chapter 3 Flashcards
sensation and perception ultimately form the basis of our?
behaviour
sensation refers to?
the physcial reality of the signals that our sensory organs pick up and send to be processed in the nervous system
perception refers to
how we interpret those signals (what we experience subjectively)
sensory receptors
refers to specialized dendrites of sensory neurons that respond to various kinds of physical stimuli by generating action potentials that are sent upstream towards the CNS for further processing
within the PNS, such neurons are bundled into what?
- nerves (collection of axons)
- ganglia (collection of cell bodies)
sensory receptros communicate which 4 properties to the CNS
- location (where stimulus is coming from)
- modality (what type of stimulus it is)
- intensity (the frequency of action potentials produced by a stimulus)
- duration (how long a stimulus last)
“lick my icky dick”
exteroreceptors
- respond to stimuli from the outside world
interoreceptors
- respond to stimuli from inside the body
chemoreceptors
- respond to chemical stimuli
olfactory receptors
- involved in the sense of smell
- a type of chemoreceptor
gustatory receptors
- taste receptor
- type of chemoreceptor
photoreceptors and hair cells
- responsible for vision (respond to specific wavelengths of electromagnetic radiation, or light)
- in the inner ear convert pressure signals from osund waves into action potentials
- semicircular canals contain endolymph which moves in response to rotational acceleration and results in the movement puts pressure on hair cells on the crista ampullaris that respond by sending info to the NS
mechanoreceptors
- responsible for touch and respond to mechanical stimuli and various specific types of touch stimuli exist
thermoreceptors
- specialize in detecting either warm or cold temperatures
nociceptors
- receptors that detect pain (different types to detect pain to mechanical, thermal, or chemical stimuli)
baroreceptor
- type of interoreceptor that detects pressure in the body such as on the walls of blood vessels
osmoreceptors
- type of interoreceptor that detects the concentration of solutes in blood and trigger responses when the blood becomes too dilute or too concentrated
proximal stimulus
- what a sensory receptor detects
distal stimulus
- is the object in the environment that causes those signals
absolute threshold
the level of intensity that a stimulus must have in order to be picked up by sensory neurons (yes-or-no phenomenon)
threshold of concious perception
- the threshold that a stimulus must cross in order for us to be able to consciously perceive it at all
just-noticable difference (JND)
- the smallest change in the magnitude of a stimulus that we can perceive as being different
- also called difference threshold
psychosocial discrimination testing
- researchers test whether research subjects can tell the difference between 2 stimuli and then link those findings to the actual physical properties of the stimuli being studied
Weber’s law
- states thar for any given sensory input, the just-noticeable difference will be a constant proportion of the original input
- works within a range of what we might encounter on a day-to-day basis, but not ones that are either so faint to be nearly undetectable or so large to overwhelm our ability to process them (stops working well at the extremes of sensory input)
signal detection theory hit
correclty detecting something that is actually present
signal detection theory miss
not detecting something that is actually present
signal detection false alarm or false positive
- we perceive something that isn’t actually there because of some other signal
signal detection theory correct rejection
we do not perceive anything that isn’t actually there
signal detection theory summarized
signal detection can vary across?
people and even within an individual depending on his or her physiological state and the general context
sensory adaptation
- Sensory adaptation is a reduction in sensitivity to a stimulus after constant exposure to it. While sensory adaptation reduces our awareness of a constant stimulus, it helps free up our attention and resources to attend to other stimuli in the environment around us.
tonic receptors
- receptor that adapt slowly to stimuli and continues to send action potentials as long as a stimulus is present
phasic receptors
- send a quick burst of action potentials in response to a stimulus and then stop and it adapts quickly to a stimulus
bottom-up processing
- refers to a pattern in which our brain starts with individual pieces of sensory information coming in and assembles them into a coherent whole
top-down processing
- refers to a scenario where the brain decides ahead of time what it’s looking for, and then assembles the individual pieces of sensory information together in a way that supports that picture
binocular cues
- the existance of 2 eyes that pick up on light from slightly different angles help us perceive depth
monocular cues
Monocular cues are all the ways that a single eye helps you see and process what you’re looking at like relative size, perspective, which objects are in front of or behind each other, and brightness to infer depth
principle of proximity
states that we perceive objects or shapes that are close to each other as forming groups
principle of similarity
states that objects that are similar in some way will be perceived as belonging to a group
principle of good continuation
posits that the human eye will follow the smoothest path when viewing lines, regardless of how the lines were actually drawn.
