Sensation (Chap 6) Flashcards
figure-ground
the organization of the visual field into objects (the figures) that stand out from their surroundings (the ground)
Gestalt theory
an organized whole. gestalt psychologists emphasized our tendency to integrate pieces of information into meaningful wholes.
Name 3 kinds of grouping
proximity, continuity and Closure (filling out blanks)
What do we mean when we say that, in perception, the whole is greater than the sum of its parts?
Gestalt psychologists used this saying to describe our perceptual tendency to organize cluster of sensation into meaningful forms of coherent groups.
Deepth perception
the ability to see objects in 3D although images that strike the retina are two-dimentional; allow ud to judge distance.
visual cliff
a laboratory device for testing depth for infants (6-14 mdr) and young animals
binocular cues
depth cues, such as retinal disparity (ulighed), that depend on the use of two eyes.
Retinal disparity
a binocular cue for perceiving depth: by comparing images from retinas in the two eyes, the brain computes distance - the greater the disparity (difference) between the two images, the closer the object.
How do we normally perceive depth?
We are normally able to perceive depth thanks to the binocular cues that based on our retinal disparity, and monocular cues including relative hight, relative size, interposition, linear perspective, light and shadow and relative motion.
Monocular cues
Depth cues, such as interposition and linear perspective, available to either eye alone.
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 (having consistent shapes, size, brightness , and color) even as illumination and retinal images changes.
Color constancy
perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object.
Perceptual adaptation
in vision, the ability to adjust to an artificially displaced or even invented visual field.
if no infant vision you may become ……
functionally blind to shape (not color though)
Bottom-up processing
analysis that begins with the sensory receptors and works up to the brain’s integration od sensory information
top-down processing
information prosessing guided by higher-level mental processes, as we construct perceptions drawing on our experience and expectations.
transduction
conversion of one form of energy into another. In sensation, the as sights, sounds and smells into neural impulses our brain can interpert
PSYCHOPHYSIS
THE STUDY OF RELATIONSHIP BETWEEN THE physical characteristics of stimuli, such as their intensity, and our psychological experience of them.
What is the rough distinction between sensation and perception?
sensation is the bottom op process whereas perception is top down mental process of organizing and interpertation sensory input
absolute treshold
the minimum stimulation needed to detect a particular stimulus 50 percent of the time
signal detection 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.
subliminal
below ones absolute threshold for conscious awareness
priming
the activation, often unconsciously of certain associations, thus predisposing ones perception, memory, or response.
Difference threshold
the minimum difference between two stimuli required for detection 50 percent of the time. We experience the difference treshold as a ‘just noticeable difference’
Webers law
the principal that to be perceived as different, two stimuli must differ by a constant minimum percentage (rather then a constant)
perceptual set
a mental predisposition to perceive one thing and not another
Illustate using sound as example; absolute threshold, subliminal stimulation and difference treshold
AT: the minimum stimulation needed to detect a particular sound 50% of the time. SS: sensory system process the sound without our awareness. DT: minimum difference for us toto distinguish between two sounds
what is the hue?
the dimension of color that is determined by the wavelength of light; what we know as the color names blue, green……..
pupil
through which light enters the eye
iris
a ring of muscle tissue that form the solored portion if the eye around the pupil and CONTROL THE SIZE of the pupil opening.
Lens
the transparent structure behind the pupil that changes shape to help FOCUS immages in the retina
retina
the light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers the neurons that begin the processing of the visual information
accomoation
the process by which the eyes lens changes shape to focus near/far objects on the retina
rods
retinal receprors that detect BLACK/WHITE/GRAY necessary for peripheral and twilight vision when CCONES dont respond.
cones
retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-loght conditions. The cones detect fine details and give rice to color sensations
optical nerve
the nerve that carries neural impulses from the eye to the brain
fovea
the central focal point in the retina arround which the wye cone cluster
Feature detectors
nerve cells in the brain that respond to specific features of the stimulus (such as shape, angle, movement)
Young-helmholtz trichromatic theory
the theory taht the retina contains three different color receptors - red, green, blue - which, when stimulated in combination can produce the perception of any color.
Middel ear
the chamber between the eardrum and cochlea contains three thin boned; HAMMER, ANVIL, TRIRUP, that concentrate the vibirators of the eardrum on the cochleas ovan window
Cochlea
a coiled bony, fluid filled tube in the inner ear –> soundwaves travelign through the cochear fluid trigger nerve impulses.
inner ear
the innermost part of the ear containing the cochlea semicircular chanais and vestibular sacs.
Cochlear implant
a device converting sound into eletrical signals and stimulating the auditory nerve through electrodes threaded into the Cochlea
place theory
in hearing the theory that links the pitch we hear with the place where the Cochleas membrane is stimulated.
gate-control theory
the theory that the spianl cord contains a neurological “gate” that blocks pain signals or allow them to pass on to the brain. The “gate” is opened by the sctivity of pain signals traveling up small nerve fibers or by information comming from the brain
sensory interaction
the principle that one sense may influence another as when the smell of food influences the taste.
What are the two key theories of color vision?
1) young-helmholtz trichromatic theory 2) opponent-process theory .. they complement each other and ourline the two stages of color vision: First retinas receptors for red, green, blue responds to different color stimuli THEN the receptors signals are processed by the opponent process cells on their way to the visual cortex in the brain.
opponent-process theory
the theory opposing retinal processes (red-green, yellow-blue, white-black) enable color vision. For example some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green.
kinesthesis
the system of sensing the position and movement of individual bodyparts
vestbular sens
the sense of body movement and position including the sense of balance –> is located in the inner ear
