BBH 311- L6

Appraisal and Coping (Richard Lazarus)

Against the backdrop of physiological responses to threat, psychologists such as Richard Lazarus and others have added and expanded important psychological dimensions to the stress concept. Research and theory in biological and psychological traditions developed independently of one another. Only later did scientists begin to integrate psychological and biological components into a unified theory of stress. Lazarus' theories were almost as exclusively psychological as Selye's were exclusively physiological. Lazarus made the study of stress more complex and challenging. Like other aspects of behavior, psychological stressors cannot be measured directly. Instead, they are inferred from responses or defined in terms of the situations in which they arise. Lazarus emphasized the role of perception and cognitive appraisal in the stress response. He suggested that unless we perceive a situation as threatening, we will not experience stress. Stressful appraisals may involve evaluation of harm or potential loss; threat of danger, harm, or loss; and challenge. When exposed to potentially stressful situations, we make a primary appraise of the setting and judge how threatening, harmful or challenging it is to us. This primary appraisal process can lead to other appraisals. Secondary appraisals are made after a situation is judged and threatening and stressful. These secondary appraisal processes turn our attention to evaluating the dangers or benefits of different types of coping with the perceived threats. For example, the perception of danger will lead to a search for a coping response that will reduce the threat. Thus, coping behaviors are an important part of the stress response (recall the Baum figure from earlier in the lesson). Theories of psychological stress have continued to evolve, and stress increasingly is portrayed as an emotional state. We will discuss coping responses and emotions in future lessons.

Autonomic Nervous System

Before we discuss the evolution of the stress concept, we need to learn about how the autonomic nervous system, a key physiological component of stress, works. The autonomic nervous system (ANS) is part of the peripheral nervous system that connects involuntary muscles in organs such as the lungs, stomach, and kidneys. The ANS controls the viscera, the organs that produce and/or supply nourishment to the body, and rid the body of waste products. These basic functions are necessary for survival. The ANS typically operates below our level of awareness, however, we often are aware of its effects (e.g., breathing). Thus, this system often is referred to as being "automatic" to preserve optimal body functioning. The ANS is subdivided in to two parts: the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). These two systems generally affect the same organs to preserve our body functioning, but do so in very different ways. These systems typically work against or in opposition to one another. The SNS arouses many systems of the body to work harder and to increase blood flow and glucose production. It is a catabolic system which means that it generally breaks down stored energy to create usable energy. The SNS arouses and mobilizes the body for action, stimulating organs needed for action and inhibiting organs that are not involved in this mobilization. The PNS counteracts arousal (SNS) when it no longer is needed. It is an anabolic system which means that it restores the body's reserves of stored energy. Together, the SNS and PNS work together to maintain homeostasis, the tendency of the body to maintain a condition of balance or equilibrium within its internal environment. Stressors disrupt this physiological homeostasis, which engages the ANS. Next we will discuss the history of the stress concept.

