American Action Fund for Blind Children and Adults
Future Reflections Winter 2018 PERCEPTION
by Marina Bedny
Reprinted from Braille Monitor, Volume 60, Number 11, December 2017
From the Editor: In recent years considerable research has focused on neuroplasticity, the ability of the brain to re-purpose certain areas usually designated for other activities. Scientists have speculated about what happens to the visual cortex in people who are blind. Does it atrophy from lack of use, or does the brain use it in new and unexpected ways? Marina Bedny is a neuroscientist who is studying the brains of blind people. At the 2017 convention of the National Federation of the Blind she described some of her findings.
My name is Marina Bedny, and I'm a professor at Johns Hopkins University in the department of psychological and brain sciences. My time is split between two things: some of my time I spend teaching undergraduate and graduate students at Johns Hopkins University; that's about a quarter of my time. The rest of my time I run a research lab. I run a lab called the Neuroplasticity and Development Lab. My lab is interested in questions about nature and nurture. Where does the human mind come from, and in particular, how does our experience in the world shape the way our brains work and shape the way our minds work and shape who we are? That is the question we're interested in. It's a very, very old question. It's been of interest to philosophers and psychologists and humans in general for thousands of years. We're pretty lucky to be living at a time when science and technology allow us to study this question using neuroscience and psychology. We can use scientific methods and techniques like functional magnetic resonance imaging (fMRI) and quantitative measures of behavior to study the mind and brain. That is what my lab does, and I'll tell you a little bit about that as we go along.
My lab specifically applies these methods to study the question of how life experience shapes our minds and brains. We base these studies on the fact that we believe in order to understand who we are; we have to pay attention not to the differences among us, but by looking at the breadth of experience. There used to be this idea in science that you can learn everything that you need to learn about people and how their minds work by studying white, male students at Ivy League colleges, right? Does that sound like the right idea of the way to do science? [chorus of no's] Right. So there's a problem with that. In reality, of course, there is no such thing as the generic person, right? Because the inherent part of being a person is the differences between us: some of us grew up on a farm, some of us grew up in the city, some of us grew up with lots of siblings, [and] some of us grew up alone. My family immigrated to this country from Ukraine when I was eleven years old, and I believe that that's part of what shaped the kind of person I am. Some of us live with vision, some of us live without. And part of understanding what it means to be a human is understanding all the ways in which humans live: blind, sighted, immigrants, women, men: all the diversity that exists.
So that is what my lab does. We work with individuals with different developmental histories and different experiences to understand how the mind and brain work. I mentioned some of the methods that we use; one is functional magnetic resonance imaging, and some is behavior. Today I'd like to share with you some of the discoveries that scientists have made over the past decade about blindness and about cognition and brain function in blind individuals. I am very honored to be here and grateful to be invited. I think it's important for the scientific community to be engaged with the blind community so that science is done better and the science delivers to the blind community and the blind community has a say in how to interpret scientific findings. [applause] Thank you.
Today I'm going to talk to you about three things quickly: some things that stay the same in blindness and cognition, some things that improve, and some cool things that the brain does in individuals who are blind. The first thing, which might sound like it's the least exciting thing, is what stays the same in blindness. But I actually think that this is a really important topic. Over the years psychologists and philosophers have had some very confused and extreme ideas about what the mind is like in blind individuals. We have scientific methods to dispel these kinds of ideas and to find out what some of the things that actually stay the same are. Probably it will not come as a surprise to you that people who are blind know what the words peek, stare, yellow, and sparkle mean. I regret to say that this comes as a surprise to some segments of the scientific community. We've been able to use cognitive and neuroscientific methods to show that what sometimes people refer to as "visual concepts" are actually known very well to people who are born blind.
