Transcript Review Unit 4 Sen_ Perception 2014-2015

Myers’ Psychology for AP*
David G. Myers
PowerPoint Presentation Slides
Altered by Loretta Merlino
Worth Publishers, © 2010
*AP is a trademark registered and/or owned by the College Board, which was not involved in the production of, and does not endorse, this product.
Introduction
Sensation activation of our senses, the raw data=
Bottom Up Processing
Perceptual set- our experience creates schemata/mental
representations and influences how we see perceive our
world
Perception brains interpretation of sensory messages
depending on our experience=Top Down Processing
These are one continuous process
Selective Attention
Selective Attention the focusing of conscious awareness
on a particular stimulus-Dichotic Listening Experiments
Cocktail party effect=in crowded Room, I am able to drown out
other Conversations, but I can hear my name
Called (also true in dichotic listening experiement)
Sensory Habitation or Adaptation/Perceptual Adaptationdiminished
sensitivity as result of constant stimulation. Ex: scent in a room or
sound of fan
Inattentional blindness failing to see visible objects when our
attention is directed elsewhere.
Change blindness failing to notice changes
in the environment
Change deafness-same as above
Pop-out=powerful stimuli grab our attention without us choosing to
attend
Thresholds
Absolute threshold the minimum
stimulation necessary to detect a
particular stimulus 50% of the time.
Difference threshold (aka just noticeable
difference) minimum change needed in a
stimulus before we detect a change.
Just noticeable difference (jnd) is computed
by :
Weber’s Law =to be perceived as
different, two stimuli must differ by a
constant percentage. Describes different
thresholds for different senses.
The more intense a stimulus the more it
needs to change before we notice a
difference ( or sense it)
Intensity of stimulus impacts
us sensing it!!!!!!!!!!!!!!!!
Thresholds
Signal Detection
• *Signal-detection theory -theory predicting how and when we detect
the presence of a faint stimulus (signal) amid background
stimulation (noise). Assumes there is no absolute threshold but our
detection depends partly on our experiences, expectations,
motivations, and alertness.
Thresholds
Subliminal Stimulation
• Subliminal Message(below threshold) below one’s
absolute threshold for conscious awareness.
• Priming= the activation, of certain
associations, predisposing one’s
perception, memory, or response.
I tell you you will notice red objects so
you do
Vision
Energy Senses =vision, hearing, touch
Chemical Senses: taste and smell
The Stimulus Input: Light Energy
Transduction (transform) conversion of stimuli, such as sights, sounds,
and smells into neural impulses our brains can interpret.
1. Wavelength = length of wave=color (or Hue)
2. Amplitude=wave’s height=brightness
The Physical Property of Waves
The Eye
Cornea transparent protective covering
Pupil adjustable opening in center of eye where light enters.
Iris a ring of muscle tissue that forms the colored portion of eye around
pupil; controls size of the pupil opening.
Lens bends light rays into retina; help focus images on retina
-accommodation =eye’s lens changes shape to focus near or far
objects on retina.
Retina light-sensitive inner surface of eye, processing of visual
information-transduction starts here(transforming of one form of
energy to another the brain can interpret)contains receptor rods
and cones -retinal focus in the eye determines visual acuity
(Visual Acuity is best in the fovea)
The Structure of the Eye
*Retina = the light-sensitive inner surface of the eye, containing
the receptor rods and cones plus layers of neurons that begin the
processing of visual information.
The Eye
The Retina
• *Rods retina receptors that detect black, white, and gray; needed
for peripheral and twilight vision
• *Cones function in daylight /well-lit conditions. The cones detect
detail, give rise to color sensations.
Cones
Rods
Photoreceptors relay visual info. to the
brain via Ganglion and Bipolar cells*******
The Retina’s Reaction to Light-
The Eye
The Retina
Retinal disparity=binocular (need two eyes) cue for perceiving
depth
The Structure of the Eye-TheRetina
Optic Nerve = carries neural impulses from the eye to the brain.
Fovea = the central focal point in retina, around which the eye’s cones
cluster. When light is focused on retina, you see color
Blind Spot = part of retina without rods/cones at the point at which optic
nerve leaves eye, creating “blind” spot b/c no receptor cells located there.