Stressors

Environmental and psychological events that pose threats or challenge us are called stressors. Under certain conditions, these events give rise to a stress reaction that is characterized by feelings such as anxiety, fear and anger. As stress unfolds, the entire body is altered. Biochemical, physiological, behavioral and psychological changes, many of which are directly related to health, occur as part of the stress response. Stressors are sources of challenges, danger or threats to an organism. Regardless of their origin or the kinds of dangers they present, stressors evoke a biobehavioral response from the organism. As you might imagine, not all events are equally stressful for everyone, and there is no single event that is stressful for everyone, although there probably are exceptions with the most extreme types of stressors - ones that involve the potential loss of life, limb or property. In those extreme circumstances, we would expect responses to the stressor to be more consistent across individuals. In general, the less severe the threat or weaker the stressor, the more variation we see in how people respond to the stressor or whether they view it as a stressor at all. Overall, stressors vary in many ways, including: Type of stressor Duration of the stressor Frequency of occurrence Take a moment to reflect on two things that have happened in the last week that you would label "stressful." As you reflect on these events, make a list for each related to the dimensions of stress listed above. As you compare and contrast the two events, think about: How are they similar? How do they differ? (E.g., perhaps your two stressors differed by type and duration.) Let's consider each of these areas more closely. Type of Stressors Below are six types of stressors. In addition to the examples provided, see if you can think of any other stressors that might fall into that type. Environmental: e.g., noise, traffic, living conditions Physical: e.g., exercise Microbial: e.g., having the flu, being sick Situational (social): e.g., family, roommates, employer Psychological: e.g., cognitive interference, multitasking Emotional: e.g., anxiety, anger These categories are general and presented to get you thinking about the many ways that our internal and external environments can trigger stress. Can you think of any other types of stressors? Also, as you review the list above, you may find that some categories blend together. Duration of Stressors There also are several general ways to categorize the duration of stressors. Can you think of other examples for each besides the ones provided? Acute: Acute stressors happen once and then are over. E.g., taking an examination or giving a speech. Repeated acute: These are stressors that occur over and over again, but are brief in duration. E.g., weekly exams in a class. Chronic: Chronic stressors are always present. E.g., poverty, job strain, a bad relationship. Anticipated: Anticipated stressors have not happened yet, but will at some point in the future. E.g., starting a new job, graduating from college, final exams week. Remembered: Remembered stressors are stressors that we do not need to experience again in order to relive the event. E.g., remembering the events of September 11th can bring back traumatic memories for many people, recalling the death of a loved on their birthday or re-experiencing the anxiety and fear associated with a traumatic event, as in Post-Traumatic Stress Disorder (PTSD) all can be stressors. Take a moment and reflect on this question: At what point would you think a repeated acute stressor become a chronic stressor? This is a great question and one that scientists spend a good deal of time trying to understand. Frequency of Occurrence By this point you probably are realizing that the stressors we encounter in our lives vary wildly by how often they occur. Some stressors, like a bad marriage, a difficult co-worker or living in poor housing conditions, occur daily. Others, such as a flat tire, occur infrequently if ever at all (depending on your car, of course!). There is a wide range of frequency with which stressors occur, and are different for everyone. Next we will review the different dimensions of a stressor.

Nonspecific Theory of Stress (Hans Selye)

Hans Selye was an Austrian-Canadian endocrinologist whose pioneering research across four decades on non-specific responses of organisms to stressors was a turning point for stress research. Selye did much to popularize the notion of stress and to bring it to the attention of scientists across many disciplines. In doing so, he stimulated extensive amounts of research, much of which came from his own lab. Selye's work on stress began as an accident. In studying sex hormones, he found that injections of extracts from ovary tissue into animals caused an unexpected and unexplainable triad of responses: Involution (shrinkage) of the thymus gland, which plays an important role in immune function Enlargement of the adrenal glands, which release glucocorticoids from the adrenal cortex. Glucocorticoids (glucose + cortex + steroid) are steroid hormones released from the adrenal cortex, and play a key role in the regulation of glucose metabolism. Gastric ulcers Following up on this discovery, Selye observed that injections of extracts of other organs as well as substances not derived from bodily tissue caused this triad of responses in the organisms (typically rats). In fact, each time he applied anything painful or harmful, such as application of hot or cold, x-ray exposure, exercise, injections of insulin, Selye observed this triad of responses. Eventually he referred to these changes as a Universal Triad of stress effects, and argued that the responses that caused these changes were non-specific because they appeared to be caused by any noxious or aversive event. Take a moment and reflect about your own experiences reacting to stress. In your experience, are your stress reactions universal? How or how not? As a result of your reflections, do you observe any problems with this theory? You are not alone. Selye's non-specific response theory has come under more fire than any other aspect of his theory. Because nearly everything that he did to his organisms resulted in the same response, Selye believed that stress was a specific syndrome that followed certain specific patterns and altered specific organs, but that is was non-specifically induced. As result, the stress response was the same regardless of the stimulus or triggering event. The stress response in this view is primarily characterized by glucocorticoid release. This theory rules out psychological mechanisms in determining responses to a stressor. This begs the question of whether or not we need psychological mechanisms or processing in order to be stressed. If we assume that the nonspecific nature of stress is limited to our initial responses to a stressor, then perhaps our later reactions are mediated by several biobehavioral factors including appraisal, which is how we view the stressors.

