The Science of Consciousness

Matthew Hunzinger: Author
J. S. Jordon: Author
Additional Credits:
This module was supported by National Science Foundation Grant #0127561.

NOTE: This module on consciousness begins with a video introduction. Links to the video are below. Watch the video. The script for the video is printed just below.


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Hi, my name is Scott, and the topic of this module is the science of consciousness. Why consciousness? Well, here's how we'll do this. I'll begin by explaining why some people think the time is right for a science of consciousness. Then I'll examine different perspectives on what consciousness is. Finally, I'll examine some of the different approaches scientists are taking in this new branch of science. Ready? Ok, here we go. Oh yeah, one more thing. Just to get a feel for why consciousness might be an interesting thing to study, go back and read the opening paragraph and, while doing so, pay attention to what it 'feels' like to read it. Notice that as you read it you actually 'feel' like you're experiencing the thoughts of another person. This is, of course, why novels are so popular. They let us into the conscious world of someone else in ways that movies find hard to do. In a movie, just as in life, you can only observe another person's behaviors. But in a novel, we get to read about their thoughts. Now go back and read the beginning of this paragraph and, once again, pay attention to what it 'feels' like to read it. This time, the feeling is different. Now, instead of feeling like you are in the conscious world of someone else, you feel like someone else (i.e., me) is talking to you. This is why I ended the first paragraph with the phrase . . . Of course the reader will know the difference. . . We are very good at discriminating which thoughts in our consciousness belong to us, and which thoughts belong to someone else. For example, right now, as you are reading this, you are probably thinking to yourself, "Wow, this Scott guy is pretty cool". Well, at least I hope that's what you are thinking. The point is, even though both thoughts are in your consciousness at the same time, you are fully aware of which of them are yours and which of them are mine. How do we do this? Believe it or not, there are people who can't do this. They generate thoughts, but they can't tell that they were the one who produced them. They therefore feel as if thoughts are being placed within their consciousness. We call these people schizophrenics, and currently, a lot of scientific research is beginning to understand why schizophrenics loose track of their thoughts. This is a very exciting scientific question, and because of new technologies we can begin to address it. The point is that consciousness -- what it feels like to be you -- is full of patterns, and like any other system of patterns, scientists want to understand it. So, with no further ado, let's make our way into the final frontier . . Commander Da . . engage! (Sorry, I had to slip in one more Star Trek allusion)


Why a science of consciousness now?

 In order to explain why some think the time is right for a science of consciousness, let's take a look at how we got here. The thing to remember is that we are talking about a science of consciousness. Philosophers have been talking about consciousness for thousands of years. It is only recently however, that consciousness has been considered a proper subject for science. To understand why, click on the link below. It will open a Powerpoint presentation. You will then go back and forth, reading instructions on this page, and going to the Powerpoint presentation whenever you are told to "click" (click the mouse in the Powerpoint window). [NOTE: This will work best if neither of the two windows are maximized, & at least parts of both windows can be seen on your monitor at the same time.]

History of Consciousness <-- (click there)

(NOTE: The Powerpoint should be opened in a separate window so that you may easily go back and forth between this document and the Powerpoint presentation.)

OK, what I need you to do is click on the mouse each time you see the word 'click'. That way, the text and images will work together. What you should see right now is the words "A Brief History of Consciousness" at the top of the screen and a large circle below the words. I'll have to explain a few things before I get to the meaning of the circle. So here we go. In the mid-1800's, a group of German philosophers began to ask whether or not consciousness could be studied scientifically. They had seen how the scientific method had led to great achievements in our understanding of astronomy, biology and chemistry. So they figured, "A science of consciousnes . . why not?" The method they developed is known as Introspection. In this methodology, a researcher presents a person an object of some sort, say . . a book, and then asks that person to describe her conscious experiences of the book, just like I asked you earlier to read the first paragraph and evaluate what it 'felt like' to read it. The idea behind Introspection is as follows: By having people pay attention to their conscious states and then report them, scientists can learn something about the patterns in consciousness. One pattern they found to be a part of all consciousness was its directedness. That is, all conscious states are 'about' something, be it an object in the environment, another thought, or even the thoughts of another person. They referred to this inherent directedness as Intentionality. Thus, given their belief that all conscious states were inherently intentional, consciousness and intentionality were considered part of the same phenomenon. The circle in the image represents this wholeness. This point will become important later as we move toward the present.

     After years of using the introspective methodology, researchers discovered over 40,000 unique conscious states. While this number is large and thorough, it is not very parsimonious. That is, chemists had developed a system that allowed them to describe most every substance in the world with just over 100 elements, what we know as the periodic table. 40,000 is just too large to be of much use. In addition, the reason they discovered so many unique conscious states is because different laboratories couldn't agree on how to label different consciousness states. This problem was due to something we pointed out in the first paragraph: I can point to your feet and count the number of toes, but I can't point to your consciousness and count its different qualities.

     When Introspection made its way to the United States, many psychologists objected and argued that a science of psychology could not be based on an unreliable variable like consciousness. Thus, they chose to measure a variable that everyone could see -- namely, behavior. As I said earlier, I can see my feet. And I can see your feet for that matter. So since I can see what your limbs are doing, and we can all agree on what your limbs are doing, behavior became the dependent variable of choice. This approach to psychology is known as Behaviorism.


