Sensation and Perception

Optical Illusions, the World of Color, and Sense of Smell and Taste

The Man Who Mistook His Wife for a Hat by Oliver Sacks. Read excerpt on pg. 123

Sensation: the stimulation of the eyes, ears, nose, tongue, and skin

Perception: the selection, organization, and the interpretation, of sensory input.

Group Question Minute: Does Dr. P have a problem with sensation or with perception?

What is Sensation and Perception?

Oliver Sacks is a physician, best-selling author, and professor of neurology and psychiatry at Columbia University Medical Center.

Psychophysics

Each person: Come up with an example on sensation and a related example of perception. Write the examples in consecutive sentences.

EX. My eyes point toward an orange. My brain registers “orange” and I begin drool.

EX. Clorox particles are floating around in the air and enter my nose. I think, “That’s bleach! I’m going to get a headache.”

“Is My Red the Same as Your Red?” see Vsauce on YouTube• Qualia: ineffable (too great and to extreme to be able to describe in words)

raw feelings• Theory of Mind: the ability to attribute mental states—beliefs, intents,

desires, pretending, knowledge, etc.—to oneself and others and to understand that others have beliefs, desires, and intentions that are different from one's own.

• The Sally-Anne Test: Sally and Anne have a box, a basket, and a cookie in the room. Sally puts the cookie in the box and leaves the room. While she’s gone, Anne takes the cookie and put it in the basket.

• Where will Sally look first? Children under the age of 4 say that Sally will look in the basket first, because they saw Anne move the cookie, so why wouldn’t Sally know?

“We are all alone in our own with our perceptions. We are alone in our own minds. We can both agree that chocolate tastes good, but I cannot climb into your consciousness and experience what chocolate tastes like to you. I can never know if my red looks the same as your red.”

[Packet] Reality Free Write:Answer any or all of these questions!

• “Daddy? How do we know we’re real? How do we know that we’re not just people in a story that someone else is writing?” – How would you answer this question?

• How do you know that what you perceive is real?

• What connects you to reality? What gives you your “reality identity?”

dreams imagination

spirituality

Altered states of consciousnessArt and stories

emotions

• Principles • Elaboration

Directions: Note key principles of perception and illusion while trying to figure out the visual strategy used in each visual

[Packet] Principles of Perception and Illusion

Basic Gestalt PrinciplesGestalt Psychology: top-down processing; the whole is more than the sum of its parts.

The key concept is perspective.

Group Question Minute: Why have our brains adapted to perceive the world using these Gestalt principles?

Perceptual Dilemma: Animal or Human?

Perceptual Dilemma: Bird or Bunny?

Perceptual Dilemma: Women or Ceramics?

Perceptual Dilemma: Honey or Hag?

Perceptual Dilemma: Innie or Outie?

Group Question Minute: What is the key component of this figure that makes it so difficult to understand?

• Colored surface can be either the outside front surface or the inside back surface

• Cannot simultaneously be both• Brain can interpret the

ambiguous cues two different ways

Muller-Lyer IllusionWhen our Eyes observe reality but

our brains re-define it

Why? Our brains base our perception of reality on “the familiar,” like building designs. “The familiar” allows our brains to make “perceptual hypotheses.”• Illusions are valuable in understanding perception because they are systematic

errors.• Illusions provide hints about perceptual strategies.• In the Muller-Lyer illusion (above) the visual system processes that judge depth

and distance assume in general that the “angles in” (left) configuration corresponds to an object whose corner is thrust toward you and closer, and the “angles out” (right) configuration corresponds to an object whose corner is thrust inward and farther away. Therefore, the “angles out” line must be bigger, since it represents the corner that is further away.

--Which line seems longer?

Which building corner is further away? If something is further away, but appears the same size as something in the foreground, is it bigger or smaller than that thing?

The converging lines convey linear perspective, a key depth cue suggesting that the upper line lies farther away. However, it comes closer to the sides of the converging lines. Therefore, our brain tells us it is bigger since it is not shrinking in proportion to the converging lines

KEY QUESTION: Do the adjoining lines angle in (suggesting that space is becoming smaller) or do they angle out (suggesting that space is opening up)?

The Ponzo Illusion (above): • Linear perspective provides context• Parallel side lines seem to converge• Top line seems farther away and almost spans the gap between converging

lines, so our brain says, “It must be longer!”• But the retinal images of the red lines are equal!

This illusion happens, because we are used to seeing images like this!

Geometric illusionsPoggendorff: Do the two diagonal segments lie on the same straight plane?

