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