Sensation and Perception Powerpoint

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Sensation and Perception
Sensation and Perception

Sensation- How are sensory receptors and nervous system receive information
(stimulus) from the environment

Perception- The process of organizing and interpreting sensory information to
recognize meaningful objects and events
TYPES of PROCESSING

Bottom Up Processing

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You notice something (your senses) and then you focus on it, access your memory that is
related to it and fully process. Start by examining small details and putting them into a
bigger picture
Top Down Processing
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Opposite. See the total picture first, then your senses see the smaller details

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Signal Detection Theory
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How and when we detect the presence of a faint stimulus amid background stimulation
(noise)
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Based on experience, fatigue level, expectations
Subliminal Stimulation
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Selective attention


Below your level of awareness
Focus of conscious awareness on a particular stimulus, even when there are loud distractions
all around
Cocktail Party Effect

The ability to listen to one person among many people talking
Types of Thresholds
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Absolute Threshold
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The minimum amount of stimulation for an organism to detect stimuli 50% of the time

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Difference Threshold


EX: When kids focusing on tv, they can’t always hear parents on the fist few attempts. However
if the kids hear something that is more interesting than what they are viewing, they will
“magically “ hear it, (like who wants Ice cream?)
The minimum difference that a person can detect between2 stimulus required for
detection 50% of the time EX: HD vs SD TV options
Sensation Threshold- 2 stimulus must be different by a constant minimum
percentage

Sensory Adaptation


You eat something hot or spicy, at first it is overwhelming but then it doesn’t feel as strong
Weber’s law

To perceive a difference between 2 stimuli they must differ by a constant percentage, not a
constant amount

Quarters shoes and envelopes example
Vision

WAVELENGTHS-One peak of one light wave to the next peak

Hue- color- Short and long wavelengths change the hue (color) we see

The rainbow displays the color hues in order from longest light waves to shortest
waves. Roy.G.Biv

All of the colorwaves together = white light (sunlight)

Short wavelengths= high frequency, bluish colors, and high pitched sounds

Long wavelengths= low frequency, reddish colors, and low pitched sounds

Light wavelengths that are LONGER than visible light are infrared waves, microwaves, radio
waves. We can’t see these.
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Intensity- correlates with the brightness of the colors we see


The higher the wave the more intense (bright) the color is
Saturation- by seeing differences in purity of light waves, we can see different shades of
color. How deep the color looks.
The Eye
Vision- The Process

STEP ONE: Gathering Light- Light reflects off of objects and is gathered by the eye. How we see color depends on light
intensity (how much energy the light contains) and light wavelength (which affects the hue).

STEP TWO: Within the Eye- Light enters through our cornea (our protective covering that helps focus light).

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Dialate- The pupil acts like a camera-is opened and closed by the muscles (iris). Opens to let light in and closes when less light is
needed.

Accommodation- The process of light entering through the pupil and being focused by the curved lens. Our eyes ability to focus, change
size, and change depending on what we look at.

Lens- changes shape to focus images onto the retina. It is a flipped image (your brain translates it correctly)

Retina- Contains sensory receptors

Optic Nerve- passes information from the eye to the brain
STEP THREE: how light we sense is turned into the ability of our brain to perceive it
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Transduction- the transfer of one form of energy to another

Light energy is transformed into electrical or neural energy that our brain interprets as light

Light activates lights in retina.
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Cones- first layer of cells activated by and detect color, daylight, and well lit conditions. concentrated close to the retina.

Rods- cells that are activated by and detect black, white, gray, twilight and low light. We have more Rods (120 million) than Cones (6-7million) and they are
scattered.

Blind spot- the area where we have no cones/rods
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Fovea- Center of the retina with the most cones.
If enough Cones/Rods are activated-Bi-polar cells (which transmit messages to the ganglion cells) the next layer is activated (the ganglion
cells). These cells send impulses to the LGN (lateral geniculate nucleus- a region in the thalamus).
STEP FOUR: In the brain

LGN sends to various lobes. The visual cortex of the brain receives these impulses.
Transduction

Order is Rods/Cones to Bipolar
to Ganglion to Optic Nerve.

