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On Perception (And Pancakes): How The Brain Keeps Vision Stable

By Alexandra Morris
CommonHealth Intern

You probably didn’t think Julia Roberts could teach you much about subtle, yet critical, brain functions.

But, it turns out, she can. Recall Roberts in her iconic film “Pretty Woman.” In one scene, she is eating a croissant. But as the camera pans back to her, the croissant turned into a pancake.

It’s likely that many of us missed that blooper, and now we know why. Scientists have discovered a brain mechanism that smooths our field of vision so that we don’t notice certain subtle visual changes — such as a croissant becoming a pancake in an otherwise identical scene.

In a paper published last month in Nature Neuroscience, researchers from the University of California, Berkeley have identified a brain mechanism that helps to stabilize our field of vision. They call it, a “continuity field” — a process the brain uses to merge similar objects seen within a 15-second timeframe.

“It seems like a very odd thing the brain is doing that could make us less accurate,” said the study’s lead author, Jason Fischer, who is now a postdoctoral fellow in the Department of Brain and Cognitive Sciences at MIT. “But in fact there is this huge benefit to it — and that is stabilizing perception over time.”

To measure this process, researchers showed study participants an image with alternating light and dark bars, or “gratings,” at a random angle every five seconds. The participants were then asked to move a white bar to match the tilt of the grating that had been shown.

Here’s the video:

Researchers found that while the white bars generally aligned with the image, there were subtle differences that were biased toward the previous three or so images. These differences could be attributed to the continuity field.

Imagine, now, for example, you are driving down a highway in the pouring rain and you’re trying to read a road sign. The windshield wipers are moving; the raindrops are hitting your windshield. As you’re looking at the sign, you’re experiencing constant interruptions in your visual stream. In that case, the changes that the continuity field is causing us to miss are the raindrops and windshield wipers — you may even fail to notice them after a while. The continuity field, for the most part, is beneficial — it blocks the stuff we don’t want to see. Continue reading

Blind Opera Superstar Andrea Bocelli Seeks High-Tech Vision At MIT

Blind opera star Andrea Bocelli speaks during a MIT workshop to introduce new technologies to empower blind people to become more independent. (Stephan Savoia/AP)

Blind opera star Andrea Bocelli speaks during a MIT workshop to introduce new technologies to empower blind people to become more independent. (Stephan Savoia/AP)

What’s a young blind Italian student to do when his beautiful blond crush, Mary, approaches?

Well, if a slew of new assistive technologies now being developed at MIT and Northeastern come to fruition, the intimate interaction might unfold like this: the blind student, wearing a cutting-edge device — a smart jacket, for instance — equipped to communicate a complex array of information privately to a blind user, will be able to sense Mary’s presence, facial expressions and body language, chat intelligently with her about literature and move in to squeeze her hand when a rival suitor approaches.

The characters here are fictional, of course. But the overarching ambitions of this research, funded by the blind Italian opera superstar Andrea Bocelli’s foundation, are both intimate and far-reaching. “The idea was a huge bet,” Bocelli said today. He was speaking through a translator at a workshop at MIT to introduce the array of new technologies to empower blind people to live, study and work more independently. “To create a tool, a device, that would basically substitute itself for the eyes.” He characterized the research as going from the “impossible to the possible.”

The genesis of the Bocelli-MIT venture was a post-concert meeting in Boston several years ago, Bocelli said. He brainstormed with several MIT professors to find out what kind of technology for the blind would “be possible.” Since then, a collaborative team of cross-disciplinary researchers have developed prototypes that may someday be able to deliver critical data to the blind: everything from dynamic information about safe walking terrain and hazards, to enhancing social interactions in real-time through wearable devices or a vibrating watch with a high-resolution tactile display that can deliver important information through the skin.

“I have to be honest, the idea of this project was not born of my own needs — I am in a privileged situation,” with an entourage of helpers all around, said Bocelli, who grew up with low vision and then became completely blind in childhood following a sports-related accident. But “there are many people, some of them my friends, that are living alone in a city, and they have the issue of going to work on their own, going grocery shopping, locating the items on the shelves…The issue is really living on one’s own.” Speaking at a news conference, Bocelli conceded that one day, he might use the technology himself: “Of course, when it will come to fruition, it will be helpful to me as well — because the main problem is that humanity has people who are never happy with what they have. This technology will be helpful first for people who are on their own, but then it will come in handy for people like me, who want to be on their own some times.”

Specifically, The Andrea Bocelli Foundation says it’s given about $500,000 to fund researchers at MIT, and Northeastern to develop these technologies.

A central endeavor is called The Fifth Sense Project (seeking to replace the missing sense of sight) Continue reading