principle of closure
- It’s the idea that your brain will fill in the missing parts of a design or image to create a whole.
principle of symmetry
- states that symmetrical objects are more likely to be perceived as part of a whole than assymetrical objects
law of Prägnanz
- concise and meaninful
- the logical link between all of the Gestalt principles is that we try to find simple and meaningful ways to represent objects that we perceive as wholes, not just as random parts (what perception is all about)
the eye is a system for
turning certain wavelengths of light into action potentials
the retina
- located at the back of the eye
- contains millions of photorecpetors, which are classified as cones or rods, and turns wavelengths into action potentials
cones
responsible for perceiving coloe and fine detial
3 kinds of cones that specialize in different wave lengths
short-wavelength type of cone
- senses blue
- wavelength of about 420nm
medium-wavelength cone
- senses green
- wavelength of about 530nm
long-wavelength type of cone
- senses red
- wavelength at 570nm
how many cones in the retina and where are they located
6 million in the central area (fovea- small central pit in the retina that only contains cones and the macula- central region around the fovea)
rods
- do not sense colour
- specialize in sening visual input in low-light conditions
- responsible for night vision
- contain rhodopsin
rhodopsin
- a pigment and a photoreceptor protein that is extremely sensitive to light
how many rods are there
120 million
where are rods located
- distributed more densely away from the center of the retina, so that peripheral vision is best for seeing dimly-lit objects at night
main structures needed to converge incoming light rays on the retina
the lens and the cornea
cornea
- located at the front of the eye
- very first thing that light passes through to enter the eye
- protects the eye from external injuries
- helps focus incoming light
lens
- finishes the job of focusin light
- structure that can change shape with the help of tiny ligaments attached to its rim to help the eye focus on objects at various distances (accomodation)
dark adaptation
- rods take a while to become active which is useful after being in a bright place for a while
- reason we see better in the dark after a few minutes
iris
- in front of the lens
- part of the eye that gives its colour
- blocks the light that isn’t supposed to get into the eye
pupil
- hole in the center of the iris
- lets light into the eye
dilator pupillae and constrictor pupillae
- 2 muscles attached to the iris
- one dilates (allows more light in)
- one constricts (letting less light in)
ciliary muscle
- part of the ciliary body whcih adjusts the lens via suspensory ligaments
division of the eye into 2 high-level parts
- anterior chamber (smaller, front-facing area)
- posterior chamber (the back of the eye)
the anterior chamber is filled with
fluid called the aqueous humor
the posterior chamber of the eye is filled with
a gel like viscous fluid called the vitreous humour
choroid
- beneath the retina lies a layer of dark, vascular tissue full of melanin called the choroid which supplies the retina with blood and absorbs excess light
sclera
- outermost layer of the eye
- gives the white colour of the eye
conjunctiva
- thin layer of epithelium that lies in front of the corna and sclear and keeps the eye lubricated
eye anatomy summarized
light ray that bounces off of something in out left visual field will hit the?
right side of the retina in each eye
a light ray that bounces off of something in your right visual field will hit?
the left ride of the retina in each eye
optic nerves cross at?
optic chiasm
the input that hits the right side of your left eye gets processed in the
left hemisphere
the input that hits the left side of your right eye gets processed in the left hemisphere
right hemisphere
the segments of the optic nerve coming from the innermost halves of both eyes are called the
nasal sides
the input coming from the outer halves of each retina are called the
temporal sides
inputs that come from the temporal sides
stay on the same side of the brain
- the input that hits the left side of your left eye stays on the left side and is processed on the left hemisphere
- the input that hits the right side of your right eye stays on the right side and is processed on the right hemisphere
when the optic nerve has reached the optic chiasm, we refer to these bundles of axons carrying visual information as?
the optic tract
the optic tract runs through?
the lateral geniculate nucleus (LGN)
what is the lateral geniculate nucleus (LGN)
the LGN is a strucutre contained in the thalamus that acts as the main relay station for input from the retinas and for sending signals to the superior colliculus
what does the superior colliculus do
controls the virual startle response and the visual cortex of the occipital lobe
magnocellular neurons and parvocellular neurons
neurons in the LGN that are big (magno) or small (parvo)
- magno specialize in detecting motion
- parvo pick up details
motion parallax
- describes the fact that objects that are close to us move further across our visual field than objects that are far from us
- one of the cues we use to perceive depth
feature detection
we are constantly picking up on many categories at the same time as we perceive things
ex. when we see an ambulance going down the street, we monitor parameters like colour, shape, timing and motion
parallel processing
- process by which we integrate all that simulatenous input
serial processing model
consciously look in one place after the another and analyze stimuli in oder
sound waves
longitudinal waves that manifest as regularly repeating changes in pressure as air molecules move back and ofrth
hair cells
have little stereocilia that poke into a fluid called the endolymph that surrounds them
the swaying movment of stereocilia open up?
