Download - Introductory Psychology: Sensation
Introductory Psychology: Sensation
Ap psychology: Unit v Sensation Vision, hearing, smell, taste,
touch, pain & body position
Similarities? Transduce stimulus energy into neural impulses More
sensitive to change than to constant stimulation Provide us with
information regarding our environment Differences? Each requires a
different form of stimulus energy Each sends information to a
different region of the brain for processing Sensation:Vision Part
one Vision: The Stimulus Input
Light energy (electromagnetic energy) Two physical characteristics
help to determine our sensory experience of light Wavelength The
distance from one peak to another Determines HUE (color) Amplitude
Height of each waves peak Determines INTENSITY (brightness) Shorter
wavelength bluish colors Longer wavelength reddish colors
Great amplitude bright colors Small amplitude dull colors Vision:
The Structure of the Eye
Cornea Location/Structure The clear bulge on thefront of the
eyeball Function Protects the eye Bends light towards acentral
focal point inorder to provide focus Vision: The Structure of the
Eye
Pupil/Iris Location/Structure Adjustable opening in thecenter of
the eye Surrounded by the iris (smallring of muscle tissue; color)
Function Controls the amount of light that is able to enter the eye
In bright conditions the iris expands, making the pupil smaller In
dark conditions the iris contracts, making the pupil larger Vision:
The Structure of the Eye
Lens Location/Structure A transparent structurethat is located
behind thepupil Function Focuses image on the backof the eye
(retina) Accommodation The process by which the eyes lens changes
shape to help focus near or far objects on the retina Vision: The
Structure of the Eye
Lens Problems Nearsightedness Also known as myopia Eyeball may be
too long Image focused in front ofthe retina Farsightedness Also
known as hyperopia Eyeball may be too short Image focused behind
theretina Vision: The Structure of the Eye
Retina Location/Structure A multilayered, light-sensitive surface
located at the back of the eyeball Function Contains cells that
convert light energy into nerve impulses Includes three layers of
cells Receptor cells (photoreceptors cones & rods) Bipolar
cells Ganglion cells Vision: The Structure of the Eye
Cones Rods Number 6 million 120 million Location(in the retina)
Center(fovea) Edge (periphery) Color sensitive Yes No Sensitivity
in dim light? Low High Ability to detect sharp detail (acuity)?
Photoreceptor Cells Vision: The Structure of the Eye
Bipolar Cells Receives message from the photoreceptors Transmits
message to the ganglion cells, whichare then considered activated
Ganglion Cells The axons of the ganglion cells converge to form
theoptic nerve Light energy Rods & Cones Bipolar cells Ganglion
cells Vision: The Structure of the Eye
Optic Nerve Location/Structure Nerve located at the backof the
eyeball Function Sends visual information to the thalamus and
thento the occipital lobes Where the optic nerve leaves the eye,
there are no rods or cones, creating a blind spot Vision: Visual
Processing
Feature Detectors Located in the visual cortex Nerve cells in the
brain that respond to specific features Shape Angle Movement
Vision: Visual Processing
Parallel Processing The processing of several aspects of a stimulus
simultaneously The brain divides a visual scene into color, depth,
form and movement Visual Information Processing
Feature Detection + Parallel Processing Color Motion Form Depth All
processed separately but simultaneously Vision: Color Vision
Young-Helmholtz Trichromatic Theory
(Hermann von Helmholtz & Thomas Young) The theory that the
retina contains three different color receptors red, green and blue
When stimulated in combination, these receptors can produce the
perception of any color Color Blindness? Dichromatic Color Vision
Individuals lack one of three receptors; usually the red or green
receptor Vision: Color Vision Opponent-Process Theory of Color
(Ewald Hering)
The theory that opposing retinal processes enable color vision
Red-Green Yellow-Blue Black-White Light that stimulates one half of
the pair inhibits the other half For example, some cells are
