Search for Longitude/Latitude

8-26-26 The Solar System By studying the geology, climatology (weather) and hydrology (water) of the other planets and moons and comparing them to those that we see on Earth, scientists can gain a better understanding of how these systems work in general, not just here. What we look for Geology: Volcanos, faults, earthquakes, mountains, and Plate tectonics Climatology: Clouds, weather, seasons, climate changes Hydrology: Oceans, lakes, rivers, and groundwork Terrestrial Planets There are 4 which are Mercury, Venus, earth, and Mars. They all are largely composed of rocks and metals and they have layered interiors Mercury - Closest to the Sun GEOLOGY: Mercury is almost entirely dead but once had active volcanoes. It is the smallest planet and lost most of its internal heat long ago. Today, it is covered with craters. WATER: It has no liquid surface water. ATMOSPHERE: It has an extremely thin and insignificant atmosphere. Venus (2nd Planet) GEOLOGY: Venus has many active volcanoes (confirmed in 2023) and is probably seismically active. It may have some form of plate tectonics. WATER: None ATMOSPHERE: A uniformly hot (867 °F), dense atmosphere composed of 96% carbon dioxide and highly corrosive sulfuric acid rain. The Moon GEOLOGY: The Moon was volcanically active in the distant past but is almost completely dead now. Only minor releases of gas and some small "lunarquakes" still occur. WATER: No liquid surface water, but ice exists in some polar craters. ATMOSPHERE: No significant atmosphere. If it were not orbiting around Earth itself is would be considered at Planet Mars (4th Planet) GEOLOGY: Mars is almost completely dead, but some volcanic activity may still be possible. Mars has the solar system's largest volcanoes, somewhat similar in type to those in Hawaii. NASA's InSight lander detected marsquakes. Scientists used them to examine the planet's interior structure. WATER: Mars has no liquid surface water today but had rivers and a shallow ocean in the past. Vast amounts of subsurface water still exist. Mars also has polar ice caps. ATMOSPHERE: It has a very thin atmosphere dominated by carbon dioxide. Seasonal planet-wide dust storms are common. Gas Giant Planets There are 2 gas giant planets in our solar system: Jupiter and Saturn. They are largely composed of the gases hydrogen and helium, with small rocky interiors. Gas giants do not have geology or oceans in the way we know them on Earth. 8-28-26 Jupiter - the Largest Planet ATMOSPHERE: Jupiter has high velocity winds and massive rotating weather systems, such as the Great Red Spot. Which are in the southern hemisphere, and storms in the northern hemisphere. Although they appear similar to hurricanes (Low pressure systems), many of Jupiter's "storms" are anticyclones (high pressure). Jupiter's Moons The only geological features to be found in the region are on a few of Jupiter's moons: Io -The most volcanically active object in the solar system, with several active lava flows and lava lakes photographed and multiple eruptions recorded. Europa - Has a liquid ocean beneath a thick layer of ice. It also has some kind of geologic activity, similar to ice-based plate tectonics. Both the European Space Agency and NASA are sending missions to examine the moon in detail. Saturn - the Ringed Planet ATMOSPHERE: Generally similar to Jupiter MOONS: Titan - the only moon with a significant atmosphere (mostly nitrogen) and weather. It has clouds and rainfall based on methane (natural gas). Methane rivers flow across its surface, and methane lakes are found in polar regions. Enceladus - like Jupiter's moon Europa, it is believed to have an ice-covered ocean. A type of water-based volcanism (geysers) is active. Water has been seen erupting out of long fractures with enough energy to be ejected into space. Ice Giant Planets There are 2 ice giant planets in our solar system: Uranus and Neptune. Similar to gas giants, they have large amounts of hydrogen and helium in their atmospheres but have large mantles of ices above their small rocky cores. They are both relatively large and lack geology or oceans Uranus ATMOSPHERE: Similar to the gas giant planets, it has very high winds. MOONS: Miranda - a geologically complex satellite with one of the highest cliffs (over 3 miles) in the solar system. Neptune ATMOSPHERE: Similar to Uranus, but warmer even though it is farther from the Sun. MOONS: Triton - despite being extremely cold, it has active nitrogen geysers. Pluto - A Dwarf Planet Pluto has an atmosphere containing nitrogen, methane, ammonia, etc. It may freeze to the surface when it is far from the Sun. NASA's New Horizons mission examined the planet, finding active nitrogen glaciers and evidence of other recent geologic activity. 