By Melanie Plenda, Freelance Journalist
Thursday, November 8, 2012
Stare at a picture long enough and certain elements begin to change. Things fall away, images appear and disappear seemingly out of and into thin air.
"In the world of vision research," says John E. Sparrow, associate professor of psychology at UNH Manchester, "Visual illusions often represent a fascinating source of material for experimental investigation. Some illusions can be explained by referencing the physiological makeup of the visual pathway, some can be explained by virtue of our perceptual learning, and some can't be explained at all."
Which is why Sparrow along with three undergraduate students are taking a semester to decipher the illusion of motion-induced blindness, also known as MIB, which describes the phenomena of stationary objects "disappearing" in the presence of a moving background. Students working on the project include Bill Robidoux of Manchester, Joseph LaBarre of Pembroke, and Tim Larochelle of Bedford.
Sparrow uses an example presented by German Psychology professor Michael Bach on his web site (www. michaelbach.de/ot). In the picture, three stationary yellow dots are suspended in a field of blue crosses on a black background. The crosses, as a block, move in a circle. At the center of the image is a dot that flashes red and then green. The observer is asked to stare at the center dot. The observer does this, and after about 10 seconds, the yellow dots seem to disappear from the picture.
"The funny thing is about this," Sparrow says. "Is that it's a pretty obvious effect, and most folks see it. But we didn't really 'discover' this--the first paper wasn't published on this--until 2001. So it's a very new phenomenon and while there have been a few studies done, researchers still don't know why this happens."
But there are some theories, Sparrow says, including the idea that if you stare at anything over a time it fades away because the cells in your visual pathway get tired. Another explanation is if you overload the system with too much information the system starts to block out extraneous information.
Sparrow says he's not ruling these theories out, but that there is evidence to suggest that neither adequately explains the phenomenon.
Using a Wheatstone Stereoscope, a contraption invented in 1838 by Charles Wheatstone that uses a series of mirrors to project a three-dimensional image, Sparrow and his team are going to shift the flat image of blue crosses and yellow dots to 3D. Sparrow is hoping by doing this, he and his researchers will discover whether depth perception plays a role in creating the disappearing illusion.
Right now, the team is still analyzing the existing, albeit scant, data from previous experiments. When that's finished, the students will each take turns being the subject and the experimenter, gather up the data and then hopefully have enough to present at a regional conference in the Spring or even publish a paper on their findings.
It's not clear yet what practical applications the group's findings may hold, Sparrow says, so at the moment it's an experiment for the sake of answering a lingering question.
Sparrow's research is just one of the many hands on and innovative opportunities for Psychology students at UNH Manchester. Clinical students have the chance to work with local partners such as The Mental Health Center of Greater Manchester to get hands on experience in a medical setting, while developmental psychology students get a chance to work with the local elderly populations through service learning projects. Students working with Sparrow get a chance to work with him and on their own independent research projects as part of UNH Manchester's New Discovery program.
"They get a chance to actually do things hands on," Sparrow says. "That's what my lab is all about."
This program along with the many others will be highlighted at an open house on Saturday, Nov. 17 from 10 a.m.-12 p.m Students may register by contacting the Office of Admissions at 641-4150 or online at www.manchester.unh.edu/openhouse. Those who attend the event will be given a free application fee waiver form.