To understand how the nervous system allows us to learn, remember, and cope with changes in the environment.
In grades 3-5, students start viewing the body as one whole system, as one whole organism. In the 6th grade and beyond, students should start to understand how organs and organ systems work together. For instance, the brain is part of the nervous system and works in conjunction with neurons (cells). The nervous system works with all other body systems, such as the musculoskeletal system.
Regarding systems in general, "Some research has found that student misconceptions about certain subjects can arise from their difficulty in recognizing natural phenomena as groups or systems of interacting objects." (Benchmarks for Science Literacy, p. 355.)
Additionally, according to studies, even after traditional instruction on the nervous system, students in the fifth grade may not understand that the brain controls involuntary behavior. If your students are in sixth grade, and do not have this understanding, you may want to emphasize this part of the lesson by doing the activity on reflexes (see Development section, Part II of the lesson) first.
In this lesson students will build on their knowledge of the brain and nervous system in order to write about how their nervous systems help them cope with a change in the environment. As students navigate the websites featured in this lesson, they will learn about different parts of the brain and nervous system. Students will encounter many terms in the context of the lesson, including: cortex, cerebellum, limbic system, brain stem, spinal cord, types of memory, neurons, and so on. It is not as important for students to learn these terms as it is for them to understand the nervous system as a whole system with different parts that work together to help humans survive and function.
Post a large picture of the human brain with the word "brain" written underneath it. Divide the class into two groups. Have one group form a line leading to one side of the picture. The other group should form a line leading to the opposite side of the picture.
Begin with the person who is furthest from the brain picture (in either line), and have that person dramatize the stubbing of his or her toe. The person standing next in line whispers "toe stubbed" to the next person. Each person in the line repeats "toe stubbed" to the next person in line until the message reaches the "brain."
Then the person in the opposite line, closest to the brain picture, whispers "pain" to the person standing next in line. The pain signal continues down the second line until it reaches the last person, who says "ouch!"
After this demonstration, discuss the following questions:
- From where to where does the message "toe stubbed" travel?
- From where to where does the message "ouch" travel?
- What is each person doing?
- What do you think each person represents?
- How would you describe the role of the brain in this process?
Then, set up the lesson by asking students to answer these questions in their science journals:
- What is the brain for? (Many students will probably say thinking. Encourage students to think about the role of the brain in the "toe stub" demonstration. Can they think of other examples that are like this? For example, getting burned or shivering.)
- How does the brain relate to other parts of the body?
- How do messages travel from the brain to other parts of the body, or from the body to the brain?
- How does the outside of the body take in information to send to the brain?
You can use the answers to these questions to assess student understanding of prerequisite benchmark ideas. For example, by the time students enter middle school they should know that the brain gets signals from all parts of the body telling what is going on there. The should also know that the brain sends signals to parts of the body to influence what they do.
Part I: The Brain/Body Connection
In this part of the lesson, students will read two articles from the Seeing, Hearing, and Smelling the World website, produced by the Howard Hughes Medical Institute. Much of the content of this website, though engaging and thought provoking, is above the benchmark threshold for the 6-8-grade level. The following articles, however, are introductory in nature, and should be easily understood by middle school students, particularly if they are instructed to focus on the idea that interactions among the senses, nerves, and brain make possible the learning that enables human beings to cope with changes in their environment.
Have small teams of students read the articles below together. Tell students to discuss with their team members any questions they might have after reading the articles and to write these questions down to share with the entire class.
Illusions Reveal the Brain's Assumptions
This article uses animations of optical illusions to illustrate how the brain resolves ambiguities and makes sense of the world.
Sensing Change in the Environment
This article describes how our senses help us detect change in the environment and explains that what we perceive through our senses is quite different from the physical characteristics of the stimuli around us.
After students have read the articles, discuss the questions that the student teams have generated. To check for understanding, ask each student to write a brief paragraph explaining how interactions among the senses, nerves, and brain make possible the learning that enables human beings to cope with changes in their environment. This can be done as a homework assignment.
