Detection of physical energy emitted or reflected by physical objects.
Set of mental operations that organizes sensory impulses into meaningful patterns.
Smallest amount of stimulus that you can detect 50% of the time.
- Difference Threshold: just noticeable difference
- Smallest difference in stimulation that a person can reliably detect.
- Ex. Cayenne pepper to bland meal (you can really taste)
- Ex. Hot pepper to spicy chili (you don't notice)
signal detection theory
Investigates the effects of distractions and inferences while perceiving the world.
top down processing
- Filling in the gaps that we sense.
- Use experiences to perceive an object.
- Faster you go, more prone to errors.
bottom up processing
- Feature analysis
- Use the feature of the object to perceive it.
figure ground relationship
- Which visual image is the figure or background.
- Ex. Vase or two faces?
- How motivated you are to detect stimuli.
- Quarterback finds receiver
- Doctor finds tumor in CAT scan
- Smell cookies if hungry and like them
- False Positive: Think you perceive stimuli but you don't (friend in crowd)
- False Negative: Don't perceive stimuli that is present (directions on test)
- Reduction or disappearance of sensory responsiveness when stimulus is unchanging
- Ex. Tights
- Never completely adapt to extremely intense stimulus
- Ex. Middle of desert, never adapt to sun, still always hot
The absence of normal levels of sensory stimulation
- Too much stimulation can lead to fatigue and mental confusion
- Ex. Ludin with Vegas
- Selective Attention: Focusing on selected aspects of the environment and ignoring other (read in restaurant)
- Extrasensory Perception
- Claim to receive and give messages about the world without relying on the usual sensory channels.
- Tend to forget about experiences that fail to define ESP
Perception of an event that has not yet happened
Direct communication from one mind to another
Study of purported psychic phenomena
- Studies are often poorly designed
- "No scientific justification for the existence of parapsychological phenomena"
Dominant sense in human beings.
Where the optic nerve leaves the back of your eye.
- Color names wavelength of light
- Short: Violet and Bue
- Long: Red and Orange
- Effected by waves
- Intensity (amount) of light emitted or reflected
- Measured in flashes or eye exams
- Effected by waves
- Complexity of light
- How wide or narrow the range of wavelenghts are)
- White light is completely unsaturated
- Effected by waves
- Protective layer on eye
- Where light comes in
Gives color to eye to let more in
Has visual receptors on it
Have rods and cones
- Young-Helmotz Theory
- 3 mechanisms in the visual system
- Each sensitive to different wavelenghts
- Produces hues
- About level of processing in retina
Oopponent Process Theory
- Theory of color rerception that treats pairs of colors as opposing or antagonistic after images
- About wavelengths
- Ex. Red Circle
- Pereceive images as groups, not isolated elements
Objects that are close together are more likely to be perceived as belonging in the same group.
Objects that are similar in appearance are more likely to be perceived as belonging in the same group.
Objects that form a continuous form (such as trail or a geometric figure) ar more liekely to be perceived as belonging in the same group.
- Similar to top-down processing.
- Objects that make up a recognizable image are more likely to be perceived as belonging in the same group even if the image contains gaps that the mind needs to fill in.
- Mono Chromates: Totally color blind/very rare/ see shades of gray, black, and white
- Trichromates: Can discriminate all colors
- Dichromates: Partially color blind/ genetic
- Facts: Passed on by mom/ Sons get it/ Very rare for females/ geneally all males can distinguish yellow & green and blue & red/ 1 in 5,000
Ability to maintaint constant perception of an object despite these changes:
- size: an objcet does not grow or shrink in size as it moves closer or farther away
- shape: depens on the familiarity with the usual shape of an object
- brightness: ocean (light reflecting off water changes)
- location: driving objects fly by, but don't really move
- Distances ove 50 feet
- Can use only 1 eye
- Requires use of 2 eyes
- Distance about 50 feet
Have cues of depth and distance
Sense of hearing
amplitude/ frequency of sound waves
Height of the wave
Actual organ of hearing
Intensity of a wave's pressure measured in decibels
- Frequency of the sound wave (how rapidly the air vibrates)
- Measured in hertz
- 16 low to 20,000 high normal hearing range
- Distinguishing quality of sound-very complex
- Relative to the breath of the range of frequencies
- All frequencies of the audible sound spectrum are present
- Sounds like hissing, not distinguishable
- Hear input in both earts
- Hear more from left, sound is from left (vice versa)
- Something goes wrong with the system of conducting sount to the cochlea
- Born with
- Hair cells in the cochle are damaged
- Usually by loud sounds
- Unit for measuring loudness
- 0: absolute threshold/lowest sound audible to human ear
- 70: can be dangerous/ level of dangerous everyday noises
- 180: Hearing loss inevitable & permanent/ rocket launching
- Chemicals stimulate thousands of receptors in the mouth
- Located primarily on the tongue, throat, cheek, and roof of your mouth
- Little bumps on tongue
- Receptor cells are insite the taste buds (500-10,000)
- Sweet, sour, salty, and bitter
- Can taste all over the place
- Sense of smell
- Difficult to analyze because over 10,000 smells
- Maybe 100 types of receptors
Gate Control Theory of Pain
- Ronald Melzack and Patrick Wall
- Some pain messages have a higher priority and must get through the gate in the spinal cord.
- Gate is not a real structure but a pattern of nerval activity that either blocks pain messages or let's them through./Usually shut
- Distracting can alleviate pain
- Thoughts and feelings can influence the reaction to pain
- Refuted by phantom pain
- Sense of body position and movement
- Skeletal muscles
Equilibrium (sense of balance) related to inner ear
visual cliff experiment
- Gibson and Walk
- 6 month old baby will crawl to edge and keep going
- Doesn't perceive depth
- People from noncarpentered cultures (no right angles) are not fooled
- Ex. Two lines that look different because of the endpoints, but are really the same length
- Visual perceptions
phantom limb sensation
- Amputees feel pain in the removed part of the body.
- Brain is capable of generating pain
rods and cones
- Connected by synapses to neurons
- Rods: Sensitive to low light/ 120-125 million
- Cones: Sensitive to bright light & color vision/ 7-8 million
the power to move something by thinking about it without the application of physical force