When this columnist closes his eyes to meditate, he ‘feels’ clearly that his mind is located in the prefrontal cortex, the mantle of nervous tissue just behind the forehead. The mind is what this cortex does and that the equivalent brain portion of non-human mammals, much smaller in size, cannot do. Everything that is mental – thoughts, feelings, desires, perceptions, memories, reasoning and consciousness of the self – is performed in or by the prefrontal cortex. Is it always so?
A number of phenomena imply that not all mental tasks totally occur in the brain. This note refers to four of such phenomena, bizarre examples of the complexity of human nature: the placebo effect, the nocebo effect, the psychological problems resulting from an overactive immune system, and the influence of the intestinal flora in mental states.
The placebo effect is the healing outcome of inert substances or sham procedures in patients with real health problems. Numerous experiments have confirmed the effectiveness of illusory drugs or fictitious treatments in the handling of many diseases; sorcerers know this quite well. Successful outcomes are not consistent. Harvard psychologist Irving Kirsch found in a meta-analysis of actual drugs versus placebos that the power of these is more positive when, as it happens in depression cases, both recoveries and declines are more in the head than in other parts of the body.
The nocebo effect, the reciprocal of the placebo effect and also real, is the harmful sequel to the health of people with negative expectations around innocuous substances or harmless circumstances. People with asthma are frequent victims of the nocebo effect. Recent research by the Monell Research Center, Philadelphia, PA, concluded that the mere possibility that a smell is harmful can increase inflammation of the airways during the following 24 hours (or even for a longer time) after the exposure. “Asthmatics are always concerned about essences and fragrances. If they believe a smell is harmful, their bodies react as if it were”, says Dr. Cristina Jaén, Director of the study.
Psychological problems arising from non-existent infections have been documented by Dr. Erich Kasten, Professor of neurophysiology at the Medical School Hamburg in Germany. According to Dr. Kasten, an overactive autoimmune system may confuse the harmful consequences of stress (the mental state resulting from physical, job-related, social or financial factors that tend to alter equilibrium), with bacterial or viral infections that do require corrective actions. Cytokines are messenger molecules generated by the immune system when it detects danger of infection. Cytokine generated inflammation, an important mechanism in disease prevention, also causes tiredness and apathy similar to those present in many diseases. When the immune system overreacts to non-pathogens (such as stress) or to harmless stimuli, it generates unnecessary alarming cytokines that lead to mood downfalls followed eventually by melancholy or depression.
The fourth ‘extra-cerebral’ phenomenon, and probably the strangest, refers to the trillions of bacteria, foreign to the human body (they exceed in number our own cells), that make up the gut flora. Those bacteria are rotatory commensals ever present in our body. According to science writer Charles Schmidt, researchers have now “a growing conviction that that the vast assemblage of microfauna in our intestines may have a major impact on our state of mind. The gut-brain axis seems to be bidirectional: the brain acts on gastrointestinal and immune functions that help to shape the gut’s microbial makeup, and gut microbes make neuroactive compounds, including neurotransmitters.” Is this not amazing? It gives sense to the expression ‘gut feeling’.
Our mind is in our head (we feel it) and the head is part of our body (we know this). What is then the need of a mind-body split? Such dichotomy comes from the inevitable categorization that social and natural sciences require (good-bad, hot-cold, one-zero…), and directly descends from the spirit-matter religious distinction. Yes, there is something that is absolute in many categorizations. But the strange effects of placebos and nocebos, the melancholy associated with infections and the anxiety generated by intestinal bacteria, the mind-body segregation does not seem to be an absolute one… At least, it should not be dealt so in health diagnoses.
Atlanta, April 19, 2015