Part II: Coping with Changes
In this activity, students use what they have learned about the nervous system to write about how the nervous system helps humans cope with changes in their environment. For example, the brain directs basic life support functions, such as your breathing and your heartbeat. It also manages movements ranging from simple reflexes, which are basic movements that you make without thinking or planning.
Optional: You may wish to introduce the assignment by having student pairs do a brief activity called Knee Jerk Reflex to help them understand how the nervous system helps human beings cope with sudden changes in their environment. Though the reflex activity is fun, and important, it emphasizes how the nervous system can react to a sudden danger in the environment. The lesson is clear: Interactions among the senses, nerves, and brain make the body react to a danger in their environment. Once they learn that the stove is hot when it is on, they know not to touch it. Other protective or reactive behavior is less obvious and can even have to do with emotions.
Challenge students to write about how their nervous systems help them cope with a larger change in the environment. First, ask students to decide on a fictional change to take place in the school. Here are some ideas:
- students no longer have chairs to sit on
- paper and pencils are no longer available
- the cafeteria no longer serves lunch
- an energy crisis forces the schools to lower the temperature in classrooms during the winter to conserve fuel
Then have students prepare an essay according to the following criteria:
- State the change in the environment and how it affects the students.
- If the change affects the students in such a way that it poses discomfort, how can the problem be solved?
- Once the problem is solved, describe the solution.
- Finally, relate all of this to the nervous system. How was the problem recognized? How were the feelings of discomfort (if there were any) acknowledged and how did the nervous system help solve the problem? What role did the nervous system as a whole play? What role did the individual parts play?
There are a number of opportunities to assess student learning in this lesson. For example, the series of questions in the Motivation section can be used not only to assess student understanding of prerequisite benchmark ideas, but also as a post assessment. Students can revisit their answers and revise or refine them based on the knowledge they have added to their understanding of the brain and the nervous system. You can use the final writing piece in the Development section to assess students' understanding of the benchmark ideas as well.
In addition, the following activity can be used to assess student understanding in a novel context, or as an extension of the ideas in this lesson:
Have students work in small groups to plan a way to model the nervous system. They can use whatever supplies they wish; you may want to assign them to bring in supplies from home. Have them build the models and then display them around the classroom.
Encourage students to label and describe everything they can. They may refer back to websites they have visited. If supplies are a problem, you may want to consider assigning a poster presentation.
To expand student understanding of the nervous system, instruct students to explore the following on the Neuroscience for Kids website: Explore the Brain and Spinal Cord. Remind students to take notes in their science journals and to draw and label any parts of the nervous system that they will be using in their models.
Extend the lesson by having pairs of students take an Sheep Brain Dissection at the Exploratorium website. The Internet tour is fun to look at and even a bit gory. Students will probably focus more on the pictures than the text, which is fine. The intent is to elicit interest and to understand that the brain has many different functions. The tour focuses mainly on memory.
Once students are done with their tour of a brain, have the pairs of students brainstorm for five minutes. Tell them to write down everything that memory helps them with. After the five minutes of brainstorming, have students write their lists on the board.
Ask students these questions:
- Could you live without memory? (Would you forget to eat, where you live, when to go to school, where the supermarket is?)
- Can you learn without memory? (What if you couldn't remember your times tables? Could you get through algebra? Could you write if you couldn't remember vocabulary words?)
- Could a person make friends without memory? Could families exist without memory? (How could you recognize people if you couldn't remember what they looked like?)
Give each pair of students a golf or tennis ball. Be sure they also have a pencil. Direct students to the Brain Geography Page on the PBS website. Tell them to read the first page and then to click on "Brain Geographer," where they will be directed to make the shape of the brain and spinal cord using their arms, hands and a ball.
One person should navigate the Web and read the page aloud while the other person uses his or her hands, arms, and the ball to shape the brain and spinal cord. Allow both students to have the opportunity to make the shape shown in the picture.
Have the pairs click on the "brain injury challenge" and take the quiz. This multiple choice game emphasizes what the students have just learned. Tell students to keep their own score and use their notes to answer the questions.
Synaptic Tag is a lesson plan that includes a game of tag to teach kids about neurotransmitters, chemicals that travel from one neuron to another, over spaces, or synapses between the cells. This will add more detail to their knowledge of neurons.