The Ghost in My Brain Read Online Free

The Ghost in My Brain
Book: The Ghost in My Brain Read Online Free
Author: Clark Elliott
Pages:
Go to
what this meant. I couldn’t conceive of it—something about time, something about calendars, something about endings, and the right-hand side of a timeline ending in nothing. The difference between life and death had lost its structure in the same way the line between my inner self and the world around me had vanished.It was too much, too hard, too fuzzy to try to understand. I just wanted to curl up with my back to the stinging wind, and disappear.
    But in another twist of irony,
I didn’t know how to lie down
. I couldn’t see the relationships between the vertical and horizontal planes around me, or how my body fit into them either. My concussed brain couldn’t make sense of motion, and the sequence of motion over time. It didn’t “get” any of this in the geometric way that would have allowed me to move. Without
seeing
, I couldn’t initiate, and without initiating I couldn’t lie down in the snow to die. . . .

THE SIZE OF THE PROBLEM: THE MAGNIFICENCE OF THE HUMAN BRAIN
    The human brain is a magnificent device, and the complexity of the human mind it supports is staggering to ponder. It is not possible for us fully to understand the enormity of the changes that take place when someone suffers a traumatic brain injury (TBI)—a concussion * —without first having some idea of the phenomenal (astronomical!) computational powers of the device we are considering.
    Some supercomputer researchers estimate they’ll need
exaflop
computing speeds (1,000,000,000,000,000,000 floating-point operations a second) to model a single human brain. Put in layman’s terms, that’s 50
million
desktop computers all networked together—and a single such modern desktop is a pretty powerful device, far more sophisticated than the big boxes of the 1960s and ’70s that might each support a company with thousands of employees. Another way to picture this is that 50 million desktop computers laid end-to-end would stretch halfway around the earth, with another three thousand miles to spare.
    For those of us who are trying to mimic some of the brain’s systems, these are not even the impressive numbers. Rather it is the
design
of the system—the organization of the software, so to speak, and the impregnated information—that is the truly extraordinary aspect of who we are.
    Imagine for a second that you are back standing outside the front door of the place you lived when you were five years old. What color is the door? Does it have glass in it? Does it open outward or inward? Are there steps in front? A landing? Is there a doorknob or a latch? On which side are the hinges? Remember that door?
    Estimates on the size of human memory vary widely. We are not even sure how to define it because, for example, retrieving information from memory also modifies it at the same time. But by almost all reckoning, it is very, very, large.
    To get a handle on the numbers, let’s imagine that we are writing everything we remember down on sheets of paper, in a 12-point font, on both sides of the paper (one byte per character). The more we have to remember, the more pieces of paper we put on our stack. The size of our memory is the height of the stack of paper. So how tall is the stack?
    Harvard researchers have been able to store large amounts of information in DNA molecules, and if our brain were made of pure DNA, our memory-capacity stack of paper might stretch out into space for 2,485,795,454 miles—or circle the earth 100 million times. So we know that biological systems can store a great deal of information! Many estimates of actual human memory capacity have the pile of paper extending a much humbler distance—merely up to the moon and back.
    But now we ask about the real magic—how did you get 238,000 miles up to the moon alongside that stack of paper, halfway back, another six hundred miles, twelve hundred feet, eight inches, fifty-eight pages, and two
Go to

Readers choose