PSYCHONEUROIMMUNOLOGY

ABSTRACT:

 

The body-mind problem is a debate surrounding the effects that the body has on the mind, and the effects that the mind has on the body. Issues affecting this debate include questions such as "Where is the mind?" and dualism versus monism. There are various techniques of measuring different effects that the mind has on the body. These techniques will be examined and contrasted, and include electroencephalography (EEG), magnetography (MEG), electrodermal activity (EDA), cardiovascular measures, Electro-oculography (EOG) and electromyograms (EMG). They all have their uses and limitations, and it is most beneficial when these are used in combination with each other. Limitations according to different cultures and individual differences are also discussed.

To investigate the Mind-Body problem, let us first define the two concepts of Mind and Body. The Mind is defined as an "integration of functions of the brain resulting in the ability to perceive surroundings, to have emotions, imagination, memory and will, and to process information in an intelligent manner." (Tabers,1989) The Body is defined as "the physical part of man as distinguished from the mind and spirit." (Tabers, 1989). Thus these give us clues as to how we could connect the "physical part of man" to the part which is responsible for the "integration of functions." The body and it’s anatomical and chemical properties effects the behaviour, which stems from the mind. For example, when you finish an ironman ultra-triathlon and your physical resources are depleted, you will most likely show weary and tired behaviour. However, the opposite is also true: Behaviour results in certain anatomical and chemical properties being affected. For example, when the mind or body has a great idea, your heart may start to beat faster and your pupils may dilate. The mind and the body are intimately related as they are continuously affecting one another throughout our daily lives.

In order to understand the mind-body problem, let us first look at how and where it began. For centuries, humans have been intrigued with the notion of consciousness. Through dreaming and being able to dialogue with oneself, we have become aware of our thought processes and mental experiences as being different from our physical experiences (McGuigan, 1994). Various schools of thought have debated whether there is a combined mental and physical realm, or whether there is just one or the other, or whether they are distinctly separate.

The combined mental and physical realm, termed dualism, proposed the coexistence of a mental energy and a physical energy. Pyschophysical Parallelism saw these energies as completely separate from each other but acting in parallel, whilst PyschoPhysical Interactionism, saw the two energies as interacting constantly. The latter view is more commonly believed today, as the connection between the mind and body has been further researched. A common example of this approach is that stress (which is in the mind) manifests itself in different physical symptoms, such as ulcers, headaches and immune diseases.

Monism, on the other hand, proposed that only one energy existed in the world, either physical or mental. Mentalism stated that to be is to be perceived, thereby suggesting there is no physical reality. If a tree falls down in a forest, will it make a sound? A question which illustrates this, if you are not in the forest then how can you hear the tree falling? If no one hears it make a sound (no one perceives the sound) then it does not exist. Materialistic Monism encouraged a more biological approach proposing that there is only physical energy and that all thoughts or ideas come from a physical source inside of our skins (McGuigan, 1994).

Researchers then began debating where the mind is situated. Various notions were put forward, such as the head or the heart or in the brain. There is at present a more systemic model of cognition which acts more as a flow of energy. If the brain has an idea, it can’t do anything with it, if it doesn’t have muscles or speech or a heartbeat. In order for the brain to have the idea, it needs to be stimulated through the eyes and ears. Thus the whole body cannot be broken down into separate entities. The mind is thus a system of co-operative co-ordination between the sense organs, the brain, the nerves, muscles, arteries and every other parts of the body. The brain is still, however, the major co-ordinating region. This ties in with our initial definition of the brain as the "integration of the functions of the brain" (Tabers, 1989) with the resulting emotional, mental and physical effects.

In order to investigate the mind-body connection, one needs to measure certain responses to different emotions or thought processes, and investigate similarities and differences. Measuring the bodily responses and brain function are two common methods. Brain function is measured directly by measuring electrical, chemical and magnetic activity in the brain. It is indirectly measured by glucose metabolism, blood volume, blood perfusion and blood oxygenation. The bodily responses are measured by methods such as monitoring the electrical activity when muscles contract, the size of the pupil, gaze direction and sweat gland activity. Once trends and patterns are discovered in this research, then inferences can be made about the body-mind connection. For example, when you are fearful, your pupils dilate.

Let us investigate what physiological changes your body will have when you are sitting at home alone watching a horror movie. At the point where grotesque "Freddie" jumps out from behind the door, your heart will be beating faster, you may become short of breath, your brain would be thinking faster, you may be sweating, your hands may be clenched and your pupils would be dilated.

