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A Little Bit More

Northern Raccoons are found across almost all of the U.S. (not Alaska or Hawaii) and much of Canada in a wide range of habitats, although they prefer hardwood forests near waterways. Human land-use practices have actually helped Raccoons flourish, and even some urban areas have populations of this adaptable mammal.

Only two other mammals can approach the human hands’ sense of touch. Both monkeys and the Northern Raccoon have an acute sense of feeling in their hands, although they lack the very fine discrimination found in humans. It’s interesting to note that humans, monkeys, and Raccoons also have disproportionately large areas of their brains devoted to the hands – further evidence of the hands’ importance.

Raccoons may seem like cuddly little animals and one might be tempted to approach a young one but it’s not at all recommended – they’re very much wild animals. Raccoons can and do get rabies so any “approachable” Raccoon should be a warning sign to steer clear. One certainly shouldn’t become afraid of these interesting mammals but a healthy respect for their wildness is important.

Activities

Science – Feel It?

We all know that we’re able to use our senses to interpret our environment. One of our most important senses is our sense of touch that may be pleasurable, indifferent, or painful. This activity will make it clear to students that their ability to “feel” - their sense of touch - is not equally distributed over all areas of their body – it varies from one place to another.

You’ll need at least three subjects for this activity. One to be experimented on (testee), one to do the experiment (tester), and one to record results (recorder). The testee should be someone who is comfortable being the “center of attention” for this to work. I doubt that your more self-conscious students will be comfortable doing this.

1. We need to have the testee expose a fair amount of their skin for testing their ability to feel sensations on different parts of their body. So, have your subject take off shoes and socks, roll up pant legs to knee, and roll up sleeves to elbow.
2. Have the testee sit in a chair and close their eyes throughout the activity. Ask the subject to relax and assure them that there will NOT be any painful sensations in this activity, we simply want to know when they feel their skin being touched by one or two objects – nothing more.
3. Tell the testee that they will be LIGHTLY touched with either one or two objects (don’t tell them what you’re using) and that you’d like to be told how many they feel – simple as that. You’re not going to tell them where they will be touched nor in what order the touching will occur.
4. A recorder will note on paper where the testee is touched, and whether the testee feels one or two touches. (ie. Neck– one touch, palm– one touch, fingertip -2 touches etc)
5. Each time the testee is touched, they should notify the recorder that they “felt one or two touches”.
6. The “mystery” tool will consist of two pencils (not too sharp), lashed together with a rubber band and is not to be seen by the testee beforehand.
7. The tester wielding the “tool” should LIGHTLY touch selected locations each time with the two points. Vary the areas touched (arm, neck, knee, lip, bottom of foot, ear, toe etc) so the subject can’t predict where the next touch will occur. Be sure all students watch the process.
8. Varying the areas touched, is the object of this activity so be sure you try different parts of their body. You can try the back of their neck, the back of their hand, palm of hand, knee, fingertip, heel, tip of toe, lips, shoulder, or wherever, but do it in a random way and always with the two pencil points.
9. Within a short number of trials, it should become apparent to all observers that although all areas are touched by two points, it often feels like just one. Some areas that are touched by two points, will actually be felt as two points. Be sure your recorder has noted areas that were “two points” were felt and the areas where only “one point” was felt.

Questions you might want to ask

(Remind the testee that they were always touched with two points.)

1. Although you were always touched by the two pencil points, why did you feel two points at some places on your body and only one on others? At the more sensitive areas of the testee’s body, their sense of touch was much more discerning than on other places and could discern when two points were touching.
2. Why would some areas on your body be more sensitive than others? Although we do have an ability to feel all over our body, the organs that register touch – our touch receptors - are not as concentrated in some areas as in others. In areas where these touch receptors are especially concentrated, as on our lips or fingertips, we’re able to feel multiple points even when they’re close together. In areas where the touch receptors are not at all concentrated, we can’t feel both points, just one. Those areas with the greatest number of touch receptors are also areas that most important for us to interpret our environment.
3. Does it make sense that some areas may be super-sensitive and others not? Yes, certain parts of our body are more vulnerable to damage or are more important in sensing our environment so these have a greater concentration of touch receptors.
4. Were you surprised by this range of sense of touch? It’s likely that most students will not have given much thought to this but if they did, they’ll probably be surprised that the testee didn’t feel equally well on all parts of their body.

Key Concepts

Adaptations and Diversity, Behavior and Regulation, Structures and Functions

Questions

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