Category: Notes

I have always thought the brain was cool but in sort of a nebulous, general way. Eagleman writes about many of the most recent findings about the brain and how cool neuroscience is. Most interesting is how much we still do not know or cannot tease out from other things. For example, we know that people use different sides of their brain to do different things, however if half a brain is removed from a child younger than eight, we find no developmental differentiation between the half brained child and a full brained child throughout the rest of their life. We still have yet to understand where all those brain functions went and what they displaced. (As a side note, there are very good medical reasons for removing half a brain–cascading seizures that could lead to death are one–and such operations are not performed arbitrarily “for the sake of science”.)

Interesting tidbit: At this point in our research, environment is a better predictor of psychosis than genes.

Humans love to think we know what random is and that we can be random when we want to. As Poundstone demonstrates, we are far less random than we imagine and, interestingly enough, we have trouble identifying randomness when we see it. For example, consider the following string (taken from the book):

–||-|–|-|-|-|-|—|-|-|-|-|-|||-|-||-|-|-|-||-||

Mostly people would consider this to be fairly random sequence (with “-” and “|” having an equal chance of appearing). It is not. The “|” has a 75% chance of appearing. A truly random sequence might look like this:

|—-|-|||-|||-||—||——|||–||——-|–||-|-

One reason for our poor randomness skills is that we imagine that things should be uniform in their randomness. The first sequence looks more random because the two symbols alternate more frequently. Gamblers often experience this problem: a run has held steady so they bet that a contrary pattern must appear. True randomness means that each outcome has an equal chance of occurring during each iteration of an event. That is, seven heads in a row does not change the 50/50 odds that the next coin flip will be heads too.

The first half of the book is filled with quick rules and explanations for examining randomness in a variety of situations.

Interesting tidbit: When vetting numbers, look at the second digits. They usually should be fairly well distributed if they are natural. Odd spikes of over usage are signs that the numbers may have been tampered with.