Station 1: Cow Brain Tissue

Directions:

Inside of this cooler is a sample of cow brain tissue. Don’t worry…it’s not as gross as you think. For this station, please sketch the appearance of the cow brain tissue. Please note any interesting features on your diagram.

Questions:

  1. Describe what the brains look like. Sketch any notable features or characteristics.
  2. Is this how you expected the brain tissue to look like?

Station 2: Depth Perception Activity #1

Directions:

Two eyes are better than one, especially when it comes to depth perception. Depth perception is the ability to judge objects that are nearer or farther than others. To demonstrate the difference of using one vs. two eyes to judge depth perception, take two pencils, one in each hand. You should hold them at the erase end horizontally facing each other at arms-length from your body. With one eye closed, try to touch the end of the pencils together. Now try with two eyes: it should be much easier. This is because each eye looks at the image from a different angle. This experiment can also be done with your fingers, but pencils make the effect a bit more dramatic.

Questions:

  1. What is depth perception?
  2. Was your depth perception better with one eye or two?
  3. How do you think depth perception relates to the nervous system?

Station 3:Depth Perception Activity #2

Directions:

Here's another demonstration of the importance of two eyes in judging depth. Collect a set of pennies (or buttons or paper clips). Sit at a table with your subject. Put a cup in front of your subject. The cup should be about two feet away from the subject. Have your subject CLOSE one eye. Hold a penny in the air about 1.5 ft. above the table. Move the penny around slowly. Ask your subject to say "Drop it!" when he or she thinks the penny will drop into the cup if you released it. When the subject says "Drop it," drop the penny and see if it makes it into the cup. Try it again when the subject uses both eyes. Try it again with the cup farther away from the subject. Try it again with the cup closer to the subject. Compare the results of "10 drops" at each distance.

Questions:

  1. Is there improvement with two eyes?
  2. Is there improvement with the cup is closer to the subject?

Station 4: Optical Illusions #1

What you see is not always what is there. Or is it? The eye can play tricks on the brain. Here are several illusions that demonstrate this point. For this activity, look at each Optical Illusion, #1-4. Answer the questions following the activity.

  1. The Magic Cube

Look at the center cube. What side is the front? Is the front as shown on the cube on the right side or is the front as shown on the cube on the left side or is there no front at all?

  1. Which of the lines shown below is longer?

Muller-Lyer Illusion

Measure them. You may be surprised to find out that they are the same length. We see the lines as different because we have been "taught" to use specific shapes and angles to tell us about size.

  1. Stare at the middle of picture with black squares 15-30 seconds. Are those really dots that appear at the corners of the squares? What happens if you focus on a dot? Now look at the middle of the picture with the white squares. Do you see dots again? What color are they?

Here is another example of the same illusion.

Are the locations of the spots different in these two pictures? Why?

  1. Do you see a vase or a face in the figure below? This type of picture was first illustrated by psychologist Edgar Rubin in 1915. Notice that it is very difficult to see both the faces and the vase at the same time. This may happen because we tend to focus our attention on only one part of the image...either the faces or the vase.

Station 5: Optical Illusions #2

  1. Here is example of creating an afterimage. Can you put the fish in the bowl? Try this. Stare at the yellow stripe in the middle of the fish in the picture below for about 15-30 sec. Then move your gaze to the fish bowl. You should see a fish of a different color in the bowl. It helps if you keep your head still and blink once or twice after you move your eyes to the bowl. The afterimage will last about five seconds.

What's Happening:in theretina of your eyes, there are three types of color receptors (cones) that are most sensitive to either red, blue or green. When you stare at a particular color for too long, these receptors get "tired" or "fatigued." When you then look a different background, the receptors that are tired do not work as well. Therefore, the information from all of the different color receptors is not in balance. Therefore, you see the color "afterimages."

Other Examples of Afterimages:
Stare at the + for about 15 seconds, then shift your gaze to the right side of the image.
/ Stare at the + for about 15 seconds, then shift your gaze to the right side of the image.

  1. Do the lines on the right side of the image look straight? Are they really straight?

The Poggendorff Illusion was created by Johann Poggendorff in 1860. Are the lines behind the rectangles straight or not? It looks as if it does not go straight across, but does it?

Poggendorff Illusion

  1. Hmmm...is the center circle on the right the same size as the center circle on the left? For many people it appears that the circle that is surrounded by the small circles is larger that the circle that is surrounded by the larger circles. However, I know that they are the same size....I copied and pasted the same exact circle into the middles!!

Titchener Illusion

This illusion shows that our brains judge size by comparing objects to things in the surroundings.

Station 6: Optical Illusions #3

9. The Wundt Illusion. Which arc is larger? You might see that the top one is smaller, but they are the same size. The top one looks smaller because the shorter arc of the top figure is next to the large arc of the bottom figure.
/ 10. Is this book opening toward you or away from you?

11. To tee or not to tee...that is the question. This inverted "T" has two lines....are they the same length? You bet they are...I copied one line and pasted it on the bottom of the first line. Measure them yourself.
/ 12. Which arc comes from the circle with the largest diameter?

It probably looks like arc C is part of the largest circle. However, all the arcs are actually from the SAME circle. Look at the same figure again - however, this time I have blocked the right and left sides of the larger two arcs. Each arc comes from a circle of identical size.

