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Psychology

<OpenstaxParagraph>
	As previously stated, scientific interest in stress goes back nearly a century. One of the early pioneers in the study of stress was Walter <OpenstaxTerm>Cannon</OpenstaxTerm>, an eminent American physiologist at Harvard Medical School (<a href="#CNX_Psych_14_01_Cannon">Figure 14.7</a>). In the early part of the 20th century, Cannon was the first to identify the body’s physiological reactions to stress.
</OpenstaxParagraph>
<OpenstaxFigure id="CNX_Psych_14_01_Cannon" src="https://openstax.org/apps/archive/20240226.174525/resources/1bc38fe421b60eb6ce39e8309915aa15ca61458d" alt="A photo of Walter Cannon is shown." mediaType="image/jpeg" width="244" height="313" />
<OpenstaxFigureText width="244">
	Figure 14.7 Harvard physiologist Walter Cannon first articulated and named the fight-or-flight response, the nervous system’s sympathetic response to a significant stressor.
</OpenstaxFigureText>
<OpenstaxH3>Cannon and the Fight-or-Flight Response</OpenstaxH3>
<OpenstaxParagraph>
	Imagine that you are hiking in the beautiful mountains of Colorado on a warm and sunny spring day. At one point during your hike, a large, frightening-looking black bear appears from behind a stand of trees and sits about 50 yards from you. The bear notices you, sits up, and begins to lumber in your direction. In addition to thinking, “This is definitely not good,” a constellation of physiological reactions begins to take place inside you. Prompted by a deluge of epinephrine (adrenaline) and norepinephrine (noradrenaline) from your adrenal glands, your pupils begin to dilate. Your heart starts to pound and speeds up, you begin to breathe heavily and perspire, you get butterflies in your stomach, and your muscles become tense, preparing you to take some kind of direct action. Cannon proposed that this reaction, which he called the <OpenstaxTerm>fight-or-flight response</OpenstaxTerm>, occurs when a person experiences very strong emotions—especially those associated with a perceived threat (Cannon, 1932). During the fight-or-flight response, the body is rapidly aroused by activation of both the sympathetic nervous system and the endocrine system (<a href="#CNX_Psych_14_01_FightFlight">Figure 14.8</a>). This arousal helps prepare the person to either fight or flee from a perceived threat.
</OpenstaxParagraph>
<OpenstaxFigure id="CNX_Psych_14_01_FightFlight" src="https://openstax.org/apps/archive/20240226.174525/resources/d4446b3d0e495e8cdc2c47d61351ddfa83f39531" alt="A figure shows the basic outline of a human body and indicates the body’s various responses to fight or flight, including: pupils dilate, heart rate increases, muscles tense and may tremble, respiration quickens, bronchial tubes dilate, and perspiration begins." mediaType="image/jpeg" width="975" height="546" />
<OpenstaxFigureText width="975">
	Figure 14.8 Fight or flight is a physiological response to a stressor.
</OpenstaxFigureText>
<OpenstaxParagraph>
	According to Cannon, the fight-or-flight response is a built-in mechanism that assists in maintaining homeostasis—an internal environment in which physiological variables such as blood pressure, respiration, digestion, and temperature are stabilized at levels optimal for survival. Thus, Cannon viewed the fight-or-flight response as adaptive because it enables people to adjust internally and externally to threats in their environment, allowing them to continue to be alive and overcome the threat.
</OpenstaxParagraph>
<OpenstaxH3>Selye and the General Adaptation Syndrome</OpenstaxH3>
<OpenstaxParagraph>
	Another important early contributor to the stress field was Hans <OpenstaxTerm>Selye</OpenstaxTerm>, mentioned earlier. He would eventually become one of the world’s foremost experts in the study of stress (<a href="#CNX_Psych_14_01_Hans_Selye">Figure 14.9</a>). As a young assistant in the biochemistry department at McGill University in the 1930s, Selye was engaged in research involving sex hormones in rats. Although he was unable to find an answer for what he was initially researching, he incidentally discovered that when exposed to prolonged negative stimulation (stressors)—such as extreme cold, surgical injury, excessive muscular exercise, and shock—the rats showed signs of adrenal enlargement, thymus and lymph node shrinkage, and stomach ulceration. Selye realized that these responses were triggered by a coordinated series of physiological reactions that unfold over time during continued exposure to a stressor. These physiological reactions were nonspecific, which means that regardless of the type of stressor, the same pattern of reactions would occur. What Selye discovered was the <OpenstaxTerm>general adaptation syndrome</OpenstaxTerm>, the body’s nonspecific physiological response to stress.
