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Journal
What is your most & least powerful senses? (10 sentences)
SENSATION & PERCEPTION
Chapter 8
SENSATION
Sect. 1 p. 207-213
Sensation
A SENSATION occurs when a stimulus activates a receptor
A STIMULUS is a change in the environment an organism responds to
Sense organs detect stimuli Eyes, ears, tongue, nose, skin Sensory information also tells the location
on the body
Perception
PERCEPTION: organization of sensory information into a meaningful experience
Uses past experiences and various sensations
PSYCHOPHYSICS: looks to understand how stimuli affect sensory experiences
Much of the world is undetectable to our human senses
Understanding Stimuli Limits What is needed for a stimulus to trigger
a response from the human body? ABSOLUTE THRESHOLD: weakest amount
of a stimulus needed to create a sensation Vision: seeing a candle flame 30 miles
away Hearing: hear a watch tick 20 feet away Taste: 1 tsp of sugar in 2 gallons of water Smell: 1 drop of perfume in a 3 room house Touch: feel a bee’s wing fall 1 cm onto your
cheek
Differences in Stimuli
DIFFERENCE THRESHOLD: smallest change in a physical stimulus that can be detected Eye exams, INTENSITY of stimuli
Just Noticeable Difference: smallest increase/decrease in the intensity of a stimulus Depends on the changes in the stimulus
Weber’s Law
**Larger/stronger the stimulus, the larger the change is needed for a person to notice any difference
Those who are able to tell subtle differences in stimuli are used as tasters, testers, experts
Sensory Adaptation
Senses most responsive to increases and decreases
Able to detect changes in environment instead of an ongoing, constant stimulus
Without sensory adaptation, senses would be bombarded all the time
These changes in stimuli allow us to react properly
Example: if you spend time in 0* temperatures, you will start to think that 10* is warm
Sensory Deprivation
Occurs when you LOSE or UNABLE to use one of your senses
When would be times that sensory deprivation occurs?
Journal
What super power do you want? (10 sent)
Signal Detection Theory
Studies relation between motivation, sensitivity, and decision making in detecting the presence (or absence) of stimuli
Recognize a stimulus (signal) against competing stimuli Tosses out idea of absolute thresholds Preattentive process
Extract information AUTOMATICALLY Attentive process
Considers only one part of a stimulus at a time
Stroop Interference
THE SENSES
Section 8.2 p. 214-222
The Light Spectrum
Vision (p. 215-218)
Most studied of all senses Steps to vision:
1. Light enters through the PUPIL (regulates amt of light)
2. Light reaches LENS (flexible structure that focuses light onto the RETINA
3. Light hits RODS & CONES (light receptive photoreceptors, change light into neuronal impulses)
4. Impulse travels along OPTIC NERVE where the signal is received at the occipital lobe
The Human Eye
Rods and Cones (functions)
Rods Sensitive at lower levels of light Useful for night-vision More numerous than cones (~75-150
million) Cones
Better for daylight use (need more light to respond)
~6-7 million Cones Sensitive to COLOR
Rods & Cones
The Blind Spot
Where the optic nerve exits the eye
No photoreceptors to process the image into an impulse to be sent to the brain
Binocular Vision
Combining two images into a single image
Retinal Disparity Difference in the image seen from each eye Necessary for depth perception
Large difference between what each eye sees means the object is near
Just because you do not want to learn does not mean you can be rude and disrespectful for those that want to pay attention or to me.
Feel free to waste your own time, but make sure it only affects you. You want an “easy semester” but are currently pissing me off.
Journal 5: Why do “people” feel entitled to get what they want when their actions are deserving of the opposite treatment? (10 sent)
Bring your books this week. You will be teaching the class. (graded assignment)
Nearsighted and Farsighted
Nearsighted Eyeball is a little longer Focusing point is slightly in front of the
retina Able to see close items, distant objects are
blurry Farsighted
Eyeball is too short Objects are focused slightly behind the
retina Close items are blurry, distant objects are
sharp
Eye Disorders
Macular degeneration Most common in older adults Retina becomes detached Difficult to read, recognize faces
Glaucoma Comes from increased fluid pressure in the
eye Pressure causes damage to the optic nerve Can cause blindness if untreated
Color Deficiency
Improper functioning of cones Able to see SOME colors Typically inherited trait from the
mother’s side Most common is red/green deficiency
Less common is yellow/blue
LASIK Surgery
1. Create a flap in the cornea
2. Use a laser to re-shape the tissue of the cornea
3. Replace flap; naturally heals
Journal of the Day
What songs or sounds “pump you up” or get you energetic? Why do you think these sounds have an affect on you? (10 sent)
HEARING & TOUCH
p. 218-219, 221-222
You Can’t Have Sound Without Vibration
Loudness measured in DECIBELS (dB) by amplitude (height) of sound wave
Range: 0-140 PITCH: frequency/rate of
vibration Low frequency= bass High frequency= squeaks
Limit: 85 db for 8 hrs. Each increase in 10 dB
makes sound 10 times louder
Process of Hearing
1. A)Outer ear receives sound waves, B)sends the sound to the auditory canal, C)causing eardrum to vibrate
