Tuesday, February 16, 2016
An area of controversy in the life sciences relates to the relative roles of genetics and the environment. Confusion commonly afflicts politics. For example, early Communists glommed on to the discredited genetic theory of “inheritance of acquired characteristics.” This theory holds that changing a person’s attitude and behavior would somehow result in changes to his or her genes, which would allow for genetic transmission of the changed attitudes and behavior to his or her children. For this idea to be true, outside influences on the brain would have to change the genes not only in brains but also in the sex cells (sperm and egg cells). The idea was held in ancient times by Hippocrates and Aristotle, but it gained scholarly imprimatur with formal publication in 1809 by Jean-Baptiste Lamarck. In the 1930s, the Russian president of the Soviet Academy of Agricultural Sciences, Trofim Lysenko, applied the doctrine to Soviet agriculture with disastrous results. At the same time, Soviet political leaders extended the mistaken doctrine to inheritance of educational and social experiences; that is, changing human nature by government policy. They expected that indoctrinating the current generation in collectivism would genetically transfer collectivist attitudes and behavior to all future generations. Cuba, North Korea, and China showed that collectivism can be transferred culturally but not biologically.
In the United States, much political angst arises from disputes over whether more effective educational and social policies will succeed in lifting people out of poverty and dysfunctional behaviors. When I was a child, I often heard the axiom, “You can take the boy out of the country, but you can’t take the country out of the boy.” Today, the corresponding axiom would seem to be, “You can take the boy out of the ghetto, but you can’t take the ghetto out of the boy.” The reality is that you can take the country or ghetto out of the boy, but this won’t transfer to his children by his genes.
What we are now discovering is that environment and experience affect the expression of genes. Whether or not genes are accessible for readout often depends on the environment. People have underestimated their capacity to sculpt their own brains, attitudes, and behavior by controlling experiences that affect gene expression. However, though people may control to some extent how their own genes are expressed, there won’t be any biological transfer to their heirs. Environmental and cultural influences do of course transfer, so one’s heirs can be taught how to likewise exert control over how their genes are expressed.
Having the right chemicals in the right environment at the right time is believed by most scientists to be all that is needed for creating life and shaping the mental life of the individual. To them, life seems like a highly improbable occurrence. But it did happen, and even more improbable, there may be a life force that sustains it.
Many scientists also think of the brain’s conscious mind as an emergent property of brain function. Emergent properties follow the rule that the whole is greater than the sum of its parts. Another way of saying this is that the properties of the whole cannot be predicted from what you know about the properties of the contributing parts. Yet, paradoxically, most scientists believe that as they learn more and more about less and less, they will somehow explain the whole.
Emergent properties apply both to molecules in a primordial soup that generate simple living organisms and to the 100 billion or so neurons of a human brain that generate a conscious mind. A physical world that can generate emergent properties is a mysterious and magical world indeed.
What gets left out in such consideration is the capacity for personal control over one’s biology, which is an important theme of this book. I contend that at the level of the individual person, mind itself—especially conscious mind—is a major force of natural selection that drives creation of mental capacity and character. To make that case, I will explain as simply as I can what neuroscientists know about how the brain works (chapter 2). Other books that discuss brain do so as if knowing how the brain works is an end in itself. I focus on the implications of such knowledge. Then I try to explain what consciousness is, what causes it, and its various states (chapter 3). Most importantly, in chapter 4, I challenge the position of many fellow neuroscientists who hold that consciousness is only an “observer” that cannot do anything, much less generate what we commonly call “free will.”
The implications for daily living could not be more profound. Accepting one’s biology and circumstance breeds helplessness and fatalism. So, it boils down to one’s belief system. Either you are “captain of your own ship, master of your own fate,” or you are shackled by the belief that change is not possible. Are we victims of biology and fate? This book will show both how the brain shapes its own destiny and how what you think and do shapes brain function.
Excerpted from Mental Biology. The New Science of How the Brain and Mind Relate, by W. R. Klemm. New York: Prometheus. See rave reviews at WRKlemm.com, click on "author."
