echoesof.science · Ages 10–11
The brain: parts, jobs and reaction time
Name: Date:
Scan to open the experiment,
the game and the quiz
echoesof.science/school/brain/ages-10-11/
Read
An adult brain weighs about three pounds (about 1.4 kg). It sits in the skull, washed by a protective fluid.
The cerebrum is the biggest part: it is where conscious thoughts and actions come from, and it holds memories. The cerebellum coordinates movements, including learned ones like playing the piano. The brain stem helps control vital jobs such as breathing and heart rate.
The cerebrum has two halves (hemispheres) joined by the corpus callosum. Surprisingly, the right hemisphere mainly controls the left side of the body, and the left controls the right.
Experiment: Reaction time: is your writing hand quicker?
- Question: is your reaction time quicker with your writing hand than with your other hand? Write a prediction.
- The holder holds the ruler at the top (30 cm end up). The catcher puts thumb and first finger at the 0 mark, open, not touching.
- The holder says 'ready' and then drops the ruler some time in the next 5 seconds, at a different moment each time so the catcher cannot guess.
- Record the cm mark at the top of the catcher's fingers. Do 5 tries with the writing hand and 5 with the other hand. Work out the mean for each.
- Fair test: same ruler, same holder, same starting position, same seat. Change only the hand. Use the chart to turn your means into seconds: about 2.5 cm ≈ 0.07 s, 15 cm ≈ 0.18 s, 30 cm ≈ 0.25 s.
| Try | Writing hand (cm) | Other hand (cm) |
|---|---|---|
| 1 | Which hand will catch at a smaller number? | |
| 2 | Which hand will catch at a smaller number? | |
| 3 | Which hand will catch at a smaller number? | |
| 4 | Which hand will catch at a smaller number? | |
| 5 | Which hand will catch at a smaller number? | |
| Mean | Which hand will catch at a smaller number? |
Questions
Name the three main parts of the brain and give one job of each.
Explain the path of the signal when you catch the falling ruler.
Which hand had the smaller mean? Turn both means into seconds using the chart.
Why did you do 5 tries and take a mean instead of doing only one try?
Sources for every fact on this sheet: echoesof.science/school/brain/sources/