Activity	General Functions Involved	Brain Area(s) Involved*
breathing		brainstem (medulla)
heart rate		brainstem (medulla)
waving hands in the air	movement	cerebrum—frontal lobe (motor cortex) cerebellum
hopping up and down on the right foot	movement	cerebrum—frontal lobe (motor cortex) cerebellum
walking around the classroom	movement	cerebrum—frontal lobe (motor cortex) cerebellum
looking out the window	vision	cerebrum—occipital lobe (primary visual cortex)
reciting the Pledge of Allegiance	speech/memory	cerebrum—frontal lobe hippocampus
doing an algebra problem	thinking	cerebrum—frontal lobe
remembering directions to get from the classroom to the school cafeteria	memory	hippocampus
reading a sentence	speech	cerebrum—parietal lobe and frontal lobe
*This is very simplified. Most mental functions invove more than one area of the brain.

Content Standard A: Scientists rely on technology to enhance the gathering and manipulation of data.

Content Standard C: Multicellular animals have nervous systems that generate behavior. Content Standard G: Usually, changes in scientific knowledge occur as small modifications in extant knowledge.

ACTIVITY 4: WHO WAS PHINEAS GAGE?

1. Give each student a copy of Master 1.6, What Happened to Phineas Gage?
Instruct students to read the story and answer the questions.

Phineas Gage was injured in an accident in the 1800s. His recovery from the injury and the resulting change in personality and behavior gave scientists new insight into brain function.^{10, 11}

Figure 1.8: Computer reconstruction of the skull of Phineas Gage illustrating the projection of the tamping rod through the brain. Reprinted with permission from Damasio H, Grabowski T, Frank R, Galaburda AM, Damasio AR: The return of Phineas Gage: Clues about the brain from a famous patient. Science 264:1102–1105. Department of Neurology and Image Analysis Facility, University of Iowa. Copyrighted 1994 American Association for the Advancement of Science.

SAMPLE ANSWERS TO QUESTIONS ON MASTER 1.6

Question 1. How did Phineas Gage change after the accident?

After the accident, Gage's personality changed. He was no longer the likeable and responsible person he was prior to the accident. Instead he was irresponsible and used profanity.

Question 2. How did Phineas Gage's accident change scientists' understanding of the brain?

Scientists learned that the brain does more than control language and movement. It also controls emotions and social behaviors. Equally important, scientists learned that the brain processes information for specific functions in specific brain areas.

Content Standard C: Multicellular organisms have nervous systems that generate behavior.

Content Standard F: An individual's mood and behavior may be modified by substances.

ACTIVITY 5: WHERE DO DRUGS ACT?

1. Now that students understand that different areas in the brain process specific types of stimuli, ask students to consider things that make them feel good, or are pleasurable. How might doing something pleasurable change brain activity?

If students understand, from Activity 2 of this lesson, that brain functions are localized to specific brain areas, they should suspect that things that make them feel pleasure will stimulate a specific brain region.

2. Display the transparency of Master 1.7, The Reward System. Tell students that part of the brain produces and regulates feelings of pleasure, which scientists call reward. This brain region is called the reward system. The parts of the brain that make up the reward system are the ventral tegmental area (VTA), nucleus accumbens, and part of the frontal region of the cerebral cortex. This brain region responds to life-sustaining activities such as eating and drinking, as well as species-sustaining sexual activity.

If students understand that PET images reveal changes in brain activity and that drugs activate the reward system in the brain, students should predict that the reward system (the VTA and nucleus accumbens) should be more active after an individual takes drugs. These brain areas should appear red or yellow in PET scans taken after drug use, whereas they would be purple or blue in PET images taken before drug use.

3. Introduce students to the idea that drugs of abuse activate the brain's reward system, or pleasure circuit. Drugs alter the way in which the reward system functions. Drugs also act on other regions of the brain, but their action in the reward system makes the drug abuser feel pleasure and want to continue taking drugs.

Students will learn more about how drugs exert these effects in the remaining lessons in this curriculum supplement.

4. Ask students to hypothesize how PET images of a person's brain would change after taking drugs of abuse.

Currently, PET technology is not sensitive enough to allow scientists to visualize this reward system activation. The VTA and nucleus accumbens are too small for PET images to detect significant activity changes. Scientists have relied on other technologies to learn that drugs of abuse do activate these brain regions.

Some students may hypothesize that PET images of the brain after drug abuse would also show changes in other regions of the brain. This is correct. Drugs do affect other regions of the brain, but it is the reward system that gives the pleasurable feelings associated with drug use. More information on the more widespread effects of drugs on the brain is presented in Lesson 4.

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