Chapter 6 - 11th edition - Exploring Psychology PDF

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11th edition...

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Chapter 6: Sensation and Perception Sensation and perception. •

Processing sensations and perceptions o Sensation The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment. o sensory receptors nerve sensory endings that respond to stimuli. o perception the process or organizing and interpreting sensory information o Bottom-up processing Analysis that begins with the sensory receptors and works up to the brain's integration of sensory information (feature analysis of stimulus that begins with sensory information). o Top-down processing Information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations (the role of expectations and knowledge in shaping perceptions).

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Transduction Conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brain can interpret.

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Thresholds o Absolute threshold Minimum stimulus needed to detect a particular stimulus 50% of the time. o Signal detection theory A theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise). Assumes there is no single absolute threshold and that detection depends partly on a person's experience, expectations, motivation, and alertness. o Subliminal [stimulation] ability to sense stimuli BELOW absolute threshold. o Difference threshold We experience it as a "just noticeable difference" or: jnd. o Priming The activation, often unconsciously, of certain associations, thus predisposing one's perception, memory, or response. o Webers Law to be perceived as different, two stimuli must differ by a constant PROPORTION (not by AMOUNT)

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Sensory adaptation diminished sensitivity as a consequence of constant stimulation. Perpetual set a set of mental tendencies and assumptions that affects Top-Down

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processing; to get ‘set in our own ways’ … hunches and biases. Context, Motivation and Emotion

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Vision: Sensory and Perceptual Processing o Wavelength the distance from the peak of one light or sound wave to the next (DETERMINES HUE). o Hue the dimension of color that is determined by the wavelength of light (blue, green, etc.) o Intensity the amount of energy in a light wave or sound wave (determined by wave's amplitude/height) (DETERMINES BRIGHTNESS) o Retina light sensitive inner surface of the eye, contains rods, cones and neurons. o Accommodation the process by which the eye’s lens changes shape to focus on near or far objects on the retina. o Iris a ring of muscle tissue that forms the colored portion of the eye. o Pupil the adjustable opening in the center of the eye through which light enters, (center of the iris). o Rods retinal receptors that detect black, white, and gray; useful in dim lighting; found in periphery of retina (Light sensitive, Value scale). o Cones receptor cells in fovea of retina that detect color and fine detail; function in daylight or well-lit scenarios (Color and detail sensitive). o Fovea center of retina (Cones Only). o Optic nerve the nerve that carries neural impulses from eye to brain. o Blind spot point at which optic nerve leaves the eye; no receptor cells located here. o Young-Hemholtz trichromatic theory three types of color receptors RGB. o Opponent-process theory opposing cells in cones blend proportions of RGB to produce colors. o Feature detectors nerve cells in the occipital lobes visual cortex that respond to specific visual features––via edges, lines, angles, and movements.

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Parallel processing processing many aspects of a stimulus or problem at once. o In terms of visual perception: brain cell teams that process and combine information about motion, form, depth, and color; which results in the interpretation of a constructed image; aka the process of visual recognition.

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Gestalt psychology: forms of perception o Gestalt an organized whole; principles of grouping; we have a tendency to integrate pieces of information into meaningful wholes.

(a) Proximity we group nearby figures together; "objects or shapes that are close to one another appear to form groups". Refers to the way smaller elements are "assembled" in a composition. (b) Continuity we perceive smooth continuous patterns rather than discontinuous ones. Rather than seeing separate lines and angles, lines are seen as belonging together. Figure (b) is alternating semicircles that are interpreted as lines. (c) Closure states that if there is a break in the object, we perceive the object as continuing in a smooth pattern. For example, we assume the circles to the left are complete but partially blocked by an illusory triangle. o Figure-ground the organization of the visual field into objects (figures) that stand out from their surroundings (ground). o Retinal disparity a binocular cue for perceiving depth o Phi phenomenon an illusion of movement created when two or more adjacent lights blink on and off in quick succession. Think of television screens pixels to produce the illusion of movement. o Perceptual constancy perceiving objects as unchanging when even as illumination and visual perspective (retinal image) is altered. The opening of a door changes from a rectangle to a trapezoid, yet we are still aware that the door is the same object; additionally, shape consistency tells us that the object is still rectangular even as it widens to the perceived outline as a trapezoid o Perceptual adaptation the ability to adjust to changed sensory input; if we do a headstand, our brain quickly adapts to the inverted vision we experience, to correctly identify what is up and what is down.

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Hearing o Audition the sense or act of hearing o Frequency number of complete wavelengths that pass a point in a given time (For example, per second) o Pitch a tone’s experienced highness or lowness; depends on frequency. o Middle Ear vibration of MOVEABLE PARTS – the eardrum vibrates and transmits sound waves through the hammer, anvil, stirrup o Inner ear the innermost part of the ear; containing the cochlea, semicircular canals, and vestibular sacs. o Cochlea coiled, boney, fluid filled tube in the inner ear; soundwaves traveling through the cochlear fluid trigger nerve impulses. o Sensorineural hearing loss more common, damage to hair receptors or auditory nerve; loud music, genetic disorders, old age. o Conduction hearing loss less common, damage in the ear ability to conduct and relay sound to the inner ear, physical damage to the eardrum or middle ear bones.

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Hearing theories Place theory the theory that links the pitch we hear to the point of stimulation in the cochlea’s membrane; kind of like a sitar where individual nerves are designated to individual resonant strings. Frequency theory the theory that the rate of nerve impulses sent to the brain matches the frequency of a tone, and our brain translates the rate of

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pulses into the perception of a tone. Other senses touch, taste, smell o Gate control theory the spinal cord has a ‘gate’ like mechanism that can either block or permit small fiber pain(outer extremities) signals to long fiber signals that reach the brain. o Hypnosis a social interaction in which one person (hypnotist) suggests to a subject that certain sensory perceptions will occur. o Disassociation split in consciousness that allow some thoughts and behaviors to occur simultaneously with others. o Olfaction sense of smell. o Kinesthesia our movement sense––our system for sensing the position and movement of individual body parts. o Vestibular sense our sense of balance––our sense of body movement and position that enables our sense of balance.

o Sensory interaction the principle that one sense may influence another; like when smell influences taste. o Embodied cognition the influence of bodily sensations, gestures, and other states on cognitive preferences and judgements; wobbly tables in a persons home makes them more easily judged as being unstable etc…

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ESP extrasensory perception o Parapsychology the study of paranormal phenomena telepathy mind to mind communication. clairvoyance perceiving remote events in real time. precognition perceiving future events. o Core argument in parapsychology both reproducible phenomenon and then a theory to explain said phenomenon are required to explain it....