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| By Laura Graser |
New technologies allow researchers to examine and observe the brain in ways that previously have not been possible. Electrodes placed on the head, such as those used for an electroencephalogram (EEG), pick up all kinds of electrical activities, but new techniques allow neuroscientists to better separate signal from noise to more accurately measure brain activity. Dr. Joel Alexander uses sophisticated EEG techniques to study the functioning of active brains. He discussed some of his findings and other research in this field at the fall Oregonians for Rationality meeting. Neuroscience is in its infancy, stressed Alexander, and he urged the audience to "maintain a healthy dose of scientific skepticism" about his results so far.
Alexander examines brain function in individuals who show "extreme" behavior for a particular trait. For example, one "extreme group" he examined was extremely bright kids. These were not just kids who did well in school, but kids who scored extremely high on the SAT at 12 years of age. He also studied extreme "lefties," i.e. left-handed people who are also left-footed, left-eyed, and have left-handed family members; gay men defined as "extreme homosexuals" in that they have never had even one heterosexual contact; individuals demonstrating outstanding early musical talent; and predatory criminals.
Normal brain functions
In general, the brain has three necessary functions: maintaining a knowledge base, fact processing, and "autometicity" or base operations automatically conducted without conscious thought. An individual's functioning in each of these processes depends upon brain maturation and previous experiences.
A person's "knowledge base" is made up of all the information that is recognized and understood: the greater this knowledge base, the richer the individual's neural networking. In the case of the brain, the old adage of "use it or lose it" is accurate in that using the brain increases the number of connections among neurons and keeps the brain active and functioning better in later life.
The "spread of activation," or the flow of electrical activity through the brain upon receiving a stimulus, is indicative of information processing. When, for example, a person hears the word "dog" the concept flows through the brain in a discernible pattern unique to each individual. The extent of the brain's activity depends upon the richness of the individual's associated knowledge base. The brain's reaction can also be timed. Different people process facts faster than others. Jeopardy champions, for example, have fast brain processing. The deja vu experience seems related to the nature of this spread of activation, occurring as the spreading activation loses its episodic flavor.
Recall and understanding depend upon the richness in one's knowledge base and are affected by the ability to access information. As we learn new information we also build in cues associated with the context in which the information is learned. This is called "context dependent learning" and includes cues from our physical environment. So for example, if a student studies with blaring music, coffee and popcorn, he will do best on the exam if he has blaring music, coffee and popcorn. These environmental cues create additional mental associations which help trigger a wider activation in neurons associated with the information being recalled. Recognition is a simple knowledge base task, while the more complex task of understanding a concept is associated with using a larger portion of the knowledge base and is demonstrated with greater neural activity. This is why multiple choice tests, which measure only recognition, are not particularly useful for testing in-depth understanding.
As neuroscientists learn more about how the brain develops they recognize there are critical times, especially in early childhood, during which the knowledge base for particular skills is created. A child who misses a developmental process during a crucial time may never develop that ability. One problem which may affect a child's ability to learn at crucial times is minor head injuries from birth trauma. Alexander suggests that increased birth weight due to better nutrition may contribute to this problem, and might account for reports of increased hyperactivity in children today. While hyperactivity may be misdiagnosed or over-diagnosed in some normally active kids, Alexander suggests hyperactivity can affect a child's ability to learn at critical developmental periods and, therefore, should not be lightly dismissed. Collecting data on birth trauma and associating it to learning disorders and hyperactivity is exceedingly difficult, and Alexander concedes no connection has been demonstrated.
"Automatic processing" is the information processing we do without conscious thought. Outstanding athletes, like Michael Jordan, and chess grandmasters have practiced their skill so often they move without consciously "thinking" about it. The more mundane of us drive a car without much conscious thought. Shifting gears and changing lanes have become "automatic" processes. Most of us have experienced the sudden realization that we are at our destination, without being able to recall the details of the drive.
There are people who, having once developed a skill, spend the rest of their lives functioning in it automatically. Even scientists can fall into the trap of doing things because they have been doing them for 30 years, rather than rethinking problems and evaluating new research. This processing style does not require much critical thinking or expansion of the knowledge base, so such a person can mentally atrophy over the years.
Conscious information processing or "control processing" is necessary when a situation is unfamiliar. A person can "control process" only one thing at a time. When a person is consciously processing one activity, everything else is processed automatically. We have a priority system built into our information processing which determines what information is consciously processed. "Permanent priorities" are those personally unique priorities which remain with a person for their lifetime, such as when we notice if someone says our name. A person may have a "current priority" that takes precedence over other information processing; for example, worries about the health of a family member. There are also "physical priorities," such as when we immediately turn attention to the sudden, loud noise behind us.
Some problems are solved gradually, but others are solved suddenly in an "ah-ha!" moment, where the answer arises suddenly, seemingly out of nowhere in our minds. Math problems sometimes yield to sudden answers, as do the three-dimensional mall pictures. Such an "ah-ha!" experience is likely the result of sudden recognition of a previously experienced process. At that moment the problem maps into a previous experience. If a person was connected to an EEG during an "ah-ha!" moment, Alexander said it would be noted on the machine.
Abnormal processing
For his research, Alexander defines the "extreme predatory criminal" as one who plans his crimes and stalks his victims. Such predatory criminals typically have a "clean" undamaged-looking brain, but show an exceptionally active brain response to visual/emotional stimulation, while the rest of the brain's reactions seem dulled. This hyperactive visual response can be observed and measured in EEG patterns. Individuals from this group typically do not abuse drugs or alcohol. Alexander's working hypothesis is that these criminals may be addicted to intense visual stimuli and begin to seek it out. While all of us are drawn to observe a dangerous situation, for example a car wreck, Alexander hypothesized predatory criminals find such stimulation exciting and seek to create a situation for its stimulatory effect.
The "standard criminal," in contrast to the predatory criminal, often has a brain damaged from drugs, blows to the head or a variety of other causes. He may have a short attention span and slower or lower than average response to visual/emotional stimulation. The combination of a knowledge base and good control processing is the basis of impulse control. An examination of the "standard criminal" often reveals damage to the frontal lobes, a portion of the brain important for impulse control and judgement. A normal, law-abiding person who has experienced a closed-head injury to the frontal lobes can undergo subtle, but real, changes in the ability to control impulses and emotions. On the other hand, some people experience massive injury to the brain and show no behavioral change. Why this is so remains a mystery.