Aftereffects of Stress (Glass and Singer)

Recall in our working definition of stress at the beginning of the lesson that we listed five interacting elements of stress. So far, we have discussed potential stressors, appraisal processes, coping and the wear and tear on the body. The last interacting element is aftereffects. Aftereffects are the effects of the stressor that appear after the stressor has ended. Glass & Singer (1972) emphasized that the effects of stress can linger after the stressor has ended and that the observed effects of stress depend on when stress responses are measured. Considering the above diagram, take a few moments and think about taking exams. How do you feel before an exam? How do you feel during an exam? And how do you feel after an exam has ended. Prior to the exam you may feel anticipatory stress - studying, thinking about the pending exam, and your thoughts may be pre-occupied with the exam details. Now, during the exam, your attention is focused and all your energy and effort are going in to performing well on the exam. Once the exam is over, how do you feel? Relieved, sleepy, excited, hungry, worried about how you may have performed. The idea is that your experience of the exam differs depending on whether it is in the future, during the exam or after the exam ends. To put this in a broader context, take a moment to think about final exam week or a huge work-related deadline. You do what you have to do to meet the demands of the challenge: work longer hours, sleep less, focus your attention with caffeine, whatever it takes. In general, people do a pretty good job rising to the occasion to meet a deadline or get through finals or whatever challenge is facing them. Now, think about what happens afterwards. What happens when you finally get to take your vacation? You get sick! Many people are left wondering why their body waits until vacation to get sick. Or, why is it that we let our guard down and dig in to the big plate of nachos after work ends on a Friday afternoon? After the stressor is over is when we let our guard down and the body begins to recuperate and recover from the demands of the stressor. Recall that sometimes we experience acute stressors (an exam, presentation, meeting with your boss), and other times if might be a chronic background stressors (living with a bad roommate, interacting with a difficult colleague). Glass and Singer (1972) examined biobehavioral responses to these different types of stressors to better understand the stress process. They reported that predictability and controllability of stressors play a key role in physiological and behavioral responses to stress. As an example, imagine you are taking two classes. In the first class your final grade is based on three announced exams. In the second class your final grade is based on three unannounced exams. How would you attend to the exam stressors in these two classes? Being able to know the dates of your exams in the first class allows you to plan your time and attention accordingly. In other words, you can choose a coping strategy that best suits you and can plan for the upcoming stressful event. In the second class, you will remain on high alert all semester anticipating an unannounced exam each time you go to class. How often will you study? How do you plan your time? How do you plan for a stressor when you don't know when it will happen? In this scenario, predictability offers you some control over the coping response you can use to respond to the situation. In other words, being able to predict a stressor will lessen its effects on you - being forewarned is being forearmed.

General Adaptation Syndrome

Selye responded to criticisms of this theory with the development of the General Adaptation Syndrome (GAS) to describe three stages of responses to stressors: alarm, resistance and exhaustion. General Adaption Syndrome - Stress curve and phases Alarm Phase This is the first phase where the organism becomes aware of the stressor or noxious stimulus. In this phase, the organism prepares to resist the stressor. Adrenal gland activity and cardiovascular and respiratory function increase. Large amounts of glucocorticoids are released from the adrenal cortex and the body is ready to respond. Resistance Phase When reserves are ready and circulating glucocorticoids have reached peak levels, the organism enters the resistance phase, applying various coping mechanisms to help achieve suitable adaptation to the stressor. During this stage, there is relatively constant resistance to the stressor, but a decrease in resistance to other stimuli (e.g., bacteria). If the organism successfully adapts to the stressor, then the response ends. Otherwise, the organism enters the exhaustion phase. Exhaustion Phase When these resistance actions are repeated many times or are prolonged because of a recurring problem or inability to adapt to the stressor, the organism enters the exhaustion phase which places it at risk for irreversible physiologic damage. In this phase, the organism has depleted all adaptive resources and resistance no longer is possible. The end result of exhaustion is the onset of diseases of maladaptation such as kidney disease, arthritis, and cardiovascular disease. This model of rise and fall in adaptation that Selye created has been invaluable as a model for understanding how stress leads to resistance and physiological damage - the links between stress and health. The specific mechanisms through which resistance and exhaustion lead to physiological damage continue to be investigated today, and we will explore many of these mechanisms in this course. The primary theme of Selye's GAS model is the non-specific response in the presence of any stressor results in a triad of biological responses that are irreversible. Summary of Selye's GAS Phase Neuroendocrine effect Alarm reaction Activation of nervous system and adrenal glands Resistance phase HPA axis activation Tissue changes Adrenal hypertrophy, gastrointestinal ulceration, thymic and lymphoid atrophy Exhaustion phase May culminate in death

