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In 1879, when Wundt started the first experimental psychology laboratory, he regarded consciousness as the main focus of psychology. By 1900, however, many psychologists were frustrated at the lack of progress toward a science of consciousness. They wanted an alternative.

By the 1920s behaviorism seemed like such an alternative. Behaviorism claimed to achieve its advances by avoiding any speculations about consciousness. Psychologists were taught to focus exclusively on measurable, observable behavior.

By the late 20th Century psychologists were once again grappling with the issue of consciousness. New tools, notably brain scanning techniques and theories of cognition, offered new approaches to studying conscious and unconscious mental activity.

How has psychology returned to one of its early themes?

Even today, a minority of psych­ologists assert that consciousness cannot be studied scientifically. Some echo the arguments put forward by the father of behaviorism, John Watson, in the 1910s and 1920s.

Watson pointed out that conscious­ness was subjective, by definition. It was defined by the fact that we experience it internally and cannot share it directly with others.

Therefore we cannot have an objective science of conscious­ness. We can only gather data if it is observable.

A psychologist sympathetic to this point of view might argue, "You can say you are studying conscious­ness when you study brain scans or attention. However, if you are studying observable things, you are in fact studying behavior."

What position, originally taken by John Watson, still finds favor with some psychologists?

Many other scientists see no problem studying consciousness. University of California philosopher John Searle expressed this point of view in his book The Re-Discovery of the Mind (1992): a biological feature of human and certain animal brains. It is caused by neuro­biological processes and is as much a part of the natural biological order as any other biological features such as photosynthesis, digestion, or mitosis. (Searle, 1992, p.90)

What viewpoint was expressed by philosopher John Searle?

Even if we accept that conscious­ness is a biological function, like digestion, big questions remain. In particular: What are the brain mechanisms of conscious­ness?

Scientists have made specific proposals. For example, Tononi, Edelman, and Sporns (1998) describe the biological substrate of conscious­ness as a dynamic core of neurons, widely distributed, not equivalent to the whole brain.

Tononi, Edelman, and Sporns (1998) say this network of neurons can organize itself in a tenth of a second to form a unified response such as a thought or a perception. They predict a "distinct set of distributed neural groups" will be identified through brain scanning as the basis of conscious experience.

What do Tononi and Edelman propose, concerning brain mechanisms of consciousness?

Critics might say this proposal is surely true, because it is so vaguely worded. It would be "verified" by any discovery of specific neural mechanisms. But, on the other hand, there must be some substrate of consciousness: some set of areas that are active whenever we are conscious.

Some neuroscientists suggest a set of circuits in the brain called the Default Mode Network (DMN) might meet that criterion. It is active when people are conscious but not devoting attention to a task (Raichle et al., 2001).

Buckner, Andrews-Hanna, and Schacter (2008) describe the DMN as "a specific, anatomically defined brain system preferentially active when individuals are not focused on the external environment." When people are daydreaming, thinking of past experiences, or trying to under­stand other people, the DMN is active.

Scholars such as Andrews-Hanna (2012) describe the DMN as active during "introspective and adaptive mental activities in which humans spontaneously and deliberately engage." Others called it "the seat of the self."

Ironically, the DMN was identified by reduced activity in certain areas when people concentrated on external, goal-directed behaviors. During these times, activity in the DMN decreases.

How was the default mode network identified?

The Default Mode Network consists of multiple, densely connected brain systems including the medial temporal lobe and the medial prefrontal areas, both locations known for complex cognitive activity. For a while, it seemed that perhaps the DMN was the long-sought "seat of consciousness."

However, the DMN is quieted during meditative states. People are definitely conscious at that time.

The DMN might best be regarded as "the seat of ordinary thinking." That type of thinking can be defined by what it is not: It is not concentrating on an external task, and it is not taking in the present moment without judgment.

Scientists knew by the 1960s (from evoked potential research) that stimulation from the environment reached the brain in about 20 ms, 1/50th of a second. By the late 1970s evidence emerged that stimuli could provoke a positive or negative emotional response immediately after arriving, before the information entered consciousness.

Robert Zajonc (1980) called this the emotions first model. Pleasantness or unpleasantness of a stimulus was judged 20 ms after exposure, even when a stimulus is quickly masked (covered with a grid or competing stimulus) so a person could not identify the stimulus consciously.

What was the emotions first model?

This fast evaluational system makes evolutionary sense. A very quick evaluation warns us away from something dangerous or prepares us for something pleasant as quickly as possible.

After that, a more complex response can occur in other brain areas within 250 ms or so (1/4 second). Harvard psychologist Arthur Blumenthal suggested in 1977 that consciousness consisted of rapid attentional integrations formed in a quarter second or less.