8-31-26 The Sun and the Earth The Sun is very significant to life on Earth and the processes that affect it. It is the major source of Earth's surface heat, and its gravity has a significant influence on tides. However, the relationship between our planet and the Sun changes over time, so the Sun's energy output. The Suns Influence Most weather systems and storms on Earth require heat energy to function. The majority of that comes from the Sun. Areas with more direct sunlight usually have more significant weather events - hurricanes in the tropics, tornadoes in mid-latitudes. Water heated by the sun plays a major role in regional weather and global climate Heat, Weather and Climate Solar radiation plays the dominant role in Earth's weather and climate. Geologic heat (volcanic eruptions, plate tectonics) and heat from human activities often plays a more limited, but still significant, role. Any changes in the relationship of the Earth and Sun will influence weather and climate. This could be on a daily, yearly or even longer cycle. The Sun's Influence The Earth is closer to the Sun in January than it is in July (by about 3 million miles). So why is winter cold? The change in distance is not a major factor on a yearly basis. However, it does play a role over longer time periods when the situation is reversed (we are then closer in July). Long term climate can be significantly affected. Seasonal Influence The tilt of the Earth's axis is the primary cause of our seasons Winter is cold because the Earth is tilted away from the sun, receiving less heat energy and days are shorter. Summer is warmer because the Earth is tilted towards the sun and days are longer. Regions near the equator have no significant seasons The Sun and the Earth Longer term variations have also been linked to the Sun. One example is The Little Ice Age (~15th to 19th centuries). This occurred during a period of lower-than-normal solar activity. It's a bit more complex than that, however. Volcanic activity almost certainly played a large part in this climatic event as well, possibly acting as a trigger to start it. Changing Earth/Sun Relationships To make things even more complicated, Earth's orbit around the Sun and the tilt of Earth's axis change over time. This is widely believed to have a major influence on long-term global climate. Fortunately, these occur over very long periods of time and are of no significant concern In the near future 9-2-26 Near Earth Objects Asteroids and Comets that can closely Approach the Earth On Oct. 15th, asteroid 2022 UP6 may pass Earth at a difference of less than 105,000 miles, closer than the Moon( (239,000) Impacts It was once thought that impact events were not significant on Earth, either now or in the past. That changed in the late 20th century. A large impact has recently been linked to massive global climate change that may have ended Earth's first ice age. Another impact may have triggered an ice age and a mass extinction event. Near-Earth Objects (NEOs) NEOs are asteroids or comets with orbits that either cross or closely approach the Earth. Most are small asteroids. There may be thousands of them in our solar system with diameters of 1 kilometer or more. A collision with an object that size would cause severe changes to our planet's climates. Significant impacts occur, on average, about once a century. Smaller ones have caused property damage and occasional injuries every few years. Scientists have discovered over 42,000 NEOs so far, but most are very small. Only a few are considered (extremely slight) impact risks. The Chelyabinsk Meteor On February 15, 2013, a meteorite over 60 feet in diameter and over 10,000 tons exploded over the Ural Mountains in Russia. The impact shock wave injured over 1500 people. NEOs: Asteroids (NEAS) Since most are small, it has been difficult to detect most of them until very recently. They can be composed of rock, metals or both. We now know that many asteroids are not very solid. They resemble large gravel piles held weakly together by gravity. Others are more metallic, made of iron and nickel. NEOs: Comets (NECs) They often travel at higher velocities than asteroids as they approach Earth's orbit. Comets are very similar to most asteroids except they contain much more ice. Although far fewer in number, they are easier to detect than asteroids because of their brightness as the ice vaporizes due to solar heating. NEC Impact A collision with a comet would not be much different than one involving most asteroids. Collisions are mainly about mass and velocity. A large comet could be more deadly than a large asteroid, if it hit with a higher velocity. NEOs: Impacts In late 2021, NASA launched the DART (Double Asteroid Redirection Test) mission to the asteroid Didymos to impact with its small moon Dimorphos in late September 2022. It was overwhelmingly successful - the impact changed the orbit of Dimorphos, demonstrating that NEOs can be redirected into safer orbits. Throughout the solar system, we can see examples of collisions between planets (and their moons) and asteroids/comets. The Moon is heavily cratered due to ancient impact events. So are most of the moons of every planet we have photographed. Mars and Mercury have many large craters. 