PSYC 100 Chapter 4 Flashcards
Primary Visual cortex
V1
Basic features of an image, low-level feature
contains feature detectors neurons
Secondary virtual cortex
V2/ Visual association cortex
start to represent object structure
After V2
Higher levels of visual cortex
Hierarchical Analysis
Ventral Pathway
Tells you what something you see is
Damage results in the imparimet of recognizing the objects identity
Dorsal pathway
Tells you where something is
Damage could cause problems in processing location, depth, and motion
MT (motion cortex)
motion region,
damage to this leads to Akinetopsia- cant see motion, but only series of static images
Motion perception
done by comparing previously perceived images to what is currently being perceived
Phi affect
perception of flashing lights as movement
Photopigment
Exist in photoreceptors, varies in how strongly they react to different wavelengths of visible light
3 types of photopigment
Each are more sensitive to one of 3:
Short-Blue, Medium-Green, Long-Red
Normal color vision
having 3 types of cones
Monochromacy
missing 2 types of cones
Dichromacy
missing 1 type of cone
Trichromatic theory
any one color patch could be matched by the additive mixing of three lights of different wavelengths, all of our color experiences could be created by combining these three wavelength components
Rods
Photoreceptors that allow us to see things at night,
do not process color
do contain a single type of photopigment whose favorite wavelengths is in the green-blue range
Opponent process theory
the responses of cones are combined in bipolar and ganglion cell layers to create 3 sets of opponent color responses, explains color afterimage
Audition
the sense of hearing
translating sound waves into sensations
Pitch
corresponds to the frequency of its wave
human hearing rage is betweeen 20000 Hz
loudness
amplitude of its wave
purity/timbre
complexity of a wave
3 properties of sound
Pitch, Loudness, Purity
Middle ear
begins at eardrum, includes ossicles, 3 bones (hammer anvil and stirrup) take signals amplify and translate into waves in the inner ear, ends at oval window
inner ear
contains the cochlea
cochlea
filled with fluid that is moved when ossicles push and pull on the oval window
cochlea causes
basilar membrane to vibrate, which causes
tiny sensory neurons (cilia) to bend and
trigger neural impulses
Place theory
specific places along the cochlea transduce specific sounds based on how the basilar membrane vibrates. best for sounds from 5000 Hz to 20000Hz
Frequency theory
hair clesss fire at the frequency of the sounds they transduce. Works up to 100 Hz
Volley theory
hair cells could fire at their highest rate slightly out of sync to bridge between 100Hz and 5000 Hz
The primary auditory cortex is
tonotopic- which means that its receptive fields are arranged by tone
Olfaction
the sense of smell
can distinguish 1000-1 trillion odors
Epithelium
Along the top of the nasal cavity, different smells are randomly represented on the epithelium
Places in brain associated with olfaction
Primary olfactory cortex and limbic system, olfactory association cortex
gustation
the sense of taste
taste buds
detect specific basic flavors, contain tiny invisible pores
each pore contains 50-100 taste receptors
supertastors
have more taste receptors than the average person, flavors taste stronger to them
tongue to brain
3 never tracks connect the tongue to the brain, thalamus, primary gustatory cortex, secondary taste regions
All sensory sensations go here except olfaction
Thalamus
pathage of smell
goes directly to the olfactory bulb then to the olfactory cortex then the limbic then the olfactory association cortex
pathage of taste
medulla and thalamus, gustatory, somatosensory cortex
somatosensation
refers generally to senses that are detected by never endings under the skin
touch, pressure, and pain
◦Light touch, deep pressure, and temperature are detected by specialized
nerve endings
◦Touch, temperature, and pain are also detected by free nerve endings
touch pain and temperature first travel to
spinal cord may activate spinal reflexes
proprioception
our sense of where our body is at any given time
alcohol can severely affect this
vestibular sense
our sense of balance, controlled by semicircular canals which are in the inner ears, also controlled in part by the cerebellum
kinesthesis
our sense of body and parts moving through space
provides info about how resistance influences our ability to move
interoception
is our internal sense of the bones and organs
Supported by the insular cortex
◦Important for detecting internal pain
and abnormalities in our bodies
perceptual set
when our expectations influence what we perceive
perceptual constancy
“correcting” for variation in order to interpret what we are perceiving
monecular depth cues
can be perceived using only one eye
ex. linear perspective
texture gradient
relative size
binocular depth cues
perceive based on differences between the eyes
convergence and retina disparity
gestalt principles
proximity, similarity, continuation, and closure
sensation
detection of physical sensations by a sense organ
bottom-up process
perception
the brain’s interpretation of raw sensory information
includes top-down processing as well, which can
change what we report about sensations.
