retina transform electromagnetic energy into nerve impulses. In hearing, vibrations in the air are picked up as mechanical energy in the outer and middle ear, are transformed into hydraulic energy in the cochlea, and are transformed into nerve impulses in the basilar membrane of the inner ear.

          By analogy, the harness on the dog transforms its visual information into proprioceptive information that can be used to determine the owner's steps. For example, a pause in the dog's forward movement indicates a change in layout. One ascertains the type of change with the foot and the subsequent movement of the harness handle. Lateral motions of the dog and the harness handle mean that there is an obstacle to be avoided by moving to the left or the right. The direction through a crowd is chosen by the blind pedestrian, but the specific route is selected by the dog. Through its choices as the pair proceed through a crowd, the dog's visual information is transformed into proprioceptive information by the harness handle. The same occurs at street corners. If the two corners of the intersection are not directly opposite each other, no problem. The dog selects the correct trajectory, and the information about the necessary angle for safe crossing is conveyed to the blind pedestrian as he or she listens to the traffic and walks across the street.

          Another difference between the guide dog and the cane is that the cane does not learn. It is incapable of pattern recognition. It cannot recognize familiar routes. It cannot make correct choices at appropriate points. It cannot recognize the entrances of familiar buildings, nor can it recognize customary pathways taken through these buildings. The cane is a passive aid while the guide dog is an active, interactive aid.

          Because of this the dog must be trained or programmed to send specific messages to deal with particular changes in layout. Further, the blind person must learn to understand the messages travelling through the harness handle. The blind person must also learn how to integrate the messages from the harness handle into the perceptual information available through other sources. If the messages do not match the information available to the blind person, e.g., the dog is distracted or requires more training, the blind person must correct the dog or update its programming. The guide dog's behavior must be consistent with the owner's expectations. If the blind person keeps those expectations high and is vigilant about keeping the animal programmed properly, the dog will perform as it should.

Backtracking and Homing

          We now come to the issues of backtracking and homing. I have deliberately introduced computer language because I believe that with dogs, as with computers, we can achieve a high degree of control over the outcomes resulting from particular inputs. With computers, of course, the key to control is parsimonious, logical, step-by-step programming. With dogs, the key to control is step-by-step shaping of behavior and consistent reinforcement. Of course, the dog is much more complex than any computer. Its natural tendencies and emotional make-up must always be taken into account in any training situation.

          As I have mentioned, dogs can learn to obey commands such as "inside," "outside," "upstairs," ":downstairs,": ":elevator,": and ":follow.": As far as I know, most of these commands are not formally taught by the majority of guide dog schools. If you choose to, you can surmount this problem with a little work. After all, information about the layout of the building is visually available to the dog, through both perception and memory. Why should we not take full advantage of this information? But the dog must be trained to transmit the information to us, and here is how it can be done.

          Let us start with the command "inside." To begin, face the doorway of a building. Give the dog the "forward" command, followed by "inside." The dog will obey the "forward" and take you to the door. Repeat this procedure several times. Then continue with the procedure, but omit the "forward" command. Simply give the "inside" command. If the dog does not move, encourage it along by nonverbal means. Repeat the procedure until the dog moves forward with only the "inside" command. Of course, praise the dog at appropriate places, e.g., after the dog has begun to move and at the doorway. Make a fuss at the door, telling the dog how good it is. Once your dog understands that, when you are facing the doorway, "inside" means to move toward the doorway, you are ready to proceed to the next step. By the way, always use the same trajectory to and from the door. In this way you are inculcating the rudiments of backtracking in the dog.

          The next step is to issue the "inside" command when you are not facing the doorway directly. Start with small angles of deviation and increase them as the dog improves. The "inside" command should cause the dog to compensate for the angle. You can verbally correct the dog if it does not compensate for the angle. When the dog does compensate and goes to the door, praise it profusely. When training is complete, you should be able to face completely away from the door, requiring the dog to make a 180-degree turn and head for the door after receiving the "inside" command. It is important that the dog be able to do this. It will help you in unfamiliar areas in which you are not sure where the door is.

          The next step involves increasing the distance between the door and the dog. Always train in a familiar area. A parking lot or a field is particularly appropriate. As you increase the distance from the door, try different facing angles. Use these strategies with different doorways. Incorporate them into the dog's working life.

          Once the dog has learned to respond to the "inside" command correctly, follow the same procedure for the "outside" command. As the dog comes to understand these commands, widen the scope of their use. A sensible and sensitive owner comes to know when the dog is ready for strict enforcement of the commands. Test your dog on these commands when you know which direction the door is. Once the dog knows the commands, you can correct it with the harness or the leash if it does not head in the appropriate direction. Remember that sometimes there may be a door in the opposite direction. I have been fooled sometimes and have had to apologize to my dogs. Fortunately, most dogs are of a forgiving nature.

          I believe that through success with these commands, over time the dog learns to pay attention to the flow of the layout of surfaces in its optic array as it moves through the environment. It learns the backtracking strategy, which usually works well: Whatever route you followed on the way into a building, do the opposite on the way out. This works very nicely in stores. One can go to a department store and follow various clerks to different displays, and experienced dogs can learn to pay attention to the layout of the store as they move through it. Unless the store has doors which face in different directions, the "outside" command will simply mean a reversal of the whole layout, that is, motion in the opposite direction.

