Science-- there's something for everyone

Friday, July 19, 2013

For chasing strategies, ears can be as good as eyes

I have a confession to make. The only reason I picked this story is because I find the idea of making college students run around a football field while blindfolded to be delightful. Aah, science! So, besides spending an amusing afternoon, what exactly did Dennis Shaffer and his colleagues from The Ohio State University find? Blind people chase moving targets the same way that sighted people do.

There are two basic ways to intercept a moving target. You can charge right at your target, following him move for move. This works well if you’re much faster than your prey, but if you’re both about the same speed, you’ll never catch up. In that case, it’s best to aim for where you expect your target to be at some time in the future, based on his speed and direction. This is called a ‘constant-angle’ strategy, and it’s one that most people instinctively employ.

Sure enough, when researchers told students to chase down someone carrying a football across a field, the students used the constant-angle pursuit strategy rather than running directly toward the ball carrier. No surprise there. However, when blindfolded students were asked to tag runners carrying beeping footballs, they also used the constant-angle strategy.

I should say that this was a very small study with only a handful of participants. Still, it’s amazing to think that people can estimate angles and direction as well with their ears as they can with their eyes. That’s something I wouldn’t have predicted.

Dennis M. Shaffer, Igor Dolgov, Eric Mcmanama, Charles Swank, Andrew B. Maynor, Kahlin Kelly, & John G. Neuhoff (2013). Blind(fold)ed by science: A constant target-heading angle is used in visual and nonvisual pursuit Pyscon Bull Rev DOI: 10.3758/s13423-013-0412-5.