Reference no: EM133519283

Discussion Post

Question I

How do we know that certain areas of the brain are specialized to do specific kinds of processing? (There are multiple sources of evidence you could point to for this one.) Are there any practical implications that result from knowing what is localized where?

Question II

Ghostly appendages: What is phantom limb syndrome? What does it tell us about neural plasticiity? (First, someone explain what plasticity is.) On a more speculative note, how does the existence of phantom limb syndrome affect your own view of the relationship between mind and body?

Question III

Speed of neural transmission. This one is actually a demonstration activity as well as a question. Please make sure that every subquestion (A, B, C, etc.) gets addressed by someone, but each person need only contribute to one of them to get credit. Here goes:

1. Get a group of people together** [if that's not possible or advisable, see below] - at least 5, but 10 or more is better; it doesn't matter who they are. Also get a stopwatch. Stand in a circle holding hands. The person with the stopwatch should squeeze the hand of the person next to them and start the clock. That person squeezes the next person's hand, and so on, until the stopwatch holder's other hand is squeezed and they stop the clock. Do this an odd number of times (at least 5 times, more is better) and record all the times. Then have everyone sit down and grab each other's right ankle with their right hand and do the same thing - record the times. Post a list of your group's times here.

2. Look at the lists of times posted and find the median time for hand-to-hand and for hand-to-foot for each group that posted. (The median is the number that has an equal amount of scores above and below it when sorted from least to greatest; it's the middle score.) Post a list with the two median times for each group and the number of people who were in the group.

**NOTE: If it is not possible or advisable to get a group of people together right now, skip parts A and B and use the following data to answer the other parts of this question. Archival data from a group of 5 people who did each task 7 times:
Hand Squeeze
.99
1.05
.82
.75
.78
.73
.85
.85 Average
.75 Median
Right ankle with right hand
1.38
1.43
1.35
1.26
.91
.96
1.32
1.23 Average
1.26 Median

3. Take the list of median times and calculate the PER PERSON times for each group - the median divided by the number of people in the group - for both conditions.

4. Compare the median per-person times for the two conditions across all the groups: hand-to-hand vs hand-to-foot. (Extra credit if you go beyond calculating averages and do a t-test or something similar.)

5. Which was faster? Why did that happen?

6. How fast do signals travel along neurons? (Someone look it up and tell us where you found it.)

7. Estimate how far the signals traveled in the two conditions of this demonstration. Were the observed times what you would expect based on how fast neurons transmit signals? If not, what do you think might have caused the discrepancy?

8. When I have used this demonstration in a classroom, I have often used two additional conditions. What do you think would happen in each of them, compared to the two conditions we tried, and why? Here are the two conditions:

A. Placing your hand on the next person's shoulder and squeezing their shoulder rather than their hand.

B. Placing *both* hands on their shoulders, and alternating left and right. So if your right shoulder gets squeezed, you squeeze the left shoulder, and vice versa.

Question IV

First read the following case study of finding evidence on the internet: Homeopathy

This question is about homeopathy specifically, not alternative medicine or natural remedies in general. Many people use "homeopathic" as a synonym for "natural." That is not what we mean here. Be sure you understand what a homeopathic remedy is.

Note that the main point of the case study is that homeopathic remedies, defined as extreme dilutions of toxins in water, can not be anything other than placebos because they would contain only water. So (barring magic or the inclusion of some other active ingredient) we can be certain, even before doing any experiments, that homeopathic remedies have no physiological effects. The question is if we did not already know that, how easy would it be to tell they don't work from doing a web search?

Do a web search on the word "homeopathy."

Part A: Is the information from the web search accurate? If the only information you had was the sites returned on the first page of the web search, would it be easy to tell that homeopathic remedies do not work (other than as placebos)? Why or why not?

Part B: How can you find accurate information? What information search strategies could help you be more likely to come to the correct conclusion, that homeopathic remedies do not work?