What does each team member see? Record on your sheet!!!

Movement Illusion: these two dimensional objects produce the illusion of movement. Look at the center of these images to see the circles rotate.

Questions:

  1. How do Optical Illusions relate to the nervous system?
  2. Did your partner see things differently or the same as you?

Station 7 or 8: Work on your science fair project topic.

Start looking for ideas for a science fair project using the online resources. Write down the topic you are choosing in your notebook. This topic will be due tomorrow in class and will be graded.

Station 9: Brain Diagram

Directions:

This is a model of the actual size of a human brain. Please sketch the brain on your sheet, noting any interesting or unusual features. Also included is an article about the human brain. Please read the article and answer the following questions:

  1. What is the job of the brain?
  2. How does it communicate with your body?
  3. What does the brain look like?

Your Brain…

From

Your brain and spinal cord make up your central nervous system. Together, they control your body -- but it's the brain which is Commander-in-chief.
What is a brain?
Okay, so your brain is wrinkled, soft and a little wet. It doesn't look like much. But it's made of more than 10 billion nerve cells and over 50 billion other cells and weighs less than 3 pounds! And it's the most extraordinary thing that you could possibly imagine! It monitors and regulates unconscious bodily processes like breathing and heart rate, and coordinates most voluntary movement. It's the site of consciousness, thought and creativity!
How does my brain communicate with my body?
Different parts of your brain do different things. Some areas receive messages from sense organs, others control balance and muscle coordination, still others handle speech, or emotion, memories, or basic motor skills, or complex calculations. You may think your heart is where you feel emotion, but it's really your brain. You may think your legs take you down the street, but it's your brain instructing the muscles in your legs to move. Your eyes may take in light and an image may be projected onto the pupil, but it's your brain that interprets what you see...you get the picture.
Are human brains different than other animal's brains?
Be glad you're a human. Because human brains are more complex than the brains of any animal on Earth! Why? It's not that they're the biggest. But human brains are larger and heavier in comparison to the human body, than any other animal. Underneath your scalp, sits a brain that, as it has grown, has continued to fold in on itself and develop deeper and deeper folds and crags. Spread out it would be the size of a pillowcase. Folded in on itself it becomes the place to think, dream, and create beautiful poetry!
Factoids:

  • A newborn baby's brain grows almost 3 times in course of first year!
  • Humans have the most complex brain of any critter on earth!
  • Your brain is divided into two sides. The left side of your brain controls the right side of your body; and, surprise, the right side of your brain controls the left side of your body.

Station 10: The Spinal Cord

Read the following article and answer the questions at the end.

Vertebrae
/ The spinal cord is the main pathway for information connecting the brain and peripheral nervous system.
The human spinal cord is protected by the bony spinal column shown to the left. The spinal column is made up of bones calledvertebrae. Although the spinal column is somewhat flexible, some of the vertebrae in the lower parts of the spinal column become fused.
Hear it...Vertebrae
Example of a vertebra

The spinal cord is located in the vertebral foramen and is made up of 31 segments: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal. A pair ofspinal nervesexits from each segment of the spinal cord.
Magnetic Resonance Image (MRI) of the Spinal Cord
/
The spinal cord is about 45 cm long in men and 43 cm long in women. The length of the spinal cord is much shorter than the length of the bony spinal column. In fact, the spinal cord extends down to only the last of the thoracic vertebrae. Therefore, nerves that branch from the spinal cord from the lumbar and sacral levels must run in the vertebral canal for a distance before they exit the vertebral column. This collection of nerves in the vertebral canal is called thecaudaequina(which means "horse tail").
/ Receptors in the skin send information to the spinal cord through the spinal nerves. The cell bodies for these nerve fibers are located in the dorsal root ganglion. The nerve fibers enter the spinal cord through the dorsal root. Some fibers make synapses with other neurons in the dorsal horn, while others continue up to the brain. Many cell bodies in the ventral horn of the spinal cord send axons through the ventral root to muscles to control movement.
In the figures below, note the differences in the shape and size of the spinal cord at different levels. The dark gray color in each segment represents "gray matter." If you use your imagination, you can see that the gray matter looks similar to anHor a butterfly. Nerve cell bodies are located in the gray matter. Surrounding the gray matter is white matter (lighter color shading) - this is where the axons of the spinal cord are located. /
Spinal Cord Segments - Outlines

Spinal Cord Segments - Photographs(not to scale)
/ Compare the relative amount of gray and white matter at each level of the spinal cord. In the cervical segment, there is a relatively large amount of white matter. This pattern is caused by the many axons going up to the brain from all levels of the spinal cord AND there are many axons traveling from the brain down to different segments of the spinal cord. In lower segments of the spinal cord, there is less white matter because there are fewer axons traveling to and from the brain.
There are also differences in the gray matter. In the cervical segment, the ventral horn (the lower half of the segment) is enlarged. Also in the lumbar segment that is illustrated, the ventral horn is large. These segments are those that contain motor neurons that control movement of the arms (cervical segment) and legs (lumbar segment).

QUESTIONS:

  1. What is the job of the spinal cord?
  2. What role does in play in the nervous system?
  3. What organ does it communicate with?