Since Behaviorism chooses to focus on behavior, it ignores conscious states and focuses on the relationship between environmental events (i.e., stimuli -- click) and behavioral events (i.e., responses -- click twice). An advantage of this approach is that the researcher has independent access to both the cause and the effect. That is, the stimulus is the cause, and it can be measured independently of the effect is causes (i.e., the behavior). In Introspection, the stimulus would be the cause, and the conscious state, the effect. The researcher however, does not have access to the effect (i.e., the conscious state) and thus has to rely on what the subject tells him about her conscious states. As we have seen, this inability to see conscious states makes it very difficult to agree on what is being measured. The behaviorists believe that having access to behavior made their behavioral methodology superior to Introspection.

      If you click again, you'll see that I have placed the work Intentionality just above the term "response". This illustrates that although the behaviorists refused to address conscious states, they still addressed the fact that an organism's behaviors are directed. That is, organisms behave in order to get things; food, sex, and shelter for example. If you click again, you'll see the words 'sensation' and 'perception' appear. Click one more time, and you'll see the term Psychophysics. These terms refer to the fact that although behaviorism became a very influential methodology, there were researchers who continued to measure conscious states. They didn't call them conscious states however, for the term consciousness wasn't being used all that much any more -- at least not by experimental psychologists. Instead, they referred to conscious states as Perceptions. The method they used therefore was much like introspection. Instead of presenting subjects with complex stimuli and asking them to give detailed reports of the richness of their conscious states however, psychophysicists presented subjects very simple stimuli, such as lines of different lengths, and asked them to indicate which line was larger. The purpose of this methodology was to investigate the lawful relationship between stimulus events and sensory or perceptual events. Psychophysics is an extremely effective methodology. In fact, due to psychophysics, it is possible for all of us to get into a friend's car and adjust the volume on the stereo without blowing anyone's ears out. This is because the increments in volume are actually increases in the amount of energy being sent to the speakers. Early on, psychophysicists discovered that the amount of energy that has to be added to a stimulus in order for you to experience it as a different stimulus (e.g., a louder or softer stimulus) is roughly the same for everyone.

      So, for roughly forty years, behaviorists studied the lawful relationship between stimuli and response, while psychophysicists studied the lawful relationship between stimuli and conscious states -- they just didn't call them conscious states -- as we saw before, they called them perceptions.

      Then, in the late 1950's and early 1960's researchers began to discover that perceptions could be directed just like behaviors. That is, it turns out that people are able to "tune" their perceptions in order to be able to detect specific things going on in the environment. For example, imagine yourself at a party. Everyone is talking and you can't make out anything anyone is saying until, all of a sudden, you hear your name. Since you do't know what the person who said your name might be saying about you, you keep still yet struggle mightily to hear what they are saying. Eventually, you pick out the voice that said your name, from amidst all the other voices in the room, and focus in on it. Much to your surprise, you discover they weren't even talking about you. As you stop trying to hear that one particular voice you suddenly find that you've lost it. It has simply become part of the background noise. Disappointed by what a boring party this has become, you make your way to the chip bowl.

      The point of this example is that we seem to have the ability to choose what aspects of the environment are able to enter into our conscious states. Again, at the time researchers began investigating this ability, the word consciousness wasn't very popular. So instead of referring to our ability to direct our conscious states as intentional consciousness, they referred to it as Attention. ("click" 4 times). In addition, they referred to the mechanism that allowed people to shift their attention as a cognitive system. This, of course, represented the advent of the field of science known as Cognitive psychology. As you have probably already learned in other modules, cognitive psychology is still rather active today. But since it now involves philosophers, computer scientists, anthropologists, and many other branches of scholarship, the field is generally referred to as Cognitive Science.

      Ok, so why did we go through all of this? If you look at the diagram as it is now, you'll see why researchers have once again become interested in a science of consciousness. If you remember from earlier, the first attempt at a science of consciousness utilized Introspection as its methodology, and for these researchers, consciousness and intentionality were part of the same thing -- consciousness was inherently directed (i.e., intentional). In order to make what they considered to be better scientific progress, the behaviorists refused to address conscious states, yet simultaneously assigned the notion of directedness (i.e., intentionality) to behavior. As a result, consciousness and intentionality were split. The persistence of the psychophysicists however, kept the study of consciousness alive, but under a different name (i.e., perception). With the advent of cognitive psychology, the name didn't change. Since then however, it has become possible to measure changes in people's brains that are associated with changes in their conscious states. For example, we now have a good idea of which areas of the brain are active as a person thinks about herself versus someone else. This ability to associate specific brain states with these very sophisticated conscious states has led some researchers once again use the term 'consciousness' as part of their scientific theories. (click). Unlike psychophysics, which could only measure the relationship between environmental events and perceptions, consciousness researchers can measure the relationship between brain states and more sophisticated types of conscious states. As you will see in later parts of this module, there is quite a bit of disagreement as to whether or not this really constitutes a science of consciousness. But for now, we at least understand why the scientific study of consciousness seems so new, when in fact it isn't, as well has how it got to where it is.

Click here for "Cognitive Approaches to Consciousness"

Copyright: 2006