A: People tend to overestimate the size of sharp angles formed where the sloping and horizontal lines meet.

Zollner: Do the long lines seem straight or curvy?

A: Also a misjudgment of angles. The stem lines seem to curve, by they’re straight.

Upside-down T: Which line is longer?

A: The horizontal line is bisected, so it seems shorter.

The Ames Room :A specially-built room that makes people seem to change size as they move around in it

These boys are actually the same size!What are the actual physical properties of the room vs how does the viewer perceive the room?

• Perceptual explanation: • (1) monocular depth perception (one eye), • (2) non-standard room (we are used to rectangular rooms), • (3) context cues like the tile, windows, clock (which all have standard sizes and

patterns)

The Three Classic Impossible Figures

The drawings are real, because they’re lines on a plane just like any other drawing.

Why does our mind become frustrated?• Appear three-dimensional, like

other figures we’re used to, so it’s difficult merely to see them as lines drawn on a plane

• We think we’re familiar with these figures (triangle, prongs, stairs), so we start off using top-down processing, but we soon recognize that these objects can’t be “wholes,” . . .

• So we begin to analyze their “parts” instead sot we can put them together into a whole. This is called bottom-up processing, but it still doesn’t work.

The Moon Illusion:The full moon appears to be much smaller when overhead than when looming on the horizon.

Size Constancy: the assumption that an object’s size doesn’t physically change no matter where or how it moves. An object merely looks bigger when it’s closer and looks smaller when it’s farther away. So, (says our brain) if it’s not the moon’s size that changes, it must be its distance! It must be closer sometimes, and farther other times, and that’s why the size appears to change.

Reason for the Moon Illusion: Due to our believing in size constancy and the consequent misperception of distance, the horizon moon appears to be at the end of a stretch of terrain receding into the distance, accompanied by distant trees, buildings and so forth, all of which indicate that it must be close enough we can get there and give us context (I know how big a tree it), while these context cues are absent from the zenith moon.

Close to the horizon= bigIn the middle of the sky= small

“You can walk to that building over there. Can you walk to outer space?”

Compared to that tree the moon must be BIG! But compared to . . . nothing . . . how big is it?

Do These Optical Illusions work elsewhere in the world?

• Not always!• Group Question Minute: Why not?• Non-Western cultures have not

been exposed to the “carpentered world,” so their brains have different habits of perception.

• Example: Instead of straight lines, right angles, and rectangular rooms, buildings, and furniture, the Zulus are used to more organic, homemade shapes.

• Play with Figures 4.38, 4.39, 4.40, and 4.41 on pg. 151and the figures on pg. 170. See if you can figure them out.

• Choose 2 of these figures. Label and write a paragraph on each illusion explaining how you think it deceives the mind/affects your perception. Some of the words in the below word bank should appear in your explanations.

[Packet] Unraveling Optical Illusions

Word Bank:Linear perspective proximityExpectation closureContext similarityAngles simplicityMonocular depth perception continuity

• Draw and decorate your own optical illusion. Make it as clever as you can!

• Tools to Help You Draw and Write:– Gestalt Principles (144)– Use of color (example figure 4.31 on pg. 145)– Pictorial cues to depth (147)– Context cues and monocular depth perception (figure 4.43 on pg. 152) – Linear perspective (pg. 150-152)– Any of the figures in the Optical Illusion section of the book (pgs. 151-

153)– Color (pgs. 138-140)

• On the back, write a R.A.C.E. paragraph answering this question about your optical illusion: What do viewers perceive when they look at your illusion and how does the trick fool their minds?

Create Your Own Optical IllusionDue Friday. This will count as a project grade.

[Packet] Outline C. 4• Write down these subtitles:

– Psychophysics (124), 9– Our Sense of Sight (129), 12– Vision and the Brain (134), 8– Perceiving Forms, Patterns, and Objects (140), 17– Perceiving Depth or Distance (146), 5– Our Sense of Hearing (154), 4– Taste and Smell (159), 28– Our Sense of Touch (162), 23• Under each of the subtitles, bullet and write 3 main points by

skimming through C. 4. THEY NEED NOT BE IN COMPLETE SENTENCES!

• Pick two subtitles from C. 4 that you would like to study in this unit. I will base C.4 activities on your preferences. (We will do “Viewing the World in Color” for sure, which is why I didn’t list it).

[Packet] ColorDiscuss and write brief answers to these

questions (pgs. 137-8).

• What are wavelengths?• How are wavelengths related to color?• Which colors have which kinds of

wavelengths?

