Unit 4- Perception and Sensation (The Eye (Iris- a ring of muscle tissue…
Unit 4- Perception and Sensation
- the dimension of color that is determined by the wavelength of light; what we know as blue, green, etc.
- the amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave's amplitude.
- the distance from the peak of one lighter sound wave to the peak of the next. Electromagnetic wavelengths vary from the short blips of cosmic rays to the long pulses of radio transmission.
- a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening in response to light intensity.
- the transparent structure behind the pupil that changes shape to help focus images on the retina.
- the adjustable opening in the center of the eye through which light enters.
- 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.
- protects eye and bends light to provide focus; where light enters the eye.
- the process by which the eye's lens changes shape to focus near or far objects on the retina.
- in hearing, the theory that links the pitch we hear with the plates where the cochlea's membrane is stimulated *High pitched sounds
- in hearing, the theory that the rate of nerve impulses traveling up the auditory nerve matches frequency of a tone, thus enabling us to sense its pitch. *Low Pitched Sounds
- a tone's experienced hinges or lowness
*depends on frequency
Frequency- number of complete wavelengths that pass a point in a given time
Low Frequencies vibrate more of membrane, including the end
High Frequencies produce large vibrations near beginning of cochlea membrane
Visible section that channels waves through the auditory canal to the eardrum
- a tight membrane that vibrates after it receives the waves
- chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, stirrup) that concentrate the vibrations of the eardrum on the cochlea's oval window
- a coiled, bony, fluid-filled tube in the inner ear; sound waves traveling through the cochlear fluid trigger nerve impulses
- the innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs
- the nerve that carries neural impulses from eye to brain.
the point at which the optic nerve leaves the eye, creating a "blind spot" because no receptor cells are located there.
- retinal receptors that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. Detect fine detail and give rise to color sensations.
- the central focal point in the retina, around which the eye's cones cluster.
- retinal receptors that detect black, white, and grey; necessary for peripheral and twilight vision, when cones don't respond.
Visual Information Processing
- The processing of many aspects of a problem simultaneously; the brain's natural mode of information processing for many functions, including vision. Contrasts with step-by-step processing of most computers and conscious problem solving.
Young-Helmholtz Trichromatic Theory
- The theory that the retina contains three different color receptors- one most sensitive to red, one to blue, one too green. When stimulated in combinations, can produce perception of any color.
- Nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement.
- opposing retinal processes enable color vision.
Sensation and Perception
-the process that allows our brains to interpret information via stimulus energies from our environment
-the process of interpreting and recognizing sensory stimuli and enables us to recognize meaningful objects and events
-enables our sensory system to detect the lines, angles, and color of objects
-allows us to interpret what our senses detect
-the conversion of one form of energy into anther. In sensation, it is the transforming of stimulus energies (in sights, sounds, smells) into neural impulses our brains interpret
is the focusing of conscious awareness on a particular stimulus
Cocktail party effect
-shows our ability to attend to only one voice among many, but when we hear our name from across the room, our attention is immediately drawn to it
-when we fail to see visible objects when our attention is directed somewhere else
-when we fail to notice the changes in our environment
The Other Senses
Mix of four senses
Body Position and Movement
- sense of position and movement
- monitors your heads position and movement (balance)
Five basic sensations: sweet, sour, bitter, salty, umami
Chemical sense: we like certain smells more because they may bring back vivid memories
- when we see a speaker say one syllable while we hear another, we may perceive a third that blends both inputs
Abilities to form Perception
Figure-Ground- the organization of the visual field into objects (figures) that stand out from their surroundings (ground).
Grouping- the perceptual tendency to organize stimuli into coherent groups.
Proximity- nearby figures grouped together.
Continuity- perceive smooth, fluid patterns.
Closure- fill in gaps to complete a whole object.
-the minimum stimulation needed to detect a stimulus 50 percent of the time
-the minimum difference between two stimuli needed for detection 50 percent of the time (experience as
just noticeable difference
- below one's absolute threshold for conscious awareness
- the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage
- depth guess, such as retinal disparity, that depend on the use of two eyes.
- by composing images from retinas in the two eyes, the brain computes distance- the greater the disparity between the two images, the closer the object.
- a laboratory device for testing depth perception in infants and young animals.
- Depth cues, such as interposition and linear perspective, available to either eye alone.
- the ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance.
- A mental predisposition to perceive one thing and not another and affects what we perceive
Sad music predisposes people to perceive a sad meaning in homophonic words ex:
mourning vs. morning
Extrasensory perception (ESP)
- the controversial claim that perception can occur apart from our sensory input
- "mind-to-mind" communication
- perceiving remote events
- perceiving future events
- the study of paranormal phenomena