Archive for May, 2010

What Does Statistics Have to Do with a Healthy Memory?

May 31, 2010

Some readers might wonder why does the HealthyMemory Blog have postings on statistics and on the display and interpretation of statistics. This is good question. There are at least three reasons why there are statistics postings on this blog.

One reason is that virtually all research into human memory use statistics. I try to spare readers the statistical details unless they are necessary to understand the results of the study. But statistics underlie these studies.

Another reason is statistical ignorance can undo the benefits of large amounts of information that are stored in memory. In these postings you will find examples of physicians giving wrong advice to their patients not a result of lacking or faulty knowledge about medicine, but rather as the result of the improper interpretation and application of statistics. You will also see examples of lawyers making illogical arguments due to an ignorance of statistics. Worse yet, judges and juries fall prey to these errors. We are constantly confronted with decisions we need to make about when to see a doctor, which medicines to take, which foods to eat, and what lifestyle changes should we consider. Typically these decisions require a correct understanding of the statistics that are presented. There is a practical need for all humans to have a fundamental understanding of statistics and an understanding of the errors in statistical reasoning that we humans typically make.

A third reason for postings on statistics is that reading and understanding them builds healthy memories. They provide new information that establish new memory circuits and require your mind to pay attention to and consider issues that have previously been ignored.

So reading and working to understand these statistical postings should help you make best use of the information you have already stored in memory. They should also facilitate your understanding of certain kinds of new information. They should help you make better decisions regarding your life. They should help you make better decisions as a citizen. And they provide exercise to build a healthy memory.

© Douglas Griffith and healthymemory.wordpress.com, 2010. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content.

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Four Ways to Present Risk Reduction

May 27, 2010

This blog posting is taken largely from the chapter, “Breast Cancer Screening,” which comes from the book, Calculated Risks: How to Know When Numbers Deceive You by Gerd Gigerenzer. I highly recommend this book. It provides important insights into risks and how they can be misinterpreted. This blog posting takes no position on screening. Its objective is to provide an accurate understanding of risks. The four ways of presenting risk reduction are not specific to breast cancer and are applicable to risk reduction in general.

Relative Risk Reduction. This is the most common means of presenting risk reduction, but the question is relative to what. The question is relative to what. Most people do not ask this question and misinterpret the statistic. Many believe that of 100 people participating in the screening that the lives of 25 will be saved. Here is the correct interpretation. Consider two groups of people, 1,000 who participated in screening and 1,000 who did not. Say within ten years (and this time period needs to be specified) 4 people in the first group and 3 in the second group died. This decrease from 4 to 3 is a relative risk reduction of 25%.

Absolute Risk Reduction. Consider the same numbers as in the preceding paragraph. The absolute risk reduction if 4 minus 3, that is 1 out of 1.000, or 01.%. In other words, if 1,000 participate in screening for 10 years, one life will be saved.

Number Needed to Treat. Again, we are considering the same data, but reporting it in a different manner. This statistic is the number needed to treat, or screen in this case, in order to save a life. The smaller the number needed, the more effective the treatment or screening. In this case the number is 1,000 because 1,000 women need to be screened to save a life.

Increase in Life Expectancy. This is the true bottom line statistic. This is the benefit expressed as an increase in life expectancy. For example, women who participate in screening from the age of 50 to 69 increase their life expectancy by an average of 12 days. Rarely, does one find benefits expressed in this manner. When news arrive that treatment x is beneficial or that lifestyle change b is beneficial, the conclusion is based on tests of statistical significance. The actual benefits can be small (in addition to future studies either failing to replicate or contradicting the study). The risk reduction statistics here are much more beneficial. Unfortunately the most popular of these, relative risk reduction, is usually presented without sufficient information for its accurate interpretation with the resulting interpretation being overly optimistic. For myself, give me the increase in life expectancy. Before I take screening test x, or engage in behavioral change b, I want to have an estimate of how many days it buys me.

Five Common Misunderstandings About Screening

May 25, 2010

 This blog posting is taken largely from the chapter, “Breast Cancer Screening,” which comes from the book, Calculated Risks: How to Know When Numbers Deceive You by Gerd Gigerenzer. I highly recommend this book. It provides important insights into risks and how they can be misinterpreted. This blog posting takes no position on screening. Its objective is to provide an accurate understanding of risks. Although the specific topic is breast cancer, for the most part it applies to disease screening in general.

Screening tests are not meant for patients with known symptoms. Screening is intended for people without symptoms. The objective is early detection.