Brain accommodates so we don’t notice blind spot
Visual Information Processing
• Feature detectors nerve cells in brain that respond to
specific features of the stimulus (shape, angle, or
movement, lines, curves, etc….discovered by Hubel &
Weisel) –cortical cells in OCCIPITAL cortex respond to
certain features*******
• Parallel processing processing many aspects of a problem
simultaneously (such as color, Motion, form, depth)
Color Vision
• *Young-Helmholtz trichromatic (three color) theory the theory that
the retina contains three different cone color receptors – one
most sensitive to red, one to green, one to blue – which, when
stimulated in combination can produce the perception of any color.
Red – Green – Blue
Colorblindness:
Monochromatic =see only shades of
grey
Dichromatic=cannot see red-green or
Blue-yellow
This helps to support the next theory:
*Color Vision-most view the combo. Of trichromactic theory and
Opponent-process as responsible for color vision
• ******Opponent-process theory stated that sensory
receptors in retina come in pairs; enable color
vision. If one sensor is stimulated, its
pair is inhibited from firing-explains
Afterimage. Stare at red-switch
Gaze to blank page, will see green
afterimage
– Three sets of colors
• Red-green
• Blue-yellow
• Black-white
After image
Hearing
The Stimulus Input: *Sound Waves
Audition (= the sense or act of hearing)
• ******Sound Waves=vibrations travel through air and collected by:
ear
1. Amplitude=height =Loudness
2. Frequency =length =pitch-(high and low pitch)
The structure of the ear
outer(auditory canal and eardrum), middle (******Bones
middle ear = the hammer, anvil, stirrup- vibrate with the eardrum.
inner.
The sound waves travel down the auditory canal to the eardrum.
The structure of the ear
Eardrum = tight membrane that vibrates when struck by sound
waves.
The structure of the ear
******Bones of the middle ear = the hammer, anvil, stirrup which
vibrate with the eardrum.
Oval window = where the stirrup connects to the cochlea.
The structure of the ear
****Cochlea = a coiled, snail shaped, bony, fluid-filled tube in the
inner ear through which sound waves trigger nerve impulses.
Neural messages sent to auditory cortex in temporal lobe
The Ear
• Inner ear
– Oval window
–Cochlea
• Basilar membrane
Damage=nerve
Deafness (caused by
loud sounds)
– Auditory nerve then to Auditory cortex
The structure of the ear
Inner Ear: aud. Nerve, cochlea, oval window
Auditory nerve = nerve which sends the auditory message to the
brain via the thalamus.
The structure of the ear
Auditory nerve
Neural impulse to the brain
The Ear
Perceiving Pitch (high/low)-Two Theories
• Basilar membrane’s hair cells
• ***Place theory=hair cells in cochlea’s basilar membrane respond
to dif. sound frequencies based on where they are located on
membrane
• ***Frequency theory=entire cochlea
• vibrates at particular frequency of a tone sending signals to
brain
The Ear
How do we Locate Sounds?
• Placement of two ears allows
Stereophonic hearing
• Localization of sounds
=if sound to right (horn),
right ear hears it
sooner and more
intense than left
Hearing Loss and Deaf Culture
• Hearing loss/Nerve Deafness:
Nerve deafness=when hair cells in Basilar Membrane
have been damaged, usually by loud noise; difficult to
treat since no way to regenerate hair cells
Conduction hearing loss=something goes wrong with other
ear parts and getting sound to cochlea (with ear
canal, eardrum,
hammer/anvil/stirrup or
oval window)
Touch
Kinesthesis the system for sensing the position and
movement of individual body parts. Receptors in
muscles & joints, and Vision send brain messages
Vestibular sense sense of Balance and how body is
oriented in space-located in Semicircular
Canals in inner ear-fluid moves in canals as position of
head moves, then signal brain
Semicircular Canals
Pain
Understanding Pain
Biological Influences:
Nociceptors =sensory receptors that detect hurtful
temperature, pressures or chemicals
******Gate-control theory:
theory that spinal cord contains a neurological “gate” that blocks
pain signals or allows them to pass on to the brain. Competing
signals (such as rubbing) can temporarily reduce pain. Some
pain messages have a higher priority than others
Endorphins, ”opiate like” or pain killing chemicals
(nuerotransmitter) in body, also swing gate shut.