stimulated by green and inhibited by red, while others are
stimulated by red and inhibited by green Here's another example of
creating an afterimage
Here's another example of creating an afterimage. Can you put the
fish in the bowl? Try this. Stare at the yellow stripe in the
middle of the fish in the picture below for about sec. Then move
your gaze to the fish bowl. You should see a fish of a different
color in the bowl. It helps if you keep your head still and blink
once or twice after you move your eyes to the bowl. The afterimage
will last about five seconds. Stare at the eye of the red parrot
while you slowly count to 20, then immediately look at one spot in
the empty birdcage. The faint, ghostly image of a blue-green bird
should appear in the cage. Try the same thing with the green
cardinal, and a faint magenta bird should appear. Sensation:Hearing
Part two Hearing: The Stimulus Input
Sound energy Two physical characteristics help to determine our
sensory experience of sound Wavelength/Frequency The distance from
one peak to another Determines PITCH Amplitude Height of each waves
peak Determines LOUDNESS Shorter wavelength high-pitch Longer
wavelength low-pitch
Great amplitude loud sounds Small amplitude soft sounds Hearing:
The Structure of the Ear
Outer Ear Relevant Structures Pinna Function Channels sound
wavesthrough the auditory canal tothe eardrum (tympanicmembrane)
Hearing: The Structure of the Ear
Middle Ear Relevant Structures (Eardrum) Hammer, Anvil, Stirrup
Function Transmits the vibrations ofthe eardrum through apiston
made of 3 tiny bones Hammer, anvil, stirrup These bones then
transmitthe message to the cochlea Hearing: The Structure of the
Ear
Inner Ear Relevant Structures Cochlea Basilar Membrane Function The
incoming vibrations cause movement in the cochleas oval window,
which then creates motion in the cochleas fluid This motion causes
movement in the basilar membrane and its hair cells Eventually, the
hair cells trigger an impulse in adjacent nerve fibers; converge to
form the auditory nerve Hearing: The Structure of the Ear Hearing:
Pitch Perception
Place Theory In hearing, the theory that links the pitch we hear
with the place wherethe cochleas membrane is stimulated We hear
different pitchesbecause different sound waves trigger activity at
different places along the cochleas basilar membrane Best explains
our perception of high-pitched sounds Hearing: Pitch
Perception
Frequency Theory In hearing, the theorythat the rate of
nerveimpulses traveling upthe auditory nerve matchesthe frequency
of a tone, thus enabling us to sense its pitch Best explains our
perception of low-pitched sounds Hearing: Sound Localization
Hearing: Hearing Problems
Conduction Hearing Loss Caused by damage to the mechanical system
that conducts sound waves to the cochlea Sound vibrations cannot be
passed from the eardrum to the cochlea Example Punctured eardrum
Sensorineural Hearing Loss Caused by damage to the cochleas
receptor cells or to the auditory nerves Also called nerve deafness
NERVE DEAFNESS CONDUCTION DEAFNESS Sensation: The Other
Senses
Partthree Sensation: Olfaction (Chemical Sense)
TO DISCUSS General structure Chemical sense Gender differences
Connection to limbic system Sensation: Gustation (Chemical
Sense)
TO DISCUSS Crudest sense General structure Chemical sense Average
adult? Lifespan? Supertasters Gender differences Instructions:
Jelly Belly Activity
In partners, you will take turns eating Jelly Bellies Instructions
for the EATER The eating partner MUST keep his or her eyes closed
The eating partner MUST keep his or her nose plugged for the first
few chews After 4-5 good chews, the eating partner should release
his or her nose Instructions for the NON-EATER The non-eating
partner should provide the eating partner with a Jelly Belly &
silently note its flavor Sensation: Skin (Somesthetic Sense)
TO DISCUSS General structure Pressure? Other sensations? Sensation
of pain Gate Control Theory Fast v. Slow Fibers Sensation:
Kinesthetic (Somesthetic)
TO DISCUSS General structure Position & motion sensors
Sensation: Vestibular (Somesthetic)
TO DISCUSS General structure Semicircular canals Otolith organs
Planes of movement