General Psychology

Scripture

• James 1:9-11Let the brother of low degree rejoice in that he

is exalted: But the rich, in that he is made low: because as the flower of the grass he shall pass away. For the sun is no sooner risen with a burning heat, but it withereth the grass, and the flower thereof falleth, and the grace of the fashion of it perisheth: so also shall the rich man fade away in his ways.

Scripture

• James 1:8

A double minded man is unstable in all his ways.

What we’ll sense and perceive…in this chapter: Sense:

especially vision and hearing smell, taste, touch, pain, and

awareness of body position How do the sense organs and

nervous system handle incoming sensory information?

How does the brain turn sensory information into perceptions?

Why is our style of creating perceptions better at perceiving the real world than at decoding tricky optical illusions?

Sensation vs. Perception

“The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.”

“The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.”

The brain receives input

from the sensory organs.

The brain makes sense out of the

input from sensory organs.

Sensation Perception

Making sense of the world

What am I seeing?

Is that something I’ve seen before?

Bottom-up processing:

taking sensory information and then assembling and integrating it

Top-down processing:

using models, ideas, and

expectations to interpret sensory

information

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Bottom-up Processing

Analysis of the stimulus begins with the sense receptors and works up to the level of

the brain and mind.

Letter “A ” is really a black blotch broken down into features by the brain that we perceive as an

“A.”

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Top-Down Processing

Information processing guided by higher-level mental processes as we construct perceptions, drawing on our experience

and expectations.

THE CHT

Perceptual Illusions

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Perceiving familiar objects as having consistent color even when changing illumination filters

the light reflected by the object.

Color Constancy

Color Constancy

Smell: The Shortcut Sense Sensations of smell take a

shortcut to the brain, skipping the trip through the “sensory switchboard” (thalamus) made by all the other senses.

Information from the nose goes not only to the temporal lobe but also to the limbic system, influencing memory and emotion.

Smell links lovers, parent and child, and other creatures to each other through chemistry.

Perceptual SetPerceptual set is what we expect to see, which influences what we do see. Perceptual set is an example of top-down processing .

Loch Ness monsteror a tree branch?

Flying saucersor clouds?

Perceptual set can be “primed.”

Old woman Young woman

Ambiguous

Context Effect on Perception

Spelling test answers:

In which picture does the center dot look larger? Perception of size depends on context.

Did context affect which word you wrote?apple payor payee pairdouble pear

Effect of Emotion, Physical State, and Motivation on Perception

Experiments show that: destinations seem farther when you’re tired.a target looks farther when your crossbow is heavier.a hill looks steeper with a heavy backpack, or after sad music, or when walking alone.something you desire looks closer.

Color BlindnessPeople missing red cones or green cones have trouble differentiating red from green, and thus have trouble reading the numbers to the right.

Opponent-process theory refers to the neural process of perceiving white as the opposite of perceiving black; similarly, yellow vs. blue, and red vs. green are opponent processes.

Opponent-Process Theory Test

The dot, the dot, keep staring at the dot in the center…

Turning light waves into mental images/movies... Perceptual Organization

We have perceptual processes for enabling us to organize perceived colors and lines into objects:grouping incomplete parts into gestalt wholesseeing figures standing out against backgroundperceiving form, motion, and depthkeeping a sense of shape and color constancy despite changes in visual informationusing experience to guide visual interpretation

The Role of Perception

Our senses take in the blue information on the right. However, our perceptual processes turn this into:1.a white paper with blue circle dots, with a cube floating in front.2.a white paper with blue circle holes, through which you can see a cube.3.a cube sticking out to the top left, or bottom right.4.blue dots (what cube?) with angled lines inside.

Figure-Ground Perception In most visual scenes, we pick out objects and figures,

standing out against a background. Some art muddles this ability by giving us two equal

choices about what is figure and what is “ground”:

Stepping man, or arrows?

Goblet or two faces?

Grouping: How We Make Gestalts“Gestalt” refers to a meaningful pattern/configuration, forming a “whole” that is more than the sum of its parts.Three of the ways we group visual information into “wholes” are proximity, continuity, and closure.

Grouping PrinciplesWhich ones influence perception?

Visual Cliff: A Test of Depth PerceptionBabies seem to develop this ability at crawling age.

Even newborn animals fear the perceived cliff.

Perceiving Depth From a 2D Image: Binocular MethodsBinocular (using both eyes) cues exist because humans have two eyes in the front of our head. This gives us retinal disparity; the two eyes have slightly different views, and the more different the views are, the closer the object must be. In an extreme example, your nose is so close that each eye sees a completely opposite half-view of it.

How do we perceive depth from a 2D image?... by using monocular (needing only one eye) cues

Monocular Cue: Interposition

Interposition: When one object appears to block the view of another, we assume that the blocking object is in a position between our eyes and the blocked object.

