Tyson has a form of Synesthesia, when he sees people or
animals he sees a series of maps - bones, veins, tendons, muscles - he
has to concentrate to turn that off. It takes constant concentration for
Tyson to keep his Synesthesia suppressed, and he often does so as his
anxiety causes him to think that people would be uncomfortable if they
knew what he could see.
It isn’t everything he
sees, it’s like an over lay his brain created for what he sees. This
applies to his own body and photographs as well. This form of
synesthesia doesn’t only apply to people. Most of the time Tyson is
concentrating hard enough not to see the maps but when in urban or rural
areas and not concentrating, if he’s seen a map of the area, he’ll see
the maps. He’ll recognize rock formations or specific building shapes
and see the maps bent and folded over to match his viewing angle.
Tyson
can also flash memories maps and then recall them exactly as and when
needed, it isn’t clear if this is part of his synesthesia or if it is a
separate condition but he assumes it is part of it.
Tyson’s
fondness of mathematics isn’t only because he enjoyed mathematics,
thought that plays a large part in it, but mathematics enabled him to
understand the maps he saw from his Synesthesia. Thought there are
likely to be other factors involved Tyson puts all credit to mathematics
for enabling to understand the images that overlapped his vision.
It
was always assumed that Tyson’s Synesthesia developed at age three, as
that was when he’d first mentioned seeing maps to his family.
Tyson trying to describe what his Synesthesia caused him to see can be seen in this post.
For those who don't want to read all of that post, the most important part is this:
Colour played a role in many different forms of Synesthesia. In some cases letters, numbers, and even sounds could be seen - or heard - as specific colours, regardless of their actual colours. In other forms, such as Tyson’s, colour was assigned depending in the significance of the object or person to the viewer.
In Tyson’s case it changed the colour that each part of the map was given. Most people and buildings were viewed in basic greens, yellows, pinks, and blacks. Important things appeared in various shades of reds, purples, greys, and blues.