How many megabytes is your brain?

Hitachi recently announced that in 2010 they plan to unveil a 5TB hard drive. This led them to note that, "By 2010, just two disks will suffice to provide the same storage capacity as the human brain."

So, according to Hitachi, the brain has a 10TB storage capacity. But how did they arrive at this number?

There's been a lot of speculation about the brain's storage capacity. The most popular method of arriving at an answer is to estimate the number of synapses in the brain and extrapolate from there. This has led researchers to come up with numbers ranging anywhere from 3TB to 1000TB. Hitachi evidently was using this method.

But there's a second method (noted on the Of Two Minds blog). Psychologists have conducted experiments to measure how much information people are actually able to memorize. This produces much smaller numbers. They've concluded that it's only about two bits per second, or a few hundred megabytes averaged over an entire lifetime.

Of course, until scientists figure out a way to allow us to download our brains to computers, all these numbers are just useless trivia. And when that happens, we can all plug into the Matrix and live happily ever after.