In a laboratory situation watching the same movie, there could be a number of different types of monitors measuring your response. We will go through each technique of measurement that can be used in this situation:

Your heart rate would be measured by an electrocardiogram (ECG) to measure the electrical activity of your heart muscles in one heart beat (Breakwell et al, 1998). Your brain activity would be measured by an electroencephalogram (EEG) or a magnetoencephalogram (MEG). The EEG would be measuring the spontaneous electrical activity, and these neurons would be causing electrical fields which would be recorded by a MEG (Breakwell et al, 1998). MEG-Electrodes are placed in different places on the scalp. This technique is particularly effective when investigating epilepsy and convulsive disorders (Tabers, 1989). Your sweat gland activity or electrodermal activity (EDA) would be measured by a electrodermal electrodes measuring the electrical properties of the skin associated with sweat gland activity. This activity has strong correlations to emotion (Gardner, 1985). Your clenched fist and other contracted muscles would be measured by electromyograms (EMG) which would monitor any motor activity on the underlying muscles (Kutas, 1998). This is measured either by small needles or electrodes on the skin (Breakwell et al, 1998). Your eye movements would be measured either by pupilometry which is the monitoring of pupil diameter or electro-oculograms (EOG) which track eye movements. A video of your eye movements, low level infrared light or laser techniques could be used to monitor eye activity (Kutas, 1998 and Breakwell et al, 1998). Eye activity has been found to be very active during thought (Gardner, 1985). Your shortness of breath and other respiratory effects such as rate and depth of breathing would be measured as well as the oxygen and carbon dioxide in each breath (Breakwell et al, 1998).

Magnetic resonance imaging (MRI), event related potentials (ERP) and positron emission tomography (PET) are other techniques used in physiological psychology. MRI’s detect blood flow and changes in blood oxygen in the brain. This shows brain structure and functional mapping. ERP’s measure attention, memory and language. PET investigates blood flow changes during cognitive processes by measuring neurochemical activities (Kutas, 1988).

However, being covered in electrodes, probes, needles, masks and monitored by videos all at once, is not feasible. It is however, beneficial to combine some of these techniques as the brain never works alone. These techniques complement each other and are specific to what is measured. All of these measurements on our fearful subject watching the horror movie will show various fear responses thereby showing that it is beneficial to combine techniques. There are many changing views at present, and various techniques are more complimentary than others. For example, functional MRI is said to complement a structural MRI and a structural MRI often complements a PET scan (Kutas, 1998).

The Mind-Body problem has been questioned more and more in recent years as the link has been proven, but specific questions have not been answered. These questions link a particular area of the brain, or a particular cells to a event or behaviour. For example, research has proven that stress of bereavement in widowers reduced the amount of lymphocyte proliferation, thereby possibly decreasing their immune systems and increasing their mortality (Ader, 1991). This explains the link between the loss of a loved one and an increased mortality particularly in elderly couples. Psychology and behavioural scientists have researched many issues and have proved many cause and effect relationships. However, the new science of psychoneuroimmunology (PNI) is examining the biological link to many of these connections, particularly in response to different kinds of stress (Ader, 1991).

The concept of the Mind-Body connection has elicited many avenues of speculation over the last few decades. Only fairly recently have we been able to directly measure the extent of this connection using psychophysiological techniques. These techniques have been given credence to the hypothesis that the mind and body should be considered as two separate energies that interact constantly. Further to these initial stimulation-response studies, scientists have begun to provide elegant evidence regarding the link between the mind and the immune system, paving the way for the science of psychoneuroimmunology. Psychneuroimmunology continues to have an increasingly profound affect on modern medicine as health professionals learn the art of assisting the body to fight illness through mental strategies and stress relief to boost the immune system. Thus we can conclude that psychophysiological techniques have indeed had a vast impact on the documenting and proving of research relating to the mind-body problem.

REFERENCES:

Books:

Ader, R. (1991) Psychoneuroimmunology. New York: Academic press.

Breakwell, M., Hammond, S. & Fife-Schaw, C. (1998). Research Methods in Psychology, Sage Publications Limited, London.

Gardner, H. (1985) Frames of Mind: The Theory of Multiple Intelligences. Basic Book Publishers, N.Y.

McGuigan, F.J. (1994). Biological Psychology: A Cybernetic Science, pp58 - 80. Engelwood Cliffs, N.J.: Prentice Hall.

Journal Articles:

Kutas, M. & Federmeier, K.D. (1998) Minding the Body. Psychophysiology, 35, 135 - 150.

Dictionaries:

Tabers’ Medical Dictionary, Thomas, C.L. (Ed) (1989) 16th edition. FA Davis Company, Philadelphia.