You might recall from the discussion of evoked responses in Chapter 2 that when people have to re-evaluate the meaning of a sentence, because of an unex­pected word at the end, it produces a change in the N400 evoked potential. As the number 400 indicates, that occurs 400 ms (nearly half a second) after a stimulus.

How quickly does the brain form organized cognitions?

Students might wonder why we have a sense of continuity in cognition, if the brain is continually making rapid integrations or snapshots of activity. However, that is consistent with many other findings.

For example, our eyes send the brain information from many eye fixations in a second or two, as we gaze around a scene. Each burst of information takes 20-50 ms, the same time frame as other incoming stimuli, but the brain knits the information together.

We experience a continuous, ongoing visual world. Conscious­ness may be formed in a very similar process, with continuous processing guided by little bursts of information formed from within, integrated with those received from the senses.

When is Consciousness Helpful?

Consciousness is arguably one of the best things about being human. We not only get to exist as living creatures: we get to know we exist, think about it, and savor it.

But what is the purpose or function of consciousness? That was the question asked by William James with his philosophy of functionalism.

Experimental psychologist George Mandler suggested one set of answers in his Presidential Address to Division 1 (General Psychology) of the American Psychological Association in 1983. Mandler suggested three functions of consciousness.

Anticipating our coming discussion of meditation and mindfulness, it should be said that Mandler was describing one variety of consciousness: competent, controlled action. Mandler identified three functions for this mental activity:

1. Learning. People typically concentrate their awareness when trying to learn something new. Not until a skill is well practiced does it become automatic.

2. Making judgments. People think consciously about alternatives and choices.

3. Troubleshooting. People use conscious mental processes to deal with unexpected situations that cannot be handled with automatic, well-learned routines.

What was Mandler's theory about the role of conscious thought?

Mandler used driving an automobile as an example. When first learning to drive, a person must pay full attention to every action. Conscious­ness accompanies the process by which we integrate lots of information and hold it in place or grasp it while learning.

After much experience, driving becomes familiar and no longer requires full attention. An experienced driver can drive on auto-pilot, letting the mind wander.

Driving on autopilot is a fine example of automaticity (auto-ma-TISS-ity). Automaticity is intelligent action without focused attention. We will discuss it as a routine part of cognitive activity in Chapter 7.

Consciousness returns to the act of driving when the driver must make a decision such as which way to turn at an intersection. This is what Mandler called making judgments.

Mandler's third category is trouble­shooting. Even when driving on autopilot, an experienced driver will snap back to full attention if something unusual or surprising happens.

For example, if an animal appears at the side of the road, attention is drawn to it. Full consciousness seems to accompany the process of rallying resources and making a decision about what to do.

How does the example of driving an automobile illustrate Mandler's points?

The example of snapping out of an absent-minded state when something unusual happens–such as an animal approaching the side of a road–shows that even when attention is elsewhere, cognitive processes outside of awareness monitor ongoing activity.

Something in the brain notices events that might require conscious inter­vention. Not only are we capable of driving while absent-minded; we are able to recognize when a situation is unusual enough that automaticity must be interrupted.

This implies great complexity under the surface of the conscious mind. In fact, the more psychologists study conscious processes, the more respect they have for unconscious processes.


Andrews-Hanna, J. R. (2012) The brain's default network and its adaptive role in internal mentation. Neuroscientist, 18, 251-270. doi:10.1177/1073858411403316

Blumenthal, A. L. (1977). The Process of Cognition. Englewood, NJ: Prentice-Hall.

Buckner, R. L., Andrews-Hanna, J. R., & Schacter, D. L. (2008). The brain's default network: Anatomy, function, and relevance to disease. Annals of the New York Academy of Sciences, 1124, 1-38.

Mandler, G. (1983). Conscious­ness: Its function and construction. [Presidential address to the General Psychology Division of the American Psychological Association.]

Raichle, M. E., MacLeod, A. M., Snyder, A. Z., Powers, W. J., Gusnard, D., & Shulman, G. L. (2001) A default mode of brain function. Proceedings of the Natural Academy of Sciences, USA, 98, 676-682. doi:10.1073/pnas.98.2.676

Searle, J. R. 1992. The Rediscovery of the Mind. Boston: MIT Press.

Tononi, G., Edelman, G. M., & Sporns, O, (1998) Trends in Cognitive Sciences, 2, 474-484.

Zajonc, R. B. (1980) Feeling and thinking: Preferences need no inferences. American Psychologist, 35, 151-175.

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