          This backtracking strategy can be useful in other settings too. Suppose you are with friends at a restaurant and wish to visit the washroom. If you don't know where it is, you can follow another person with your dog. Often sighted people will ask if they should wait until you are finished. If your dog knows the backtracking strategy, it can guide you smoothly back to the table. You can use a command like "find the seat" or "find the table." The dog should retrace its steps to your seat. Praise the dog for finding the table if it is successful. If it fails, you can practice this skill by showing the dog the table you want, starting with short distances. Do this a few times in different restaurants. The dog will catch on fairly quickly, particularly if the other people at the table are familiar or if there is another dog at the table. The dog has learned to backtrack, to retrace its steps from the table to the washroom.

          The training procedures for "inside" and "outside" also work for "upstairs" and "downstairs." Dogs often confuse up and down at first, but discrimination can be taught with persistent and systematic training. Ideally, you should be able to walk out of any subway train in any station and give the "upstairs" or "downstairs" command. If the station is unfamiliar, no problem. The dog can be expected to perceive the layout of the station and find the appropriate staircase on the platform.

          Occasionally, experienced dogs will correct themselves; first they go in one direction. Suddenly they stop and then turn around and go in another direction. Sometimes the stairs may not be immediately visible to the dog. Unless you want a particular staircase among several available, it is important not to choose a direction for the dog upon leaving the train. After all, you want to encourage the dog to take the initiative. You will be amazed at the accuracy dogs can achieve. Of course, do not expect this to happen overnight. The step-by-step approach discussed earlier must be followed first. The same procedure applies to elevators.

          Sometimes when training "inside" and "outside" you will find the dog mistakes large window panes for doors. Try to teach the dog that the handle of the door is the distinguishing feature. A mat in front of the door can also help discrimination. Tap the handle with your hand or the mat with your foot, and praise the dog for paying attention.

          Finally, let me say a few words about homing. In my experience dogs who are well-travelled and expert with the backtracking technique and successful with the "inside," "outside," "upstairs," and "downstairs" commands develop a homing sense. This is what is happening when dogs anticipate customary turns on a familiar route. This tends to happen close to home, hence the term "homing." The common wisdom that, unless you are following, you should make the dog go to the curb before turning the corner is correct. Near home most dogs go to the curb reluctantly. They are very glad to turn in the accustomed direction. You can encourage the homing ability by doing the following: once you have the dog go to the edge of the curb, instead of giving the appropriate directional command (usually "left" or "right") turn your body in the desired direction and tell the dog "OK." The dog should take off in the appropriate direction, happy to go in the direction it wants. The dog will learn that at a corner the OK command means choose the appropriate direction. Do this in familiar areas, and praise the dog for the correct choice. I have found that there are great dividends to this technique.

          For well-seasoned dogs home is not just where you customarily live. For my dogs home also means the hotel room in which they were last fed or the room in which our luggage was left. The entrance to the hotel means the entrance to home. Particular relief areas may also be involved. It is always interesting to see this ability develop with each new dog. All dogs have it. It is just a question of developing the skill. I remember recently staying at the faculty club at the University of British Columbia for a few days. I decided that I wanted to pick up submarine sandwiches at a restaurant, which was not too far from campus. It was fairly late at night, and I had some difficulty getting directions across the campus and out to the restaurant. On the way back we found our way to the university, but the faculty club was at least a fifteen-minute walk through the campus. We had been there only a day or two, and I was not familiar with the layout and did not know the names of the buildings. If we didn't succeed in getting back on our own, I knew that I could eventually find somebody to take me back to the faculty club. I could also call a cab from the nearest open building or restaurant, but I wanted to try the route. On the way back Schubert first turned toward several incorrect buildings. Some were places in which I had received directions on the way to the restaurant. I told him "no" and prevented him from going toward them. We walked around, and I found the interaction between my sense of direction and his choices quite interesting. In these situations, unless I know he is absolutely wrong, I like to let him make his own decisions. Sure enough, after about fifteen minutes, things began to seem familiar. In about ten more minutes we arrived at the faculty club. I was very proud of my young Schubert and very proud of our accomplishment. On the way back to the club somebody driving through the campus had offered me a lift. I politely refused, although at the time I wondered about the wisdom of my choice. The person told me I was amazing and that he could never do what I do. I told him that he probably could if he wanted to, thanked him for the offer, and kept going.

          Schubert used the information about distant layout available to him to chart our course back to the faculty club. He was not wandering aimlessly. He had a purpose in mind. Without him I would not have persisted. With my cane I would have been alone, and that would not have been as much fun. I would not have had information about distant layout available to me, which would have made the task less rewarding. I would have gotten back to the club, probably through the use of human visual information.

          To me there is something very special about canine vision. It belongs to dogs. A well-trained guide dog is always waiting for its owner, ready to serve, intelligent, yet extremely simple at heart. Dogs are not amazed at what we do, nor do they feel more fortunate than we because they have vision. They offer their vision freely and leave it up to us to use it effectively. Dogs have always been one of God's gifts to humanity. They have served us in many capacities. I am proud to be a guide dog handler, and I am proud to show the world what dogs can do for us. Of course, most people misunderstand the interaction completely. They believe that in some way guide dog users are in the custody of their dogs. The dog leads, and we passively hang on. The degree of misunderstanding about cane use is equally devastating.

          In the Federation one of our tasks is education. Hopefully, by competent use of both travel aids we will be able to increase the public's understanding of blindness. With proper training and opportunity blindness need not be the crippling disability people believe it to be. We have a right to first-class citizenship. We have a right to competitive employment, to family, to children, and to growing old with dignity. In the National Federation of the Blind we are learning to take what is rightfully ours. We will educate the public as we go, but we will never turn back.




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