To understand the advantages, disadvantages, and potential of diagnostic imaging technologies in brain research.
By the time students reach the high-school level, they should be developing a deeper and broad-based understanding of the relationships linking technology and science. (Benchmarks for Science Literacy, p. 47.)
While teaching this lesson, it is important to be aware of where your students are in terms of understanding the dynamic relationship between technology and science. For example, research has shown that high-school students do not distinguish between the roles of science and technology unless explicitly asked to do so. Students tend to associate science with medical research and believe it is more beneficial to society than is technology, which they associate with pollution or weapons. Students appear to understand the impact of science on technology but they do not always appreciate the impact of technology on science. (Benchmarks for Science Literacy, p. 334.)
This lesson provides students with a brief introduction to various diagnostic imaging technologies used in brain research. They will explore how these technologies have provided answers about the structure and function of the brain and the new questions they have enabled scientists to ask. Keep in mind that the focus is on the imaging technologies themselves and not on the detailed structure and function of the brain.
Ask students the following questions:
- What do you know about the brain?
- How did scientists gather that information?
Allow an open discussion which may elicit specifics about the structure of the brain, the function of the two hemispheres and other components, the role of neurotransmitters and electrical impulses, and diseases that affect the brain. Answers to the second question may include dissection of brains, observation of behavior, and technologies such as X rays, CT scans, and other imaging techniques. Have students think about the impact of imaging technology on brain research.
Tell students that this lesson will give them the opportunity to learn about imaging technologies that are used to investigate the structure and function of the brain.
As students do the lesson, ask them to keep in mind the following questions:
- How does imaging technology help scientists answer questions about the brain and ask new ones that will further advance their knowledge?
- How might what scientists learn about the brain help them develop new technologies?
Have students access the student esheet. Students will get a brief overview of several current imaging technologies by completing Step 1 of the esheet. Be sure that students use the Brain Imaging Technology student sheet to record notes.
Assign students to small groups to investigate one of these technologies more in-depth, as described in Step 2 of the esheet. A couple of websites are provided; you can extend this assignment by providing or encouraging students to find other websites or print materials to use in their research.
Have students share their research with the class, as outlined in Step 3 of the esheet. Encourage students to record what they learn from their classmates' reports in their charts. A sample chart is provided for your information on the teacher sheet.
Have students complete the Understanding What You Learned section of the esheet. As they think about imaging technologies of the future, ask them to review the charts they have created and consider what they have learned about the strengths and weaknesses of current technologies and what scientists still need to learn about the brain. You might want to emphasize some problems with current technologies—expense, lack of detailed information, and inadequate speed.
Have students share their "Brain Machines for Tomorrow" with the class and participate in a discussion of the questions they considered at the beginning of the Development section:
- How does imaging technology help scientists answer questions about the brain and ask new ones that will further advance their knowledge? (The various technologies make it possible to view both the structure and the function of the living brain. The more scientists learn about how the brain is put together and what it does, the more detailed and useful questions they can ask. Questions that students think imaging technology should focus on might include how memories are stored and recovered, how people recognize faces, why people dream, and what changes occur in the brain as people age.)
- How might what scientists learn about the brain help them develop new technologies? (The more information about the brain scientists learn from current technologies, the more specifically they can design new machines. For example, current imaging technologies have shown that the brain processes information extremely quickly, though these machines are too slow to track most of this activity in detail. New technologies will be designed to record brain activity more quickly and accurately.)
Encourage students to keep up with the real "Brain Machines for Tomorrow" by following new developments in imaging technology on the Internet and in news magazines and newspapers.
The following online resources may be used to supplement students' understanding of imaging technology and the brain:
- How Your Brain Works offers easy-to-understand information about the basic functioning of the brain.
- The Whole Brain Atlas, sponsored by Harvard Medical School, provides basic information about brain imaging technology as well as many images of normal and diseased brains.
This lesson is part of a series of Science NetLinks lessons dealing with optical technology. The other lessons in the series include Magnify It! (K–2), Seeing Around Corners (3–5), and Looking into Space (6–8).