"Psychosocial factors have profound and complex effects on the human immune system and therefore on a person’s bodily health and general well-being."

For the last few decades people have acknowledged a certain connection between the mind and the body, although only recently has research begun on various issues linking the physiological processes within the body to psychosocial factors which often induce stress (Volhardt, 1991).

Stress itself is a concept which is difficult to define, as different people have different responses to different stressors. Something that elicits stress in one person, may not illicit stress in another. Ader (1991) measures stress according to a Social Adjustment Rating Scale, which states that if you have a high score (i.e. you have had many psychosocial stressors in the past year) then you are more likely to suffer from illness in the next 2 years. However the terms Eustress and Dystress are also introduced. Eustress are the stressors that benefit people, such as a wedding or getting a promotion. Dystress causes deterioration. Falling pregnant could be termed as dystress if you are a single teenager who does not want the baby, whereas it could be eustress for a married couple who have planned a family.

There are a vast number of emotional states, and each person’s body is likely to have a slightly different biochemical response to stress. Hormones and neurotransmitters may be produced in differing amounts, and thus immunological consequences may also be different (O’Leary, 1990). Ann O’Leary also differentiates different kinds of stress. Acute stress, chronic stress and stress related to social disruption have different effects on the bodily processes and thus the immune function. These stressors have also been studied as "adverse life experiences", in particular chronic stress and stress related to social disruption.

Acute stress is said to happen after a single event. Research cited by O’Leary shows that an acute stress event is related to immune cell functioning decreasing, although studies have shown either an increase or decrease in the lymphocyte count. Fischer et al, (1972) found higher lymphocyte counts in Apollo astronauts during splashdown. Kiecolt-Glaser et al (1984) studied the effects of examinations on medical students and found a decrease in lymphocytes, a decrease in natural killer (NK) cells and a decrease in helper T cells (Ader, 1991).

Chronic stress was researched by Arnetz, 1987 studying unemployment in Sweden, where the unemployed receive 90% of their previous pay, and thus this excludes many factors such as loss of food or shelter. Thus only the psychological effects of unemployment were studied with findings that showed a decrease lymphocyte response to pathogens (O’Leary, 1991).

Stress with social disruption focuses predominantly on mortality studies following bereavement. Bartrop et al (1977) found a decrease in lymphocytes in surviving spouses 8 weeks following bereavement. Shortly after, Schleifer et al (1979) did a prospective study 1 weeks before and 5-7 weeks after the bereavement, and found a decrease in the lymphocytes reactions to antigens (Volhardt, 1991).

Thus it is clear that various types of stressors and psychosocial factors (such as loneliness, unemployment, grief and exam stress) do compromise the immune system in various ways. Maier et al (1994) cites a study by Lysle et al (1990) where just thinking about a stressful event brings about changes in the immune system, and how a learned signal, e.g. just a light or tone, can be associated with stress. The implication of this on our health and the treatment of diseases is profound as it promotes a holistic and systemic way to view people.

Immunosuppressive behaviour affect PNI studies, and studies have been done on various behaviours, such as sleep patterns, drug use and alcohol use (Kaplan, 1991). Palmblad et al, (1976) found decreased lymphocytes responses to mitogens during sleep deprivation studies. Excessive cigarette smoking, alcohol consumption, and the use of drugs have all shown various negative affects on the immune system (Kaplan, 1991).

Kaplan (1991) links dysphoria to decreases in immune functioning. Dysphoria is characterised by loneliness, anxiety, hostility, unhappiness, depressive affect and clinical depression. O’Leary (1991) describes social-deprivation stress where Russell et al (1980) studied medical students according to the UCLA Loneliness Scale and found correlations between high scoring students (more loneliness) and a decrease in NK cell activity. Reduced immunocompetence has also been related to recently divorced and separated women who are possibly lonely (Kiecolt-Glaser, 1987 in O’Leary, 1991).

Vulnerability characteristic or personality characteristics that one is either born with or develops, have been examined by many researchers. Themes of "hardiness", a fighting spirit and independence have been found to correlate well with immune competence. Greer et al (1979) studied women with breast cancer and their attitude following a mastectomy (Volhardt, 1991). Women with a fighting spirit were found to survive longer that woman who had stoic appearances or an attitude of hopelessness. Fry and Kobasa (1982) described "hardiness" as a deeply involved commitment, a sense of controlling your own health and being challenged by change (Ader, 1991). Studies showed that people with more "hardiness" characteristics, showed a higher NK cell activity and more immune competence. Ader also cites an interesting study by Simonton and Simonton researching cancer patients recovery and prognosis according to their personalities. The more independent, uncooperative and seemingly "difficult" patient showed better recovery that the "martyrs" who always put themselves last, relinquish their will and spirits and are seen as the "perfect patients. Suppressing one’s emotions has also been found to be linked to an impaired immune function (Jamner et al, 1988 and Temoshok et al, 1985). The inhibition of power motivation and a strong belief in one’s own locus of control have also been linked to immune responses (O’Leary, 1990).