2. Bones of the middle ear (hammer, anvil, stirrup) vibrate and push against the COCHLEA (where sound waves are translated into nerve impulses)
3. Pressure against the cochlea causes liquid inside the cochlea to move, causing small hairs to pick up the motion
4. Tiny hairs are attached to sensory cells which turn the vibration into neuronal impulses (signals)
5. Auditory nerve carries impulse to brain
Parts of the Ear
Signs of Hearing Loss
Tinnitus: Ringing, buzzing, hissing in the ear
Muffled hearing Fluid leaking from the ear Watching/listening to TV/music at a
higher volume than once used to Pain, itching, irritation in the ear Difficulty distinguishing what people are
saying
Hearing Problems
Conduction deafness Physical movement of outer ear or middle
ear bones are unable to carry sounds further into the ear
Typical hearing aids provide assistance Sensorineural deafness
Damage to the cochlea, hair cells, or auditory neurons
Aided by a surgically implanted cochlear implant
1 in 5 teenagers have some sort of hearing loss
Cochlear Implant
Touch
Skin is the largest organ of the body Receptors tells the brain about the
environment Mechanoreceptors: Relate to PRESSURE Thermoreceptors: found most abundantly in
face/ears Warmth: after 113* F pain receptors take over Cold: stop working once the skin temp hits 41*
F Nocireceptor: Pain
Sensations on the skin serve as an early detection and protection system against potential harm
Pain (is Temporary)
Pain can be the result from numerous stimuli Can affect a number of sense organs
Localized pain Sharp, occurs immediately as injury
happens General pain
Throbbing, dull pain occurs after the injury happens
Gate Control Theory Lesson pain by shifting attention away from
pain impulse or send other signals to compete with impulse
Journal Question
Draw an awesome picture
SMELL, TASTE, & OTHER SENSES
p. 220-221
Smell
One of the chemical senses Smell molecules reach a membrane
where the smell receptors are located Receptors send message through the
olfactory nerve to the brain
Parts of the Nose
Taste
Second chemical sense Uses liquid chemicals
to stimulate taste buds Also sends information
about texture and temperature
Taste made up of: Sour Salty Bitter Sweet Savory/Umami
Flavor made up of smell, taste, and tactile (pressure) sensations
As you get older, sense of taste doesn’t change, but rather sense of smell deteriorates
“Supertasters” have twice as many taste buds as normal individuals
Taste and smell are more “pleasure” senses than vital senses in humans
Taste buds on the Tongue
Vestibular System
Regulates the body’s sense of balance
Located within the inner ear (the three semicircular canals)
Elicits a response by spinning, falling, and tilting the body or head
Kinesthesis
Sense of movement and body position
Works in conjunction with vestibular and visual senses
Maintain balance and posture
Uses receptors in muscles, tendons, and joints to make smooth, coordinated movements
Journal of the Day
If a tree falls in the woods and no one is around to hear it, does it make a sound?
No Need to Write this Down, Discussion Only
Quiz next class.
PERCEPTION
Section 3, p. 223-231
Importance of Perception
Confront changes in environment, adapt to change
Comprehend numerous stimuli that attack the senses
Learn to perceive starting at 1 month old Influenced by our needs, beliefs,
experiences Perceptual set: see what you want to see
Uses bits of information to create larger picture and make sense of the world Gestalt (“pattern,” “form”)
Ideas of Gestalt
Closure: Group based on completed figures instead of missing parts
Continuity: See continuous patterns Proximity: Group elements that are close to
each other Similarity: in a mixed group, see similar
objects as group Simplicity: Perceive pattern in simplest
shapes possible
Figure-Ground Perception
Ability to tell the difference between a figure and its background
Listening to one sound or voice over all others
Perceptual Inference
Filling in gaps in what our senses tell us
Depends on experience
"Aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is taht the frist and lsat ltteers be at the rghit pclae. The rset can be a toatl mses and you can sitll raed it wouthit porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe."
Subliminal Perception
Ability to notice stimuli that only affect the unconscious mind Auditory or visual messages below the
absolute threshold that are perceived less than 50%
Originated via advertising/marketing
Depth Perception
Ability to recognize distance and 3D Monocular Depth cues
Used with a single eye Relative height: objects farther away
appear higher Interposition: with overlapping images,
whole object appears closer Texture-density gradient: less detail further
away Binocular Depth cues
Used with both eyes Convergence: eyes turn inward to look at
nearby objects
Interposition, Relative Height
Texture-density Gradient
Constancy
Perceiving objects in the same way regardless of changes in angle, distance, or lighting
Illusions & Mirages
Incorrect perceptions formed by distorted perceptual cues
Mirage: atmospheric optical illusion where an observer sees a nonexistent body of water or image of a distant object
How mirages work
Extrasensory Perception (ESP) Receiving information about the world
using ways other than normal senses Clairvoyance
Perceive objects without sensory input Telepathy
Reading someone’s mind or transferring thoughts
Psychokinesis Moving objects with only your mind
Precognition Able to foresee events