If I move my hand from a hot surface: Initiated in the spinal
cord, not motor cortex
Taste(or *gustation)
taste and smell are chemical senses –respond to chemicals rather than energy
-Humans sense 5 types: Sweet, sour, salty, bitter,
Umami (protein)
-Taste buds on tongue, cheeks, roof of mouth
Age and taste=taste smell decreases with age
Sensory interaction one sense influences another (smell
and taste; sight and hearing, etc..)
Smell
• Smell aka Olfaction
– *Chemical sense
– Odor molecules
– *Nerve fibers from
******Olfactory bulb
connect to brain at
amygdala and
then to hippocampus
(both connect to emotional
Impulses/memory) –may be
why smell is powerful
memory trigger
– Olfactory nerve
The Thalamus
• *****Thalamus
–Sensory
–switchboard
for all the senses
EXCEPT smell
Smell (olfaction)
Perceptual Organization
• ****Gestalt (form or whole) an organized whole. Gestalt
psychologists emphasized our tendency to integrate pieces of
information into meaningful wholes or groups-this is innate and
inevitable. The whole is different from the sum of its parts
• Figure-ground tendency to view certain figures of a scene as figures
and the rest as a background
• Grouping stimuli together:
• Proximity-things near each other are related
• Similarity-things that Resemble each other are related
• Continuity-things that form a flowing line are viewed as continuous
ratherthen broken up
• Connectedness perceive things as single units
• Closure –we fill in gaps to create a complete an object
Form Perception
gestalt rules:Figure and Ground
• *****Figure-ground tendency to view certain figures of a scene as
figures and the rest as a background
Form Perception
Grouping – Proximity-see 3 sets of two lines rather than 6
Form Perception
Grouping – Similarity-see as vertical columns of similar shapes, not as
horizontal rows of dissimilar shapes
Form Perception
Grouping – Continuity: we see 1 wavy and 2 straight lines, not
semicircles
Form Perception
Grouping – Connectedness-do not see these as 2 circles and 1 line
Form Perception
Grouping – Closure=fill in gaps to create a
complete object
Depth Perception
• Depth perception the ability to see objects in three
dimensions although the images that strike the retina are
two-dimensional; allows us to judge distance; believed to
be innate and starts at crawling
– Visual-cliff
a laboratory
device for testing
depth perception
in infants and
young animals
Depth Perception
Binocular Cues
• ******Binocular cues depth cues, such as retinal
disparity, that depend on the use of two eyes.
– Retinal disparity a binocular –NEED TWO EYES-cue
for perceiving depth. By comparing images from the
retinas in the two eyes, the brain computes distance –
the greater the disparity (difference) between the two
images, the closer the object.
Depth Perception
Depth cues are either Mononocular or
binocular Cues
Monocular cues
– Relative height-things higher seem taller
– Relative size-closer items appear bigger
– Interposition-something that blocks another item is
perceived as closer –a tree blocking a horse
– Linear perspective-parallel lines seem to converge
with distance
– Relative motion-objects that are stable appear to
move as we move (in a car)
– Light and shadow
Perceptual Constancy
• Perceptual Constancy perceiving objects as unchanging (having
consistent shapes, size, lightness, and color) even as illumination
and retinal images change. Size, shape and brightness are types of
constancy
Motion Perception
• Stroboscopic movement
******Phi phenomenon an illusion of movement
created when two or more adjacent lights blink
on and off in quick succession. Ex: neon,
blinking arrow sign
Perceptual Set
Perceptual set (experiences, assumptions, expectations,
motivation and emotion)a mental disposition to perceive
one thing and not another. What establishes our
perceptual sets?:
-Mental predisposition-schema (with below pic, it
depends on which pic I looked at first
– Schemas-try to fit things into existing ones
Perceptual Set
*Context Effects
****Context effects (our brain
interprets info, say words, in the context in which they are
heard or seen: die v dye, mourning v morning)
Similar to what we learned in Memory
Even perception can be seen from a
biopsychosocial approach (as in the case with pain)