</OpenstaxParagraph>
<OpenstaxFigure id="CNX_Psych_14_01_Hans_Selye" src="https://openstax.org/apps/archive/20240226.174525/resources/9b8a6fbb06dc305d1050e1498e1a512cd7a31b7d" alt="A stamp featuring Hans Selye is shown." mediaType="image/jpeg" width="325" height="189" />
<OpenstaxFigureText width="325">
	Figure 14.9 Hans Selye specialized in research about stress. In 2009, his native Hungary honored his work with this stamp, released in conjunction with the 2nd annual World Conference on Stress.
</OpenstaxFigureText>
<OpenstaxParagraph>
	The general adaptation syndrome, shown in <a href="#CNX_Psych_14_01_Adaptation">Figure 14.10</a>, consists of three stages: (1) alarm reaction, (2) stage of resistance, and (3) stage of exhaustion (Selye, 1936; 1976). <OpenstaxTerm>Alarm reaction</OpenstaxTerm> describes the body’s immediate reaction upon facing a threatening situation or emergency, and it is roughly analogous to the fight-or-flight response described by Cannon. During an alarm reaction, you are alerted to a stressor, and your body alarms you with a cascade of physiological reactions that provide you with the energy to manage the situation. A person who wakes up in the middle of the night to discover her house is on fire, for example, is experiencing an alarm reaction.
</OpenstaxParagraph>
<OpenstaxFigure id="CNX_Psych_14_01_Adaptation" src="https://openstax.org/apps/archive/20240226.174525/resources/7b8e075a73cce599a7fd57d981d9b1de55b759de" alt="A graph shows the three stages of Selye’s general adaption syndrome: alarm reaction, resistance, and exhaustion. The x-axis represents time while the y-axis represents stress levels. The x-axis is labeled “Time” and the y-axis is labeled “Stress resistance.” The graph shows that an increase in time and stress ultimately leads to exhaustion." mediaType="image/jpeg" width="649" height="346" />
<OpenstaxFigureText width="649">
	Figure 14.10 The three stages of Selye’s general adaptation syndrome are shown in this graph. Prolonged stress ultimately results in exhaustion.
</OpenstaxFigureText>
<OpenstaxParagraph>
	If exposure to a stressor is prolonged, the organism will enter the <OpenstaxTerm>stage of resistance</OpenstaxTerm>. During this stage, the initial shock of alarm reaction has worn off and the body has adapted to the stressor. Nevertheless, the body also remains on alert and is prepared to respond as it did during the alarm reaction, although with less intensity. For example, suppose a child who went missing is still missing 72 hours later. Although the parents would obviously remain extremely disturbed, the magnitude of physiological reactions would likely have diminished over the 72 intervening hours due to some adaptation to this event.
</OpenstaxParagraph>
<OpenstaxParagraph>
	If exposure to a stressor continues over a longer period of time, the <OpenstaxTerm>stage of exhaustion</OpenstaxTerm> ensues. At this stage, the person is no longer able to adapt to the stressor: the body’s ability to resist becomes depleted as physical wear takes its toll on the body’s tissues and organs. As a result, illness, disease, and other permanent damage to the body—even death—may occur. If a missing child still remained missing after three months, the long-term stress associated with this situation may cause a parent to literally faint with exhaustion at some point or even to develop a serious and irreversible illness.
</OpenstaxParagraph>
<OpenstaxParagraph>
	In short, Selye’s general adaptation syndrome suggests that stressors tax the body via a three-phase process—an initial jolt, subsequent readjustment, and a later depletion of all physical resources—that ultimately lays the groundwork for serious health problems and even death. It should be pointed out, however, that this model is a response-based conceptualization of stress, focusing exclusively on the body’s physical responses while largely ignoring psychological factors such as appraisal and interpretation of threats. Nevertheless, Selye’s model has had an enormous impact on the field of stress because it offers a general explanation for how stress can lead to physical damage and, thus, disease. As we shall discuss later, prolonged or repeated stress has been implicated in development of a number of disorders such as hypertension and coronary artery disease.
</OpenstaxParagraph>

