Posts Tagged ‘Robert Bjork’

What Can Pharmacology Offer for a Healthy Memory?

February 1, 2012

For some people, the answer might be everything, or given time, everything. They believe that pharmacology will eventually provide a cure and/or a preventative to Alzheimer’s and dementia, and that it will enhance cognitive performance so that we can learn more and master more difficult subjects. This is to say nothing about the eventual beneficial effects to the economy and society. A recent article1 has motivated this blogger to post some cautionary remarks. It should be remembered that our cognitive abilities are the product of evolution. A common misconception is that evolution produces optimal results. No, evolution satisfices, that is provides a satisfactory solution to environmental challenges. These solutions involve trade-offs. For example, a woman’s pelvis is the sized so that it can both support bipedalism and the large cranium of an emerging baby.

Although our cognitive abilities might not be optimal, they have been shaped by evolution. We have two systems for processing information, System 1, which is fast, and System 2 which is slow but more thorough (See the Healthymemory Blog Post, “The Two System View of Cognition”and “Thinking Fast and Slow). Without System 1 we would have become extinct a long time ago. But without System 2 both our cognitive and cultural achievements would be extremely limited. One way of thinking about trade-offs is to think of an inverted U. Initially more of a factor is beneficial. However, at some point (the apex of the inverted U) more of this factor is causing losses someplace else.

Robert Bjork has suggested that there is a symbiosis of forgetting, remembering, and learning.2 John Anderson has written an entire book3 documenting how human cognition has been shaped to deal with the environment in an effective manner. Luria’s famous book, The Mind of a Mnemonist, about an individual referred to as “S” who had a phenomenal memory and earned his living by giving performances using his fantastic memory, had too much of a good thing. For example, he had difficulty remembering faces, which appeared to him as changing patterns. Research has also indicated that savant-like abilities such as S‘s can be induced in normal participants by turning off particular functional areas of the brain via repetitive transcranial magnetic stimulation.4

There are also individual differences determining whether pharmacology will be beneficial. Individuals of normal or above-average cognitive ability often show negligible improvements or even decrements in performance from certain drugs. One study5 found that modafinal improved performance only among individuals with lower IQs. In another study6, low-performing individuals showed enhanced performance, but high-performing individuals showed reduced performance after taking amphetamines. Inverted U shaped dose-response curves are quite common.7

This is not to say that there is no role for pharmacology in fostering a healthy memory. Clearly in the preceding examples low-performing individuals were showing benefits. But more is not necessarily better. Long term side effects of medication must also be considered.

1Hills, T. & Hertwig, R. (2011). Why Aren’t We Smarter Already: Evolutionary Trade-Offs and Cognitive Enhancements. Current Directions in Psychological Science, 20:373.

2Bjork, R.A. (2011). On the Symbiosis of Forgetting, Remembering, and Learning. In A.S. Benjamin (Ed.) Successful Remembering and Successful Forgetting: A Festschrift in Honor of Robert A. Bjork. (pp 1-22). London, England:Psychology Press.

3Anderson, J.R., (1990). The Adaptive Character of Thought. Psychology Press.

4Snyder, A. (2009). Explaining and Inducing Savant Skills: Privileged Access to Lower Level Less Processed Information. Philosophical Transactions of the Royal Society B, 364, 1399-1405.

5Randall, D.C. Shneerson, J.M., & File, S.E. (2005) . Cognitive Effects of Modafinil in Student
Volunteers May Depend on IQ. Pharmacology Biochemistry and Behavior, 82, 133-139.

6Farah, M.J., Haimm, C., Sankoorika, G., & Chatterjee (2009). When We Enhance Cognition with Adderall, Do We Sacrifice Creativity? A Preliminary Study. Psychopharmacology, 202, 541-547.

7Cools, R., & Robbins, T.W. (2004). Chemistry of the Adaptive Mind. Philosophical Transactions of the Royal Society London, A, 362, 2871-2888.

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