Long wave-lengths, low frequency

Medium wave lengths, medium frequency

Short wavelengths, high frequency

Color Blindness

http://colorvisiontesting.com/ishihara.htm#p late with 10 answer

Color Vision

• Read about (1) trichromatic theory on pgs. 138-139 and (2) opponent process theory on pgs. 139.

• Summarize each in detail on your packet paper.

• Answer these questions:– Which of these theories does afterimage prove?

Why?– Which of these theories does the colorblind test

prove? Why?

So, which theory is right?

• Both!

Add a “summary” section to the questions you just answered. In it, explain how these theories together explain color vision! Begin with, “A wave of light bounces into your eye.” Include these words: cone, wavelength, bipolar cells

What is the difference between a cone receptor and an opponent-process cell?

Evolution and Our SensesA Journey into Color

(Spiral)Color and Evolution• Sensation:• Phase #1: Physical Evolution: • Journal write: Pretend you are being hunted

by something that wants to harm you. What could you infer from what’s happening around you because of color?

• Read David Hubel’s article on color vision. After doing so, use conclusions you draw from the article to answer these questions:

• Why would the author indicate that color vision is less important in modern days than it once was for our ancestors?

• Why can some animals see color, while others can’t?

• Why do you think it would be important for insects to have color vision, while it’s not important for reptiles (for example)?

• Write your analysis on how our behavioral needs as a species drives our physical adaptation (the adaptation of our bodies).

Perception: Color and Society

•Phase #2: Psychological Evolution:•Now that we have color vision, we use it

for its maximum purpose. Today’s use of color vision are often part of our social psychology.

• Gray Elegance, humility, respect, reverence, stability, subtlety, timelessness, wisdom, Anachronism, boredom, decay, decrepitude, dullness, dust, pollution, urban sprawl

• Red Passion, strength, energy, fire, love, excitement, speed, heat, leadership, masculinity, power, Danger, fire, gaudiness, blood, war, anger, revolution, radicalism, aggression, stop

• Blue Seas, skies, peace, unity, harmony, tranquility, calmness, coolness, confidence, water, ice, loyalty, conservatism, dependability, cleanliness, technology, winter Depression, coldness, idealism, obscenity, ice, tackiness, winter

• Green Nature, spring, fertility, youth, environment, wealth, money (US), good luck, vigor, generosity, go, grass, Aggression, inexperience, envy, misfortune, jealousy, money, illness, greed

• Yellow Sunlight, joy, happiness, optimism, idealism, wealth (gold), summer, hope, air, Cowardice, illness (quarantine), hazards, dishonesty, avarice, sissification, weakness

• Purple Sensuality, spirituality, creativity, wealth, royalty, nobility, ceremony, mystery, wisdom, enlightenment, Arrogance, flamboyance, gaudiness, mourning, profanity, exaggeration, confusion

• Orange Buddhism, energy, balance, heat, fire, enthusiasm, flamboyance, playfulness, Aggression, arrogance, flamboyance, gaudiness, overemotion, warning, danger, fire

• White Reverence, purity, snow, peace, innocence, cleanliness, simplicity, security, humility, marriage, sterility, winter, Coldness, sterility, clinicism, surrender, cowardice, fearfulness, winter, unimaginative

• Black Modernity, power, sophistication, formality, elegance, wealth, mystery, style, Evil, death, fear, anonymity, anger, sadness, remorse, mourning, unhappiness, mystery

• Brown Calm, depth, natural organisms, nature, richness, rusticism, stability, tradition, Anachronism, boorishness, dirt, dullness, filth, heaviness, poverty, roughness

Western Culture Associations with Color

(Spiral) Color and Personality

•Step #1: Rate yourself on the personality quiz on your own paper.

•Step #2: Add up your totals. What’s your “brightest color?” Second brightest?

•Step #3: Write an analysis of why you think a test like this exists. In other words, why would we ever equate color with personality?

VISIONARY GREEN • Looks Forward And Sees Impact Of Actions

Taken Now. • Explores All Facets Before Deciding. Checks for

Accuracy. • Careful Planner. Enlivened By Work. • Status Quo Buster. Designer Of Change.

Inventive. • Systematic. Logical. Theoretical. Self-Sufficient. • Often Not In The Mainstream. Persistent.

Thorough. • Intellectual. Inquisitive. Impartial. Improvement

Oriented. • Famous Greens: Hermione, Cinna, Socrates,

Sherlock Holmes, Benjamin Franklin, Carl Jung, Thomas Edison, Eleanor Roosevelt, Katherine Hepburn, Rosalyn Carter

TRADITIONAL GOLD• Respects Authority Rules, Routines, Policies. • Allegiant, Faithful, Dependable, Prepared,

Efficient. • Remembers The Traditions That Work. Values

Family. • Work Comes Before Play. Practical. Systematic.