14.1.3 Early Contributions to the Study of Stress

1 Introduction to Psychology

1.1 What Is Psychology?

1.1.1 Why Study Psychology?

1.2 History of Psychology

1.2.1 Wundt and Structuralism

1.2.2 Functionalism

1.2.3 Freud and Psychoanalytic Theory

1.2.4 Wertheimer, Koffka, Köhler, and Gestalt Psychology

1.2.5 Pavlov, Watson, Skinner, and Behaviorism

1.2.6 Maslow, Rogers, and Humanism

1.2.7 The Cognitive Revolution

1.2.8 Multicultural And Cross-Cultural Psychology

1.2.9 Women in Psychology

1.3 Contemporary Psychology

1.3.1 Biopsychology and Evolutionary Psychology

1.3.2 Sensation and Perception

1.3.3 Cognitive Psychology

1.3.4 Developmental Psychology

1.3.5 Personality Psychology

1.3.6 Social Psychology

1.3.7 Industrial-Organizational Psychology

1.3.8 Health Psychology

1.3.9 Sport and Exercise Psychology

1.3.10 Clinical Psychology

1.3.11 Forensic Psychology

1.4 Careers in Psychology

1.4.1 Other Careers in Academic Settings

1.4.2 Career Options Outside of Academic Settings

2 Psychological Research

2.1 Why Is Research Important?

2.1.1 Use of Research Information

2.1.2 NOTABLE RESEARCHERS

2.1.3 The Process of Scientific Research

2.2 Approaches to Research

2.2.1 Clinical or Case Studies

2.2.2 Naturalistic Observation

2.2.3 Surveys

2.2.4 Archival Research

2.2.5 Longitudinal and Cross-Sectional Research

2.3 Analyzing Findings

2.3.1 Correlational Research

2.3.2 Causality: Conducting Experiments and Using the Data

2.3.3 Reliability and Validity

2.4 Ethics

2.4.1 Research Involving Human Participants

2.4.2 Research Involving Animal Subjects

3 Biopsychology

3.1 Human Genetics

3.1.1 Genetic Variation

3.1.2 Gene-Environment Interactions

3.2 Cells of the Nervous System

3.2.1 Neuron Structure

3.2.2 Neuronal Communication

3.2.3 Neurotransmitters and Drugs

3.3 Parts of the Nervous System

3.3.1 Peripheral Nervous System

3.4 The Brain and Spinal Cord

3.4.1 The Spinal Cord

3.4.2 The Two Hemispheres

3.4.3 Forebrain Structures

3.4.4 Midbrain and Hindbrain Structures

3.4.5 Brain Imaging

3.5 The Endocrine System

3.5.1 Major Glands

4 States of Consciousness

4.1 What Is Consciousness?

4.1.1 Biological Rhythms

4.1.2 Problems With Circadian Rhythms

4.2 Sleep and Why We Sleep

4.2.1 What is Sleep?

4.2.2 Why Do We Sleep?

4.3 Stages of Sleep

4.3.1 NREM Stages of Sleep

4.3.2 REM Sleep

4.4 Sleep Problems and Disorders

4.4.1 Insomnia

4.4.2 Parasomnias

4.4.3 Sleep Apnea

4.4.4 Narcolepsy

4.5 Substance Use and Abuse

4.5.1 Substance Use Disorders

4.5.2 Drug Categories

4.6 Other States of Consciousness

4.6.1 Hypnosis

4.6.2 Meditation

5 Sensation and Perception

5.1 Sensation versus Perception

5.1.1 Sensation

5.1.2 Perception

5.2 Waves and Wavelengths

5.2.1 Amplitude and Wavelength

5.2.2 Light Waves

5.2.3 Sound Waves

5.3 Vision

5.3.1 Anatomy of the Visual System

5.3.2 Color and Depth Perception

5.4 Hearing

5.4.1 Anatomy of the Auditory System

5.4.2 Pitch Perception

Question	Answer
first stage of the general adaptation syndrome; characterized as the body’s immediate physiological reaction to a threatening situation or some other emergency; analogous to the fight-or-flight response	alarm reaction
set of physiological reactions (increases in blood pressure, heart rate, respiration rate, and sweat) that occur when an individual encounters a perceived threat; these reactions are produced by activation of the sympathetic nervous system and the endocrine system	fight-or-flight response
Hans Selye’s three-stage model of the body’s physiological reactions to stress and the process of stress adaptation: alarm reaction, stage of resistance, and stage of exhaustion	general adaptation syndrome
third stage of the general adaptation syndrome; the body’s ability to resist stress becomes depleted; illness, disease, and even death may occur	stage of exhaustion
second stage of the general adaptation syndrome; the body adapts to a stressor for a period of time	stage of resistance