Some Like It Hot | Biology
Topic: Senses, Adaptation, Information Processing
Viewer Challenge/At-Home Version:
Fool Your Senses?
Use water to test your sensory perception of temperature.
Materials
- Three bowls or containers large enough to put two hands in
- Warm water (NOTE - be careful not to make the water too hot!)
- Cold water, with a few ice cubes in it
- Room temperature water
- Towel to protect your work surface (optional)
- A clock to time yourself (optional)
Directions
- Prepare a work surface that can get a little wet by either laying down a towel, or removing any objects that should not get wet.
- Fill one bowl with warm water, one with iced water and one with room-temperature water.
- Put one hand into the warm water and one in the iced water for one minute.
- Take your hands out of the water and put them both into the room-temperature water. How does the water feel? Does it feel hot, warm, room-temperature, cold or very cold? If it is hard to say, pay attention to what you would say if you felt only with your right hand and what would you say if you felt only with your left hand? Do your hands agree or disagree about the temperature of the water?
How does it work?
Sensory adaptation is the brain's way of protecting itself from overload.
When you submerge your hands in hot and cold water, the brain is getting the same message repeatedly. Thermoreceptors in one hand are sending the message, 'Cold, cold, cold,' while thermoreceptors in the other hand are sending the message, ‘Hot, hot, hot.’ And the brain is saying, 'I know, I know. Now leave me alone until you have something different to tell me.’
Your body adapted to heat on one side and cold on the other. The room temperature water is cooler than the hot water, and warmer than the cold water. So when you switch to the room temperature water, the receptors that got used to the hot water, send signals that sense it as cold; and the receptors that got used to the cold water sense the room temperature water as hot, even though they are both feeling water that is the same temperature.
Adaptation can also occur when we repeatedly smell something, like popcorn or when we look at something for a prolonged period. In all cases, the brain has adapted to the constant message it is receiving, and turns down its sensitivity to the particular smell or sight.
New York State P-12 Science Learning Standards
The content in these videos and accompanying activities touch upon various concepts from the New York State Science Learning Standards - Grades 3-5 and Middle School (Grades 6-8).
Grade 4
- Structure, Function, and Information Processing
Middle School (Grades 6-8)
- Structure, Function, and Information Processing