Specific Patterning of Biological Responses (John W. Mason)

Since Selye proposed the GAS nonspecific theory of stress researchers found evidence of specific patterning or responding of the adrenal corticosteroids to specific stressors. Mason was a noted psychobiologist who argued that psychological distress precedes the adrenal response to stress (e.g., cortisol, epinephrine) and may be necessary for a physiological stress response to occur. In short, while there may be circumstances in which the nonspecific stress response occurs without psychological input (e.g., viral invasion), the best research evidence suggests that awareness of a noxious condition and attempts to deal with it are crucial for a physiological stress response to occur. Thus, both perception and sensation are critical to the stress process. For example, Mason found that physical stressors (e.g., heat application) do not elicit an adrenal stress response when perception and sensation of the stressor are eliminated. Even earlier work by Symington and colleagues (1955) found that dying patients who remained conscious until they died displayed physiological symptoms of stress such as enlarged adrenal glands compared to dying patients who were in a coma until they passed away. Similar findings were reported regarding victims of a nightclub fire. Survivors of the fire were more likely to be free of post-traumatic stress disorder symptoms if they lost consciousness during the disaster compared to those victims who remained conscious (Adler, 1943). Similarly, Mason (1968) compared stress responses between starving rats that were fed non-nutritive food pellets and those who were not fed any food pellets. Rats who ate food pellets displayed fewer symptoms of stress compared to those who did not eat, even though both groups received similar caloric intake. In addition to clarifying the role of psychosocial stimuli in stress with regard to Selye's model, Mason focused on specific patterning of adrenal stress responses upon experiencing anger or fear. He expanded the cascade of biological responses induced by stressors to not only include the HPA- and SAM-axis responses, but also important energy regulators such as insulin, growth-related hormones, as well as sex hormones. In many ways, Mason was one of the forefathers of Biobehavioral Health in that he pointed to the importance of developmental hormones in biological responses to stress and the implications for general health and well-being.

