Bell Activity 3/1/2013

Learning Targets: At the end of class, you will be able to-

-Describe the importance of sensation and perception

-Define: stimulus, signal-detection theory, Weber’s law

-Create an experiment

1.) How do things look the way they do?

2.) What is this color?

3.) How do we know if everyone else is seeing the same color?

4.) How do we know we are moving and if we are, where we are going?

Sensation & PerceptionSensation & Perception

School Tour

1. Write down all of the places that you went (or think you went).

2. How do you know that these are the places you went?

Sensation & PerceptionSensation & Perception

SensationSensation: Occurs when a stimulus : Occurs when a stimulus activates a receptoractivates a receptor

Ex: Changes in heat, light, sound, Ex: Changes in heat, light, sound, physical pressure, etc.physical pressure, etc.

PerceptionPerception: The organization of sensory : The organization of sensory information into meaningful experiences.information into meaningful experiences.

Ex: Vision incorporates colors, intensity of Ex: Vision incorporates colors, intensity of light, distance, etclight, distance, etc

Fraser’s SpiralFraser’s Spiral

Now, cover up half of the spiral

So…How do we use

sensation and

perception together to

understand our world?

Combination of senses and past experiences

Sensation & PerceptionSensation & Perception Our knowledge of the world comes from Our knowledge of the world comes from

chemical & electrical processes occurring chemical & electrical processes occurring in the brain.in the brain.

StimulusStimulus: Any aspect of or change in the : Any aspect of or change in the environment to which an organism environment to which an organism responds.responds. A stimulus can be measured by size, duration, A stimulus can be measured by size, duration,

intensity or wavelength.intensity or wavelength.

Sensation & PerceptionSensation & Perception

Sensation occurs anytime a stimulus Sensation occurs anytime a stimulus activates a receptoractivates a receptor

PsychophysicistsPsychophysicists study the relationship study the relationship between stimuli & sensory experience.between stimuli & sensory experience.

Sensation & PerceptionSensation & PerceptionThresholds, Differences & RatiosThresholds, Differences & Ratios

Absolute ThresholdAbsolute Threshold: minimum amount of : minimum amount of physical energy needed to produce a physical energy needed to produce a sensation 50% of the time.sensation 50% of the time. In general, the senses have very low absolute In general, the senses have very low absolute

thresholdsthresholds

Ex: In a dark room, project low-intensity beam of light Ex: In a dark room, project low-intensity beam of light against the wall. Slowly increase the intensity of the against the wall. Slowly increase the intensity of the light until it can be seen. Then, start with a bright light light until it can be seen. Then, start with a bright light and lower it until the participant cannot see it any and lower it until the participant cannot see it any longer.longer.

Sensation & PerceptionSensation & PerceptionAbsolute Thresholds of the 5 SensesAbsolute Thresholds of the 5 Senses

Vision: seeing a candle flame 30 miles away on a clear Vision: seeing a candle flame 30 miles away on a clear night.night.

Hearing: hearing a watch ticking 20 ft. away.Hearing: hearing a watch ticking 20 ft. away. Taste: tasting 1 teaspoon of sugar dissolved in 2 gallons Taste: tasting 1 teaspoon of sugar dissolved in 2 gallons

of water.of water. Smell: smelling 1 drop of perfume in a 3 room houseSmell: smelling 1 drop of perfume in a 3 room house Touch: feeling a bee’s wing falling a distance of 1 Touch: feeling a bee’s wing falling a distance of 1

centimeter onto your cheek.centimeter onto your cheek.

*In general, the senses have very low absolute thresholds.*In general, the senses have very low absolute thresholds.

Sensation & PerceptionSensation & Perception

Difference thresholdDifference threshold: the just noticeable : the just noticeable difference, minimum amount of energy needed difference, minimum amount of energy needed to produce a change in sensation.to produce a change in sensation.

Sensory experiences depend more on changes Sensory experiences depend more on changes in the stimulus than on size or amount of in the stimulus than on size or amount of stimulus (3lb. into and empty backpack vs. 3 lbs stimulus (3lb. into and empty backpack vs. 3 lbs in a 100 lb. backpack)in a 100 lb. backpack)

Weber’s LawWeber’s Law: The larger or stronger a stimulus, : The larger or stronger a stimulus, the larger the change required for an observer to the larger the change required for an observer to notice.notice.

Sensation & PerceptionSensation & Perception

Sensory AdaptationSensory Adaptation: : Senses respond to Senses respond to increases and increases and decreases in decreases in stimulus. stimulus.

Example: Eyes Example: Eyes adjusting to darkness adjusting to darkness in a room.in a room.

