Walk Straight? I Can do That…
Anyone who has ever played pin the tail on the donkey knows how hard it can be to walk in a straight line while blindfolded. Now imagine doing that over a distance of fifty yards, or even a few miles. It has been proven that, while blindfolded, people tend to walk in circles even though they think they are going straight. In a NPR article written by Robert Krulwich he states that “Jan Souman, a research scientist in Germany, co-wrote a paper…about…human tendency to walk in circles” (Krulwich). The main reason for this is believed to be that people need to have a visual landmark of some kind to be able to navigate in a straight path. When someone is blindfolded, that visual landmark has been taken away.
While researching this topic, I found it very beneficial for me to perform my own experiments. In my original experiments, there will be more variations later, the goal of the participant was to walk in as straight of a line as possible. The distance they walked was fifty yards. I told them to stop once they had reached the extended line of where the target was. It was then measured how far to the left or right the walker was from the target. The average miss was by forty yards, with one participant walking in a complete circle. This, again, proves that people have a much harder time navigating when there is an absence of a visual landmark.
Animals actually use many of the same techniques we do to keep on a straight path. It is proven that many migrating birds use the sun as a navigation tool, and many migrating land animals use visual landmarks. For example, in an article for the website How Stuff Works, Ed Grabianowski says “whales traveling in the Pacific Ocean near the North American coast use…their landmark…the entire continent of North America” (Grabianowski). However, many animals will migrate using scents or magnetic fields. In these cases they can be easily drawn off course by a similar scent or a man made magnetic field that may replicate the magnetic fields of the planet. There was a study done at the University of North Carolina by Dr. Kenneth Lohmann in association with his wife and two graduate students with sea turtles that make their eight thousand mile migration route the first time that they ever see it. The turtles were first intentionally moved off course, and using the magnetic fields of the planet they were easily able to get back on track. However, a second experiment was preformed where the turtles were introduced to many man-made magnetic fields throughout their journey. The turtles went off course and were unable to find their way to their normal migration spot. In an article in Science Daily, it was written that “when exposed to a magnetic field like the one that exists in northern Florida, most of the reptiles swam eastward, a direction that would carry them out to the north-flowing Gulf Stream” (Lohmann, Lohmann and Cain). It might be possible that when we lose our sense of sight, we might be able to tap into our other senses and navigate in a different way.
Knowing that people can easily end up going in circles without a visual landmark, and that there are other ways to navigate other than with a sense of sight. The question is raised of how ancient sailors were able to navigate the open ocean without going in giant circles. Well, the most popular among the ancient sailors was to use the sun and stars as a navigation tool to stay on as direct of a path as possible. However, there were times when the sun or stars weren’t out and the navigators had to use different methods of navigation. Written on a PBS site, NOVA, Peter Tyson states that the ancient Norsemen “One method they relied on was watching the behavior of birds…If the beak of this seabird is full, sea dogs know, it’s heading towards its rookery; if empty, it’s heading out to sea to fill that beak” (Tyson). There were also ancient compasses and maps that they could use although they were not thought to be as reliable.
I also decided to test a theory that someone can use auditory clues to replace a visual landmark in navigation. To test this, I took the same participants and had them run the same experiment over again, however, this time with the noise. The noise that was used was a loud and continuous beeping similar to that of an alarm clock. It was placed at the target area. The walker was told to stop when they had walked the fifty yards and was even with the extended line of the target. All of the participants hit the target perfectly. However, they all took a curved path in getting there. This leads me to believe that the auditory clue can effectively replace a visual landmark, although it is not the most efficient way to navigate.
There have been other tests that are similar to the one that I have conducted, most notably at the Helsinki University of Technology. In their experiment the “test task [of the participants] was to find a sound source in a dynamic virtual acoustic environment” (Lokki, Grohn and Savioja). They were testing to see if sounds could help someone navigate through a virtual environment, and eventually find the source of the sound in the virtual world. In the results they found that “in most cases subjects did find the target area.” and that “over half the subjects made less than three errors” (Lokki, Grohn and Savioja). This provides substantial evidence that someone can walk in a straight while blindfolded, so long as there is a noise to guide them.
Next I looked into what Jan Souman calls “reorientation techniques” (Souman, Neth and Engel). Reorientation is the ability for the walker to have realized that they have gone off path, and to be able to correct themselves into a straight path. Jan Souman researched this in a virtual environment, and had two possible methods of returning the walkers to a straight path. One was a freeze turn, where the walker turned one hundred and eighty degrees but it looked to them that they went three hundred and sixty degree. In the other method he would have the walker turn a full three hundred sixty degrees, and have the virtual world stay still. However, all of the methods he tried to use had no success.
In my own experiment I attempted to try a reorientation technique that consisted of me telling the participant if they missed to the left or the right and by how much. I then allowed them to walk again and see if they were able to fix their previous mistakes. I found that if the participant made any corrections it was always an over compensation. For example, if they failed to the right, they would over compensate for their mistakes and end up missing to the left.
I then looked into if the walker would listen to direction while walking. To perform this I walked behind each participant, telling them if they were going left or right. The participant listened one hundred percent of the time. Through the directions given, each person was able to correct their minor mistakes, and find their way to the target area in a relatively straight path. So, even though the participants were not able to learn from their mistakes and correct themselves on their own, they were able to take direction from a third party and respond to feedback.
Walking in a straight line while blindfolded is impossible. However, when there is a distinct noise for the walker to follow they are able to get to the target area, even though they may not take the straightest path in getting there. It seems that people are unable to teach themselves how to correct their own mistakes while they are blindfolded, but at the same time can respond to feedback.
Grabianowski, Ed. How Animal Migration Works. 18 March 2012.
Krulwich, Robert. A Mystery: Why Can’t we Walk Straight. 7 march 2012.
Lohmann, Kenneth, et al. Baby Sea Turtles Use Earth’s Magnetic Field To Navigate Across Atlantic Ocean And Back. 12 October 2001. 16 April 2012.
Lokki, Tapio, et al. A Case Study of Auditory Navigation in Virtual Acoustic Enviornments. 3 April 2012.
Souman, Jan, et al. Velocity-Dependent Dynamic Curvature Gain. 8 March 2012.
Tyson, Peter. Secrets of Ancient Navigators. 6 October 1998. 8 March 2012.