AP Psych Unit 3: Sensation/Perception
How do we locate sounds?
Using two important auditory cues: which ear receives the sound first which ear receives a more intense sound Why are we not so good at locating sound that comes from ahead, behind, overhead or below us? Because the sound reaches our ears simultaneously this automatically causes us to turn our heads towards the sound
bottom-up processing
analysis that begins with the sensory receptors and works up to the brain's integration of sensory information occurs when our sensory receptors detect external stimulation and send the raw data to the brain for analyzing
somatosensory cortex
area at the front of the parietal lobes that registers and processes body touch and movement sensations
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 brains can interpret.
conduction hearing loss
hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea SOUND CAN NOT GET THRU OUTER OR MIDDLE EAR Ex: pebble in ear, muffled
Interposition
if one object partially blocks our view of another, we perceive it as closer Tree blocking building, assumed that tree closer than building
relative size
if two objects are similar in size, we perceive the one that casts a smaller retinal image to be farther away
retinal disparity
images from the two eyes differ, and the closer the object the larger the disparity "Finger sausage"
sensory restriction
includes loss of a sense such as sight, resulting in increase perception in other senses
perceptual adaptation
means by which the brain accounts for the differences that the subject may witness, particularly alterations in the visual field. Example; displacement goggles, new glasses
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. receptors that respond to light
rods
retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don't respond receptors that respond to light
How the eye transforms light energy into neural messages
1. Light enters into the cornea ( protect eye and bends light) 2. Light passes through pupil (adjustable opening) surrounded by the iris, a colored muscle that adjust light intake and dilates / constricts to light intensity 3. The lens is behind the pupil to focus incoming light rays into an image onto the retina. 4. The optic nerve carries information to the brain to the thalamus to distribute. 5. A blind spot is created where the optic nerve leaves the eye, where there are no receptor cells. 6. Cones cluster in / around the vulva, the retinas area of central Focus.
How the ear transforms sound energy into neural messages
1. The ear transforms sound energy into neural messages, starting with the visible outer ear channeling sound waves through the auditory canal to the eardrum. 2. The middle ear then transmits eardrums vibrations through a piston of three bones (Hammer, Anvil, and stirrup) to the cochlea to the inner ear. 3. Incoming vibrations cause the cochlea, the oval window membrane, to vibrate so fluid that fills the semicircular canals. 4. This motion causes a ripple in the basilar membrane, bending hair cell linings. Hair cell movement triggers impulses in nerve cells, where axons converge to form the auditory nerve, sending neural messages (thalamus) to the temporal lobes auditory cortex.
linear perspective
A monocular cue for perceiving depth; the more parallel lines converge, the greater their perceived distance.
cocktail party effect
Ability to concentrate on one voice amongst a crowd situations that require direct attention
restored vision
After cataract surgery, blind adults were able to regain sight. These individuals could differentiate figure and ground relationships, yet they had difficulty distinguishing a circle and a triangle
Ponzo illusion
An illusion of size in which two objects of equal size that are positioned between two converging lines appear to be different in size. Also called the railroad track illusion.
Schemas
Concepts or mental frameworks that organize and interpret information.
How is our perception of pain a biopsychosocial phenomenon?
Biological: When distracted from pain, the body is soothed by a release of endorphins (natural painkillers) Sociocultural: Pain varies with social situation and cultural traditions. We experience pain when everyone else is as empathy mirrors pain for ourselves Pain: the body's way of telling you something is wrong and a behavior change is necessary Editing memories of pain, transforming what we actually experienced causes an overlooking of pain duration Recording a pain's peak moment when it was at its most unbearable Registering how the pain felt at the end, forgetting the peak
top-down processing
Information processing guided by high level mental processes When we construct perceptions drawing on our past experiences and expectations Sensitivity to sound- baby crying- baby sad/needs assistance the use of preexisting knowledge to organize individual features into a unified whole
How can perception be viewed as a biopsychosocial phenomenon?
Is perception innate or acquired? (version of reality) Biological: - entry level sensory analysis - unlearned visual phenomena - critical period of sensory development Psychological: - selective attention - learned schemas - Gestalt principles - emotional context effects - perceptual sets Social-cultural: - cultural assumptions/expectations - physical context effects
How do we sense our touch/body's position and movement?
Our sense of touch is controlled by a huge network of nerve endings and touch receptors in the skin known as the somatosensory system. This system is responsible for all the sensations we feel - cold, hot, smooth, rough, pressure, tickle, itch, pain, vibrations, and more. 1. Starts off as signals generated by touch receptors that travel along sensory nerves connected to neurons in the spinal cord 2. Move to the hypothalamus where the info is spread 3. The last place is the somatosensory cortex where the signals turn into perceived touch 4. The most sensitive areas like the lips stimulate a larger area of the cortex
Sensation vs. perception
Sensation: the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment Perception: the process of organizing/interpreting sensory information, enabling us to recognize meaningful objects/events Sensation is arrival of info to brain (basic intake), perception is interpretation of info in brain (add meaning)
How do we experience smell?
Smell, or olfaction, happens when chemicals in the air enter the nose during the breathing process. Smell receptors lie in the top of the nasal passage. They send impulses along the olfactory nerve to the olfactory bulb at the base of the brain.
Parallel processing- brain processing visual information
The processing of many aspects of a problem simultaneously Serial (step-by-step) processing of computers The brain can simultaneously process different aspects of stimuli such as motion, shape, and depth; this helps the brain paint a full picture of the scenario
opponent process theory of color vision
Theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision. -Some cells are stimulated by green and inhibited by red -Some cells are stimulated by red and inhibited by green -Explains why neurons are stimulated for certain colors and not others the theory that receptor cells for color are linked in pairs, working in opposition to each other
trichromatic theory of color vision
Theory that the retina has 3 color receptors (red, green, and blue) which, when stimulated together can produce the perception of any color
How do we experience taste?
