PSY260 - Quiz #3 Study Guide with
Complete Solutions
Describe the process of how light is converted into chemical energy and sent to the
brain? - ANSWER-1. light goes through the retina into the ganglion cell and bipolar cell
(both are transparent)
2. light reaches and activates the photoreceptor
3. the photoreceptor turns it into an electrochemical message (transduction)
4. the message travels back all the way to the ganglion cell through action
potentials/neurotransmitters and gets sent to the brain via the optic nerve
how are action potentials used to show different color? - ANSWER-The frequency and
different combinations (all firing, not all firing, etc)
how do eyes differ in myopia? corrected? - ANSWER-
how does the nervous system determine color and brightness? - ANSWER-by
comparing the responses of the 3 different types of cones
If all three cone are activated, what color is perceived? - ANSWER-white
if light with a wavelength of 530 nm went into your eye, what would happen? -
ANSWER-Green cones would activate, photopigment would split, sodium channels
would close, hyperpolarization occurs, action potential sends signal
if the M-Cone and L-cone are activated, what color is perceived? - ANSWER-yellow
what are ganglion cells - ANSWER-- proper neurons
- make action potentials
- forms the optic nerve
- act as a barrier as well
what are photoreceptors - ANSWER-receives light stimulus and starts the process of
transduction to create an electrochemical message.
what are some problems with refraction through the eye? - ANSWER-1. nearsighted
(myopia) - eyeballs too long (light does not reach the retina)
2. farsighted - eyeballs too short (light goes too far from receptors
3. astigmatic - eyeballs are bumpy (refracts at different points)
what are the 3 main parts in the anatomy of an eye? - ANSWER-1. cornea
2. iris
, 3. lens
what are the 3 sensory processes? what do they do? - ANSWER-1. reception (sensory
receptors, environmental stimulus absorbed via senses)
2. transduction (Change the stimulus energy into an electrochemical neuronal change)
3. coding (Correspondence between stimulus featuresand neuronal activity)
what are the three main layers of cells in the retina? - ANSWER-1. photoreceptors
2. bipolar cells (transparent)
3. ganglion cells (transparent)
what are the two types of photoreceptors? what are their functions? - ANSWER-rods =
shape, peripheral vision, sensitive to low light
cones = color, detail
what can you do and not do when the V4 is damaged? - ANSWER-you won't be able to
locate objects but you can describe them
what can you do and not do when the V5 is damaged? - ANSWER-can locate, but not
describe objects
what do illusory contours and surfaces show - ANSWER-Show that the brain actively
constructs perception as it can create edges, shapes, or surfaces when no visual
boundaries exist.
- demonstrates that the perception is not just sensory input, but the brain's interpretation
too
what do people with more than 3 types of cone experience? - ANSWER-they see more
color and can tell the difference between wavelengths extremely easy
- birds
- genetic
what does light causing a hyperpolarization of the photoreceptor mean? - ANSWER-1.
During the dark, the photoreceptor is:
- actively releasing neurotransmitters that inhibit the bipolar cell.
- The resting membrane potential is only -30 mV
- Sodium is entering the cell
2. When light hits the photopigment:
- the retinal changes shape from 11-cis to all-trans retinal
- this new shape makes the opsin and retinal "bleach"
- this causes sodium channels to close
- no more sodium (Na+) enters
Complete Solutions
Describe the process of how light is converted into chemical energy and sent to the
brain? - ANSWER-1. light goes through the retina into the ganglion cell and bipolar cell
(both are transparent)
2. light reaches and activates the photoreceptor
3. the photoreceptor turns it into an electrochemical message (transduction)
4. the message travels back all the way to the ganglion cell through action
potentials/neurotransmitters and gets sent to the brain via the optic nerve
how are action potentials used to show different color? - ANSWER-The frequency and
different combinations (all firing, not all firing, etc)
how do eyes differ in myopia? corrected? - ANSWER-
how does the nervous system determine color and brightness? - ANSWER-by
comparing the responses of the 3 different types of cones
If all three cone are activated, what color is perceived? - ANSWER-white
if light with a wavelength of 530 nm went into your eye, what would happen? -
ANSWER-Green cones would activate, photopigment would split, sodium channels
would close, hyperpolarization occurs, action potential sends signal
if the M-Cone and L-cone are activated, what color is perceived? - ANSWER-yellow
what are ganglion cells - ANSWER-- proper neurons
- make action potentials
- forms the optic nerve
- act as a barrier as well
what are photoreceptors - ANSWER-receives light stimulus and starts the process of
transduction to create an electrochemical message.
what are some problems with refraction through the eye? - ANSWER-1. nearsighted
(myopia) - eyeballs too long (light does not reach the retina)
2. farsighted - eyeballs too short (light goes too far from receptors
3. astigmatic - eyeballs are bumpy (refracts at different points)
what are the 3 main parts in the anatomy of an eye? - ANSWER-1. cornea
2. iris
, 3. lens
what are the 3 sensory processes? what do they do? - ANSWER-1. reception (sensory
receptors, environmental stimulus absorbed via senses)
2. transduction (Change the stimulus energy into an electrochemical neuronal change)
3. coding (Correspondence between stimulus featuresand neuronal activity)
what are the three main layers of cells in the retina? - ANSWER-1. photoreceptors
2. bipolar cells (transparent)
3. ganglion cells (transparent)
what are the two types of photoreceptors? what are their functions? - ANSWER-rods =
shape, peripheral vision, sensitive to low light
cones = color, detail
what can you do and not do when the V4 is damaged? - ANSWER-you won't be able to
locate objects but you can describe them
what can you do and not do when the V5 is damaged? - ANSWER-can locate, but not
describe objects
what do illusory contours and surfaces show - ANSWER-Show that the brain actively
constructs perception as it can create edges, shapes, or surfaces when no visual
boundaries exist.
- demonstrates that the perception is not just sensory input, but the brain's interpretation
too
what do people with more than 3 types of cone experience? - ANSWER-they see more
color and can tell the difference between wavelengths extremely easy
- birds
- genetic
what does light causing a hyperpolarization of the photoreceptor mean? - ANSWER-1.
During the dark, the photoreceptor is:
- actively releasing neurotransmitters that inhibit the bipolar cell.
- The resting membrane potential is only -30 mV
- Sodium is entering the cell
2. When light hits the photopigment:
- the retinal changes shape from 11-cis to all-trans retinal
- this new shape makes the opsin and retinal "bleach"
- this causes sodium channels to close
- no more sodium (Na+) enters