ion-channels thay let small cations flow into the cell
ion-channels that let small cations flow into the cell trigger what
an influx of calcium ions through voltage-gated ion cannels
the influx of calcium that leads to the release neurotransmitters at one end of the cell to ?
the vestibulocochlear nerve at which point neural signals are transmitted
(transduction of sound)
ear is divided into the?
outer, middle and inner ear
hair cells are located in the?
inner ear within the organ if Corti
summarize the ear
sound waves enter the ear and cause the endolymph that surrounds the hair cells in the inner ear to vibrate which causes the hair cells in the organ of Corti to release neurotransmitters that trigger nerve signals that move into the brain towards the auditory cortex
the outer ear consits of?
- external structures of the ear
- earlobe
- pinna (or auricle)
function of the pinna (or auricle)
funnel incoming sound waves into the external auditory canal
auditory canal
a tube that extends inward to the eardrum
what other name do we call the earderum
tympanic membrane which is the dividing point between the outer ear and middle ear
function of the tympanic membrane
- vibrates in response to sound wafes
- high frequency sound waves cause it to vibrate at a high frequency
- low frequency sound waves cause it to vibrate at a low frequency
middle ear contains?
- ossicles
- malleus (hammer), incus (anvil), stapes (stirrup)
- a connection to the nasal cavity (Eustachian tube)
function of the ossicles
the malleus (hammer) is connected to the tymapnic membrane and sends vibrations to the incus (anvil) which then connects to the stapes (stirrup) whcih then connects to a membrane known as the oval window
what is the oval window
the boundary between the middle ear and the inner ear
function of the Eustachian tube
- a valve that equalizes the pressure between the middle ear and the environment “ears pop”
inner ear
contains fluid-bathed hair cells that can translate vibrations into nerve signals
the basic framework of the inner ear is known as the
bony labyrinth
the bony labyrinth contains
- the membranous labryinth that contains endolymph and perilymph
the cochlea is located where
in the inner ear and is responsible for hearing
the cochlea is divided into how many layers called
3 layers called scalae
place theory
Place theory is a theory of hearing that states that our perception of sound depends on where each component frequency produces vibrations along the basilar membrane.
basic logic of how the ear helps us perceive sound
outer ear gathers up the sound waves
middle ear is the amplification system
inner ear does the actual job of hearing by converting mechanical signals into neural signals
the nerve signals generated by the hair cells in the organ of Corti are transmitted through the?
vestibulocochlear nerve (auditory nerve)
left hemisphere of the brain
specializes in processing speech
right hemisphere of the brain
specializes in processing background noise and instrumental music
hair cells in the inner ear are also responsible for
- vestibulaar sense (balance and dimensional space)
- semicircular canals sense rotational acceleration
semicircular canals and in a bulge called an
ampulla which contains hair cells
inner ear also contains
vestibulae which sense linear acceleration
vestibulae contain 2 structures
utricle which detects acceleration in the horizontal plane
saccule which detects acceleration in the vertical plane
utricle and saccule contain what
(calcium carbonate specks) otoliths which help stimulate hair cells
somatosensation
Somatosensation is a mixed sensory category and includes all sensation received from the skin and mucous membranes, as well from as the limbs and joints. Somatosensation is also known as tactile sense, or more familiarly, as the sense of touch.
nerves on the skin are?
not evenly distributed
two-point threshold
refers to the minimum distance between 2 points that are stimulated at the same time on the skin such that we can perceive the 2 points as distinct from each other
physiological zero
the temperature at which an object in contact with the skin feels neither warm nor cold. (29-32 degrees Celcius)
gate theory of pain
The gate control theory of pain describes how non-painful sensations can override and reduce painful sensations.
information about taste is processed in the
taste center of the thalamus and then sent to the gustatory cortex in the brain
information about smell
processed in the olfactory bulb then passed to the olfactory tract then to other parts of the brain including the lymbic system
senses constanly ?
interact
synapse of vision