Sensation & PerceptionSensation & Perception Signal Detection Signal Detection

TheoryTheory:: ( (Abandons the Abandons the idea of a true absolute idea of a true absolute threshold)threshold) based on the based on the notion that a stimulus notion that a stimulus (signal) must be detected (signal) must be detected in the presence of in the presence of competing stimuli.competing stimuli.

Ex: Being able to study Ex: Being able to study in a room with a radio in a room with a radio playing and a TV on, etc.playing and a TV on, etc.

Bell Activity 3/5/2013

Learning Targets: At the end of class, you will be able to-

-Create an experiment to find absolute threshold

-Describe how vision works

1.) What is the relationship between sensations and perceptions?

2.) Eyes adjusting to light differences is referred to as ____.

3.) How do 3-D movies work?

In the Computer Lab

Go to Mr. P’s site: http://spetersopsych.wikispaces.com/

Click on the “Unit 4” link Play the “Eye Hop Game” and take the

“Depth Perception Test.” Take the Color Blind Test; From this site,

write down 10 things you learned about color blindness.

VisionVision Most studied of all the

senses How does vision

occur? Light enters through the pupil & reaches the lens that focuses light on the retina.

Vision

The retina contains two types of receptor cells: rods and cones.

Rods and cones are responsible for changing light energy into impulses which travel along the optic nerve to the occipital lobe.

Vision

Cones work best in daylight and are sensitive to color.

Rods are used in night vision

What Happened?

Answer: The receptors for green, yellow and black became fatigued (neuron firing shifted)

Vision The Electromagnetic Spectrum: Includes

radio waves, microwaves, infrared radiation, X-Rays and gamma rays.

Visible light represents a very small portion of the spectrum

Vision

Binocular Fusion- receiving 2 images but combining them into 1. We receive two images from our eyes and form one composite image of the two views.

Vision Retinal Disparity- differences between the two

images (closing one eye and looking at object). This is essential to creating our sense of depth perception.

Stereopsis-Phenomena of seeing depth as a result of retinal disparity

Vision When your eyeball is

not perfectly shaped, your vision will be impaired because the focal point has been changed

Nearsightedness: Eyeball is too long

Farsightedness: Eyeball is too short

Bell Activity 3/6/2013

Learning Targets: At the end of class, you will be able to-

-Describe the function of senses such as taste, touch, smell and hearing

1.) What are the receptor cells in the eyes called?

2.) How does retinal disparity help us with our vision?

3.)What songs remind you of important events in your life?

Ex: http://www.youtube.com/watch?v=pIotIGFN2oc

4.) What smells do you associate with childhood?

*Remember only water is allowed outside of the Commons-School Policy!

Hearing Depends on vibrations

of the air (sound waves) that pass through various bones & fluids until they reach the inner ear.

Hair-like cells change sound vibrations into neuronal signals that travel along the auditory nerve to the brain.

Hearing Loudness depends on

the amplitude of vibrations; strength/sound-pressure is measured in decibels. (0-14-, anything over 110 can damage)

Pitch: the experience associated with a sound’s frequency: the “highness” or “lowness” of a sound.

Hearing-Pathway of Sound

The ear is designed to capture sound-

Outer ear receives sounds Earflap directs sounds down a

short tube called the auditory canal to vibrate

Causes the eardrum to vibrate

Hearing

Bones in the Middle Ear pickup vibrations and push against cochlea

Cochlea: Sensory cells in the cochlea turn the vibrations into neuronal impulses

Hearing

2 Types of Deafness Conduction: when

anything hinders physical motion through the ear (hearing aides)

Sensorineural: Damage to the cochlea (cochlea implant)

Hearing

http://www.youtube.com/watch?v=KGn9McPK7Qw

Smell and Taste

Chemical Senses: receptors are sensitive to chemicals rather than light or sound.

Smell- molecules enter nose in vapors, the vapors come into contact with smell receptors in nose. Messages are sent to the brain by the olfactory nerve.

Smell and Taste Taste- chemical stimulate

receptors (buds) on tongue, messages sent to brain with data about texture & temp.

4 primary taste sensations: sour, salty, bitter & sweet.

6 smell experiences: flowery, fruity, spicy, resinous, putrid & burned.

Much of taste is also produced by smell, temp and texture.

Smell and taste play a much more important role in “lower animals”

““Hey Bud!” ResultsHey Bud!” Results

Touch

Skin provides brain w/ info. about environment: pressure, warmth, cold & pain

Pressure varies from place to place (fingertips v. calf) serve as protection/warning.

