Optimal Memory Design and Benefits of Forgetting

Optimal Memory Design and Benefits of Forgetting

During speaking events, I am frequently complimented for my “phenomenal memory.” People are impressed by the relative ease with which I quote Bible passages from memory or recall the details of arcane scientific discoveries made decades ago. However, my wife, Kathy, has a different opinion. She is amazed by my “spectacular memory lapses.” Thirty seconds after answering the phone I forget who called or what the call was about. Furthermore, she often needs to remind me of the names of close friends and relatives. Now, however, thanks to some recent scientific breakthroughs, I can attempt to explain to Kathy that there are advantages to being able to forget.

The discovery of the benefit of memory lapses arises from research on rodents. Rodents (short-legged mammals) are listed in Genesis 1 as one of three sets of land mammals that God created especially to assist human beings.1 In the launch of civilization rodents provided humanity with an effective, economic source of clothing. No other set of animals produces luxuriant fur at such low cost.

Today, rodents serve humanity’s need for medical advances. Rodent DNA is remarkably similar to human DNA. Hence, they make an excellent laboratory proxy for humans. Moreover, because of rodents’ small size, short generation times, the ease with which they adapt to crowded conditions, and their broad diet spectrum, scientists can perform medical experiments on tens of thousands of mice, rats, and others for relatively little cost.

In the ongoing search for cures to dyslexia, Alzheimer’s disease, and other forms of dementia, several different teams of researchers are again turning to rodents for answers.2 The researchers noted with much astonishment that the molecular pathways the brain uses to form long-term memories are virtually identical in rodents and humans. This similarity allows scientists to genetically engineer mice in order to alter the molecular pathways in attempt to improve the memory of mice—with the hope that eventually the same can be done for humans.

So far, four neuroscience research teams have discovered that by inducing slight differences at the molecular level they can achieve in mice dramatic improvements in learning and memory.3 Some scientists go so far to claim they are “improving on evolution.”4 In fact, the “improvements” already have launched a black market for “intellectual steroids” on university campuses and high-tech firms. But, like the steroids used by athletes, do these chemical enhancements of cognitive abilities come with unexpected costs?

Ongoing research with super-smart mice indicates that enhancing the cognitive capacities of normal mice indeed has deleterious side effects. These include greater physical and mental stress, chronic pain, and increased cancer risk. And there are cognitive side effects as well.

The problem observed with the super-smart mice is that they seem to remember too much. In some strains fear responses kick in even in reaction to benign stimuli. Other strains have no trouble solving a difficult maze but fail to solve simple mazes. The problem seems to be that the cognitively enhanced mice remember too much irrelevant information.

The super-smart mice manifest an uncanny resemblance to a very rare cognitive disorder in humans. In the 1920s, Russian newspaper reporter Solomon Shereshevsky had such a perfect memory that he never needed to take notes. In fact, after a single reading of Dante’s Divine Comedy, Shereshevsky could recite the entire poem by heart. However, his mind was so fixated on particulars that he could not grasp metaphors. He was unable to comprehend the imagery in the poems he was reciting.

Apparently, the ability to forget is an important cognitive attribute. Years ago, a research team demonstrated through computer models that slight imperfections in memory are necessary for humans to see connections between different but related events.5

Researchers are now drawing the conclusion that the brains of normal mice and normal humans manifest optimized memory designs. As for humans, our memory systems allow us to both particularize and generalize, to engage in concrete, literal thinking but also to think abstractly and metaphorically. Such consistent optimization is the hallmark of a supernatural, super-intelligent Creator, not the outcome of naturalistic evolution.

God has created the human race with a diversity of memorization and forgetfulness abilities so that, by dividing our labor and specializing, we can work together to achieve great accomplishments. In this context it would be unwise and harmful to attempt to improve upon God’s optimal designs. However, just like physical steroids have given relief to humans suffering from physical disorders, so, too, mental steroids hold great promise to cure the maladies of the mind, such as Alzheimer’s disease and dementia. For these marvelous medical advances we again can thank our Creator for the manner in which He designed rodents in advance of our creation to serve us.

  1. Genesis 1:24-25.
  2. Jonah Lehrer, “Small, Furry … and Smart,” Nature 461 (October 15, 2009): 862-64.

  3. Steven A. Kushner et al., “Modulation of Presynaptic Plasticity and Learning by the H-ras/Extracellular Signal-Regulated Kinase/Synapsin I Signaling Pathway,” Journal of Neuroscience 25 (October 2005): 9721-34; Ya-Ping Tang et al., “Genetic Enhancement of Learning and Memory in Mice,” Nature 401 (September 2, 1999): 63-69; Rusiko Bourtchouladze et al., “A Mouse Model of Rubinstein-Taybi Syndrome: Defective Long-Term Memory Is Ameliorated by Inhibitors of Phosphodiesterase 4,” Proceedings of the National Academy of Sciences, USA 100 (September 2, 2003): 10518-22; Juan M. Alarcón et al., “Chromatin Acetylation, Memory, and LTP Are Impaired in CBP+/- Mice: A Model for the Cognitive Deficit in Rubinstein-Taybi Syndrome and Its Amelioration,” Neuron 42 (June 24, 2004): 947-59; Dan Ehninger et al., “Reversing Neurodevelopmental Disorders in Adults,” Neuron 60 (December 26, 2008): 950-60.

  4. Jonah Lehrer, 862.

  5. J. L. McClelland in Memory Distortion: How Minds, Brains, and Societies Reconstruct the Past, edited by D. L. Schacter (Cambridge, Massachusetts: Harvard University Press, 1995): 69-90.