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Cells and Systems 6-8 / Week 07 / Wednesday
3/6
Week 07 · Senses and Signals

Wednesday

Windowsill Lab: React and remember
// Receptors notice, the brain decides
⏱ about 20 min

Wednesday: Windowsill Lab: React and Remember

Rocket holds a plastic ruler by its top end, a few centimeters above the table. Raven's open hand waits at the zero mark.

"No warning," Raven says. "Just drop it."

Rocket waits, waits, and lets go. Raven pinches the ruler. "Fifteen centimeters," she reads.

"My turn!" Rocket says. Nova hovers low over the table. "Predict first," she says. "Will your catch be higher or lower?"

"Lower. I am fast," Rocket says. He catches at 21. He stares at the number. "The ruler is lying."

Raven laughs. "What do you notice? The ruler tells us how long your eyes, brain and hand took."

"Then let me try again," Rocket says. Raven writes trial two.

Your mission

Today you run two investigations. First, a ruler-drop test measures how far a ruler falls before you catch it.

A shorter distance means the catch happened sooner. Eyes noticed, the brain decided, the hand closed.

Second, a memory game tests how many objects your brain can store after one short look.

Every number is a science reading for your own Log. Nobody's results are compared with anyone else's.

  • A plastic or wooden ruler marked in centimeters, 30 centimeters long
  • A table and a chair
  • A partner to drop the ruler and hold the tray
  • A tray or towel and ten small household objects, such as a spoon, a button, a crayon and a paper clip
  • A cloth to cover the tray, a timer, your Windowsill Log and a pencil
Safety first
Use a plastic or wooden ruler only, held low over the table. Never hold it near anyone's face or eyes.
Keep the drop under 30 centimeters. The ruler falls onto the table if the catch is missed.
Memory objects are looked at, not tasted or put in the mouth. Choose objects too big to swallow.
Wash your hands after handling the objects.
  1. Sit with your forearm flat on the table and your hand open just past the edge, thumb and fingers apart.
  2. Your partner holds the ruler vertically so the zero mark hangs between your thumb and fingers.
  3. Without warning, your partner lets go. Pinch the ruler as fast as you can.
  4. Read the centimeter mark just above your thumb. Record it in the table as trial 1.
  5. Repeat four more times. Record trials 2 to 5.
  6. Now your partner spreads ten objects on the tray while you look away. Then you look for 30 seconds.
  7. Your partner covers the tray. Write down every object you remember. Count how many you got right.
Ruler dropTrial 1Trial 2Trial 3Trial 4Trial 5
Centimeter mark where I caught it
Memory gameObjects on the trayObjects I rememberedObjects I forgot
Round 1 (30 seconds)10
PREDICT AND EXPLAIN
  • Read the question.
  • Tap your answer.
A catch at 12 centimeters compared with a catch at 20 centimeters means the hand closed:
Which sense organ noticed the ruler start to fall?
Before you see the ruler move, where must the signal go before the hand can act?

Reading your result

The nervous system acquires information from sensory organs, processes it, and may start a response such as movement. The ruler measured that chain.

Your five trials probably differ. A single try can vary, so scientists repeat a test and look at all the results.

If you caught sooner on later trials, your brain may have stored something from the first drops. That is memory helping a reaction.

In the memory game, the objects you remembered were stored by your brain after one look. The hippocampus processes memory formation.

Looking is the stimulus. Storing is the brain's second choice, alongside acting right away.

What the lab showsTrue or false?
A smaller centimeter mark means a quicker catch.?
The eyes alone decide when the hand should close.?
Repeating the drop five times gives better evidence than one drop.?
The memory game tests information the brain stored.?
WHY THIS EXERCISEImmediate behavior and stored memory are the two outcomes this week's standard names.
How many objects were on the memory tray? Type a number.
WHY THIS EXERCISEKnowing the total lets you turn your count into a fraction remembered.
Draw your five ruler catches as five bars on a graph. Mark which trial was your quickest.

Quick hands and good records. Tomorrow you will read a table of the senses and a map of the brain.

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