In some AS people, face blindness (prosopagnosia) may exist alone or be accompanied by place blindness (topographic agnosia). In the adult AS population that I have worked with, about 30 pecent seem to have place blindness. There are not national statistics as this condition is often not identified in either the general or in the AS community.

Often confused for being absentminded or lazy, people with topographic agnosia have no innate memory for places. Just as a person with face blindness has a short-term memory for faces, the person with place blindness has a short-term memory for places. This means, that a person living on a street for five years would not be able to recognise the other houses on the street or in the neighbourhood if seen out of context. In testing for place blindness, a husband asked his place-blind wife to keep her eyes shut while he drove around their neighbourhood. He stopped in front of a house four houses down from theirs and asked her to tell him if she had ever seen it before. She hadn't. Despite their many walks in which they had passed it, she had no memory of it. Topographic Agnosia also explains why a person who loved hiking and being out-of-doors would never go by herself and couldn't remember the individual hikes. Unless they included waterfalls or a unique bridge or old growth, all the hikes looked the same to her.

One of the most striking cases of topographic agnosia was of a three-year-old child who was later diagnosed with AS.

Three-year-old Ellen was one of six children. While she seemed to love to be outdoors, unlike her other sisters and brothers, she would not leave the house except with her mom present. Instead, she looked longingly from the back window at her yard. One day, feeling somewhat frustrated, her mom ties a long cord around Ellen's waist and tied the other end loosely to the large tree in the middle of the back yard. Ellen played happily for hours knowing her boundaries. Later, several neighbourhood children came by and untied Ellen. Ellen let out a howl and wouldn't stop screaming until her mom rushed out and retied the cord. Decades later, Ellen discovered that not only did she have AS, but she also had a neurological condition that can accompany AS called geographic agnosia or place blindness. She needed that rope, because she was unable to recognise her house versus the next-door neighbour's house. Without that rope, she was lost and had no way to return home. But to others, this appeared as just strange behaviour.

Fortunately, for Ellen, her mom trusted her instincts and devised a plan, which while unorthodox, helped her child.

Like face blindness, place blindness is an incredibly frustrating condition. But unlike face blindness, it's harder to hide, especially as an adult. The person with topographic agnosia tends to look forgetful or scatter-brained. The person with topographic agnosia relies on landmarks to get from one location to another. There are no shortcuts, they must go the same way each time, and they must start out at the same location each time. If there is a change in landmarks, such as a change in a billboard, a detour in the road, or hedges cut down, the person can be irretrievably lost. Usually there is no innate sense of direction. Like face blindness, it can vary in intensity. One young man was lost for forty-five minutes two blocks from his new house. Some find maps useless, while others won't leave their home without a map. Each finds a solution. One young man, for whom maps were not helpful, would study a three-dimensional satellite/aerial imagery computer program to get a sense of where he was going. A successful businessman would simply get the managers at the various branches to pick him up from the airport rather than rent a car and navigate himself. Another would say out loud the landmarks as she passed them, so that she could process them for her return trip. She relied on her auditory processing because her visual processing was impaired. And whenever possible, she did "dry runs" of the trip, so that there would be fewer instances of getting lost.

Like face blindness, topographical agnosia tends to run in a family. In one family, there were three generations of people with this condition. Only two of them also had AS. While they would joke about the condition, they would always give themselves extra time to get lost for appointments.

What is especially interesting is that while at least half also have face blindness right along with the place blindness, the others seem to have a better than average ability to remember places. One man with severe face blindness was able to successfully navigate the New York subway system in three days. A twenty-one-year-old-man was able to immediately recognise a person he had gone to school with seven years earlier despite the fact that each was about a foot taller, thirty pounds heavier and looked significantly different from their younger selves.

There is little formal research on topographic agnosia. Anecdotal accounts on the internet abound. Like the preliminary research on prosopagnosia, most of the researchers on topographic agnosia are studying people with brain injuries resulting in this condition. Over the next decade we may see more research in this area. But in the meantime, here are some general recommendations.

1. Always give yourself fifteen to thirty extra minutes for important engagements.
2. Do a dry run, if possible.
3. If you can afford it, get a GPS (Global Positioning System) for yout car.
4. Always keep a map in your car.
5. When you are going to a new place, and need to return by the same route, say the names of the landmarks out loud. Keep the directions general remembering the name of the street and if possible a landmark such as a gas station, rather than turning right or left it will be reversed on your return trip. That way, you are using a different part of the brain and have a much greater chance of remembering.

There are no cures or easy solutions for either face blindness or place blindness. Both are incredibly frustrating conditions for both the person with them and those around them. The brain is a remarkable machine that, if trained, can circument areas that are not functioning well.