Orderly. • Identifies With Groups. Strives For A Sense Of

Security. • Thorough, Sensible, Conventional, Proper. • A Right Way To Do Everything. Stick-To-Itivness. • Evaluates Actions As Right Or Wrong. • Stable. Organized. Punctual. Helpful. • Famous Golds: Number 1 in Monsters Inc., Effie

Trincket, President Coin, Mother Teresa, George Washington, Santa Claus, Henry Ford, Florence Nightingale

ADVENTUROUS ORANGE• "Just Do It" Action Oriented. • Quick-witted, Charming, Spontaneous • Playful. Injects fun into work. • Lives In Here & Now. Risk taker. Creative. • Enjoys Diversity, Variety, Competition. • Multi-tasker, Cheerful, Energetic. Bold. • Quick Thinking and Acting. Takes Charge. • High Visibility Performer. Accepts Challenges. • Enjoys Problem Solving. Negotiator. • Performs Well Under Pressure. Resilient. • Famous Oranges: Kid in Up, Kid in Hotel

Transylvania, Milo, JFK, Amelia Earhart, Lucille Ball, Rhett Butler, Franklin Delano Roosevelt, Winston Churchill, Garfield

NURTURER BLUE• Sensitive To Needs Of Others. • Sincere. Expresses Appreciation. • Cooperative. Collaborative. Creative. • Caring. Team Builder And Player. • People Person. Engages Others. • Artistic. Inspirational. Spiritual. • Inclusive. Mediator. Peacemaker. • Idealistic. Intuitive. Romantic. Loyal. • Seeks Unity And Harmony. Caretaker. • Famous Blues: Pacha, Peeta, Mozart, Dorothy

(Wizard of Oz), Thomas Jefferson, Cinderella, Ghandi, Mohammed Ali, Jimmy Carter

(Spiral) Appreciating Art and Illusion

• Read through this personal application activity on pgs. 166-171.

• Focus on the pictures and how Gestalt principles, linear perspective, and color are used to create illusion.

• Journal Write: Write a personal connection explaining how you experienced the effects of the above visual principles in one or more of these art pieces. Why did that particular art piece appeal to you?

[Packet] Map Your Chemical Senses

•Instructions: By the end of this lecture, you should have labeled diagrams of your tongue and your nose. Follow these steps:

1. Draw a big tongue on one side of your paper.

2. Draw a big nose on the other side.3. Use facts and graphics from the lecture

to create a comprehensive picture of these sense organs with

1. Parts with their labels2. Facts about each part (at least 15 total)

Stimulus: chemical particles

Example of one note:

The Chemical Senses: Taste•Taste (gustation)•Physical stimulus: soluble chemical

substances ▫Receptor cells found in taste buds Taste buds

are clusters of taste cells that line the trenches around papillae (bumps).

All About Taste Buds• Photograph of tongue surface (left), magnified 75

times.• 10,000 taste buds line the tongue and mouth.

▫ Taste receptors are down inside the “bud”• Taste cells only live about 10 days. They travel

toward the center of the “bud” and then die.• Four primary tastes: sweet, sour, bitter, and

salty. Individual taste cells specialize in one of these four areas, but each is capable of sensing all four.

• Children have more taste buds than adults.

How Taste Happens

• Taste results from a complex blend of the 4 different “tastes.”

• Pathway: taste buds -> neural impulse -> thalamus -> cortex

• Group Question Minute: Why would taste preferences vary dramatically among people of different cultures and countries?

• Taste: learned, social, biological process You learn to eat what people around you are eating

(social). You eat what is available to you in your environment

(learned). Your taste receptors adapt to your taste preferences

early in life (biological). You inherit taste preferences (evolutionary)

The Chemical Senses: Smell•Smell (Olfaction) operates much like the

sense of taste in that stimuli are chemical. •Group Question Minute: Why can’t you

taste your food when you have a cold?•Smell determines taste. •Physical stimuli: substances carried in the

air ▫dissolved in fluid, the mucus in the nose

•Olfactory receptors=olfactory cilia and are located in the upper portion of the nasal passages.

How Smell Happens• Chemicals

dissolve in mucus and travel to the cilia.

