There's More to Thinking Than You.. Think

Why Neuroscience May Be Able to Explain Consciousness

Page 109 “Directed Freewrite” – Read over this brief essay, and write down the main points in the essay, but in a more conversational and less academic tone. Use everyday words to explain some of the “fifty-cent words” here, and express the points in this article in a way that your fifteen-year-old sibling (or cousin) could understand.

In the piece, “Why Neuroscience May Be Able to Explain Consciousness”, Francis Crick, a biologist, and Cristof Koch, a professor, speak about how they disagree with David J. Chalmers view. Instead, they both insist that by understanding the brain scientifically will ultimately answer questions about our consciousness.

Francis Crick and Cristof Koch believe that right now, the best approach to explaining consciousness is to solely concentrate on finding the processes in our brain that are the most responsible for consciousness. By locating specific neurons (messengers in our brain) in the cerebral cortex (a certain segment of our brain) that only deal with consciousness, we might come across what David J. Chalmers calls the big problem: a full understanding of a subjective experience that makes these processes occur.

Unfortunately, Crick and Koch are not as enthusiastic as Chalmers was about this early stage. They see Chalmers’ “big problem” being broken down into a few questions. Questions like: Why do we experience anything at all? What leads us to a particular conscious experience? Why are some of our experiences private from others? They believe they have an answer to the last question and an idea about the first two, having to deal with a phenomenon known as “explicit neuronal representation.”

The best way to define Francis Crick and Cristof Koch’s definition of “explicit” is by providing an example. When we look at another persons’ face cells in our eyes fire rapidly, like the pixels on a television screen, in order to create a representation of their face. At the same time, these cells respond to many other features of the image we are looking at, such as shadows, lines, and uneven lighting. An individual can also lose these visuals from a stroke or other brain trauma, which is called “prosopagnosia.” Prosopagnosia is the individual’s inability to recognize certain and familiar faces consciously, or on their own. There are many other parts that can be damaged which lead to other deficiencies.

At each stage visual information we receive is reencoded, or retransmitted in a different way. Cells in our eyes respond to light and the neurons in the visual area of our brain are best at responding to lines or edges that we see. Neurons higher up respond to faces and other objects that we find familiar. On top of those neurons, there are some that function our pre-motor and motor structures in the brain, where they actually fire the neurons that create actions such as speaking, or our reflexes and movement.

In order for us to describe a visual experience, the information has to be transmitted to a certain part of the brain that deals with motor output. After that, it then becomes available for us to speak about. This process always involves reencoding the information.

It’s not possible to convey with words and ideas the exact nature of an experience we’ve had. However, it is possible to distinguish the difference between our own subjective experiences (knowing the difference between red and orange). This is all possible because a difference in a high-level visual area in our brain will still be associated with a difference in our motor stages. What Crick and Koch get form this is that we can never explain to other people the true nature of any of our own experiences, only its relation to other ones.

The other two questions are much more difficult. Crick and Koch prefer an alternative approach, which involves the concept of “meaning.” Meaning derives the linkage among representations with others spread throughout the brain and spinal system in a network that is similar to a dictionary. The more diverse that these connections are, the richer the meaning is. Of course, groups of neurons can take on new functions, or jobs, which allow our brain to learn new categories like new faces.

Chalmers suspects that information is the key concept, which might be true. It would be very useful to try to determine what a neural network must have in order to generate a meaning. It’s possible that some exercises can suggest meaning. The big problem of consciousness might just appear in an entirely new way, or it might just disappear someday.