Pain makes it possible to prevent damage (emergency system)

TouchPain-Sharp localized pain

immediately after an injury

-Dull, generalized pain you feel afterward

-Gate Control Theory of Pain: You can lesson pain by shifting attention away

-Referred Pain: Pain in area away from the actual source.

Balance and Body Senses Regulated by the vestibular

system (inside inner ear) The vestibular system

contains the semicircular canals with contain moveable fluid. Over stimulation can result in dizziness.

Kinesthesis: Sense of movement & body

position Cooperates with the

vestibular system and visual senses to maintain posture and balance.

Balance and Body Senses

Without kinesthesis, your movements would be jerky and uncoordinated.

Other body sensations come from receptors that monitor internal body conditions.

Referred pain-pain in an area that is actually away from the actual source.

Bell Activity 3/7/2013

Learning Target: At the end of class, you will be able to-

-Find taste locators on the tongue

-Describe the senses-Explain the Gestalt

Principle of Perception

1.) What serves to protect the body from outside harm?

2.) What are the two types of deafness?

3.) What relays messages about smell to the brain?

4.) In your mind, what do teachers do?

Remember, water is the only drink allowed outside of the Commons area-School Policy!

Bell Activity 3/8/2013

Learning Targets: At the end of class, you will be able to

-Describe the five principles of Gestalt

-Describe how we develop perceptions

-Explain the importance of subliminal messaging

1.) Which system regulates our balance?

2.) What are the 2 types of pain?

3.) What makes our movements fluid as opposed to jerky and uncoordinated?

*Test on Tuesday!*Vocab due on Monday.

Perception

The process of the brain receiving information from the senses, organizing it and then interpreting it into meaningful experiences.

Principles of Perception The brain receives information from

the senses and organizes/interprets it into meaningful experiences unconsciously.

Gestalt: (whole experience) the experience that comes from organizing bits and pieces of information into meaningful objects and patterns. The whole is greater than the sum of parts (ex. music).

If the elements of a pattern are close to one another or similar they are perceived as belonging to each other.

Gestalt Principles: Proximity, Similarity, Closure, Continuity, Simplicity

5 Principles of Gestalt

Principles of Perception

Figure-Ground Perception: The ability to discriminate between figure (object) and ground (background); 3-D v. 2-D

Principles of PerceptionPerceptual Inference Perceptions that are not based on

current sensory information. Otherwise known as “filling in the gaps”. We use learned information to help us draw conclusions.

Often depends upon previous experiences-but not always (babies won’t fall off of the “cliff”).

People and animals must be actively involved in their environments to develop perception

Learning to Perceive

Perceiving is something we learn to do. Involvement with one’s environment is

important for accurate perception. (Ex: Blind patients who gain sight do not know difference between

squares an circles

Perception is based on our needs, beliefs, and expectations. You see what you want to see.

(Ex: Bias in politics, stereotypes, etc)

Computer Activity

Go to Mr. P’s Web Site: http://spetersopsych.wikispaces.com/home

Click on the Unit 4 link Go to the “illusions” and “more illusions”

links Click on the different optical illusions Pick 15 of the optical illusions and explain

how they work

Subliminal Perception

Brief auditory or visual messages presented below the absolute threshold

Ability to detect stimuli that only affect the subconscious mind

Controversial

Bell Activity 3/11/2013

How would a Psychophysicist (someone who studies the relationship between sensation and perception) answer the following question?

If a tree falls in the forest and no one is around to hear it, does it make a sound?

Learning targets: At the end of class, you will be able to-

-Identify examples of subliminal messages

-Discuss factors that shape our perceptions

-Review for the sensation and perception test

Bell Activity Answer

A Psychophysicist would say that the answer is….

NO!

Why? From a scientific point of view the physical event happens (there is sound waves created) but, the psychological event cannot happen unless an organism is present to experience the event (turn sound waves into impulses sent to the brain to be interpreted)

Subliminal Political Ad?

http://www.youtube.com/watch?v=QKAWBu_GOoA

Subliminal Messages in Fast Food

http://www.youtube.com/watch?v=YoIIkTs2j3Q

Other Factors That Shape our Perceptions

Monocular Depth Cues: Cues that can be detected with just one eye (bigger=closer)

Binocular Depth Cues: Cues that depend on the cooperation of both eyes (retinal disparity)

Motion Parallax: Apparent movement of objects in relation to other objects as you move

Linear Perspective: Parallel lines converge in the distance

Relative Motion: How other objects move in relation to your movements

Constancy: We perceive things to be unchanged regardless of light, distance, angle, etc.