Bearing in mind that psychosocial stressors of any kind, and different personality types impact on our immune functioning, and thus our health, let us now examine the implications of these findings to treatment of illness, and ways to promote health.

Various research has been done with similar methodologies. Kiecolt-Glaser et al (1984) and Bradley et al, (1985) researched geriatrics and rheumatoid arthritis suffers respectively. Both studies divided the sample population into 3 groups and gave one group social support, one group no intervention and the last group relaxation training and cognitive behavioural therapy respectively. In both studies that last group was found to have greater immune competence (O’Leary, 1990). Much research on social support has been done supporting it’s link to improved health (Pilisuk and Parks (1986) in Volhardt, 1991). A greater degree of social outreach has been shown to enhance the immune function. This study by McClelland and Kirshnit (1984) showed increased immunoglobin levels when subjects watched a film about Mother Teresa’s work (Volhardt, 1991). Hypnosis studies by Pelletier and Herzing (1988) have shown the hypnotic ability had helped various diseases, mostly skin related, however there has been criticism owing to the placebo affect in this study (Volhardt, 1991 and Kiecolt-Glaser, 1986). Physical exercise has been studied as a behavioural intervention and has been found to stimulate the immune function (Laperriere et al, 1988 in O’Leary, 1990). Kobasa et al (1982) found that "hardiness" combined with exercise was effective as an immunecompetence enhancer, as the hardiness helped to cognitively transform the stressful event, and the exercise decreased the strain of the stress on the organs (Volhardt, 1991). Ader (1991) even suggests medicinal mushrooms, algae, herbs, fasting, cultivating a sense of humour, sunlight, service activities, touch and music as promoting a healthy immune system.

The pyshosocial stressors and various studies on stress on the immune system have been discussed. It is evident that the "tip of the iceberg" is showing fascinating linkages between the mind and body. There are many difficulties with this research however, as many variables come into play. Psychoimmunological relationships have been proven to differ between the young and the old, and various therapies are possibly more effective at different ages, as social support is more important to the ageing population (O’Leary, 1990). It has also been mentioned that different stressors and different pyshosocial events can affect people in different ways and have different outcomes (Maier et al, 1994). It is a fascinating field of research as it directly affects many of your own behaviours, for example: your own attitude towards disease, your attitude to life, the way you express your emotions and your relaxation practices. Psychosocial factors impact on our bodies, and perhaps it is how we understand, interpret and deal with them that will determine our general well-being.

Five Methodological problems and possible ways of alleviation.

Healthy subjects are often subjects of various immunological research (e.g. medical students) and the changes in immune function have a small significance. Even if there was a large change in immune function, these subjects may not fall ill. Glaser et al (1987) tried to alleviate this difficulty by studying self-reported illness during exam time. Many criticism remain because results may be affected by exam demands and neuroticism. Research that studies non-healthy populations overcomes this problem (e.g. HIV-1 sufferers or RA patients).

The relationships between the psychosocial stress and the immune function may also be affected by changes in diet, exercise and sleep patterns, in particular studies involving students at exam times. They may be taking in more caffeine and alcohol in order to stay awake or relax respectively, and may not have adequate time for exercise and healthy eating. Is the stress itself causing immune changes or is it all these other factors? O’Leary (1990) discusses how some studies have built the same sleep and food variables into their studies however results do not account for any changes to immunity. This problem can be overcome by doing further studies using more laboratory situations to discount other factors.

Patient heterogeneity is a difficulty as, for example, studying depressives requires one to be specific about whether they are hospitalised or not, their age, their sex, and these factors affect the immune response of the individuals (Miller et al, 1993). The solution is thus to study only a specific population of depressives, e.g. 20 - 30 years olds, females, hospitalised - in order to draw inferences from the study. This posed problems in research settings, as the population of this specific population may not be large enough to draw reliable inferences.

Variability in immune assays is a clinical difficulty, as lymphocyte proliferation occurs at different rates over a number of days and the culture should be double checked by different laboratories (Miller et al, 1993). The solution here, could possibly be take a number of samples, or cultures from one source and study them continuously for a number of days.

