Mimicking the Brain: Using Computers to Investigate Neurological Disorders

By Seachrist, Lisa | Science News, July 22, 1995 | Go to article overview
Save to active project

Mimicking the Brain: Using Computers to Investigate Neurological Disorders


Seachrist, Lisa, Science News


Deep within the brain a single neuron fires. That electrical signal

triggers a biochemical chain reaction that courses from neuron to neuron, ultimately forming a set of connections that brings alive a scenic vista, a child's touch, or the memory of a long-ago event. Arresting any part of that signal devastates the cognitive activities that appear to make us human.

While the speed and precision of the human brain lead some people to refer to it as the ultimate computer, the brain maintains a distinct advantage over the computer--resilience. When crucial interactions between neurons falter, the brain reroutes signals in an attempt to maintain the ability to think, remember, and perceive. "When you damage just one small part of the computer, the whole thing will collapse," says neurologist and computer scientist James Reggia of the University of Maryland in College Park. "The brain is very different. It is able to adjust its own circuitry."

Despite this resilience, the brain has its limitations. Neurological diseases such as Alzheimer's and Parkinson's cause progressive losses of vital cognitive functions that no degree of brain-initiated rewiring can repair.

Scientists do not know why some conditions spur the brain to large-scale reorganization of the synapses, or junctions between neurons, whereas others result in permanent damage. The problem lies in a basic dichotomy in neuroscience: Remarkable gains in elucidating the way neurons communicate with each other on the molecular level simply haven't explained the biology of how we think, sense, and feel.

For the past decade, researchers have employed a controversial tool to decipher this puzzle: computer systems known as neural networks. These networks simulate elementary, but poorly understood, brain functions such as reading and language (SN: 11/26/88, p. 344). Scientists exploring artificial intelligence have also made extensive use of neural networks. Now, some researchers are using them to model disorders of the brain, with an eye to discovering better therapeutic strategies.

Reggia organized a workshop at the University of Maryland in June to explore ways in which computational models of brain disorders ranging from phantom limb pain to stroke to Alzheimer's will enable scientists to test theories of how and why the brain responds to disease and trauma.

"The complexity of the brain makes it necessary that we use computational models to understand how disease affects the brain," says Reggia. Otherwise, "it's almost like trying to understand the climate without using computer models."

Psychiatrist-turned-computer-modeler Manfred Spitzer of Heidelberg University in Germany used neural modeling to tackle the enigma of phantom limb pain.

For over a hundred years, physicians have reported that amputees not only continue to feel their amputated limbs, they often suffer cramping, burning, and shooting pains in specific regions of those limbs. Researchers have traced the origin of such pains to reorganization of the brain area that formerly processed sensations in the absent limb. As neurons in that area adapt to some new purpose, their activity manifests itself as phantom pain (SN: 6/10/95, p.357).

Spitzer, however, questioned just how such a reorganization would occur. Paraplegics, like amputees, suffer loss of stimulation from large sections of their bodies, and presumably their brains contain areas that cease activity for want of stimulation and become ripe for reorganization. Yet the paralyzed don't suffer phantom limb pain.

The cortex of the brain creates specific areas that both receive neural impulses from various parts of the body and issue instructions to them. Spitzer and his colleagues developed a neural network that mimics this mapping electronically. When the team deprived the network of a specific input, as might happen after amputation of a limb or loss of stimulation as a result of paralysis, the areas of the network responsible for that input didn't undertake any new functions, says Spitzer.

The rest of this article is only available to active members of Questia

Sign up now for a free, 1-day trial and receive full access to:

  • Questia's entire collection
  • Automatic bibliography creation
  • More helpful research tools like notes, citations, and highlights
  • Ad-free environment

Already a member? Log in now.

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Project items

Items saved from this article

This article has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this article

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this article

Cited article

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited article

Mimicking the Brain: Using Computers to Investigate Neurological Disorders
Settings

Settings

Typeface
Text size Smaller Larger
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

While we understand printed pages are helpful to our users, this limitation is necessary to help protect our publishers' copyrighted material and prevent its unlawful distribution. We are sorry for any inconvenience.
Full screen

matching results for page

Cited passage

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited passage

Welcome to the new Questia Reader

The Questia Reader has been updated to provide you with an even better online reading experience.  It is now 100% Responsive, which means you can read our books and articles on any sized device you wish.  All of your favorite tools like notes, highlights, and citations are still here, but the way you select text has been updated to be easier to use, especially on touchscreen devices.  Here's how:

1. Click or tap the first word you want to select.
2. Click or tap the last word you want to select.

OK, got it!

Thanks for trying Questia!

Please continue trying out our research tools, but please note, full functionality is available only to our active members.

Your work will be lost once you leave this Web page.

For full access in an ad-free environment, sign up now for a FREE, 1-day trial.

Already a member? Log in now.