Heat, Human Proprioception, and Visual Perception Lab

Introduction

Human proprioception is the ability to sense body position relative to what is around you. Proprioception allows us to rely on our muscles to send signals to our brain about where they are in space and what they are capable of in that position.

There are five main taste receptor types: sweet, salty, sour, bitter, and umami. Each receptor is more abundant on different areas of your tongue and detect different things. Four of them are quite obvious; sweet detects sweet, sour detects sour, and so on. The umami receptor detects proteins.

There are many different types of perception. We perceive smell, taste, space, direction just to name a few. The way we perceive things is based on signals that travel through the nervous system. These signals can result in physical reaction or the release of chemicals.

Metabolic rate is the amount of energy that an organism expends within a certain amount of time. Metabolic rate increases exponentially with body temperature and smaller animals have higher metabolic rates. This is because the smaller the heart of the animal, the more blood circulation is needed.

Pre-Lab Questions

1. Where are each of the receptor types located/more abundant on your tongue?

2. Do you get any sensory information from your muscles? Explain.

3. How well will the mice be able to handle changes in their metabolic rate? Explain.

4. What does the left side of the brain specialize in? What does the right side of the brain specialize in?

Equipment and Materials

• mberry Miracle Fruit Tablets
• Beef Jerky
• Lemons
• Limes
• Milk Chocolate Bars
• Dark Chocolate Bars
• Salt & Vinegar Chips
• Pin the Tail on the Donkey Game
• Tape Measure
• Massagers
• Blindfolds
• 12-15 Adult Mice
• Metabolic Chambers (Mice Submarines)
• 12-15 Adult Goldfish
• Beakers
• Thermometers
• Computer
• Projector/Monitor

Activity 1: Effect of “mberry” on Taste Receptors

Goal: Figure out which receptor(s) the mberry is affecting.

• Retrieve an mberry tablet and cut it in half. Put one of the halves on your tongue and roll/move it over all areas of your tongue, like a mint, until it is fully dissolved. You may take the other half of the tablet home. After the tablet is fully dissolved, obtain one piece of each of the following foods: beef jerky, lemon/lime, milk chocolate, dark chocolate, and salt & vinegar chip. Eat each food and be sure to make note of any unusual tastes and significant observations. Record your observations in the table below.

Activity 2: Pin the Tail on the Donkey

Hypothesis: Group 2 will be less accurate than Group 1 because their muscle proprioception had been altered; tricep muscles would signal that the muscles are longer than they actually are.

The class will be spilt into two groups.

• Group 1 Instructions: Each member will be able to look at the game set up before being blindfolded. After the participant is blindfolded, they will try to pin the tail on the donkey. Each student gets one attempt. Using a tape measure, the distance between the pinned tail and the target will be measured and recorded.
• Group 2 Instructions: Each member will be able to look at the game set up before being blindfolded. After the participant is blindfolded, they will try to pin the tail on the donkey while another student is using a massager to massage the triceps muscle on the back of their arm. Each student gets one attempt. Using a tape measure, the distance between the pinned tail and the target will be measured and recorded.

You can copy the recorded data in the tables below.

Activity 3: Metabolic Rate Relationships – Mice and Goldfish

Hypotheses:

• The goldfish will demonstrate an exponential relationship between heat and metabolic rate.
• The metabolic rate of the mice will result in a “V” shape relationship between heat and metabolic rate due to their small TNZ.

Part I: Mice in Submerged Metabolic Chamber

• Mice will be placed into metabolic chambers (available from Carolina) that will act as airtight submarines. The chambers will be submerged into water that is below, above, and at room temperature and the metabolic rate of the mice will be measured and recorded by measuring the amount of oxygen consumed in mL per minute.
• The instructor will help to set up the metabolic chambers and place the mice inside.
• Using the thermometer that is in the chamber, measure and record the temperature every 30 seconds in the corresponding table.

Part II: Goldfish Metabolic Rate

• The metabolic rate of the goldfish will be measured by monitoring their gills and counting the number of breaths they take per minute. Dissolved oxygen may be monitored as well.
• First, use a thermometer to measure the temperature of the water in the bag containing the fish, record this temperature as the room temperature. Set a timer for 30 seconds and count the number of times you see the gill flaps move, this is their breath. Multiply your number by two and record it in the corresponding table.
• Repeat this process in beakers containing cold and warm water. Measure and record the temperatures in the tables below.
• When transferring the goldfish into the beakers, do not drop/dump out the fish. Use a fish net to gently scoop up the fish and carefully transfer the fish into the beaker.

Activity 4: Color Distinction

Hypothesis: Participants will be slower naming/saying the actual colors than they are reading the names of the colors.

• Participants will watch a video that will display the name of a color written in different colors. Say the color not the word. Try to say them as fast as you can.
• After there have been at least three participants, we will discuss what is happening.

Activity 5: Ballerina Video Perception

Goal: Figure out why this video is about perception and that the ballerina is not actually changing direction.

NOTE: For this activity, do not communicate or work with your peers.

• Everyone will watch a video of a ballerina spinning via the projector/monitor.
• Use the stopwatch function on your phone to time yourself.
• Once the video starts, start your timer.
• As you are watching the video, you will see the ballerina change the direction in which she is spinning. When you see her change direction, stop your timer and record your time below.

Time When the Ballerina Changed Direction:

• After everyone has recorded their time, we will share and discuss the times recorded.

Post-Lab Questions

1. Based off of your taste observations and notes, which taste receptor(s) was affected by the mberry? Explain.

2. Which group from Activity 2 was more accurate or closer to the target on average?

3. What was happening to the signals that were being sent from group 2’s triceps muscles?

4. Using your collected data, draw a graph showing the metabolic rates for both the mice and the goldfish. Give a brief explanation and summary of your graphs.

5. Why did people have a hard time saying the color rather than the word?

6. How do you know that the ballerina isn’t actually changing direction?