WHERE IS MY HOME?
Ever found yourself completely confused about directions back to your home upon taking a slight departure from the daily commute? You are not alone. With technology, many of us have become so reliant on the Maps app on our phone that we are not good at finding our way on our own. But what if you did not have the technology? What if your life depended on getting back home immediately? Though that might be an impossible scenario for humans and not worth worrying about, desert ants find themselves in such a situation every day. Taking a longer route back would increase chances of being dehydrated or being eaten by a predator. With a fraction of the brain size as humans and without access to technology, it does a surprisingly good job!
Path Integration, as scientists like to call the task, involves maintaining a mental model of where home is. It is not that complicated a task once you give some thought to it — one needs to maintain just two items of information as one navigates away, (i) the direction back to home, and (ii) the distance to home. With just these two nuggets of information, together called a vector, you can get back home through the shortest possible (straight) route. The issue, however, is to keep these two values up-todate in the mind; keeping this home vector updated within your brain as you take every step in the direction in which you travel.
Most animals make use of two kinds of signals to continuously update the home vector; (a) internal cues such as those from internal sensory system, and (b) external cues such as visual landmarks. In fact, some animals are such experts at path navigation that they can do a fairly accurate job just using internal cues. Imagine if humans were to have such capabilities — kidnap victims would find their way back even if they were transported under a blindfold, making many movie plots pointless or uninteresting!
As you read, computing researchers are working on using navigation-related weaknesses in the human mind to make virtual reality games more efficient. Recent research shows that gamers wearing a virtual reality video headset can be videotricked into believing they took a little turn while they might have almost turned around. This allows usage of a small hall to mimic a large field in a virtual reality treasure hunt game — the gamers might actually be walking zig-zag within the hall believing they are walking far and wide in the playing field. (Dr Deepak P. is a computer scientist and academic staff at Queen's University Belfast, UK. URL: http://member.acm.org/~deepaksp)