Take a look at one of the smaller slices of a mouse brain pictured above—one of the two on the left side of the Petri dish that’s about the size of the dot on a lower-case “i.” How many neurons do you think it contains?
Need a hint? It’s approximately the same as the number of grains of rice that could fit inside two pasta sauce jars.
The answer is 50,000. Most estimates from young students passing through the braiNY exhibit at the American Museum of Natural History yesterday were too low. Many of the kids were impressed by that number. Not all. One young girl took one look at the small mouse brain and declared, “A mouse is dumb.” When it was suggested that this is a good thing, as we wouldn’t want mice that are smarter than humans, she shrugged and said, “I guess.”
The specimen was at the same table as several other animal skulls, which gave students an idea of the size of their brains. An accompanying poster illustrated the idea further: a giraffe, for example, has a relatively tiny brain given its overall size.
Another table hosted by Columbia University was popular for its Hoberman sphere, a ball-like object that could easily expand and contract. Its purpose was to explain why our brains have folds. While not directly proportional to the human brain, the sphere showed how a folded brain has the same surface area but much smaller volume. This serves two purposes: (1) our brains can take up less space, meaning our heads don’t have to as big, and (2) information can pass among neurons quicker because they are closer to each other. I already knew that, but I did learn the name of the folds: sulci, the plural of sulcus.
Another group of stations had interactive brain games. One involved spotting a bird that flashed on a screen for a split second; the more you played the game, the faster you were likely to identify the bird, showing that repetition can lead to improvement. Another game provided multiple options for different scenarios—for example, your mom told you not to eat until dinner, but you really want a cookie—and had on-screen readings of your avatar’s mood levels based on your answers. It was far from exact science, but it was still fun.
The table that illustrated procedural memory, however, was not fun. It was terribly frustrating. Participants sat down and tried to draw the outline of a star while looking at the star and their hand in a mirror (there was a divider that blocked your view of your actual hand). After watching children try and fail, I gave it a try, assuming I was better than a fifth-grader at just about anything. I was wrong. Moving directly up, down, left, or right was not too difficult after I realized I had to do the opposite of what I thought. Moving diagonally was another story; my brain couldn’t quite comprehend where to guide my hand.
While the aforementioned skull display showed some of our brains’ superiority to animals’ brains, another showed how we lack in certain departments. A fish brain gives it a superior sense of smell and 360-degree “vision”—it can sense movement all around it, which helps when it is trying to stay close to its school or detect predators.
Whether comparing two humans or a fish and a mouse, no two brains are the same.