AP unit 3: sensation and perception
Bottom-up processing
When the environment influences our thinking (sensation)
Volley principle
When they fire in rapid succession, neural cells can reach a combined frequency of around 1000 waves per second
Perceptual set
mental predispositions of what we expect to see influences what we really see
Absolute threshold
minimum amount of stimulation needed to detect senses 50% of the time
Lens
shapeshifting clear structure behind pupil to help focus images
Salty
sodium needed for physiological processes
Subliminal perception
stimuli that is below your absolute threshold and we can't detect 50% of the time.
Organ of Corti
strucutre in Cochlea that produces neural impulses in response to sound waves
Psychophysics
studies the relationships between physical characteristics of a stimulus
Proximity
tendency to group nearby figures together
Continuity
tendency to see continuous patterns instead of discontinuous ones
Perception
the brain recognizes and interprets sensory input; allows us to recognize meaningful objects & events
Different threshold
Minimum difference between 2 stimuli that a person can detect 50% of the time.
Blind spot
-a result of the optic nerve leaving the eye -no receptor cells anymore
Cochlea
-bony tube filled with fluid in the inner ear - vibrations of sound cause its membrane to vibrate and shakes the fluid -shaking of the fluid causes ripples in basilar membrane & bends hair cells that line the surface
Smell (olfaction)
-chemical sense in which odorants enter the nasal cavity and stimulates 5 million receptors to sense smell. - brain region for smell is connected to the one for memory; strong memories= strong scents
Inner ear
-consists of cochlea, semicircular canals, vestibular sacs
Sensory adaptation
-diminished sensitivity caused by constant stimulation -helps u get less distracted by background information
Relative size
-monocular cue -Tendency to perceive that the object hat looks smaller is farther away
opponent process theory of color vision
-opposing retinal processes allow us to see color - color processes: red vs. green perception and blue vs. yellow perception
How experience and culture affect perception
-past learning shapes perception -norms & stereotypes of a group of people affect perception
Helmholtz's place theory
-theory that connects the pitch we hear to what area of the cochlea membrane is stimulated -Believes different sounds are caused waves triggering activity at different places along the cochlea's basilar membrane - explains our ability to hear high-pitched but not low-pitched sounds
Frequency/temporal theory
-theory that the brain recognizes the pitch by looking at the frequency of neural impulses -sound waves cause basilar membrane to vibrate, triggering neural impulses at the same rate.
Steps of Stimulus Processing
1.Light waves 2. Cornea 3. Pupil 4. Lens 5. Retina (rods/cones: transduction + trichromatic theory) 6. Bipolar cells; ganglion cells 7. Opponent process theory of color vision 8. Feature detectors: Parallel processing 9. Perception
Weber's Law
2 stimuli need to differ by constant min percentage instead of amount
Cognitive style
A way of processing stimuli in environment that affects how we look at the world -Field-dependent and independent approach
Selective Attention
-When our attention is somewhere else, we can't notice part of our environment
Gestalt Psychology
-Emphasized that our conscious perception is whole -We first try to find the object that is different from its surroundings -Organize stimuli by grouping
Inattentional blindness
-Inability to see something in our direct view because our attention is elsewhere
Interposition
-Monocular cue - We see the object as closer if it partially blocks our view of another object
Figure-ground
-Organizing our visual field by looking for objects that stand out from surroundings
Perceptual constancy
-See objects as the same even when the angle, distance, and light is different
Umami
(savory and MSG) Proteins that grow and repair tissue
Fovea
- Area in the retina that is the center of the visual field - very concentrated w/ cones
Kinesthesis (Proprioception sense)
- How we sense the movement and position of ourselves and body parts -senses strength of effort exherted -Without it we would have to watch our limbs in order to coordinate movement
Taste
- Our tongue has receptors for different types of tastes and they have survival functions - Sweet, Sour, Umami, Salty, Bitter
Rods
- Receptors in the retina that recognizes black, white and gray color - Responsible for peripheral vision and seeing in the dark when cones are not responsive
Cones in retina
- Receptors in the retina that works in daylight and well-lit conditions - concentrated amt. in fovea -processed by opponent-process cells
Cochlear implant
- a device tha converts sound into electrical signals -Stimulates auditory nerve by the electrodes inside the cochlea -helps children improve in oral communication -only helps adults regain hearing if their brain learned how to process sound when they were a child
Parallel processing
- a way of processing functions -Brain divides visual picture into smaller aspects and works on them simultaneously
Feature detectors