transduction
the energy outside the body is turned into a nerve signal
sense receptors
what allow transduction to occur
sensory adaptation
continuous stimulus
takes place at the level of receptors
ex. no longer smell your perfume
perception adaptation
continuous perception
at a higher level of neurons representing the stimulus
ex. seeing emotional faces
Psychophysics
the study of how we perceive sensations
absolute threshold
the very minimum required to
perceive a sensation 50% of the time
liberal bias
more likely to say “yes”, can lead to false alarm
conservative bias
more likely to say “no”, can lead to a “miss”
signal detection theory
Understanding how humans make decisions under conditions of uncertainty
just noticeable difference
minimum change in a stimulus for an
observer to detect a difference 50% of the time.
weber’s law
difference thresholds increase as the stimulus size increases
the stronger the stimulus, the bigger difference is required to be noticeable
doctrine of specific nerve energies
that the type of sensation
reported depends on the receptor, NOT the input
McGurk effect
Seeing a mouth can affect what you hear
light
electromagnetic energy
photons
Basic unit (of all forms of electromagnetic radiation)
wavelength
hue
amplitude
brightness/intensity
of different waves:
saturation
humans are best at perceiving
RGB
what dictates which parts of the spectrum animals
are sensitive to.
receptors
cornea
the transparent layer at the front of the eye,
that covers both the pupil & iris
pupil
a hole in the iris
iris
a muscle that gives eyes distinctive color,
controls the size of pupils to adjust how much light
enters
lens
lies inside the eye, helps bend/focus light
through accommodation (changing its shape)
* Shape of the eye also helps focus light; incorrect
the shape can lead to near- or far-sightedness
fovea
an area with high visual acuity in the center of the visual field
retina
a thin membrane on the back of
the eye
contains both rods and cones
Cones and Rods locations
Cones are concentrated in the fovea, some in the periphery
◦Rods are concentrated in the periphery
What are cones for
Cones are good at color processing and have
high acuity (fine detail)
What are rods for
Rods can’t process color but have high
sensitivity (good at detecting changes)
What has more convergence, rod or cone
rods:
Cones in the fovea have more of a one-on-one
connection to cells farther down the line, showing
less convergence
Rods in the periphery demonstrate a much
greater degree of convergence, as many
individual rods are connecting later cells (ganglion
/ bipolar).
Convergence
the way our eyes move together and point inward when we look at near objects.
cone work best in
bright light condition
rods work best in
low light condition and are the main groups of cells we rely on at night
what happens after light hits the retina
rod and cone cells send signals to the next layers of cells in the retina called ganglion cells.
These cells pass their input out of the eye through the
optic nerve.
blind spot
An area in the middle of the visual field where there are no photoreceptors and no information can be received.
the process from the eye to the brain
Information from each visual hemifield reaches the
contralateral side of the retina, gets grouped together at
the optic chiasm to the contralateral side of the brain
hemisphere
AKA
retina-optic chiasm- a specialized visual nucleus of the thalamus- primary visual cortex (V1)
Left visual field
right side of the retina, right brain hemisphere
Right visual field
left side of the retina, left brain hemisphere
images formed at V1
up-down flipped, left-right flipped
2. retinotopically organized
sound wave
air pressure compression & expansion, caused by object’s vibration
pinna
helps catch the sound waves and send to ear canal
olfaction process
odor molecules combine with olfactory receptor proteins on olfactory cilia which belong to
olfactory receptor neurons on the epithelium
Odors bind to odor receptors like a
lock and key
taste is influenced by
- olfactory signals
- visual signals
- auditory signals
why is pain controlled by top-down processes
pain is gated by neurons in the spinal cord
closure
we automatically fill in gaps between elements to perceive a complete image.
proximity
We group closer-together elements, separating them from those farther apart.
similarity
elements that are similar are perceived to be more related than elements that are dissimilar.
continuation
we are more likely to see continuous and smooth-flowing lines rather than broken or jagged ones.