• Pathway: Olfactory cilia -> neural impulse -> olfactory nerve -> olfactory bulb (brain)

Does not go through thalamus

[Packet] Odor-Rama Chart (3 columns, 11 rows)

Cup # Odor Description Odor Guess

Odor-Rama (Continued)• Proctor• Select a cup. Do not let the

smeller see inside!• Carefully open the bag

inside the cup.• Once the smeller has closed

his/her eyes, wave the bag underneath his/her nose.

• When finished, trade cups with someone or take another one from the table. DO NOT JUST LEAVE THE CUP ON THE DESK!

• Trade off with smeller about half way through

• Smeller• Close your eyes and smell

the contents of the cup when the proctor presents it to you.

• SILENTLY fill in the corresponding row on the chart. The proctor can contribute to helping you describe the odor, but you must guess what it is.

• Write down what you guessed on your chart.

Odor-Rama Key• 1. pickles• 2. soy sauce• 3. mustard• 4. salsa• 5. cinnamon • 6. watermelon Airheads• 7. Gatorade powder• 8. garlic powder• 9. wet dog food• 10. orange chunks (including peel)• 11. brown sugar

Odors, Men, and Women•Fact: Women tend to do better in odor

recognition tests than men.•Class survey.•3rd - •7th - Girls (%) , Boys (%)•Group Question Minute: Why are females

more accurate in odor recognition tasks?•Evolutionary Psychology•So, really what’s the difference between

smell and taste? Let’s do a little activity to help us . . .

[Packet] Taste CatalogueFood You’ve Eaten Taste Description Smell Descriptionin the past 24 hoursBanana chalky (it was still green) dull-sweetGranola Bar sweet, sticky chocolaty, strongPancakes dry, sweet, hot sour (yogart in them), moistBacon salty, hard, crispy, fatty fatty, heavy

Was taste easier to describe, or was smell easier to describe? Why?

So, what is different about smell?• Odors are not easily classified, and primary

odors have not really been delineated. Humans can distinguish among about 10,000 odors, but for some reason have a hard time attaching names to odors quite frequently.

• Group Question Minute: Why do people have a hard time attaching names to odors as opposed to taste and visual perceptions, for example?

• Odors are invisible.• Odors are transient.• Odors are sometimes unexpected.• Therefore, odors’ lack of “concreteness” affects our ability

to verbally classify them into “types.”

[Packet] Cutaneous Comics

•You’re going to be given some information about touch.

•After the presentation, you must make a 3-frame comic strip depicting some kind of cutaneous experience and incorporating at least 3 vocabulary words from the presentation.

•Pgs. 162-164

Cutaneous ReceptorsHow your skin detects thing

Overview

Background Knowledge•Feeling originates in the bottom layer of

the skin, the dermis, below the epidermis, the outermost layer of the skin.▫Dermis is filled with tiny nerve endings that

registers info. Carries info to the spinal cord

•Receptors are found all over in clusters around the skin in the form of onion or jelly-like material. Receptors are not distributed evenly.▫When squeezed, layers rub against each

other creating electrical nerve impulses.

•About 20 touch receptors▫Common: heat, cold, pain, pressure▫Sensitive: hands, lips, face, neck, tongue,

fingertips, chest, upper arm, sole of feet, and between the legs. The more nerve endings = the more sensitive

•Mechanoreceptors tell about sensations of pushing, pulling, and movement▫Free Nerve Ending, Pacinian Corpuscle,

Messiner Corpuscle•Thermoreceptors tell about sensation of

temperature. ▫Krause Corpuscle, Ruffini Endings

Merkel Receptor

(Pressure)

and vibration

, including flutter

Ruffini cylinder

(Stretching)

I’m gonna make it! I’m gonna make it! My Pacinian pressure sensors detected upon leaving the branch that this was going to be a great jump!

Almost there! The air is cold, though. My Krause Corpuscles are registering cold. But I’m going to make it, so who cares!?

Oops. Never mind! My free nerve endings are going to be screaming in a few seconds! Oh, the pain!

Gee, Maw! I love harvest time! I love digging around in the soil, ‘cause it scrapes off the dead skin on my epidermis, and then my body grows a new layer! Super pro-tection ‘gainst the natural elements is what that is!

Oh, Paw! There you goes with your countrified jargon again! The city slickers, they call that “ex-foliation!” Wow, Bessie’s head sure is warm! The Ruffini’s end organ receptors in my hand can sense her heat. I hope she’s not comin’ down with the fever!

No, Maw, they call that the “Mad Cow Disease.” Only cows in the “Old Country” git that sickness. Bessie’s fine for sure! She got plenty a’ energy! Just this morning, she give me a kick in the knee! My free nerve endings can testify to it, ‘cause, wooeeee! It hurt like the dickins!