9-4-26 Craters on Earth Once thought to be rare, scientists have now discovered over 194 confirmed impact craters on Earth. The vast majority don't look like the Moon's craters, however. Erosion and other surface processes on Earth have buried or deformed most of our craters. Barringer Crater in Arizona formed from an object about 150 feet in diameter. An Ancient Impact in Ohio In southern Ohio, the remains of an ancient impact crater are located beneath Serpent Mound. The heavily eroded crater is about 5 miles in diameter. 20th Century Impact In 1908, a comet exploded as it disintegrated over Tunguska, Siberia. Forests were destroyed over an area of 810 square miles, but no crater was left behind. This type of "impact" may be fairly common. It is estimated that if the impact would have occurred a few hours later, Moscow might have been destroyed. Importance of Plate Tectonics The process of plate tectonics reshapes the Earth's surface over time and is the key to our understanding of: Earthquakes, tsunami, volcanoes Formation of major mountain ranges Formation and evolution of ocean basins Plate Tectonics and Earth's Interior Structure Unlike the earlier theory of continental drift, which only dealt with moving pieces of continental crust, plate tectonics involves the oceans as well. It also includes layers deeper in the Earth's interior- the lithosphere and the mantle. Earth's Structure CRUST: Oceanic Crust - relatively thin, composed of basalt (a volcanic rock) Continental Crust- thicker, made of granite. Basalt is denser than granite - this is very important in plate tectonic activity. Deeper Earth Structure MANTLE: The mantle is separated from the crust by a boundary layer. The rocks in this layer are solid, but due to high temperatures and pressures, they flow very slowly. The Earth's Core OUTER CORE: The outer core is molten (liquid) and largely made of iron and nickel. The Earth's magnetic field originates here. INNER CORE: The inner core is solid due to very high pressures. It is also mostly made of iron and nickel. The Earth's Interior: Other Layers The Lithosphere: The crust and uppermost part of the mantle Rocks in this layer are solid and brittle It is broken into pieces called plates The Asthenosphere: Part of the mantle below the lithosphere Rocks here are solid, but can flow slowly Plate Tectonics - The Basics Most of the large plates are named after the continents that they contain. The majority of the Pacific Ocean is also on one plate. Smaller plates are just as important as large ones- they are responsible for many earthquakes and volcanoes, such as those in Washington, Oregon and northern California. Plate Tectonics Plates are made of oceanic lithosphere (basalt), continental lithosphere (granite) or both. As the plates move, they interact with each other. This causes most of the world's large earthquakes, mountain ranges and major volcanoes. Geologic activity is generally found at or near plate boundaries. Divergent Plate Boundaries Plates separate & move away from each other. New plate material (oceanic lithosphere) is created as molten material fills in the rift. Most are located in the oceans (central Atlantic, caster Pacific, etc.), but some are on land (east Africa, Iceland). Location of Earthquakes and Volcanos The Mid-Atlantic Ridge Although it is mostly underwater, there are several islands located on top of it, such as Iceland and the Azores. The average spreading rate is about 1 inch per year. MAIN POINTS: New oceanic plate material is created. Small earthquakes are common, large ones are rare. Volcanic activity is common. Convergent Plate Boundaries Plates collide with each other. Plate material may be destroyed by subduction (if oceanic lithosphere is involved). Continental lithosphere does not subduct. The type of geologic activity depends upon what kind of lithosphere is involved Ocean-Ocean Convergent One of the ocean floor plates is subducted. Volcanic activity creates island-arcs on the surviving plate. Earthquakes are common and may be large. Examples – Japan, Indonesia, Aleutian Islands Ocean continent convergent The ocean floor plate is subducted, the continental plate is not. Volcanoes form on the edge of the continent. Earthquakes may be common and are potentially very large. Examples – west coasts of North and South America Continent Continent Convergent Neither plate is subducted. Significant volcanic activity is unlikely. Earthquakes are relatively common and are potentially very large. Major mountain ranges are created. Examples – Himalaya Mts. and the Alps MAIN POINTS: Oceanic plate material is destroyed. Continental plate material isn’t subducted. Earthquakes of all sizes can occur. Volcanic activity is common if ocean floor is involved, but not at continent-continent boundaries. Transform Plate Boundaries Plates “slide” past each other. No new plate material is created, no old plate material is destroyed. Most are found on the ocean floor, but some are on land – The San Andreas Fault. Volcanoes do not tend to form here. Motion along a transform plate boundary is not always smooth or continuous. Bends in the boundary can cause some sections to lock-up for long periods. This occurs near Los Angeles. Their last major earthquake was in 1857. Unlike the other plate boundaries which are created by movements of the asthenosphere, these