Bottom-up Processing Analysis of the stimulus begins with the sense receptors and works up to the level of the brain and mind. 1 Letter “A” is really a.

Bottom-up ProcessingAnalysis of the stimulus begins with the

sense receptors and works up to the level of the brain and mind.

1

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

“A.”

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

and expectations.

2

THE CHT

Figure 4.26 Bottom-up versus top-down processing

Vision

5

Physical Characteristics of Light

1. Wavelength (hue/color)

2. Intensity (brightness)

6

Wavelength (Hue)Hue (color) is the dimension

of color determined by the wavelength

of the light.

Wavelength is the distance

from the peak of one wave to the peak of the

next.7

LongerWavelength

LowerFrequency

LongerWavelength

LowerFrequency

ShorterWavelength

HigherFrequency

ShorterWavelength

HigherFrequency

Properties of...LIGHT

SmallerAmplitude

DullColors

SmallerAmplitude

DullColors

HigherAmplitude

BrightColors

HigherAmplitude

BrightColors

Properties of...LIGHT

Intensity (Brightness)Intensity: Amount of energy in a

wave determined

by the amplitude. It is related to perceived

brightness.

10

Visual Information Processing

11

Optic nerves connect to the thalamus in the middle of the brain, and the thalamus

connects to the visual cortex.

Some cells in the visual cortex respond only to certain types of visual information, for example, a diagonal line moving up and down.

These cells are called feature detectors.

Psychology, 4/e by Saul Kassin ©2004 Prentice Hall

VisionHubel & Wiesel’s Experiment

Shape Detection

13

Specific combinations of temporal lobe activity occur as people look at shoes,

faces, chairs and houses.

Isha

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Trichromatic Theory of Color Vision

Helmholtz 1852

Human eye has 3 types of coneHuman eye has 3 types of conereceptors sensitive to differentreceptors sensitive to different

wavelengths of lightwavelengths of light.

Short Medium Long

People see colors because thePeople see colors because theeye does its own “color mixing”eye does its own “color mixing”

by varying ratio of coneby varying ratio of coneneural activityneural activity

Opponent Process TheoryEwald HeringEwald Hering - Eye contains 3 - Eye contains 3

mechanisms that produce mechanisms that produce antagonisticantagonistic

responses to three pairs of colorsresponses to three pairs of colors

R

G

B

Y

B

W

Why?Why?Afterimages & Color DeficiencyAfterimages & Color Deficiency

Color BlindnessGenetic disorder in which people are blind to

green or red colors. This supports the Trichromatic theory. Guys more often color blind

16Ishihara Test

Opponent Colors

17

Gaze at the middle of the flag for about 30Seconds. When it disappears, stare at the dot and report

whether or not you see Britain's flag.

Hearing

18

Hearing

The Stimulus Input: Sound Waves

Sound waves are compressing and expanding air molecules.

19

Sound Characteristics

1. Frequency (pitch)2. Intensity

(loudness)

20

The Ear

21

Dr. Fred H

ossler/ Visuals U

nlimited

The EarOuter Ear: Collects and sends sounds to the eardrum.

Middle Ear: Chamber between eardrum and cochlea containing three tiny bones (hammer, anvil, stirrup) that concentrate the vibrations of the eardrum on the cochlea’s oval window.

Inner Ear: Innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs. 22

CochleaCochlea: Coiled, bony, fluid-filled tube in

the inner ear that transforms sound vibrations to auditory signals.

23

Auditory Pathway

Intensity (Loudness)

Intensity (Loudness):

Amount of energy in a wave,

determined by the amplitude, relates to the perceived

loudness.

25

Loudness of Sound

2670dB

120dB

Richard K

aylin/ Stone/ Getty Im

ages

Frequency (Pitch)

Frequency (pitch): The dimension of

frequency determined by the wavelength

of sound.

Wavelength: The distance from

the peak of one wave to the peak

of the next.27

Perceiving Pitch

Georg von Békésy1899-1972 (T.W. Theory)

Place Theory - pitch determined bypoint of maximal vibration on

basilar membrane. Helps explain howwe hear HIGH pitch sounds

Traveling Wave Theory 1957Traveling Wave Theory 1957

Frequency Theory - pitch determined by the rateat which the hair cells fire…

•Helps explain how we hear LOW pitch sounds Volley Principle-neural cells alternate firing like Volley Principle-neural cells alternate firing like soldiers so that some shoot while others reloadsoldiers so that some shoot while others reload

Localization of SoundsBecause we have two ears, sounds that reach one ear faster than the other ear

cause us to localize the sound.

29

Localization of Sound1. Intensity differences

2. Time differences

Time differences as small as 1/100,000 of a second can cause us to localize sound. The head acts as a “shadow” or partial sound

barrier.

30

Conduction Hearing Loss Caused by damage to the eardrum or bones

in the middle ear. Sensorineural Hearing Loss

Caused by damage to the structures of the inner ear.

Psychology, 4/e by Saul Kassin ©2004 Prentice Hall

HearingHearing Disabilities

Touch

The sense of touch is a mix of four distinct skin senses—pressure, warmth, cold, and pain.

32

Bru

ce A

yers

/ Sto

ne/ G

etty

Im

ages

PainPain tells the body that something has gone

wrong. Usually pain results from damage to the skin and other tissues. A rare disease exists in

which the afflicted person feels no pain.

33Ashley Blocker (right) feels neither painnor extreme hot or cold.

AP Photo/ Stephen M

orton

Biopsychosocial Influences

34

Gate-Control Theory

35

Melzack and Wall (1965, 1983) proposed that our spinal cord contains neurological “gates” that either block pain or allow it to be sensed.

Gary C

omer/ PhototakeU

SA.com

Taste

36

Traditionally, taste sensations consisted of sweet, salty, sour, and bitter tastes. Recently, receptors

for a fifth taste have been discovered called “Umami”.

Sweet Sour Salty Bitter Umami

Sensory Interaction

37

When one sense affects another sense, sensory interaction takes place. So, the taste of strawberry interacts with its smell and its

texture on the tongue to produce flavor.

Smell

38

Like taste, smell is a chemical sense. Odorants enter the nasal cavity to stimulate 5 million receptors to sense smell. Unlike taste,

there are many different forms of smell.

Smell and Memories

39

The brain region for smell (in red) is

closely connected with the brain

regions involved with memory (limbic

system). That is why strong memories are

made through the sense of smell.

Body Position and Movement

40

The sense of our body parts’ position and movement is called kinesthesis. The

vestibular sense monitors the head (and body’s) position.

http://w

ww.heyokamagazine.com

Whirling Dervishes Wire Walk

Bob D

aemm

rich/ The Im

age Works

Summary of the Senses

41

Selective Attention

We focus on a very limited aspect of what we experience and ignore the rest

Other forms of S.A. are change blindness and inattentional blindness

42

Facial Recognition

After blind adults regained sight, they

were able to recognize distinct features, but

were unable to recognize faces.

Normal observers also show difficulty in facial recognition when the

lower half of the pictures are changed.

43

Courtesy of R

ichard LeG

rand

Extrasensory Perception (ESP) The ability to perceive something without

ordinary sensory information. This has not been scientifically demonstrated.

Parapsychologists distinguish between three types of ESP: Telepathy – Mind-to-mind communication Clairvoyance – Perception of remote events Precognition – Ability to see future events

Psychology, 4/e by Saul Kassin ©2004 Prentice Hall

ESP