Sends info to thalamus- area
called lateral geniculate nucleus
(LGN).

Then sent to cerebral cortexes.

Where the optic nerves cross is
called the optic chiasm.
Trichromatic Theory vs Opponent Processing Theory
Trichromatic Theory:
Opponent Processing Theory:
Three types of cones:
The sensory receptors come in pairs.

Red
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Red/Green
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Blue

Yellow/Blue
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Green

Black/White

These three types of cones can
make millions of combinations of
colors.

If one color is stimulated, the
other is inhibited.

Does not explain afterimages or
color blindness well.
Vision Complications
 Myopia-
Near sighted- nearby objects are
seen more clearly than distant ones
 Hyperopia-
faraway objects are seen more
clearly than closer ones
Hearing

The height of the wave gives us the amplitude of the sound.

The frequency of the wave gives us the pitch if the sound.
Place Theory

Different hairs vibrate in the
cochlea when they hear different
pitches.
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So some hairs vibrate when they
hear high and other vibrate when
they hear low pitches.
The Ear
Transduction in the ear

Sound waves hit the eardrum then anvil then
hammer then stirrup then oval window.

Everything is just vibrating.
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Then the cochlea vibrates.

The cochlea is lined with mucus called basilar
membrane.

In basilar membrane there are hair cells.

When hair cells vibrate they turn vibrations
into neural impulses which are called organ of
Corti.

Sent then to thalamus up auditory nerve.
Deafness
Conduction Deafness


Something goes wrong with the
sound and the vibration on the
way to the cochlea.
Nerve (sensorineural)
Deafness

The hair cells in the cochlea get
damaged.

Loud noises can cause this type of
deafness.
You can replace the bones or get
 NO WAY to replace the hairs.
a hearing aid to help.
 Cochlea implant is possible.
Optical Illusions
Aoccdrnig to 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 ltteer be at the rghit
pclae. The rset can be a toatl mses and
youcan sitll raed it wouthit a porbelm. Tihs is
bcuseae the huamn mnid deos not raed ervey
lteter by istlef, but the wrod as a wlohe.
*This was not a real study and it is not always accurate!*
Tricks Of The Brain
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Awareness Test
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https://www.youtube.com/watch?v=Ahg6qcgoa
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Eye Hallucination videos
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https://www.youtube.com/watch?v=tVgOLWVY
ytM
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https://www.youtube.com/watch?v=IWk5NkxQF8
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https://www.youtube.com/watch?v=QTC0F3gJhQ

https://www.youtube.com/watch?v=hrhGTR54
E5k
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https://www.youtube.com/watch?v=I8Bwzkz50
BI
After Images

http://izismile.com/2011/11/11/mind_blowing
_afterimages_optical_illusions_3_pics_11_gifs2.html
Brain Perception
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http://luxemodo.com/best-opticalillusions/

http://brainden.com/best-illusions.htm

http://illusionoftheyear.com/cat/top10-finalists/2015/
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Each year has different illusions
http://channel.nationalgeographic.com
/brain-games/videos/einstein-andmonroe/
Brain Games Television Show

http://channel.nationalgeographic.com
/brain-games/

http://www.dailymotion.com/video/xq
1rfl_national-geographic-test-yourbrain-episode-2-perception_shortfilms

45 minute show with many illusions
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Resources

Mr. Duez- powerpoints and videos
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References

This powerpoint presentation was adapted
using information from the Barron’s AP
Psychology 5th edition prep book.
Sensation and Perception
Crash Course Psychology



Sensation and Perception
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Discovering Psychology

Sensation and Perception

Weseley, Allyson, Robert McEntarffer,
and Robert McEntarffer. AP®
Psychology. Hauppauge, N.Y.: Barron's
Educational Series, 2014. Print.
Fineburg, A., & Myers, D. (2010). Myers'
Psychology for AP*: Teacher's
edition (Teacher's ed.). New York: Worth
/BFW.
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