Blink

“After 145,” Grossman says, “bad things begin to happen.
Complex motor skills start to break down. Doing something
with one hand and not the other becomes very difficult.... At
175, we begin to see an absolute breakdown of cognitive
processing.... The forebrain shuts down, and the mid-brain —
the part of your brain that is the same as your dog’s (all
mammals have that part of the brain) — reaches up and hijacks
the forebrain. Have you ever tried to have a discussion with an
angry or frightened human being? You can’t do it. ... You might
as well try to argue with your dog.” Vision becomes even more
restricted. Behavior becomes inappropriately aggressive. In an
extraordinary number of cases, people who are being fired upon
void their bowels because at the heightened level of threat
represented by a heart rate of 175 and above, the body
considers that kind of physiological control a nonessential
activity. Blood is withdrawn from our outer muscle layer and
concentrated in core muscle mass. The evolutionary point of
that is to make the muscles as hard as possible — to turn them
into a kind of armor and limit bleeding in the event of injury.
But that leaves us clumsy and helpless. Grossman says that
everyone should practice dialing 911 for this very reason,
because he has heard of too many situations where, in an