The greatest methodological problem with PNI research is the difficulty is separating the psychological and physical influences when we have seen studies that show that even a stressful thought will affect your immune response. Foss and Rothenberg (1988) liken PNI to the systems approach and indeed the view of PNI is a holistic view of all internal and external component working together (Volhardt, 1991). To overcome this problem when doing research, prospective studies or highly specific studies need to be done to find causal links between two related aspects of research. Antoni et al (1990) when researching HIV-1 infections, proposes long-term longitudinal studies for this difficult.

A conclusions about the state of knowledge regarding PNI implications of depression, schizophrenia and HIV-1 infection.

Popular research subjects include depression, schizophrenia and HIV-1 infection, and how these relate to the immune functioning. The research is in these areas is showing new complexities and different inferences constantly.

Over 30 studies have been done on depression, with inconsistent results (Miller et al, 1993). People suffering from Major Depressive Disorder have been shown to have impaired immune systems (O’Leary, 1990). More complex connections have been shown between depression, adrenal steroids and immune responses (Miller et al, 1993). Various studies have been criticised for patient heterogeneity and variability in immune assays (Miller et al, 1993). Research in the area of depression appears to be inconclusive, although various studies show a link between depression and poor immune functioning.

Ganguli et al (1993), has been researching Schizophrenia for 10 years, and it’s link to the immune system, more specifically characteristics of autoimmune diseases such as rheumatoid arthritis and multiple sclerosis. Although this research is not conclusive about the role of autoimmunity in schizophrenia, there does appear to be a link. The issue of vulnerability factors is discussed in this research questioning whether autoimmune diseases lead to schizophrenia (Ganguli et al, 1993).

Research on HIV-1 infection has also been found to be a very complex area of study. Many biological pathways exist in the HIV-1 infection and a link has been found to exist, but whether it hastens the progression of the virus is not conclusive (Kemeny, 1994). Antoni et al, (1990) did a study on seropositive and seronegative gay subjects before and after being giving the news about their antibody status. The seropositive subjects showed an increase in immune functioning before being giving the news, possibly because they were able to mobilise their "fight" response. After being given the news, their immune function returned to base line. The seronegative subjects showed no differences either before or after. This could possibly be due to an already compromised system that is insensitive to psychosocial stressors (Antoni et al, 1990). This research thus questions the role of a "sluggish" immune system and whether psychosocial stressors will in fact suppress the immune system. O’Leary (1990) also debates the clarity of HIV research, as other opportunistic infections may mask the psychoimmune relationships.

Thus research in the areas of depression, HIV-1 infection and schizophrenia all appear to show a relationship to the immune functioning of the body, but tend to be inconclusive and inconsistent as to the exact nature of the relationship.

REFERENCES:

Books:

Ader, R. (Ed.) (1991). Psychoneuroimmunology. New York: Academic Press.

Journal Articles:

Antoni, M.H., Schneiderman, N., Fletcher, M.A. & Goldstein, D.A. (1990). Psychoneuroimmunology and HIV-1. Journal of Consulting and Clinical Psychology, 58 (1), 38 - 49.

Ganguli, R., Brar, J.S., Chengappa, K.N.R., Yang, Z.W., Nimgaonkar, V.L. & Rabin, B.S. (1993). Autoimmunity in schizophrenia: A review of recent findings. Annals of medicine, 25 (5), 489-496.

Kaplan, H.B. (1991), Social psychology of the immune system: A conceptual framework and review of the literature. Social Science and Medicine, 33 (8), 909-923.

Kemeny, M.E. (1994). Psychoneuroimmunology of HIV infection. Psychiatric Clinics of North America, 17 (1), 55 -68.

Kiecolt-Glaser, J.K., & Glaser, R. (1992). Psychneuroimmunology: Can psychological interventions modulate immunity? Journal of consulting and Clinical Psychology, 60 (4), 569-575.

Maier, S.F., Watkins, L.R. & Fleshner, M. (1994). Psychneuroimmunology: The interface between behaviour, brain and immunity. American Psychologist, 49 (12) 1004 - 1017.

Miller, A.H., Spencer, R.L., McEwen, B.S. & Stein, M. (1993). Depression, adrenal steroids and the immune system. Annals of Medicine, 25 (5), 481-487.

O’Leary, A. (1990). Stress, emotion and human immune function. Psychological Bulletin, 108 (3), 363 - 382.

Volhardt, L.T. (1991). Psychneuroimmunology: A literature review. American Journal of Orthopsychiatry, 61 (1), 35-47.