1. Define the term “sense of self” by explaining that it means to know who you are, or your identity. Ask students to describe things that are part of their identity

Assessment:
This activity asks students to integrate information and concepts they have learned in Lessons 1 to 4.

If students need help getting started, remind them of Lessons 1 and 2, when they discovered the unique responses they each had to different tasks and situations. Students likely will list being a member of their family, having particular friends, their special talents, and things they do and do not like to do. Affirm all of these by agreeing that their past experiences (memories), their unique talents, and their likes and dislikes all contribute to who they are, the unique way they each think about and respond to the world.

2. Display a transparency of Master 5.1, The Brain: Our Sense of Self. Ask students to think about the statement and decide whether they agree or disagree with it.
3. Ask students who agree with the statement to raise their hands. Ask several of these students to explain their reasoning. Then ask several who disagree with the statement to give their reasons.

Encourage students to think more deeply by asking questions such as, “Do other parts of the body help you know who you are?” and “How about other parts of the nervous system?” Some students may say that “who they are” is determined by their entire body. Others may state that the entire nervous system determines how they know who they are. Accept all responses at this time.

4. Ask, “How could you collect evidence to support your opinion?”

Assessment:
This question provides an opportunity for an informal assessment of student preconceptions and is a lead-in to, “Let’s investigate.”

Students may have no suggestions, or they may suggest that they could do something to change a particular region of a person’s brain or other part of the nervous system and see how that affects a person’s behavior. Move quickly to Step 5.

5. Explain that while it would be unethical to damage a healthy brain deliberately, scientists can study the effects of injuries to the nervous system on a person.
6. Introduce students to the case studies by explaining that they are written from the perspective of a physician who has patients with nervous system damage.
7. Display a transparency of Master 5.2, Case Study—John M. Ask students to follow along as you read aloud.
8. Lead a class discussion about the case history by asking students to respond to the following questions:

• Do you think John still has the knee-jerk reflex?
  He probably does. Students should use their understanding from Lesson 3 to explain that because John can no longer choose to move his legs, the voluntary neural pathways between his lower body and his brain no longer function. However, the knee-jerk reflex is an involuntary neural pathway that does not require the brain.
• Does the knee-jerk reflex contribute to your sense of self?
  Students may have different opinions. Ask students if they felt that demonstrating (or being unable to demonstrate) the knee-jerk reflex on themselves changed their identity or the way they think about themselves.
• Remember the memory game you played in Lesson 1. Do you think John would perform about the same on this game now as he did before the accident? How about the word game?
  According to the case history, John’s aptitude for physics was unchanged after the accident. This evidence suggests that John’s cognitive abilities (“thinking abilities”) were unchanged by the injury.
• Do abilities in areas such as memory and language contribute to your sense of self?
  Again, students may have different opinions. Most will probably agree that thinking of themselves as good or not good at games and puzzles is part of what makes them “who they are.”

Tip from the field test: Leading students through this discussion of John’s case history provides students with a model for the analyses of case histories expected of them in the final assignment of this unit.

9. Continue the discussion by asking the following questions:

• Do you think John still understands football plays?
  The evidence from the case history suggests that John’s cognitive abilities have not changed; therefore, he likely does still understand football plays.
• Do you think he is still interested in sports in general?
  The evidence from the case history regarding John’s participation in wheelchair races suggests that John is still interested in and still enjoys sports.
• Does not being able to play football make John a different person?
  Students’ opinions will vary.

10. Focus the class discussion even more on sense of self by asking students questions such as, “Did John lose his ‘sense of self’?” “Does he have a different identity?” “Does he still think the same way?” Have students support their opinions with evidence from the case history and their understandings about how the brain and nervous system function from the previous lessons.

Students likely will have different opinions. Lead them to the idea that, fundamentally, John is the same person he was before the accident; that is, his sense of self has not changed.

Some students may argue that John is now a different person and support that opinion by pointing out that he would likely now make different decisions in situations such as the bike-riding or, for John, wheelchair-riding, scenario in Lesson 2 than he would have before the accident. If the accident had not occurred, he might have gone on to be a professional football player and made lots more money than he will as a physicist. They may feel that this changes John’s identity.

Point out that although John cannot do all the things he did before, the core person has not changed. Although some of John’s neural pathways are “broken,” those that make him who he is have not changed. He can still draw on the same past experiences and unique abilities in his approach to life. Evidence from the case history supports this: he remained an outgoing, upbeat person; his talent for physics was the same. Although he can no longer play football, he remains interested in sports, as evidenced by his participation in wheelchair races. John is still the same person.

11. Give a copy of Master 5.3, Three Case Studies, to each student.
12. Tell students that they will evaluate three more case studies as a homework assignment. They should

Content Standard C:
Disease is a breakdown in structures or functions of an organism.

Content Standard F:
The potential for accidents and the existence of hazards imposes the need for injury prevention. Students should understand the risks associated with natural, chemical, biological, social, and personal hazards.

• read each case study;
• write one paragraph for each case study in which they state whether the patient has lost his/her identity, or sense of self, and support their opinion with evidence from the case study and the concepts they learned in Lessons 1 to 4; and
• write a final paragraph in which they indicate whether they agree or disagree with the statement on Master 5.1, The Brain: Our Sense of Self, and why they agree or disagree.

Students should conclude that Frank’s injury caused him to change his identity, or sense of self. The case study included evidence that he no longer thought about or responded to the world in the same way. He no longer finds things funny that once were funny to him. His personality also changed: he once was calm and easygoing and now is angry and unhappy. Frank seems to have become a different person.

Although she is no longer able to do all of things she could before the accident, Lisa has not lost her identity. She continues to work effectively at the same kind of job she had before the accident and to enjoy teaching children. While the accident apparently damaged the region of her brain that receives visual information, it did not change the fundamental, core person.

Mandy’s sense of self has changed drastically as her Alzheimer’s disease has progressed. Her memories are gone, and her personality has changed dramatically. Students should recall from Lessons 1 and 2 that people have different responses to situations partly because of their past experiences. Because Mandy cannot remember many of her past experiences, she responds to situations differently from how she did before she was stricken by Alzheimer’s.

Students may agree or disagree with the statement “The brain contains your sense of self; it makes you who you are.” Those who agree may use the examples of Frank’s and Mandy’s brain injuries to support their opinion—because of damage to their brains, Frank and Mandy are now different people from who they were before. Students who disagree with the statement may indicate that while Frank’s and Mandy’s cases seem to support the statement, Lisa’s case invalidates it. Although her brain was injured, Lisa is fundamentally the same person she was before. The most insightful students will state, correctly, that the three case studies support the idea that some, but not all, regions of the brain contain our sense of self.