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87 terms

Psych Unit 6: Sensation/Perception

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Sensation
The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.
Perception
The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.
Bottom-up processing
Analysis that begins with the sensory receptors and works up to the brain's integration of sensory information.
Top-down processing
Information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations.
Absolute threshold
Minimum stimulation to detect a particular stimulus 50% of the time.
Difference threshold
Minimum difference between two stimuli that a subject can detect 50% of the time. The more intense a stimulus, the larger the increment needed to notice a difference.
Signal Detection Theory
Predicts how and when we detect the presence of a faint stimulus and background stimulation.
Subliminal
Below one's absolute threshold for conscious awareness.
Priming
The activation, often unconsciously, of certain associations, thus predisposing one's perception, memory, or response.
Weber's Law
To perceive a difference between two stimuli, they must differ by a constant minimum percentage.
Sensory adaptation
Diminished sensitivity with constant stimulation. After constant exposure to a stimulus, our nerve cells fire less frequently.
Selective attention
The focusing of conscious awareness on a particular stimulus.
Transduction
The conversion of one form of energy into another.
Wavelength
The distance from the peak of one light or sound wave to the peak of the next.
Hue
The dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, and so forth.
Intensity
The amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave's amplitude. Large amplitude=bright color, loud sound while small amplitude=dull color, light sound.
Pupil
The adjustable opening in the center of the eye through which light enters.
Iris
A ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening.
Lens
The transparent structure behind the pupil that changes shape to help focus images on the retina.
Accommodation (eye)
The process by which the eye's lens changes shape to focus near or far objects on the retina.
Retina
The light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information.
Acuity
The sharpness of vision.
Nearsightedness
A condition in which nearby objects are seen more clearly than distant objects because distant objects focus in front of the retina.
Farsightedness
A condition in which faraway objects are seen more clearly than near objects because the image of near objects is focused behind the retina.
Rods
Retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don't respond.
Cones
Retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations.
Optic nerve
The nerve that carries neural impulses from the eye to the brain.
Blind spot
The point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there.
Fovea
The central focal point in the retina, around which the eye's cones cluster.
Feature detectors
Nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement.
Parallel processing
The processing of several aspects of a problem simultaneously; the brain's natural mode of information processing for many functions; including vision.
Young-Helmholtz Trichromatic Theory
The retina contains three different color receptors--one most sensitive to red, another to green, and another to blue. When stimulated in combination these can produce the perception of any color.
Opponent-process Theory
Opposing retinal processes enable color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green.
Color Constancy
Perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object.
Frequency
The number of complete wavelengths that pass a point in a given time.
Audition
The sense or act of hearing
Pitch
A tone's experienced highness or lowness, depends on frequency.
Outer Ear
Pinna or Auricle is the outer ear. It plays a role in the spatial focusing of hearing.
Middle Ear
(Air filled). The Tympanic Membrane or eardrum - a thin, rigid, semi-transparent membrane between the external and middle ear. It vibrates when sound waves hit it, passing those vibrations on to the ossicles.
The Ossicles
Bones of the middle ear - connect the external ear to the inner ear. The Malleus or hammer is attached to the inner aspect of the tympanic membrane. The Incus or anvil connects the malleus to the stapes. And the Stapes or stirrup is attached to the oval window.
Inner Ear
(Fluid filled). Converts mechanical energy to neural impulses. The Vestibule - antechamber to both the semicircular canals and the cochlea. Also helps with balance. The semicircular Canals - there are 3 semicircular canals; superior, lateral, and posterior. These are fluid filled and help detect angular acceleration. This helps with balance, etc.
The Cochlea
A snail shaped chamber where the sound waves are converted into neural impulses.
Basilar Membrane
Runs the length of the cochlea and covered by hair cells/sensory neurons. When the Basilar Membrane bends in response to the wave traveling through the surrounding fluid, the hair cells are stimulated.
Place Theory
The theory that links the pitch we hear with the place where the cochlea's membrane is stimulated.
Frequency Theory
The rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch.
Conduction deafness
When the ear looses the ability to conduct a sound wave.
Nerve (sensorineural) deafness
Damage to the cilia. can be treated by a hearing aid or a cochlear implant.
Cochlear Implant
A device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea.
Gate-control Theory
The spinal cord contains a neurological gate that blocks pain signals or allows them to pass on to the brain. The gate is opened by activity in small nerve fibers and closed by activity in large fibers or info from the brain.
Sensory Interaction
One sense may influence another
Hyperalgesia
An extreme sensitivity to something that others would only find mildly painful.
Kinesthesis
The system for sensing the position and movement of individual body parts.
Vestibular Sense
The sense of body movement and position, including the sense of balance.
McGurk Effect
when the ear hears one sounds, but the eye sees a mouth form a different sound, the brain's interpretation can be a mixture of the two sounds
Synaesthesia
One sort of sensation produces another
Visual Capture
When vision competes with other senses, vision usually wins.
Gestalt
An organized whole
Figure-ground
The organization of the visual field into objects that stand out from their surroundings.
Grouping
The perceptual tendency to organize stimuli into coherent groups.
Depth Perception
Seeing objects in three dimensions, allowing us to judge distance.
Visual Cliff
A device for testing depth perception in infants and young animals.
Binocular cues
Depth cues that depend on the use of two eyes.
Retinal Disparity
A binocular cue for perceiving depth, by comparing images from the two eyeballs, the brain computes distance. The greater the difference, the closer the object.
Convergence
A binocular cue for perceiving depth, the extent to which the eyes converge inward when looking at an objects. The greater the inward strain, the closer the object.
Monocular Cues
Depth cues available to either eye alone
Relative Size
If two objects are similar in size, we perceive the one that casts the smaller retinal image as farther away.
Interposition
If one object partially blocks our view of another, we perceive it as closer.
Relative Clarity
Because light from distant objects passes through more atmosphere, we perceive hazy objects as farther away from sharp, clear objects.
Texture gradient
A gradual change from a coarse, distinct texture to a fine, indistinct texture signals increasing distance. Objects far away appear smaller and more densely packed.
Relative Height
We perceive objects higher in our field of vision as farther away. This may contribute to the illusion that vertical dimensions are longer than identical horizontal dimensions.
Relative Motion
As we move, objects that are actually stable may appear to move.
Linear Perspective
Parallel lines appear to converge with distance.
Relative Brightness
Nearby objects reflect more light to our eyes.
The Phi Phenomenon
An illusion of movement created when two or more adjacent lights blink on and off in quick succession.
Perceptual Constancy
Perceiving objects as unchanging even as illumination and retinal images change.
Perceptual Adaptation
The ability to adjust to an artificially displaced or even inverted visual field.
Perceptual Set
A mental predisposition to perceive one thing and not another.
Parapsychology
The study of paranormal phenomena.
Extrasensory Perception (ESP)
Perception can occur apart from sensory input.
Telepathy
Mind-to-mind communication.
Clairvoyance
Perceiving remote events
Precognition
Perceiving future events
Touch
Our sense of touch is actually a mix of at least four distinct skin senses-pressure, warmth, cold, and pain.
Inattentional Bias
When you are attending to something, you might miss something else.
Ponso Illusion
Illusion with monsters/red boxes. They are actually the same size.
Muller-Lyer Illusion
Lines with arrows, they are actually the same size.
Human Factors Psychology
Explores how people and machines interact and how machines and physical environments can be made safe and easy to use.