Categories of Stressors

Some stressors are universally threatening and intrusive, as in the case of natural disasters. Other stressors are less universal and perhaps more psychological - such as traffic and overcrowding. Stressors differ in their scope, intensity and the number of people affected. There are four general categories of stressors based on the dimensions we just discussed: cataclysmic, personal, background, and chronic. Cataclysmic Stressors These sudden, sometimes catastrophic, events are powerful and elicit a universal stress response. They also require a significant coping effort. Events such as hurricanes, floods, torture, imprisonment and natural disasters would fall in to this category. The events of September 11th also are a cataclysmic event. These events initially evoke a dazed or freezing response by victims. Cataclysmic stressors typically affect a large group of individuals at the same time, which can play a key role in the recovery and coping process. In these situations we often find people helping one another to rebuild which can increase social cohesion in affected communities. The devastating 2011 Joplin tornado outbreak, Boston marathon bombing, and 2011 Tōhoku earthquake and tsunami disaster are great example of the cohesiveness brought to a community in the time of a disaster. Social media sites, such as gofundme pages now provide an opportunity to support survivors of cataclysmic events around the globe. Personal Stressors As with cataclysmic events, personal stressors can be unexpected and powerful. In contrast, however, personal stressors affect fewer people at any given time. This distinction is important because it alters the number of people with whom an individual can share the experience, such as loss of a parent or job, and divorce. These are incredibly stressful and personally challenging events that can create isolation and loneliness in people as they navigate the process with only a few people who can share in their pain. Sheryl Sandberg, COO of Facebook, challenged the isolation associated with the sudden loss of a spouse through her open, honest, and very public Facebook postings (Links to an external site.) Links to an external site. in the aftermath of her husband, David Goldberg's, death while on a family vacation in 2015. Yet despite the outpouring of support that someone as public as Sandberg has received in her darkest personal tragedy, she also recognizes the background stress that the loss of her partner has created in her life. Background Stressors Background stressors are persistent, repetitive, routine stressors that happen almost daily in our lives. As Sandberg eloquently notes in her 2016 Mother's Day Facebook posting (Links to an external site.) Links to an external site. , work-life balance became work all the time when she became a single parent overnight. These daily hassles in our lives are repetitive, stable and typically low-grade problems we encounter in the daily routines of our lives: commuting to and from work, caring for a sick child or parent, financial strains, etc. These stressors by themselves are less powerful than the cataclysmic or personal stressors noted above. However, over time, the cumulative effects of the daily hassles we experience over and over again can pose health threats. These stressors are chronic and the effects are cumulative. For example, on any given day, commuting to work in traffic by itself is not particularly threatening. At any given time, the traffic is coped with and not especially threatening. However, if this is your daily commute to and from work, then this commuter traffic is experienced often and, perhaps, indefinitely. This commute is not going to get better over time. In fact, it might get worse. Stressors such as these - persistent and unending - are chronic stressors and include environmental, job, illness, and parenting stressors. In these situations, the benefits of sharing these stressors with others are minimal. Even though many people share the highway for their work commute, the intensity is not sufficient to cause people to work together to change the outcomes, as seen with cataclysmic stressors. Chronic Stressors Daily hassles can be chronic stressors, but not all chronic stressors are mild like commuter traffic. Some chronic stressors can be quite dramatic and lead to long-term disruptions in daily life. An example would include people living in the nuclear fallout zones near the Fukushima Daini nuclear reactor plant in Japan 5 years after the earthquake-tsunami disaster. Residents in the downstream areas from the Fukushima nuclear plant disaster are faced with chronic threats associated with believing that they may have been exposed to radiation, and that their children will develop cancer or show genetic abnormalities sometime in the future as a result of this exposure. These cancers or health consequences of exposure may take years to be detected and are associated with years of worry and concern. This chronic uncertainty leads to persistent stress and worry.

Fight or Flight (W.B. Cannon)

Stress has been the focus of medicine and health for centuries. Yet most of what we know about stress has been learned over the last 120 years. The notion of stress as a term was formalized at the beginning of the 20th century by W.B. Cannon. A physiologist, Cannon was among the first to use the term "stress" to describe a powerful psychophysiological process that could contribute to medical disturbances. He suggested that stress had both physiological and psychological components. In studying emotions, he referred to "great emotional stress" to describe a powerful psychophysiological process that appeared to influence emotion. Cannon described the "fight-or-flight" response to threat that is used by organisms to survive. Recall that, when threated, the sympathetic nervous system (SNS) readies the organism by producing a heightened state of arousal. This heightened arousal state is caused by direct SNS activation of the adrenal medulla which results in release of the catecholamines, epinephrine and norepinephrine, in to the blood stream. Labelled the sympathetic-adrenal-medullary (SAM) axis, the flood of catecholamines into the bloodstream in response to threat immediately readies the organism to flight or flee by increasing the speed and intensity of body responses such as breathing and heart rate. In this sense, the stress response is a biochemical phenomenon related to our survival. There is very little time for processing the threat when confronted with some events. Consider a situation where you are driving down the highway and a deer darts from the woods into your lane. Your responses are immediate and you experience sensations such as a rapid heart rate, rapid breathing, pupil dilation, dry mouth and sweating as your tend to the challenge. Arousal occurs in an instant and increases the speed of your responses (swerving out of the way) to save your life. In these cases, the SAM axis response to stress increases your ability to overcome the threat (fight) or to flee. There is very little (or none) cognitive processing that takes place in the immediacy of the events. In this way, the SAM axis/fight-or-flight response to stress is a response designed to enhance our survival in the face of threats. It is an evolved response that has been maintained across species and evolution. Thus, the fight-or-flight response is a basic component of the stress response and one that still is studied today.