Perhaps more importantly, one of the things that we've studied is numerical cognition and mathematical reasoning in individuals who are blind. There's sometimes this idea in the educational field that mathematics is particularly challenging for children who are blind. Well, we studied numerical understanding in blind individuals, both how blind people estimate number when you present them with tones and you ask them, "How many tones did you just hear?" That's a basic kind of numerical ability that actually ends up being important for mathematical learning early on. We also measured mathematical behavior. One of the things that we find is that the cognitive building blocks and the tools of math are exactly the same in people who are blind and sighted. Unfortunately, what is different is access to math education. One of the things that we found when we asked blind people is that blind children in high school get shuttled out of math courses. I'm sure that this is not news to anyone, but one of the things that this research is showing is that there is absolutely no excuse for blind children not to be achieving the same way as sighted children in math and science. [applause]
Another thing that we've been studying is some things that improve, some things that get better with blindness. Scientists have been interested in this question for a long time; it often comes up in the context of "Do blind people hear better? Do blind people have better sensory perception?" The answers to these questions are, of course, very complicated. There are some things that blind people get better at with practice, and some things that don't change at all. One of my favorite examples is tactile perception. It turns out that proficient Braille readers are better at tactile perception with their fingers, but this varies; the more proficient at Braille reading they are, the better they are at this skill, and it is specific to their Braille-reading hand and their Braille-reading finger. So they're no better, for example, at somatosensation on their lips, they're just better with their Braille-reading finger.
It turns out that there are other things that blind people are better at that are not actually sensory. Our recent research shows that blind people are actually better at understanding sentences that have complex grammatical constructions. In a second I'll talk to you a little bit about why that might be so, but we can do a little bit of an experiment right now. I'm going to tell you a sentence, and then I'm going to ask you a question about it. I want you to shout out yes or no, okay? Here we go: while the old cat licked the puppy with floppy ears chased after the squeaky toy. Was the cat licking the puppy? Shout it out. Yes? Okay, so this is a very hard question. The answer is actually no. Some of you probably got it; some of you didn't. It turns out that on average, it kind of leads you down the wrong path. But on average blind people are much better at answering these kinds of questions—obviously blind people are just as different from each other as sighted people are, so there's lots of variation among blind people--but on average blind people are better.
Another interesting thing that turns out to be the case is that blind people are better at remembering lists of words and letters—actually almost twice as good as sighted people are. They're particularly better at remembering the order of words in a list and the order of the letters. So it seems like being blind actually improves your memory. Why this is so is not clear. One potential reason is that you just have to practice more, right? When you go to the restaurant and there is no Braille menu available, what do you have to do? You have to remember what was on the menu, whereas the sighted person sitting next to you can just glance back at it. So here are some of the ways the mind changes and adapts in blindness.
One of the interesting things that my lab does is actually study brain function. People change as their environment and their lives change, and our brains change, too. One of the main things that my lab does is study the function of the so-called visual cortex in blind individuals. This is the part of the brain that does vision in the sighted. About thirty years ago if you'd asked a neurologist or neuroscientist what happens to this part of the brain in a blind person, they'd say it does nothing or maybe it atrophies, right? No. What research has shown is that the visual part of the brain takes on new functions in blind individuals. It responds to sound; it responds to touch. One of the things that my lab has been working on that I think is pretty exciting is showing that the visual part of the brain in blind individuals is actually involved in higher-level cognitive functions. So one of the things we find is that blind individuals use this so-called visual part of the brain during language processing—for example, when understanding those complex sentences I told you about before. They use it during memory tasks and when solving math equations. So this part of the brain is being used like a flexible machine to do other things when it's not doing vision.
The best technology we've got is our brain, and it turns out that everybody's brains adapt to being the best for their lives and can be used in flexible ways.
In conclusion, I'd like to say that I hope my being here is part of a broader dialog between the scientific community and the blind community. In particular it's important for the blind community to be aware and in charge of the scientific insights that are available and also to give back and give their insights for making science better. One of the things that I would love to see more of—it's already getting there, but I would like to see more of it—is leaders in the scientific fields who are blind. [applause] I'd like to see students who are coming to work in our lab becoming the next generation of blind scientists, because the only way that science is going to reflect all the right things about people is if everyone participates in science and becomes a leader in the field. Thank you. [applause]