Monocular Cue: Relative Size

We intuitively know to interpret familiar objects (of known size) as farther away when they appear smaller.

Monocular Cues: Linear Perspective and Interposition

The flowers in the distance seem farther away because the rows converge. Our brain reads this as a sign of distance.

Tricks Using Linear

Perspective These two

red lines meet the retina as being the same size

However, our perception of distance affects our perception of length.

Monocular Cue: Relative Height

We tend to perceive the higher part of a scene as farther away.

This scene can look like layers of buildings, with the highest part of the picture as the sky.

If we flip the picture, then the black part can seem like night sky… because it is now highest in the picture.

Monocular Cues: Shading Effects

Shading helps our perception of depth. Does the middle circle bulge out or curve inward?

How about now?

Light and shadow create depth cues.

Monocular Cues: Relative Motion

When we are moving, we can tell which objects are farther away because it takes longer to pass them.

A picture of a moon on a sign would zip behind us, but the actual moon is too far for us to pass.

Motion PerceptionWe perceive motion in many ways. Objects moving toward us

We perceive this motion by watching the changing apparent size of an object.

Objects moving to one sideWe perceive relative motion, although we often judge huge objects inaccurately. In what way? Why?

Objects traveling in a more complex path, such as in an arc through the air coming toward usBaseball players, and even dogs, can run right to where a fly ball is going to land by keeping the ball in a constant apparent position in the sky.

Perceptual Constancy

Our ability to see objects as appearing the same even under different lighting conditions, at different distances and angles, is called perceptual constancy. Perceptual constancy is a top-down process.

Examples: color and brightness constancy shape and size constancy

Color Constancy This ability to see a consistent color

in changing illumination helps us see the three sides as all being yellow, because our brain compensates for shading.

As a result, we interpret three same-color blue dots, with shades that are not adjusted for shading, as being of three different colors.

Brightness ConstancyOn this screen, squares A and B are exactly the same shade of gray. You can see this when you connect them. So why does B look lighter?

Shape ConstancyShape constancy refers to the ability to perceive objects as having a constant shape despite receiving different sensory images. This helps us see the door as a rectangle as it opens. Because of this, we may think the red shapes on screen are also rectangles.

The Moon Illusion

Why do we perceive the moon as a different size depending on its location?

One possible theory is that our ancestors assumed overhead objects were closer than objects on the horizon.

The moon, like one of these monsters, seems larger because we see it as farther away.

The moon appears larger on the horizon than overhead.

Size Constancy We have an ability to use distance-related context

cues to help us see objects as the same size even if the image on the retina becomes smaller.

The Ames room was invented by American ophthalmologist Adelbert Ames, Jr. in 1934.

The Ames room was designed to manipulate distance cues to make two same-sized girls appear very different in size.

Perceptual Adaptation After our sensory information is

distorted, such as by a new pair of glasses or by delayed audio on a television, humans may at first be disoriented but can learn to adjust and function.

This man could learn eventually to fly an airplane wearing these unusual goggles, but here, at first, he is disoriented by having his world turned upside down.

Embodied Cognition

holding a warm mug promotes social warmth. social rejection looks like pain reception in the brain. words on a heavy clipboard seem… weighty. being ignored (cold shoulder) makes a room seem

colder. leaning left physically leaning left politically. in a foul smelling room, people were more likely to

suspect bad intentions (foul play) by others.

It’s no coincidence that we use sensation words to describe feelings. Studies seem to show that:

Embodied cognition refers to the effect of body experience on feelings, attitudes, thoughts, and judgments.

Smell: The Shortcut Sense Sensations of smell take a

shortcut to the brain, skipping the trip through the “sensory switchboard” (thalamus) made by all the other senses.

Information from the nose goes not only to the temporal lobe but also to the limbic system, influencing memory and emotion.

Smell links lovers, parent and child, and other creatures to each other through chemistry.

Sensing Body Position and Movement

Kinesthesis (“movement feeling”) refers to sensing the movement and position of individual body parts relative to each other.

How it works: sensors in the joints and muscles send signals that coordinate with signals from the skin, eyes, and ears

Without kinesthesis, we would need to watch our limbs constantly to coordinate movement.

Extrasensory Perception (ESP)Extrasensory Perception (ESP) can defined, literally, as perception without sensation. However, this definition would also include dreams and hallucinations (both of which involve perception without sensation).Believers in ESP think that it involves getting accurate information directly to the mind, skipping the known senses.Types of ESP include:telepathy (“reading” messages from other minds).clairvoyance (“seeing” remote events).precognition (“knowing” the future).The evidence for ESP is anecdotal and controversial; people seem to notice times when predictions come true and perceptions match reality, but tend to disregard the times when they do not.