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The Bionic Body


 
Teaching Guide
Uncovering  a signal
Coordinated Control
Nuclear Transplants
Uncovering a Signal
Quiz
EEG/Face illustration

In "Mind Over Matter", you witnessed some amazing examples of the use of brain waves to control the movement of objects like a sailboat or a jet. When you think about moving a body part, your intentions generate a unique signature in your EEG (electroencephalogram) pattern. To the naked eye, however, this signature is "lost" within the gross electrical activity of your brain. In order to distinguish it from the background clutter, scientists use the computer to subtract all signals that are not related to this intentional movement. Once this specific movement signal is isolated, it can be can measured and stored within the computer circuitry. When this signal occurs again, the computer can distinguish it from the jumble of brain activity. Its detection triggers a voltage that stimulates the target muscle. The muscle receives the external impulse and reacts as if it had been stimulated directly by the brain and nerve tract.

In this activity, you'll compare and contrast representations of three different EEG recordings. Although these are not actual EEGs, they do represent wave characteristics and interactions that scientists examine in order to locate appropriate movement signals in the brain.

Note to educators

 

OBJECTIVE
This activity page will offer:

  • information on EEG impulse control
  • an opportunity to interpret and analyze waveforms
  • an arena to develop inquiry skills

MATERIALS

  • transparency sheet
  • marker
  • copy of the EEG tracing included with this activity

 

Chart 1- no movement


Chart 2 Movement of Index Finger


Chart 3- Movement of thumb and index finger

PROCEDURE

PART 1 - MOVEMENT OF INDEX FINGER

  1. Examine the three graphic representations of EEG signals.
  2. Place a sheet of clear plastic over the "no movement intention" recording. Carefully trace the pattern onto the plastic.
  3. Place this traced pattern over the Recording #2, titled "movement of the index finger." Identify and record any differences that can be used to distinguish this movement from the background EEG activity.

QUESTIONS

  1. What do these three patterns represent?
  2. Did the "movement" EEG differ from the "No movement" recording? Is so, how?
  3. What was the signal strength of each of the first signal spikes?
  4. At about what time did the last signature spike occur?
  5. Identify the strength and time of occurrence of all new spikes associated with the movement of an index finger.

PART 2 -Movement of Thumb and Index Finger

Now that you know how to isolate and identify a signal spike, determine the differences in signal characteristics between the index movement and the movement of the thumb and index finger (Recording #3).

HINT: You'll need another sheet of transparency paper.

PT. 3 - Destructive Inderstanding

When signals occur at the same time, their values can either reinforce or reduce each other. If the wave spikes are in sync and are both positive or both negative, they reinforce each other. This type of signal increase is called constructive interference. If, however, the in-sync signals have opposite values (one positive, the other negative), the spikes can cancel each other out. This type of interaction is called destructive interference. Check out the spike that occurs in the index finger movement at 0.1 seconds.

  1. What is this signal's strength? Was this spike present in the no movement EEG?
  2. Is this spike present in the movement of the thumb and index finger?
  3. What does this suggest about the signal generated to move the thumb alone?
  4. Make a guess. What is the most likely value of a thumb signal spike that occurs at 0.1 seconds?
  5. Explain.

EXTENSIONS

MIXED UP THOUGHTS

Your brain isn't foolproof. Even when it comes to simple movements, you can confuse its processing and send messages to the wrong muscles. In this activity, you'll examine how confusion can send control impulses to the wrong receivers. So hang on tightly, as we challenge your mind's control over your body's movement.

PART 1 - A Confusing Clasp

  1. Extend both of your arms in front of you.
  2. Rotate both hands so the palms face outward.
  3. Move one hand over the other. As your palms align, clasp your hands together. The fingers from the right and left hand should alternate with each other.
  4. Fold your clasped hands inwards and rotate the hands around so that they point upwards.
  5. Have a partner point to a finger. Your job is to raise only that finger as quickly as you can. Think it's easy? Just give it a try and you'll see how easy it is to confuse your perception

QUESTIONS

  1. What happened when you tried to lift the finger identified by your partner?
  2. Which fingers were least likely to be confused?
  3. Suppose you didn't invert your clasp. Would you still confuse the fingers? Why or why not?

ON YOUR OWN

How might you use the right/left reversal of a mirror to produce a confused response? Think about it. Then, create a strategy for inquiry that would use a reflected image to trick a person into moving the wrong body parts. After gaining approval from your teacher, try your strategy for inquiry and report your finding to the class.

PSYCHOKINEISIS - MIND, MATTER & PSUEDOSCIENCE

The word psychokinesis brings to mind all sorts of concepts from detecting EEG (electroencephalogram) signals to bending metal spoons. Although scientists have only recently approached valid investigations into thought control, the concept of "mind over matter" has long been a popular thread of pseudoscience. People have claimed that they can use their thoughts to warp utensils or move objects along a table surface. Some individuals have claimed the ability to read other's thoughts or transmit their own thoughts through telepathy. What do you think? Look for justification or evidence to support your thoughts.

JUMP SPOT, JUMP - A WRITING CONNECTION

Several years ago, the US military looked at the feasibility of using thought control to pilot jets. Although the program is now defunct, the researchers did observe limited success. Hooked to a machine that could detect brain waves, subjects learned to control the up and down movement of a spot using their thoughts. When they set their mind in a certain pattern, the electrical signals of the brain sent out a distinct signal that computers interpreted as either "up" or "down" jumps. When thought patterns changed, the spot went in the opposite direction. That was it - or was it? Suppose the lab unleashed an incredible power of thought control and wanted to keep this ability as top-secret in the US arsenal. Write a science fiction story that extends this story from the published facts to the limits of your imagination.

BI-METALLICS, PSEUDOSCIENCE & INQUIRY

Have you ever seen a magician bend a spoon while the spoon lies within the hand of an audience member? If so, you know it is a powerful display. Although the magician may claim that the bend is a function of mental powers, the real force lies within expansion due to heating. The spoon, like an older household thermostat, consists of two different metals sandwiched together. As the metals heat up within your hand, they expand at different rates. This causes the spoon to bend. Obtain pieces of a bimetallic strip from your instructor or a local plumbing/heating store. Examine the small strips and explore their behavior when warmed and cooled. Design an inquiry project using a controlled experiment that explores the bending properties of this strip. Share your design with your instructor. With your instructor's approval perform the inquiry and share your results with the class.

WEB CONNECTION

Robot Rats
In this BBC news article, lab rats that have had an electrode embedded into their brains can use thoughts to control a robotic arm.

Voluntary Motor Movement
This resource explores the control of voluntary motor movement from the intention to the final action

Thought-controlled Flight
Information on the now defunct Air Force project that had hoped to demonstrate the viability of thought-controlled flight

Psychokinesis and Quantum Mechanics
A controversial convergence of psychokinesis and quantum mechanics is presented within this article - an excellent arena for critical thought analysis


Answers

The activities in this guide were contributed by Michael DiSpezio, a Massachusetts-based science writer and author of "Critical Thinking Puzzles" and "Awesome Experiments in Light & Sound" (Sterling Publishing Co., NY).

Academic Advisors for this Guide:

Corrine Lowen, Science Department, Wayland Public Schools, Wayland, MA
Suzanne Panico, Science Department, Fenway High School, Boston, MA
Anne E. Jones, Science Department, Wayland Middle School, Wayland, MA

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