mainly exist to connect divergent and/or convergent boundaries to one another. Despite their lack of volcanism, hot water (hydrothermal) systems are common and are major sites of exotic ecosystems. MAIN POINTS: Oceanic plate material is neither created nor destroyed. Earthquakes of all sizes can occur, but extremely large ones are not common. Significant volcanic activity is not likely. THINGS TO REMEMBER Divergent activity creates new ocean floor material. Convergent activity destroys old ocean floor material. Transform activity does not create or destroy plate material, it just moves it to new locations. OTHER PLANETS AND MOONS: Know the geology, oceans and atmospheric conditions of the other planets (and their notable moons), types of planets. NEAR-EARTH OBJECTS (NEOs): Asteroids and comets; impacts of NEOs; ancient impacts on Earth PLATE TECTONICS: The layers of the Earth – their composition and properties. What is significant about each layer. Earlier versions of the theory (Continental Drift, etc.) and how they differ from plate tectonics. PLATE TECTONICS: Types of plate boundaries – geologic activity (volcanoes, earthquakes, etc.), what kind of motion occurs (separation, collision, etc.), creation and destruction of ocean floors.

Exam Review Chapters 1, 2, & 3. Chapter 1 The Science of Psychology Behavior: Everything, we do that can be directly observed. Behavioral approach: an approach to psychology emphasizing the scientific study of observable behavioral responses and their environmental determinants. Biological approach: an approach to psychology focusing on the body, especially the brain and nervous system. Case study or case history: an in-depth look at a single individual. Cognitive approach: an approach to psychology emphasizing the mental processes involved in knowing: how we direct our attention, perceive, remember, think, and solve problems. Control group: The participants in an experiment who are as much like the experimental group as possible and who are treated in every way like the experimental group except for a manipulated factor, the independent variable. Correlational research: research that examines the relationships between variables, whose purpose is to examine whether and how two variables change together. Critical thinking: The process of thinking deeply and actively, asking questions, and evaluating the evidence. Dependent variable: The outcome; the factor that can change in an experiment in response to changes in the independent variable. Double-blind experiment: An experimental design in which neither the experimenter nor the participants are aware of which participants are in the experimental group and which are in the control group until the results are calculated. Evolutionary approach: An approach to psychology centered on evolutionary ideas such as adaptation, reproduction, and natural selection as the basis for explaining specific human behaviors. Experiment: A carefully regulated procedure in which the researcher manipulates one or more variables that are believed to influence some other variable. Experimental group: The participants in an experiment who receive the drug or other treatment under study—that is, those who are exposed to the change that the independent variable represents. Functionalism: James’s approach to mental processes, emphasizing the functions and purposes of the mind and behavior in the individual’s adaptation to the environment. Humanistic approach: An approach to psychology emphasizing a person’s positive qualities, the capacity for positive growth, and the freedom to choose any destiny. Hypothesis: A testable prediction that derives logically from a theory. Independent variable: A manipulated experimental factor; the variable that the experimenter changes to see what its effects are. Longitudinal design: A special kind of systematic observation, used by correlational researchers, that involves obtaining measures of the variables of interest in multiple waves over time. Mental processes: The thoughts, feelings, and motives that people experience privately but that cannot be observed directly. Natural selection: Darwin’s principle of an evolutionary process in which organisms that are best adapted to their environment will survive and produce offspring. Naturalistic observation: The observation of behavior in a real-world setting. Placebo: In a drug study, a harmless substance that has no physiological effect, given to participants in a control group so that they are treated identically to the experimental group except for the active agent. Placebo effect: The situation where participants’ expectations, rather than the experimental treatment, produce an experimental outcome. Population: The entire group about which the researcher wants to draw conclusions. Psychoanalysis: techniques involves an analyst unlocking a person's unconscious conflicts by talking with the individual about his or her childhood memories, dreams, thoughts, and feelings. Psychodynamic approach: an approach to psychology emphasizing unconscious thought, the conflict between biological drives (such as the drive for