These receptor cells, or taste buds, bind with molecules from the food or drink being consumed and send signals to the brain. The way our brains perceive these stimuli is what we refer to as taste, with there being five recognised basic tastes: salty, bitter, sweet, sour and umami (meat, savory)
Gestalt Psychology
a psychological approach that emphasizes a figure formed a "whole" different than its surroundings ("The whole is greater than the sum of its parts")
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. false alarms old car, convince ourselves we hear "clunks"
pitch
a tone's experienced highness or lowness; depends on frequency
monocular cues
depth cues, such as interposition and linear perspective, using 1 eye relative size
binocular cues
depth cues, such as retinal disparity, that depend on the use of two eyes retinal disparity
sensory adaptation
diminished sensitivity as a consequence of constant stimulation Example; forgetting watch is on wrist, can't feel it unless mentioned Reduced sensitivity, freedom to focus on information changes in our environment w/o being distracted by uninformative background stimulation
ESP
extrasensory perception; the controversial claim that perception can occur apart from sensory input; includes telepathy, clairvoyance, and precognition
change blindness
failing to notice changes in the environment Example: guy asking for directions, switches places w/ another after interruption of a wood board passing by, person doesn't realize their talking to a new guy because he fits the basic criteria
inattentional blindness
failing to see visible objects when our attention is directed elsewhere
perceptual constancy
perceiving objects as unchanging (having consistent lightness, color, shape, and size) even as illumination and retinal images change Knowing from the nose-bleed seats that the players on the field are human-sized even though from far away they look miniature Shadow over newspaper but newspaper isn't black
Volley theory of pitch perception
states that groups of neurons of the auditory system respond to a sound by firing action potentials slightly out of phase with one another so that when combined, a greater frequency of sound can be encoded and sent to the brain to be analyzed.
Detection- - brain processing visual information
the ability to determine the presence of an object
depth perception
the ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance
priming
the activation, often unconsciously, of certain associations, thus predisposing one's perception, memory, or response Example: if a child sees a bag of candy next to a red bench, they might begin looking for or thinking about candy the next time they see a bench
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 (height)
Fovea
the central focal point in the retina, around which the eye's cones cluster
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
Wavelength
the distance from the peak of one light wave to the peak of the next
selective attention
the focusing of conscious awareness on a particular stimulus, as in the cocktail party effect
Amplitude
the height of a wave's crest determines volume
difference threshold
the minimum difference between two stimuli required for detection 50 percent of the time "just noticeable difference" For example, if you were asked to hold two objects of different weights, the just noticeable difference would be the minimum weight difference between the two that you could sense half of the time.
absolute threshold
the minimum stimulation needed to detect a particular stimulus 50 percent of the time, necessary to detect light, sound, pressure, taste and odor Example: see a candle burning from miles away Smell 1 singular drop of perfume in a three bedroom apartment
sensorineural hearing loss
the most common form of hearing loss, also called nerve deafness; caused by damage to the cochlea's receptor cells or to the auditory nerves INNER EAR DAMAGE Example: caused by excessive noise exposure
frequency theory of pitch perception
the nerve impulses that travel up the auditory nerve, which sends information about sound to the brain, have the same rate as the frequency of the tone you are hearing the basilar membrane receives the sound wave and starts vibrating, this causes neural impulses moving along the brain at the same pace as the sound wave
Frequency
the number of complete wavelengths that pass a point in a given time measured in Hertz (Hz) determines the pitch ( tone's high or lowness) of the sound.
figure-ground
the organization of the visual field into objects (the figures) that stand out from their surroundings (the ground).
grouping
the perceptual tendency to organize stimuli into coherent groups
blind spot
the point at which the optic nerve leaves the eye, creating a "blind" spot because no photoreceptor cells are located there When both eyes are open blind spots can not be detected and even when one eye is closed the brain still does a good job of "covering up" the areas that can not form image detection It is located where blood vessels have major entry points to the eye that are utilized by the retina
perceptual set
the predisposition or 'readiness' to perceive something in accordance with what we expect it to be. often referred to as expectancy because various psychological factors (such prior experience and context) create an expectation to perceive information in a particular way. Expecting to see young woman, don't see old woman until it is pointed out
sensory interaction
the principle that one sense may influence another, as when the smell of food influences its taste
Weber's Law
the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount) Adding 1 pound to 10 pounds is noticeable Adding 1 pound to 100 pounds is less noticeable
accommodation
the process by which the eye's lens changes shape to focus near or far objects on the retina Lens flattens when focusing on distant objects Lens rounds when focusing on nearby objects
vestibular sense
the sense of body movement and position, including the sense of balance equalibrium
Psychophysics
the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them
gate-control theory
the theory that 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 the activity of pain signals traveling up small nerve fibers and is closed by activity in larger fibers or by information coming from the brain. Example: rubbing area around stubbed toe blocks some pain messages
place theory of pitch perception
the way we hear sound is determined by the location of the vibrations produced by the frequency within the cochlea's basilar membrane
Gibson and Walk's Visual Cliff
to measure infants ability to perceive depth; most infants older than 6 months will not crawl out over the deep side, indicating that they can perceive depth
closure
we fill in gaps to create a complete, whole object
relative height
we perceive objects higher in our field of vision as farther away than those that are lower
subliminal threshold
when stimuli are below one's absolute threshold for conscious awareness a. we can unconsciously sense (literally=below) b. w/o awareness, stimulis= suggestive powers, detected 1/2 the time
kinesthesis
your sense of the position and movement of your individual body parts example: being able to sense the position of your limbs during the night