Can Stress Be Positive?

The experience of threat, harm, or any of the types of stressors discussed thus far is unpleasant, negative, and motivates us to find a way to reduce our discomfort. Yet not all stressors are negative events! Getting married, graduating from college, and having a baby are positive events, but certainly carry a certain burden of stress. It usually is the negative aspects of the events that are labelled stressful (Baum, 1990). The birth of a child is a significant, positive event that also is associated with disrupted routines, sleep patterns, interpersonal relationships and work, which can be labelled as stressful and negative. Selye (1984) coined the term eustress, or "good" stress, as the stress associated with positive events, such as getting married, graduating, moving, starting a new job. Eustress is differentiated from distress, the stress associated with negative events and a common description of our reactions to the negative stressors in our lives. The primary different between the two is the perception of the stressor or the context. Examine the figure below. Note that low levels of stress keep us in our comfort zone and that eustressors fall on the left side of the inverted U-shaped curve. In contrast, stressors that are perceived as distressing can push us over the peak of the curve into active and persistent coping, similar to Selye's exhaustion phase. In terms of the inverted u-shaped curves we discussed several weeks ago, low levels of stress or pressure can be motivating or even exciting - eustress. At some point, however, high levels of stress can lead to distress and, in the case of Selye's GAS, exhaustion. Consistent with his generalized nonspecific stress response theory, Selye (1984) argued that the body cannot differentiate between eustress and distress as both types of stressors require adaptation and change. It also may be that regardless of whether it is positive or negative, stress is induced by a negative component of the stressor (i.e., newborn baby associated with sleep loss). The concept of stress continued to evolve into the 1990s with a focus on the stress process, including stress appraisals, coping, social support and individual differences in the ways our bodies respond to stress.

