Chapter 4.2 Flashcards
Light
is a form of electromagnetic radiation that travels as a wave
amplitude of light waves affects mainly the preception of
brightness
wavelenght affects mainly the preception of
color (hue)
purity influences perception of
saturation, or richness of colors
wavelengths do not have _______
color
different wavelengths are interpreted by the brain as
color
light receptors are activated when
when the light hits the retina
the cornea an dlens
focus the light on the retina to form clear images of objects
cornea
covers the eye and helps to focus the light onto the retina
the cornea accounts for ____% of the eyes focusing power
80
Lens
- helps focus light onto the retina
the lens accounts for ____% of focusing power
20
the corneas position
fixed in place
the lens position
flexible and adjusts to focus the light from near and far objects
the lens ajustments are called
accommodations
cilliary muscles
tighten to change the curvature of the lens to refocus the light onto the retina
when focusing on a close objects the lens becomes
fatter (rounder)
when focusing on a distance object, the lens becomes
flattened
presbyopia
- changing eye as we age
- the distance of the near point for focusing the eye changes as we age
presbyopia is also called the
old eye
near point
- limits of accommodation
- the point at which the lens can no longer adjust to focus an image
image at the near point
- blurry
myopia is also known as
near-sightedness
myopia
- the inability to see far objects clearly
what is the most common need for glasses in adults
myopia
hyperopia is also known as
far-sightedness
hyperopia
- can see far objects clearly, but near objects are blurry
- glasses can correct
Retina
- the neural tissue lining the inside back surface of the eye
- absorbs light, processes images, and sends visual information to the brain
the retina contains the
fovea
fovea
- responsible for acuity
- area of central vision
- contains mostly cones
what are the two types of photoreceptors
- cones
- rods
photoreceptors line the _______
retina
cones
- specialized visual receptors that play a key roles in daylight vision and color vision
rods
- specialized visual receptors that play a key role in night vision and peripheral vision
once vision is processed through the receptors, signals are sent out through the _______. ________
optic nerve
are there more rods than cones
rods
where are the most cones present
fovea
two theories that attempt to explain how we perceive color:
- trichromatic theory
- opponent-process theory
trichromatic theory
- color vision depends on activity of three diffrent color receptor types
what are the three different color receptor types in trichromatic theory
- red
- green
- blue
opponent process theory
- color vision is related to opposing responses by blue and yellow, and red and green
what theory does a good job at explain some types of color blindness
trichromatic theory
normally humans are ______
trichromats (3 kinds of cones )
very rarely, people are _________
monochromats (1 kind of cone, no color vision)
what can trichromatic theory not explain
afterimages
what are afterimages
- when you look at a color for a long time, and then look away, you may see a differently colored replica of the same image
dual process theory incorporates both ________ and ________ theory to explain color vision
trichromatic and opponet process theory
hubel & weisel (1960s)
- found other cells that fire to certain patterns/ orientations
- simple vs. complex feature detector cells
sound waves
are vibrations of molecules that travel through a medium, such as air
no sound is present in a ________, because
- vaccum
- no molecules to vibrate
sound waves move at a
fraction of the speed of light
sound waves are characterized by their
- amplitude
- wavelenghts
- purity
frequency
- the rate at which waves vibrate
- measured as cycles per second
- rouchly corresponds to our preception of pitch
amplitude (sound)
- the intensity of sound, usually measured in decibels
- amplitude roughly corresponds to our preception of loudness
complexity (timbre)
of sound
- provides information about the nature of a sound.
- contributes to the sounds uniqueness
perceived loudness doubles about every
6-10 dB
what are the three major parts of the ear
- external (outer)
- middle
inner
outer ear is comprised of
- ear cannal
- pinna
tympanic membrane
the tympanic membrane is known as the
ear drum
the ossicles are part of what part of the ear
middle
ossicles
- form a three stage lever system that converts relativly large movemnts into smaller motions with greater force
the ossicles serve to amplify
tiny changes in air pressure
the inner ear consists mainly of the
cochlea
cochlea
- fluid filled, coiled tunnel that contain receptors for hearing
what are the receptors for hearing
basilar membrane
what main theories of pitch perception
- place theory
- frequency theory
place theory
- holds that perception of pitch corresponds to the vibration of different portions, or places, along the basilar membrane
frequency theory
- holds that perception of pitch correspond to the rate, or frequency, at which the entire basilar membrane vibrates
frequency theory works for tones up to
100Hz
what are the two different types of deafness
- conductive deafness
- nerve deafness (sensorineural)
conductive deafness
- is dues to a malfunctioning of the ear, especially a failure of the eardrum of the ossicles of the inner ear
Nerve (sensorineural) deafness
- is due to damage of the auditory nerve
what are the common causes of hearing loss
- noise - induced hearing loss
- age - related hearing loss (prebycusis)
olfaction is linked with
gustation
what is olfaction
smell
what is gustation
taste
olfaction and gustation is heavily linked to
memory and recognition
- allows us to develop association between objects in the world and expected smells
gustatory receptors are
taste buds that line the trenches around tiny bumps on the tongue
5 main qualities of taste
- bitterness
- sourness
- sweetness
- saltiness
- umami
umami is
- savory
- MSG
perceptions of taste are often
learned
variation sensativity to taste
- nontasters
- supertasters
- medium tasters
what are the olfactory receptors
cilia
olfactory cilia
- receptors for smell
- hair-like structures located in the upper portions of the nasal passages
pheromones
- odourless chemicals that serve as social signals to members of ones own species
- signals are uses for mating and menstruating
what explains that humans give off and are susceptible to other humans pheromones
Stern & McClintock (1998)
flavor is a combination of
taste and smell
somatosensory system
- responsible for sensation of touch, tenpurature, and pain
what are the four main components of the somatosensory system
- nocioception
- hapsis
- proproception
- balance
nocioception
- the perception of pain and temperature caused by the activation of free endings in the skin
hapsis
- the preception of objects using touch and pressure
proprioception
- knowledge of the position of your limbs in space
balance
- controlled by the vestibular system in the inner ear
skin
- largest organs in the body
- contains receptors for touch and pain
- also important first line of defence in the immune system
epidermis
- the skins outermost layer
- comprised of dead skin cells
dermis
below the epidermis
subcutaneous
- below the dermis
- fat layer
mechanorecptors respond to
physical stimuli
- mechanical, thermal, and chemical energy that impinges on the skin
mechanoreceptors are distributed __________ across the bodys surface
unevenly
inflammatory pain
-pain caused by damage to the tissues and inflammation od joints or by tumor cells
neuropathic pain
- pain caused by lesions or other damages to the nervous system
pain signals are transmitted to the brain in 2 pathways
- fast pathway (delta-A pathway)
- slow pathway (C fibre pathway)
proprioceptive system
- monitors the position of various parts of the body. Allows us to move efficiency
proprioceptors sense
muscle stretch and force
vestibular system
- responds to gravity and keeps you informed fo your bodys location in space
- allows us to maintain balance
- shares space in the inner ear with the auditory system
what makes up the largest part of the vestibular system
semicircular canals
the vestibular system is important in
balance and for coding rotation and tilit of the head