Wednesday, February 03, 2016
The human brain contains a distinct network that serves as its executive agent. This network is primarily based in the dorsolateral prefrontal, parietal, and cingulate cortices. It regulates the many “top down” neurobehavioral functions that are so characteristic of human brain. Deficiencies in the function of this network underlie numerous neuropsychiatric conditions, but even underlie much of the failings of us all. The ability to regulate emotions and direct rational actions is typically associated with success in life, and inability to do so often leads to dire consequences.
This network can be trained to develop more robust capacity for executive control. This, as we all experience, is what parenting and schooling are about. Such training is especially crucial in early childhood when the challenges of school are first encountered. Even so, such training takes many years and for most of us may never be completed.
The question arises: can such executive control training be expedited? One possibility has recently arisen from several studies showing that working memory capacity can be expanded by a relatively short training time, and in the process general intelligence may be improved. Since the same system that determines intelligence is also operative in executive control, it seems reasonable that working memory training might also enhance executive control. To pursue this possibility in a specific context, researchers have hypothesized that inappropriate or maladaptive behaviors might be reduced by effective working memory training based on emotion-laded stimuli.
In a study by Suaznne Schweizer and colleagues in England, subjects in their early 20s were assessed for emotional control before and after 20 training days of 20-30 minute sessions. The experimental groups received dual n-back training with a simultaneously presented face and a word that was either emotionally negative or neutral. After each picture-word pair, subjects were to press a button to indicate if either or both members of the pair matched the stimulus presented n-positions back. Tests began with n = 1 and increased as subjects gain proficiency.
Not surprisingly, errors in both trained and untrained subjects increased at levels beyond n = 1, and the error rate was comparable for both groups. Results also indicated that subjects reported less distress when they consciously willed to suppress the distress compared with the null state of just attending to negative stimuli. But this distress reduction occurred only in the emotional working memory training group.
No change in neural activity levels was indicated in brain scans as a result of placebo training, but significant increases occurred in the executive control regions of interest as a result of emotional working memory training, irrespective of the level of n-back achievement.
The study also compared emotional responsivity before and after training. Subjects were asked to just pay attention or to pay attention and cognitively suppress their emotional reaction. Subjects rated their emotions on a numerical scale from negative to positive while viewing films that were emotionally neutral (such as weather forecasts) or that were emotionally disturbing (such as war scenes, accidents, etc.). Training caused no change in the group that viewed only neutral images, but in the groups viewing disturbing scenes, training decreased the perceived distress in a group told just to attend the scenes and was even more effective in the group told to suppress emotional reaction.
The emotional working memory training produced benefits that transferred to the emotional response task. Trained subjects not only regulated their emotions better but also developed greater brain-scan activity during the emotional task in the predicted brain regions of interest, the executive control loci. In other words, the training actually changed brain function on a lasting basis. Traditionally, we have always thought that the sole benefit of n-back memory training is to expand the amount of information that can be held in working memory. But now we see that such training can improve our ability to control emotions. Emotional working memory training improves the ability to suppress disturbing emotional responses and does so presumably because the executive control network is more activated. Thus, such training might also enhance many executive control functions, particularly responses to emotionally disturbing circumstances. A new tool for self-control may have been discovered.
Banich, M. T., Mackiewicz, K. L., Depue, B. E., Whitmer, A. J., Miller, G. A. , Heller, W. (2009) Cognitive control mechanisms, emotions and memory: a neural perspective with implications for psychopathology. Neurosci. Biobehav. Rev. 33, 613-630.
Beck, A. T. (2008) The evolution of the cognitive model of depression and its neurobiological correlates. Am. J. Psychiatry. 165, 969-977.
Schweizer, S., Grahn, J., Hampshire, A., Mobbs, D., and Dalgleish, T. (2013). Training the emotional brain: improving affective control through emotional working memory training. J. Neurosci. 33(12), 5301-5311.
Readers of this column can learn more about n-back training and numerous other ways to improve brain function in "Memory Medic's" e-book, Improve Your Memory for a Healthy Brain. For a limited time only, this book is priced at 99 cents, available in all formats from Smashwords.com.