Screening does not reduce the incidence of breast cancer. That is the purpose of preventive measures. Early detection does not lead to prevention, although it is hoped that it leads to a cure and mortality reduction.

Early detection does not necessarily imply mortality reduction. For example, if there is no effective therapy, early detection has no effect on mortality. In these cases, early detection does not increase life expectancy. Instead it increases the time the patient consciously has to live with cancer.

All breast cancers do not progress. Sometimes mammography detects a form of breast cancer called “ductal carcinoma in situ.” In fact, the majority of cancers found in the screening of younger women are “ductal carcinomas in situ.” Half or more of these lesions do not seem to progress.

Consequently, early detection is not always beneficial. If a cancer would not progress, or would not progress enough to kill the woman during her life, early detection is harmful rather than beneficial. Invasive treatments such as mastectomy or lumpectomy with radiation with radiation might severely reduce her quality of life. Prostate cancer can progress very slowly in some men. So slowly that a man can die from something else before he even knows he has prostate cancer. Consequently, some men have undergone surgery that resulted in incompetence and/or impotence for a cancer that they might have outlived had they not undergone the surgery.

More on Restoring Attentional Resources

May 23, 2010

In the nineteenth century the famous psychologist William James made a distinction between two types of attention: 1 involuntary attention, when attention is captured by inherently important or intriguing stimuli, and voluntary or directed attention, when attention is directed by cognitive-control processes.  Paying attention, concentrating, make demands on attentional resources. When attentional resources are depleted you have difficulty concentrating and experience mental fatigue. Fortunately, there are techniques for restoring attentional resources. See the Blog Post “The Relaxation Response.” Another approach comes from Attention Resource Theory (ART) 23. According to ART, directed attention involves resolving conflict when there is a need to suppress distracting stimulation, which depletes attentional resources. According to ART, interactions with nature can restore these attentional resources. A previous blog post, “Restoring Attentional Resources,” discussed ART. Given the importance of this topic and as we all suffer from mental fatigue and difficulties concentrating, this current posting expands upon the previous post.

A recent article, “This Side of Paradise: Discovering  Why the Human Mind Needs Nature,4” provides a concise update on ART. During waking hours voluntary attention can be restored when a person’s involuntary attention becomes heavily engaged thus giving direct attention a breather. Research has indicated that nature is especially conducive to this involuntary engagement.

One might wonder what is so special about nature. Might not television be suited to distracting the mind? The objective of television is to keep the viewer from changing channels. So rather than lightening the load on direct attention, television actively captures it. Consequently research5 has found a direct correlation between the amount of time someone spends in front of a television and that person’s irritability. This research has also found that exposures to nature affect a wide variety of cognitive activity ranging from dampening road rage to boosting the spirits and attentional capacities of cancer patients.

Other research found that patients whose hospital window overlooked nature recorded shorter postoperative stays, required less potent pain medication, and evaluated their nurses more positively after gall bladder surgery than patients who looked onto a brick wall.6

An interesting question is how effective are virtual implementations of nature. One study involved three groups of 30. One group sat near a glass window that overlooked a nature scene. The second group viewed a similar scene on a high-definition plasma television; and the third group sat near an empty wall. After working in these environments heart rates were measured to gauge how quickly subjects in each setting recovered from stressors. Although the glass window group overlooking a natural scene showed significant restorative value, no significant differences in recovery to stress were found between the plasma screen group and the blank wall group. Nevertheless, it would be premature to conclude that there is no value to virtual nature. Another study workers in offices with virtual natural scenes over a sixteen week period reported higher well being, cognitive functioning, and connection with the environment.

            So attention is extremely important to memory and cognitive functioning.  Attention is depleted and needs to be restored.  Attentional resources vary throughout the day.  These are important points to remember when planning your day.  It is also important to engage in effortful Type 2 processing7.   As we age the vast repository of memory and experience makes it both easier and more likely to rely upon Type 1 processing.  Although this is one of the potential benefits of aging, there remains a need to continue to engage in appropriate Type 2 processes to ward off cognitive decline.

1James, W.  Psychology:  The briefer course.   New York:  Holt.

2Kaplan, S. (1995).  The restorative benefits of nature:  Toward an integrative framework.  Journal of Environmental Psychology, 15,  160-189

3Kaplan, S. (2001).  Meditation, restoration, and the management of mental fatigue. Environment and Behavior, 33, 480-506.

4Jaffe, E. (2010) Observer, 23, 10-15.

5 Kaplan, S., & Berman, M. G. (2010). Directed attention as a common resource for executive functioning and self-regulation. Perspectives on Psychological Science, 5, 43-57.

