Saturday, March 26, 2011

Artificial Intelligence and Humanity I

This post was based and inspired on the writings of Brian Christian


Turing test

The objective of the Turing test, created by Alan Turing in the year 1950, consists in evaluating during small conversations, if computers could imitate humans. The test incited the creation of Chatterbots such as ELIZA, launched on 1966. Later on the Loebner prize was created, offering a monetary award for the first chatterbot that could pass the test, this competition still takes place once a year.

The classic Turing test consists in one room with judges that make questions for 5 minutes to computers or to humans that are in a second room. After conversations take place judges reveal which chats they think they had with chatterbots and which with humans. The chatterbot that is considered the best is the one that fools the higher percentage of judges. Turing believed that the test would have been passed by the year 2000; far from his prediction a new record that was able to deceive only 30% of the judges was recently achieved.

Controversy

The principal question Turing wanted to solve with this test end up generating lots of controversy because it derivated mainly in three others "Can machines think?", "Are machines intelligent?", "Do machines have a conscience?" Lots of arguments where stated in favor and against them (including the ones that follow), but no unanimous conclusion was reached:

  • How we could tell if a machine was intelligent. After all, mankind has tried to define intelligence for ages and had made little progress except to decide that whatever it is, we've got it.
  • How do you know if the machine actually understands what it is doing, seeing, or saying? A particularly strange side effect of being a conscious being is that you can never truly know that someone other than you is conscious.
  • Not until a machine can write a sonnet or compose a concerto because of thoughts and emotions felt, and not by the chance fall of symbols, could we agree that machine equals brain-that is not only to write it but know that it had written. Neither until they can feel an emotion (Jefferson).
  • Computers can’t originate anything we explicitly tell them to do (Lovelace).
My preferred theory concludes that machines can't think; I argue that thinking cannot be separated from feelings (Damasio) and that it also includes an intuitive component.
Questions and thoughts
  • Do things have an essence, and if so is it possible to describe it? (Like Plato did in the Allegory of the Cave)?
  • What makes something to be something? We guide ourselves mostly by external appearances and actions. But indeed I think the evaluation would be more accurate if we compare that something internal structure and organization.
  • Can we extend the meaning of consciousness? By adding an exception to inanimate objects that does not include the act of thinking, emotions, intuition or any other aspect of the brain, in this case being conscious would mean only to have knowledge of their own existence.
  • Our brains consider that a certain entity is or is not something often by doing lots of assumptions. Instead we could assign a degree of credibility of what we think the entity is.

Tuesday, March 15, 2011

The other brain by R. Douglas Fields

The brain is a world consisting of a number of unexplored continents and great stretches of unknown territory - Santiago Ramon y Cajal


This amazingly easy to read and understand book, written by Douglas Fields give us a new and fascinating perspective of how the brain functions. Allowing to understand, not only to neuroscientists, the most recent discoveries about the brain. As its name indicates this book is focused in the study of glial cells which are located in the brain and make up to approximately 85% of the cells in it.

In the past neuroscientists dedicated themselves to study only neuron cells to understand the human behavior trough the brain functioning. But two decades ago they realized that glial cells also played an important role in how the mind works. The evolution of brain knowledge is similar to the history of DNA knowledge: scientists first thought that genes caused beings to express certain traits and the rest was junk DNA; but later on they discovered that the so-called "non-coding" parts of the DNA also had an important role in the organism.

According to J. Kwasniak there are (at least) two types of junctions between neurons: chemical synapses and electrical synapses. In chemical synapses there is a tiny space between the membranes of the two neurons, molecules of neurotransmitter are bled into this space by one neuron and taken in by the other. In this way a signal is sent from the pre-synaptic neuron to the post-synaptic one. The signaling occurs when the pre-synaptic cell is firing and the post-synaptic cell is influenced to fire more easily, or less easily in inhibitory synapses. But there is a slightly simpler junction found both in the brain and in other tissues. It is a cluster of tiny channels in one cell membrane that lines up with a similar set of channels through another cell’s membrane so that small chemicals or electrical currents can pass directly between the two cells. The tiny channels can be opened and closed. We think of the brain as using only chemical synapses when actually the gap junctions exist in many areas of the brain, especially between glial cells. They are noted to pass electrical currents in the form of charged ions but may also signal using calcium ions and other chemicals. A group of cells connected by gap junctions have, in effect, a continuous cytoplasm as far as small molecules and electrical charge are concerned. The activity of cells using gap junctions is another whole level of activity in the brain.

Fields explains what is known about how this cells function trough a mix of scientific history, descriptions of the latest neurobiological techniques and chronicles of scientific experiments.He describes the role and importance of glial cells by detailing how they participate in different types of illnesses such as brain cancer, spinal chord injury, “mad cow” infection, HIV and degenerative brain diseases. These new insights of the glia offer hope for breakthroughs in healing these illnesses.

Fields also suggests trough additional evidence that glia play a key role in maintaining mental health, addictions, regulating pain, processing memories, wiring up the baby’s brain and many other functions.

This book envisions that “we are glimpsing a far greater universe of brain function than we had ever imagined.”


Read the Scientific American articles from the author