Microworld: Dynamic
Programming
Click the Hyperlink
above to visit the Microworld.
Authors:
Priyan
Weerappuli and
J.T.
Ratnanather
Dynamic
programming has many applications, some of which we'll investigate in this
workbook. One of these is in modelling the cortical surface of the brain.
The first question that might come to mind when hearing about the brain is
why is it shaped the way it is, and why is it so folded?
The
brain is shaped the way it is simply because it has to fit into your skull,
and it is folded because in order to be as large as possible (have the greatest
surface area) it must fold in on itself, similar to crumpling a piece of paper
to get it to fit through a small hole that it wouldn't fit into if it were
flat.
Dynamic
programming is used to generate the gyri (the ridges of the folds), and the
sulci (the valleys) that form boundaries of cortical regions - an example
of this can be seen on page 8 of this tutorial. This allows us to focus on
portions of the brain in order to, for example, compare similar regions in
the brains of more than one individual.
Dynamic
programming can also be used to generate:
1. Individual gyral and sulcal curves that can be compared by Metric Pattern Theory.
2. Cortical surfaces or manifolds i.e. cortical regions with boundaries delineated by gyral and sulcal curves that can be compared by Metric Pattern Theory.
Dynamic
programming is an important tool of computational anatomy. Imagine the cortex
of the brain as a folded sheet within which there is a series of sulci and
gyri that are the valleys and ridges respectively. Though one would think
that due to the functional significance of these structures, they would appear
uniformally in almost all human brains, even the gyri and sulci that appear
in all normal brains exhibit a great range of variability in size and configuration.
In
order to better understand the brain itself one must be able to look beyond
the variations that exist between different people and concentrate on the
basic structures that are universal. We can begin to do this by characterizing
the sulci or the gyri in terms of the geometry of the cortical surface.
Number
of Pages: 12
Animation: Yes
Grade Level:14-15
Return to the listing of MathwrightWeb Microworlds
| - James E. White, Ph.D. , Library Director, | ||
| author of this website, Mathwright 2000, MindScapes, | ||
| MathwrightWeb, and Mathwright32 |