sex) and society’s demands, and early childhood family experiences. Psychology: The scientific study of behavior and mental processes. Sample: The subset of the population chosen by the investigator for study. Sociocultural approach: an approach to psychology that examines the ways in which social and cultural environments influence behavior. Structuralism: Wundt’s approach to discovering the basic elements, or structures, of mental processes. Theory: A broad idea or set of closely related ideas that attempts to explain observations and to make predictions about future observations. Validity: The soundness of the conclusions that a researcher draws from an experiment. In the realm of testing, the extent to which a test measures what it is intended to measure. Variable: Anything that can change. Wilhelm Wundt is most often regarded the "founding father" of modern psychology. He was also the founder of structuralism. William James was the founder of functionalism. J. B. Watson and B. F. Skinner believed that psychology should focus on an organism's visible interactions with the environment—that is, behaviors. Ethical Guidelines developed by the American Psychological Association include: • informed consent. • confidentiality. • deception. • debriefing. Chapter 2 The Brain and Behavior Action potential: The brief wave of positive electrical charge that sweeps down the axon. Adrenal glands: glands at the top of each kidney that are responsible for regulating moods, energy level, and the ability to cope with stress. Amygdala: An almond-shaped structure within the base of the temporal lobe that is involved in the discrimination of objects that are necessary for the organism’s survival, such as appropriate food, mates, and social rivals. Association cortex: Sometimes called association areas, the region of the cerebral cortex that is the site of the highest intellectual functions, such as thinking and problem solving. Autonomic nervous system: The body system that takes messages to and from the body’s internal organs, monitoring such processes as breathing, heart rate, and digestion. Axon The part of the neuron that carries information away from the cell body toward other cells. Basal ganglia Large neuron clusters located above the thalamus and under the cerebral cortex that work with the cerebellum and the cerebral cortex to control and coordinate voluntary movements. Brain stem The stem like brain area that includes much of the hindbrain (excluding the cerebellum) and the midbrain; connects with the spinal cord at its lower end and then extends upward to encase the reticular formation in the midbrain. Cell body The part of the neuron that contains the nucleus, which directs the manufacture of substances that the neuron needs for growth and maintenance. Central nervous system (CNS): The brain and spinal cord. Cerebral cortex: Part of the forebrain, the outer layer of the brain, responsible for the most complex mental functions, such as thinking and planning. Chromosomes: In the human cell, threadlike structures that come in 23 pairs, one member of each pair originating from each parent, and that contain DNA. Corpus callosum: The large bundle of axons that connects the brain’s two hemispheres, responsible for relaying information between the two sides. Dendrites: Treelike fibers projecting from a neuron, which receive information and orient it toward the neuron’s cell body. Deoxyribonucleic acid (DNA): A complex molecule in the cell’s chromosomes that carries genetic information. Dominant-recessive genes principle: The principle that if one gene of a pair is dominant and one is recessive, the dominant gene overrides the recessive gene. A recessive gene exerts its influence only if both genes of a pair are recessive. Endocrine system: The body system consisting of a set of glands that regulate the activities of certain organs by releasing their chemical products into the bloodstream. Forebrain: The brain’s largest division and its most forward part. Frontal lobes: The portion of the cerebral cortex behind the forehead, involved in personality, intelligence, and the control of voluntary muscles. Genes: The units of hereditary information, consisting of short segments of chromosomes composed of DNA. Genotype: An individual’s genetic heritage; his or her actual genetic material. Glands: Organs or tissues in the body that create chemicals that control many bodily functions. Glial cells: The second of two types of cells in the nervous system; glial cells (also called glia) provide support, nutritional benefits, and other functions and keep neurons running smoothly. Hindbrain: Located at the skull’s rear, the lowest portion of the brain, consisting of the medulla, cerebellum, and pons. Hippocampus: The structure in the limbic system that has a special role in the storage of memories. Hormones: Chemical messengers that are produced by the endocrine glands and carried by the bloodstream to all parts of the body. Hypothalamus: A small forebrain structure, located just below the thalamus, that monitors three pleasurable activities—eating, drinking, and sex—as well as