Modern Concept of Stress: Stress as a Process

There are as many definitions of stress as there are things in our world that can get our heart racing and cause us to lose sleep. As we navigate the world of stress, it is important to develop a working definition as our foundation. In order to do that, let's first consider a general definition of stress, and expand that out into the working definition we'll use for this course. General Definition The following is a general definition of stress which assumes that organisms live in a world that contains threats (e.g., predators) and challenges (e.g., finding food) and that the world poses constantly changing demands that require organisms to adjust continually. "Stress is a process in which environmental or psychological events, called stressors, come to threaten an organism's safety and well-being." Baum, Grunberg & Singer (1982) This definition is by no means the only way to define stress. However, it is a useful start to think about stress in its environmental and evolutionary context if we are to understand the cascade of biobehavioral responses we call the stress response. The Stress Response We have a repertoire of complex biobehavioral responses designed to enhance our safety and well-being when faced with stressors. These responses are dependent on the situation...fight-or-flight in some situations, being vigilant in other situations, for example. Stress helps us run faster, increase our vigilance, and otherwise act more quickly or with greater efficacy in order to meet the demands of each situation. In other words, stress acts to amplify our coping responses or biobehavioral attempts to overcome or adapt to a stressor. Stress does not make the responses, stress makes the responses better. From an evolutionary perspective, it makes sense - we encounter harms and threats every day in our lives. You may recognize that moving away from home to start a new job, join the military or go to college may trigger considerable efforts on your part to succeed. As a result, these events are associated with biological and behavioral changes as we struggle to adapt to our new environment. On another level, extreme events such as the loss of a loved one, divorce, experiencing a natural disaster, losing a job, or financial strains can lead to changes in mental and physical health. It is not always clear that a stress response is useful in all situations. When stress is unusually prolonged or intense, these mental and physical changes may actually harm us. Thus, what starts out as an adaptive response to our environment can turn in to something that damages our health. In other words, when stressors occur, a complex biobehavioral response is evoked. This response can affect our health and well-being. Stress is a general activation process in which the body "turns itself on," becomes more vigilant and alert, and gathers strength to perform strong, quick reactions and/or sustained resistance to a stressor. In this BBH model of stress, mind and body are one as the central nervous system mediates reactions that affect and influence our thoughts, feelings, behaviors, memories and actions. A Circular Process? The concept of stress can be circular which complicates our understanding of it. In lay terms, stress is a pressure or tension we feel and the implication is that this feeling is aversive. When people say they are stressed, they are referring to the negative feelings and anxiety associated with having too much to do or coping with an unpleasant event. On the other hand, stress is something people identify as the presence of an event that requires coping and adjustment, and causes distress or tension. So, in one case stress is the feeling and in the other case stress is the object or event causing the discomfort. Yet stress is both a feeling AND the event causing discomfort. Thus, as much as we try to describe stress in simple terms to ourselves, stress is far too complicated to be reduced to our general definition. So let's now consider the working definition of stress we'll be using in this course. A Working Definition of Stress "Stress is a process by which environmental events (stressors) challenge or threaten us, how these threats are interpreted, how they make us feel, how we respond and adjust to them." (p. 63, Baum et al. 1997). The key word in this definition is PROCESS. Stress is a process that unfolds both in the environment and inside the individual. This psychophysiological definition of stress as a process includes five interacting elements: Stressors Appraisal processes Coping Aftereffects Wear and tear There are many aspects of this definition of stress that may not be universally accepted. Most scientists agree that both the presence of a stressor and awareness of the stressor by the organism are necessary to trigger a stress response, the mechanisms through which these processes occur vary greatly. This week we will discuss these complex, interacting biobehavioral elements of stress, theories, and how stress affects our health.

Dimensions of Stressors

We've already seen some ways in which stressors can vary. More specifically, Lazarus & Cohen (1977) have identified three general dimensions of stressors. These are: Duration of the stressor Magnitude of the stressor Number of people affected by the stressor Earthquakes might be a useful analogy to help conceptualize these dimensions. Duration: Similar to what was described on the prior page, duration relates to the how long the stressor lasts. Similar to earthquakes, stressor durations can be short, long or somewhere in between. Magnitude:The magnitude of the stressor refers to the intensity of the stressor. Number Affected: This refers to the number of people affected by the same stressor occurrence. For example, some stressors affect only an individual (you backed your car up in to a stop sign and damaged your tail light), a small group of people or an entire community (a tornado). These stressor dimensions play a large role in determining biobehavioral responses to the event.

Predictability and Controllability of Stressors

With regard to control, having some control over a stressor (whether real or perceived) lessens the effect of the stressor. To examine the biobehavioral effects of control over a stressor, Klein and colleagues (2004) asked men and women to complete several cognitive tasks for 25 minutes while being exposed to unpredictable bursts of noise that included loud office sounds (e.g., phones ringing, people speaking in different languages). Participants were placed into one of three conditions: no noise exposure, unpredictable noise exposure without control, and unpredictable noise exposure with perceived control. Many physiological and behavioral measures of stress responses were collected before, during and after the stressor, including heart rate and blood pressure. Take a few minutes to review the two figures below. As you review them, consider what might be different between that they had control? How might these differences influence blood pressure and heart rate responses after the stressor ends? Can you think of any stressors in your life that would apply to these two conditions of perceived control, and having no control? How do these experiences differ for you? These 2 graphs reveal that having perceived control reduces blood pressure and heart rate responses after the stressor. In other words, individuals who believed they had control over the unpredictable noise stressor were able to recover more quickly from the stressor. These individuals did not experience the aftereffects of stress as did those men and women who did not have control over the stressor. How do you think these results can apply to everyday life experiences that you have? Lesson 7 will review the biobehavioral consequences of stress and how we can cope with stress.