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Psychology

<OpenstaxParagraph>
	Two physical characteristics of a wave are amplitude and wavelength (<a href="#Figure_05_02_Wave">Figure 5.5</a>). The <OpenstaxTerm>amplitude</OpenstaxTerm> of a wave is the distance from the center line to the top point of the crest or the bottom point of the trough. <OpenstaxTerm>Wavelength</OpenstaxTerm> refers to the length of a wave from one peak to the next.
</OpenstaxParagraph>
<OpenstaxFigure id="Figure_05_02_Wave" src="https://openstax.org/apps/archive/20240226.174525/resources/f368dda40a3cd7572e8e21cb3d51ffc7a238290e" alt="A diagram illustrates the basic parts of a wave. Moving from left to right, the wavelength line begins above a straight horizontal line and falls and rises equally above and below that line. One of the areas where the wavelength line reaches its highest point is labeled “Crest.” A horizontal bracket, labeled “Wavelength,” extends from this area to the next peak. One of the areas where the wavelength reaches its lowest point is labeled “Trough.” A vertical bracket, labeled “Amplitude,” extends from the center line to the “Crest” or from the center line to a “Trough.”" mediaType="image/jpg" width="651" height="230" />
<OpenstaxFigureText width="651">
	<strong>Figure 5.5</strong> The amplitude or height of a wave is measured from the peak to the trough. The wavelength is measured from peak to peak.
</OpenstaxFigureText>
<OpenstaxParagraph>
	Wavelength is directly related to the frequency of a given wave form. <OpenstaxTerm>Frequency</OpenstaxTerm> refers to the number of waves that pass a given point in a given time period and is often expressed in terms of <OpenstaxTerm>hertz (Hz)</OpenstaxTerm>, or cycles per second. Longer wavelengths will have lower frequencies, and shorter wavelengths will have higher frequencies (<a href="#Figure_05_02_Frequencies">Figure 5.6</a>).
</OpenstaxParagraph>
<OpenstaxFigure id="Figure_05_02_Frequencies" src="https://openstax.org/apps/archive/20240226.174525/resources/e2011b502808ff751fc90883eef9ec20d3e1979d" alt="Stacked vertically are 5 waves of different colors and wavelengths. The top wave is red with a long wavelengths, which indicate a low frequency. Moving downward, the color of each wave is different: orange, yellow, green, and blue. Also moving downward, the wavelengths become shorter as the frequencies increase." mediaType="image/jpg" width="510" height="171" />
<OpenstaxFigureText width="510">
	<strong>Figure 5.6</strong> This figure illustrates waves of differing wavelengths/frequencies. At the top of the figure, the red wave has a long wavelength/short frequency. Moving from top to bottom, the wavelengths decrease and frequencies increase.
</OpenstaxFigureText>

5.2.1 Amplitude and Wavelength

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

5.2.2 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

5.4.3 Sound Localization

Question	Answer
height of a wave	amplitude
number of waves that pass a given point in a given time period	frequency
cycles per second; measure of frequency	hertz (Hz)
length of a wave from one peak to the next peak	wavelength