emotion, stress, and reward. Limbic system: A set of subcortical brain structures central to emotion, memory, and reward processing. Midbrain: Located between the hindbrain and forebrain, an area in which many nerve-fiber systems ascend and descend to connect the higher and lower portions of the brain; in particular, the midbrain relays information between the brain and the eyes and ears. Motor cortex: A region in the cerebral cortex, located just behind the frontal lobes, that processes information about voluntary movement. Myelin sheath: A layer of fat cells that encases and insulates most axons. Neocortex: The outermost part of the cerebral cortex, making up 80 percent of the human brain’s cortex. Nervous system: The body’s electrochemical communication circuitry. Neural networks: Networks of nerve cells that integrate sensory input and motor output. Neurons: One of two types of cells in the nervous system; neurons are the nerve cells that handle the information-processing function. Neurotransmitters: Chemical substances that are stored in very tiny sacs within the neuron’s terminal buttons and involved in transmitting information across a synaptic gap to the next neuron. Occipital lobes: Structures located at the back of the head that respond to visual stimuli. Ovaries: Sex-related endocrine glands that produce hormones involved in women’s sexual development and reproduction. Pancreas: A dual-purpose gland under the stomach that performs both digestive and endocrine functions. Parasympathetic nervous system: The part of the autonomic nervous system that calms the body. Parietal lobes: Structures at the top and toward the rear of the head that are involved in registering spatial location, attention, and motor control. Peripheral nervous system (PNS): The network of nerves that connects the brain and spinal cord to other parts of the body. Phenotype: An individual’s observable characteristics. Pituitary gland: A pea-sized gland just beneath the hypothalamus that controls growth and regulates other glands. Plasticity: The brain’s special capacity for change. Prefrontal cortex: an important part of the frontal lobes that is involved in higher cognitive functions such as planning, reasoning, and self-control. Resting potential, The stable, negative charge of an inactive neuron. Reticular formation: A system in the midbrain comprising a diffuse collection of neurons involved in stereotyped patterns of behavior such as walking, sleeping, and turning to attend to a sudden noise. Somatic nervous system: The body system consisting of the sensory nerves, whose function is to convey information from the skin and muscles to the central nervous system about conditions such as pain and temperature, and the motor nerves, whose function is to tell muscles what to do. Somatosensory cortex: A region in the cerebral cortex that processes information about body sensations, located at the front of the parietal lobes. Stem cells: Unique primitive cells that have the capacity to develop into most types of human cells. Stress: The responses of individuals to environmental stressors. Stressors: Circumstances and events that threaten individuals and tax their coping abilities and that cause physiological changes to ready the body to handle the assault of stress. Sympathetic nervous system: The part of the autonomic nervous system that arouses the body to mobilize it for action and thus is involved in the experience of stress. Synapses: Tiny spaces between neurons; the gaps between neurons are referred to as synaptic gaps. Temporal lobes: Structures in the cerebral cortex that are located just above the ears and are involved in hearing, language processing, and memory. Testes: Sex-related endocrine glands in the scrotum that produce hormones involved in men’s sexual development and reproduction. Thalamus: The forebrain structure that sits at the top of the brain stem in the brain’s central core and serves as an important relay station. Left Hemisphere • verbal processing, speech, grammar Right Hemisphere • spatial perception • visual recognition • emotion Chapter 3 Sensation and Perception Absolute threshold: The minimum amount of stimulus energy that a person can detect. Apparent movement: The perception that a stationary object is moving. Auditory nerve: The nerve structure that receives information about sound from the hair cells of the inner ear and carries these neural impulses to the brain’s auditory areas. Binding: In the sense of vision, the bringing together and integration of what is processed by different neural pathways or cells. Binocular cues: Depth cues that depend on the combination of the images in the left and right eyes and on the way the two eyes work together. Bottom-up processing: The operation in sensation and perception in which sensory receptors register information about the external environment and send it up to the brain for interpretation. Cones: The receptor cells in the retina that allow for color perception. Convergence: A binocular cue to depth and distance in which the muscle movements in an individual’s two eyes provide information about how deep