That Troublesome Body Hooked Up To My Brain… A healthy brain is CRUCIAL for sustaining a healthy body
Many scientists demonstrated the neurobehavioral benefits of a regular dose of physical exercise. For example, see Ratey JJ, Hagerman E (2008) Spark: The Revolutionary New Science of Exercise and the Brain. The neurological bases of these effects are increasingly well documented. As an entry into this literature, see, e.g., Cotman C and Berchtold NC (2002) Exercise: A behavioral intervention to enhance brain health and plasticity. Trends Neurosci 25:295; Kramer A et al (2013) Exercise, cognition, and the aging brain. J Appl Physiol 101:1237; or Voss MW et al (2010) Plasticity of brain networks in a randomized intervention trial of exercise training in older adults. Front Aging Neurosci 2:doe:10.3389/fnagi.2010.00032. Because physical exercise up-regulates processes that control learning rates, regular physical exercise amplifies the impacts of our (and other) computer-based and everyday life learning experiences. E.g., see Curlic DM, Shors TJ (2013) Training your brain: Do mental and physical (MAP) training enhance cognition through the processes of neurogenesis in the hippocampus? Neuropharmacology 64:506. The short answer to this question is “yes”—but actually, there are MANY extra-hippocampal contribution to impacts of physical exercise + cognitive exercise as well!
One of the most enlightened perspectives about exercise and the brain arose from out in left field, contributed by an Israeli physicist, Moshe Feldenkrais. As a young man working in France, the rather remarkable Dr. Feldenkrais met and became a disciple of the founder of judo, Jigoro Kano. From his scientific/engineering perspective and from his experiences as a judo practitioner, Feldenkrais understood that the neurological control of movement was based on training that accommodated movement variability, appreciated the role of the body core in the genesis of almost all movements, and understood that the feelings, mental constructions, and other cognitive correlates of movement were an intrinsic part of their neurological “representations”. In my view, the clearest descriptions of this perspective—which are in great agreement with my own neuroscience-based perspective—have been provided by a brilliant student of Feldenkrais’, Anat Baniel. See Baniel A (2009) Move Into Life: The Nine Essentials for Lifelong Vitality, Harmony Books, New York; and for an application of these methods to address rehabilitation issues in children, Baniel A (2012) Kids Beyond Limits, Perigee, New York.These principles are also well understood by an enlightened group of physical and occupational therapists. My UCSF research collaborator Nancy Byl, the Chairman of PT at my university, and her colleagues and students who come from this school are among the enlightened—but unfortunately, many PTs and OTs are not knowledgeable about, and do not very intelligently apply brain science-guided therapeutics in their clinical practices.
For studies showing how your expectation of pain can make it hurt, see, e.g., Fields HL (2000) Pain modulation: expectation, opioid analgesia and virtual pain. Prog Brain Res 122:245; or Hoffman GA et al (2005) Pain and the placebo: What we have learned. Perspect Biol Med 48:248.
The study of soldiers wounded at Anzio represents one of the bases of origin of what is often called the “placebo effect”. See Beecher HK (1955) The powerful placebo. JAMA 149:163. Note that Beecher described a number of other conditions in which he attributed the magnitude of pain attributable to the context in which it arose, or to the degree to which the injury negatively altered or disrupted the life of its ‘victim.’ Many hundreds of more-contemporary studies that support and elaborate this example could be cited.
The ongoing adjustments in blood flow based on vestibular, proprioceptive, cutaneous and visual feedback (e.g., when you move from a supine to a seated to an erect posture) is well understood, and is described in any standard medical physiology textbook. The evaluation of dizziness and postural stability expressed after a rapid change in posture is widely used by cardiovascular medical specialists to evaluate the quality of the autonomic nervous system control of cardiovascular dynamics in normal and frail patient populations.
In studies conducted in my own research laboratory designed to determine the origins of focal dystonias, we trained adult monkeys at a task that progressively de-differentiated the quality of sensory feedback from the skin surfaces and from proprioceptors innervating their hands. Sure enough, after 20 or 30 or 40 training sessions, monkeys completely lost control of their hands (see Byl NN et al, 1997, A primate genesis model of focal dystonia and repetitive strain injury. I. Learning-induced de-differentiation of the representation of the hand in the primary somatosensory cortex in adult monkeys. Neurology 47:508; Byl NN et al, 2002, Correlation of clinical neuro-musculoskeletal and central somatosensory performance: Variability in controls and patients with severe and mild focal hand dystonia. Neural Plast 9:177). In parallel, we showed that the quality of sensory information from those hands had been dramatically degraded.Importantly, on the path to developing a dystonia, many monkeys developed a “repetitive strain injury”. We believe this arises because the degradation of the quality of information from the hand affects the brain’s control of autonomic nervous system responses. The resulting change in blood flow patterns (evident by temperature changes, skin blanching, and a reduction of heart rate variability) leaves the superficial tissues in the arm under-perfused. These ‘dry’ tissues are thereby subject to the micro-trauma that is the basis of the inflammation = the RSI, affecting the carpal tunnel, or affecting superficial fascia in the forearm (“fasciitis”). Clinical support for this interpretation has come from clinical treatment of these patients by my UCSF colleague Nancy Byl. She trained individuals with longstanding RSIs, using a strategy that primarily emphasized the progressive improvement of the quality of representation of innocuous (cutaneous; proprioceptive) inputs from the hand in the affected limb. In the great majority of treated patients, the carpal tunnel syndrome or fasciitis rapidly evaporated, paralleled by what was interpreted as a recovery of more normally dynamic blood perfusion of the arm.
For an introduction to a very interesting literature about “food addiction,” begin with a review by one of my favorite UCSF colleagues: Dallman M, et al (2005) Chronic stress and comfort foods: self-medication and abdominal obesity. Brain Behav Immun 19:275. There are many books written about food addiction, mostly from a self-help perspective. The more scientific among them are beginning to talk about something that has been clear for several decades: a) eating too much IS, neurologically, an addiction of the most fundamental class; and b) is, after all, a distortion in control, in your brain.
The stimulus to urinate is richly contextualized by our experiences in life. In the right place and context, the micturition reflex is triggered “on”, and with high efficiency and a helluva lot of practice, we relieve the pressures and experience the small pleasures that are associated with these oft-repeated actions. EVERY brain-rewarded action is subject to positive distortions as we repeat those rewarded actions—In this case many thousands of times. Just as our brain, anticipating the rewards associated with alcohol or food or drugs, induces the “craving” for that addictive substance—so, too, can the brain, anticipating the rewards associated with micturition grow to “crave” it, triggering the micturition reflex. In detail, things are more complicated (the regulation of micturition involves complex processes that both stabilize control and trigger the reflex; dopamine regulation is involved in both aspects of control), of course. But there is almost no question that this common human problem is just another of MANY classes of dysregulation in our brain’s reward systems, as they apply to an a) oft-repeated, b) highly contextually predictable, and c) rewarded behavior. I cited this example because the clinicians who treat these conditions largely assign blame to the bladder, urinary tract and spinal cord. They should understand that the brain is definitely also a major player in this game!
