Will Robots Inherit the Earth?
LIMITS OF HUMAN MEMORY
If we want to consider augmenting our brains, we might first
ask how much a person knows today. Thomas K. Landauer of
Bell Communications Research reviewed many experiments
in which people were asked to read text, look at pictures, and
listen to words, sentences, short passages of music, and non-
sense syllables.  They were later tested in various ways to see
how much they remembered. In none of these situations were
people able to learn, and later remember, more than about 2
bits per second, for any extended period. If you could main-
tain that rate for twelve hours every day for 100 years, the
total would be about three billion bits less than what we can
store today on a regular 5-inch Compact Disk. In a decade or
so, that amount should fit on a single computer chip.
Although these experiments do not much resemble what
we do in real life, we do not have any hard evidence that
people can learn more quickly. Despite those popular legends
about people with photographic memories, no one seems to
have mastered, word for word, the contents of as few as one
hundred books or of a single major encyclopedia. The com-
plete works of Shakespeare come to about 130 million bits.
Landauers limit implies that a person would need at least four
years to memorize them. We have no well-founded estimates
of how much information we require to perform skills such
as painting or skiing, but I do not see any reason why these
activities should not be similarly limited.
The brain is believed to contain the order of a hundred tril-
lion synapses which should leave plenty of room for those
few billion bits of reproducible memories. Someday though,
it should be feasible to build that much storage space into a
package as small as a pea, using nanotechnology.