and/or far away something is. Depth perception: The ability to perceive objects three-dimensionally. Difference threshold: The degree of difference that must exist between two stimuli before the difference is detected. Feature detectors: Neurons in the brain’s visual system that respond to particular features of a stimulus. Figure-ground relationship: The principle by which we organize the perceptual field into stimuli that stand out (figure) and those that are left over (ground). Frequency theory: Theory on how the inner ear registers the frequency of sound, stating that the perception of a sound’s frequency depends on how often the auditory nerve fires. Gestalt psychology A school of thought interested in how people naturally organize their perceptions according to certain patterns. Inner ear: The part of the ear that includes the oval window, cochlea, and basilar membrane and whose function is to convert sound waves into neural impulses and send them to the brain. Kinesthetic senses: Senses that provide information about movement, posture, and orientation. Middle ear: The part of the ear that channels and amplifies sound through the eardrum, hammer, anvil, and stirrup to the inner ear. Monocular cues: Powerful depth cues available from the image in one eye, either the right or the left. Noise: Irrelevant and competing stimuli—not only sounds but also any distracting stimuli for the senses. Olfactory epithelium: The lining of the roof of the nasal cavity, containing a sheet of receptor cells for smell. Opponent-process theory: Theory stating that cells in the visual system respond to complementary pairs of red-green and blue-yellow colors; a given cell might be excited by red and inhibited by green, whereas another cell might be excited by yellow and inhibited by blue. Optic nerve: The structure at the back of the eye, made up of axons of the ganglion cells, that carries visual information to the brain for further processing. Outer ear: The outermost part of the ear, consisting of the pinna and the external auditory canal. Pain: The sensation that warns an individual of damage to the body. Papillae: Rounded bumps above the tongue’s surface that contain the taste buds, the receptors for taste. parallel processing: The simultaneous distribution of information across different neural pathways. Perception: The process of organizing and interpreting sensory information so that it makes sense. perceptual constancy: The recognition that objects are constant and unchanging even though sensory input about them is changing. perceptual set A predisposition or readiness to perceive something in a particular way. place theory: Theory on how the inner ear registers the frequency of sound, stating that each frequency produces vibrations at a particular spot on the basilar membrane. retina The multilayered light-sensitive surface in the eye that records electromagnetic energy and converts it to neural impulses for processing in the brain. Rods: The receptor cells in the retina that are sensitive to light but not very useful for color vision. selective attention: The act of focusing on a specific aspect of experience while ignoring others. semicircular canals: Three fluid-filled circular tubes in the inner ear containing the sensory receptors that detect head motion caused when an individual tilts or moves the head and/or the body. Sensation: The process of receiving stimulus energies from the external environment and transforming those energies into neural energy. sensory adaptation: A change in the responsiveness of the sensory system based on the average level of surrounding stimulation. sensory receptors: Specialized cells that detect stimulus information and transmit it to sensory (afferent) nerves and the brain. signal detection theory: An approach to perception that focuses on decision making about stimuli in the presence of uncertainty. subliminal perception The detection of information below the level of conscious awareness. Thermoreceptors: Sensory nerve endings under the skin that respond to changes in temperature at or near the skin and provide input to keep the body’s temperature at 98.6 degrees Fahrenheit. top-down processing The operation in sensation and perception, launched by cognitive processing at the brain’s higher levels, that allows the organism to sense what is happening and to apply that framework to information from the world. trichromatic theory: Theory stating that color perception is produced by three types of cone receptors in the retina that are particularly sensitive to different, but overlapping, ranges of wavelengths. vestibular sense: Sense that provides information about balance and movement. visual cortex: Located in the occipital lobe, the part of the cerebral cortex involved in vision. volley principle: Principle addressing limitations of the frequency theory of hearing, stating that a cluster of nerve cells can fire neural impulses in rapid succession, producing a volley of impulses. Weber’s law: The principle that two stimuli must differ by a constant minimum percentage (rather than a constant amount) to be perceived as different.