Check this out: Here's a grid, nothing special, just a basic grid, very grid-y.
But look closer, into this white spot at the center where the two central vertical and horizontal lines intersect.
Look very closely.
Notice anything funny about this spot?
Yeah, nothing.
But keep looking.
Get weird and wilkersonjack@example.org.
Now, keeping your gaze fixed on this white spot, check what's happening in your peripheral vision.
The other spots, are they still white?
Or do they show weird flashes of grey?
Now look at this pan for baking muffins.
Oh, sorry, one of the cups is inverted.
It pops up instead of dipping down.
Wait, no spin the pan.
The other five are domed now?
Whichever it is, this pan's defective.
Here's a photo of Abraham Lincoln, and here's one upside down.
Nothing weird going on here.
Wait, turn that upside down one right side up.
What have they done to Abe?
Those are just three optical illusions, images that seem to trick us.
How do they work?
Are magical things happening in the images themselves?
While we could certainly be sneaking flashes of grey into the peripheral white spots of our animated grid, first off, we promise we aren't.
You'll see the same effect with a grid printed on a plain old piece of paper.
In reality, this grid really is just a grid.
But not to your brain's visual system.
Here's how it interprets the light information you call this grid.
The white intersections are surrounded by relatively more white on all four sides than any white point along a line segment.
Your retinal ganglion cells notice that there is more white around the intersections because they are organized to increase contrast with lateral inhibition.
Better contrast means it's easier to see the edge of something.
And things are what your eyes and brain have evolved to see.
Your retinal ganglion cells don't respond as much at the crossings because there is more lateral inhibition for more white spots nearby compared to the lines, which are surrounded by black.
This isn't just a defect in your eyes; if you can see, then optical illusions can trick you with your glasses on or with this paper or computer screen right up in your face.
What optical illusions show us is the way your photo receptors and brain assemble visual information into the three-dimensional world you see around you, where edges should get extra attention because things with edges can help you or kill you.
Look at that muffin pan again.
You know what causes confusion here?
Your brain's visual cortex operates on assumptions about the lighting of this image.
It expects light to come from a single source, shining down from above.
And so these shading patterns could only have been caused by light shining down on the sloping sides of a dome, or the bottom of a hole.
If we carefully recreate these clues by drawing shading patterns, even on a flat piece of paper, our brain reflexively creates the 3D concave or convex shape.
Now for that creepy Lincoln upside down face.
Faces trigger activity in areas of the brain that have specifically evolved to help us recognize faces.
Like the fusiform face area and others in the occipital and temporal lobes.
It makes sense, too, we're very social animals with highly complex ways of interacting with each other.
When we see faces, we have to recognize they are faces and figure out what they're expressing very quickly.
And what we focus on most are the eyes and mouth.
That's how we figure out if someone is mad at us or wants to be our friend.
In the upside down Lincoln face, the eyes and mouth were actually right side up, so you didn't notice anything was off.
But when we flipped the whole image over, the most important parts of the face, the eyes and mouth, were now upside down, and you realized something fishy was up.
You realized your brain had taken a short cut and missed something.
But your brain wasn't really being lazy, it's just very busy.
So it spends cognitive energy as efficiently as possible, using assumptions about visual information to create a tailored, edited vision of the world.
Imagine your brain calling out these edits on the fly: "Okay, those squares could be objects.
Let's enhance that black-white contrast on the sides with lateral inhibition.
Darken those corners!
Dark grey fading into light grey?
Assume overhead sunlight falling on a sloping curve.
Next!
Those eyes look like most eyes I've seen before, nothing weird going on here."
See?
Our visual tricks have revealed your brain's job as a busy director of 3D animation in a studio inside your skull, allocating cognitive energy and constructing a world on the fly with tried and mostly -- but not always -- true tricks of its own.
When I opened Mott Hall Bridges Academy in 2010, my goal was simple: open a school to close a prison.
Now to some, this was an audacious goal, because our school is located in the Brownsville section of Brooklyn -- one of the most underserved and violent neighborhoods in all of New York City.
Like many urban schools with high poverty rates, we face numerous challenges, like finding teachers who can empathize with the complexities of a disadvantaged community, lack of funding for technology, low parental involvement and neighborhood gangs that recruit children as early as fourth grade.
So here I was, the founding principal of a middle school that was a district public school, and I only had 45 kids to start.
Thirty percent of them had special needs.
Eighty-six percent of them were below grade level in English and in math.
And 100 percent were living below the poverty level.
If our children are not in our classrooms, how will they learn?
And if they're not learning, where would they end up?
It was evident when I would ask my 13-year-old, "Young man, where do you see yourself in five years?"
And his response: "I don't know if I'm gonna live that long."
Or to have a young woman say to me that she had a lifelong goal of working in a fast-food restaurant.
To me, this was unacceptable.
It was also evident that they had no idea that there was a landscape of opportunity that existed beyond their neighborhood.
We call our students "scholars," because they're lifelong learners.
And the skills that they learn today will prepare them for college and career readiness.
I chose the royal colors of purple and black, because I want them to be reminded that they are descendants of greatness, and that through education, they are future engineers, scientists, entrepreneurs and even leaders who can and will take over this world.
To date, we have had three graduating classes, at a 98 -- (Applause) At a 98-percent graduation rate.
This is nearly 200 children, who are now going to some of the most competitive high schools in New York City.
(Applause) It was a cold day in January when my scholar, Vidal Chastanet, met Brandon Stanton, the founder of the popular blog "Humans of New York."
Brandon shared the story of a young man from Brownsville who had witnessed violence firsthand, by witnessing a man being thrown off of a roof.
Yet he can still be influenced by a principal who had opened up a school that believes in all children.
Vidal embodies the story of so many of our underprivileged children who are struggling to survive, which is why we must make education a priority.
Brandon's post created a global sensation that touched the lives of millions.
This resulted in 1.4 million dollars being raised for our scholars to attend field trips to colleges and universities, Summer STEAM programs, as well as college scholarships.
You need to understand that when 200 young people from Brownsville visited Harvard, they now understood that a college of their choice was a real possibility.
And the impossibilities that had been imposed upon them by a disadvantaged community were replaced by hope and purpose.
The revolution in education is happening in our schools, with adults who provide love, structure, support and knowledge.
These are the things that inspire children.
But it is not an easy task.
And there are high demands within an education system that is not perfect.
But I have a dynamic group of educators who collaborate as a team to determine what is the best curriculum.
They take time beyond their school day, and come in on weekends and even use their own money to often provide resources when we do not have it.
And as the principal, I have to inspect what I expect.
So I show up in classes and I conduct observations to give feedback, because I want my teachers to be just as successful as the name Mott Hall Bridges Academy.
And I give them access to me every single day, which is why they all have my personal cell number, including my scholars and those who graduated -- which is probably why I get phone calls and text messages at three o'clock in the morning.
(Laughter) But we are all connected to succeed, and good leaders do this.
Tomorrow's future is sitting in our classrooms.
And they are our responsibility.
That means everyone in here, and those who are watching the screen.
We must believe in their brilliance, and remind them by teaching them that there indeed is power in education.
Thank you.
(Applause)