6Ulrich, R.S., (1984). View through a window may influence recovery from a surgery. Science, 224, 420-421.

7See the previous post on this blog “The Two System View of Cognition”

Another Memory Stunt to Build a Healthy Memory

May 20, 2010

Here’s another memory stunt that should impress, friends, enemies, and strangers. Should you protest that you are not interested in impressing any of these parties, then consider this memory stunt as memory exercise. The task is to recall the states of the union in the order in which they were admitted to the union. At the end of this list you’ll find tips on how best to accomplish this stunt.

  1. Delaware
  2. Pennsylvania
  3. New Jersey
  4. Georgia
  5. Connecticut
  6. Massachusetts
  7. Maryland
  8. South Carolina
  9. New Hampshire
  10. Virginia
  11. New York
  12. North Carolina
  13. Rhode Island
  14. Vermont
  15. Kentucky
  16. Tennessee
  17. Ohio
  18. Louisana
  19. Indiana
  20. Mississippi
  21. Illinois
  22. Alabama
  23. Maine
  24. Missouri
  25. Arkansas
  26. Michigan
  27. Florida
  28. Texas
  29. Iowa
  30. Wisconsin
  31. California
  32. Minnesota
  33. Oregon
  34. Kansas
  35. West Virginia
  36. Nevada
  37. Nebraska
  38. Colorado
  39. North Dakota
  40. South Dakota
  41. Montana
  42. Washington
  43. Idaho
  44. Wyoming
  45. Utah
  46. Oklahoma
  47. New Mexico
  48. Arizona
  49. Alaska
  50. Hawaii

Tricks for these stunts can be found in the previous blog posts, “More on Remembering Numbers,” and “Remembering Names.”

  1. Picture Della Wearing a Tie
  2. Picture Noah landing the ark in Pennsylvania
  3. Picture Ma wearing a New Jersey

    You take it from here.

© Douglas Griffith and healthymemory.wordpress.com, 2010. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content.

Another Embarrassing Failure of Prospective Memory

May 18, 2010

Readers of the Healthymemory Blog will remember that prospective memory is the memory to do things. Readers might also remember an earlier posting “An Embarrassing Failure of Prospective Memory.” This posting related the story of my forgetting a breakfast appointment with the Dean of the College of Behavioral Sciences. Readers of this blog should also remember that transactive memory refers to external storage of memories, be they on the internet, in a book, or on a calendar or list. I was so confident that I would remember breakfast with the dean that it did not provide any reminders of the appointment anywhere and consequently forgot the appointment. It was this overconfidence in my personal memory that led to this embarrassment.

I’ve just returned from an Alaskan Cruise with my wife. I had planned to take my blue blazer and my college jacket with me. Moreover, I had imagined placing both the blazer and the jacket in my bag when I thought about packing for the trip. We packed and left for the motel. The motel was a park and fly motel that solves the parking problem and also provides for extra winks for an early morning flight. When we unpacked in the motel, I was amazed not to find either the blue blazer or the jacket. I was certain that I had packed them. This was another example of overconfidence in personal memory. Unfortunately, imagining that you are doing something can be confused with actually doing it. Apparently that was what happened in this instance.

The remedy for this is another instance of transactive memory, a checklist. Unfortunately, I am not much of a list maker. There was a serendipitous end to this story. There was time to go to a mall and shop for the missing items. I ended up getting a fine sports coat and a fine jacket, as well as good prices on both. So sometime failures of prospective can be beneficial. However, others can be disastrous. See the blog posting, “Prospective Memory and Technology.” There you will find accounts of parents going to pick up their children only to discover that they had forgotten to drop them off. Under certain conditions, these children died.

© Douglas Griffith and healthymemory.wordpress.com, 2010. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content

Transactive Memory and TV

May 16, 2010

The Healthymemory Blog has had many postings on Cyberspace and Transactive Memory. These have usually been written with the objective of illustrating the potential of the internet for cognitive growth and a healthy memory. However, it is important not to overlook fun and enjoyment.

As many popular television shows are wrapping up their seasons this week, it is timely to remind people of the internet as an aid to television viewing. Synopses of most programs can be found simply by searching for them on the internet. Should you need to get caught up before seeing the season finale, this is one means of doing so. It can also lead you to means of watching the shows online. You might choose to read about the episodes first before spending valuable personal time viewing them.

Generally speaking, the internet can serve as an inexpensive guide to television viewing enabling you to separate the wheat from the chaff on this vast wasteland.

So, go to your browsers and start searching!