- brain nerve cells that respond to the particular features of a stimulus (ex:shape) -Recieves information from ganglion cells in retina
Middle ear
- chamber in between the eardrum and cochlea -contains hammer, anvil, stirrup -Picks up vibrations and transmits them to the cochlea
Change blindness
- inability to detect minor changes in visual field
retina
- light-sensitive inner surface of eye - has receptor rods/cones and layers of neurons -beginning of visual formation processing -converts light energy into neural impulses (Transduction)
Vestibular sense
- our ability to feel the position of our head and body - vestibular sacs & semicircular canals have receptors that send messages about head's position to the cerebrellum -Helps us balance and stay upright
Signal Detection theory
- predicts how & when we detect the presence of a small signal - detection partly depends on experience, expectations, motivation, alertness - why we respond to same stimulus differently and when environment changes
Retinal disparity
- the difference between the 2 images our eyes see - greater the difference, the closer the object
Depth-perception
-Ability to see objects in 3D when the images our retina sees are 2D -Lets us guess how far an object is from us
Pupil
Adjustable opening in the center of the eye that light enters through
Visual cliff
An experiment used to test for depth perception; apparent drop from the floor but not an actual one
Papillae
Bumps on tongue that are covered by taste buds
functional fixedness
Cognitive bias which a person only uses an object in the way it is normally used
Prosopagnosia
Cognitive disorder that you are unable to recognize your own face and others'
Iris
Colored muscle that surrounds the pupil and controls its size -Dilates/constricts pupil based on light intensity
Monocular cues
Depth cues for each eye separately
Binocular cues
Depth cues that need the use of 2 eyes
Wavelength
Distance from a wave peak to the next -determines the color we see, our sensory experience, intensity
Sensorineural hearing loss
Hearing loss as a result of damaged cochlea receptor cells or auditory nerves - biological factors: heredity/age
Amplitude
Height of a wave that determines the intensity
Relative clarity
Less blurry objects are closer than cloudier objects
Motion perception/parallax
Our brain presumes shrinking objects as retreating and objects that are getting bigger as coming closer.
top-down processing
Our thinking determines what our senses detect (perception)
Linear Perspective
Parallel lines seem to meet in the distance (monocular cue)
Relative height
Perceive objects higher in the field of vision are farther away
Field-dependent approach
Perceive the world as a whole with not a lot of detail (Levelers)
Field-independent approach
Percieve aspects of environment as separate from each other with a lot of detail (sharpeners)
Observer characteristics of perception
Personality: Our unique way of thinking and behaviors Motivation: desires and needs to shape perceptions Values: we deem as important to shape perception
Closure
Tendency to fill in gaps to create a complete picture
Shape constancy
Tendency to see the shape of a familiar object as the same even when different shapes are sent to the retina
Accommodation
The lens focuses the rays by changing its own thickness
Gate Control theory
The theory that spinal chord consists of neurological gates that can push away pain or allow it to be sensed
Brightness constancy
Think that the object has same brightness even when light changes
Color constancy
Thinking a familiar object has the same color even when the light changes reflected wavelengths
Vision capture
Vision competes with other sense and normally wins
Perceptual adaptation
We are able to adjust to a distorted visual field
Priming
We create associations that create predipositions that affect our senses
size constancy
We detect objects to have the same size no matter its distance from us
Mcgurk Effect
When one sound component is used with a visual component of a different sound, there is a sense of a third sound
Relative motion
When we're moving, stable objects look like they're moving too
Trichromatic theory of color
Young and Helmhotz - retina contains 3 color receptors: red, blue, green -Combinations of these 3 receptors can make any color
Outer ear
channels sound waves through auditory cannal and the eardrum, causing a mechanical chain reaction
Synethesia
condition in which when one sense is activated, another unrelated one is activated too.
Transduction
converting one form of energy into another that our brain can use
Conduction hearing loss
hearing loss as a result of damaging our mechanical system that directs sound waves to cochlea
Phi phenomenon
illusion of a movement as a result of 2/more nearby lights blinking on and off in quick patterns
Context effect
interpreting what we see by the context of it
Optic nerve
nerve that takes neural impulses from the eye to the brain
Sweet
our energy source
Bitter
possible poisons
sour
potentially toxic acid
Tactile touch
pressure, cold, warmth, pain
Sensation
process of detecting environmental stimuli and converting them into signals that can be detected by the nervous system
Sensory restrictions
there is a critical period for normal sensory & perceptual development