Chapter 6 (Sensation) + Chapter 7 Flashcards
___: any energy capable of exciting a receptor
Stimulus
To Perceive a Sensation . . . (4 Steps)
- A stimulus sufficient to initiate a response in the NS must be present
- A receptor must convert the stimulus to a nerve impulse
- The conduction of the nerve impulse must be transmitted from the receptor to the brain
- Interpretation of the impulse must occur in a specific portion of the brain
The level of response is determined by the _____ of the stimulation
intensity
(– Rate law!!)
These types of receptors continue to fire at a relatively constant rate as long as
the stimulus is maintained . . . Slow/fast to adapt
tonic receptors, slow to adapt
(example sitting down for a while, the constant pressure is being sensed by the tonic receptors)
These types of receptors respond with a burst of APs when the stimulus is first
applied . . . But quickly ____ their rate of firing when the stimulus is maintained . . .
Phasic Receptors, reduce
(example sitting down, the sudden sensation of sitting down is done by phasic receptors)
_____ are specialized nerve cells that transduce energy into neural signals
(T/F the have Axons?)
receptors
(F, they form synapses with dendrites of other sensory neurons)
Receptors are “___” specific
mode,
“Law of Specific Nerve Energies”: sensory messages
are carried via separate pathways to different areas of
the brain, but all use the same neural impulse
You would use your ____ to detect EMR emitted by objects.
Color is related to ___
Brightness is related to ____
visual system
wavelength
Intensity
An eye consists of: (3 parts)
– Aperture (pupil) to admit light
– Lens that focuses light
– Photoreceptive elements (retina) that transduce the light stimulus
The path of light: (6 steps)
cornea, aqueous humor, pupil, lens, vitreous humor, retina
This type of eye movement has the eyes rotate to keep an object on corresponding
parts of the retina (coming closer and farther away)
Vergence movements
This type of eye movement is following an object to keep it on the same part of the
retina (the fovea, to maximize detail and color appreciation). The eye is moving up, down, left, right
Pursuit movements
This type of eye movement has the eyes fixate on objects during “smooth pursuit”
* Eyes also “jump back and forth” – they are not stationary! (constant refresh on your visual system)
Saccadic Movements
What are the three layers of the retina
– Photoreceptor layer (back of the eye): receptors in this layer
transduce light into electrochemical impulses (eventually,
action potentials)
– Bipolar layer
– Ganglion cell layer
The ganglion cell layer is _____ and the photoreceptor layer is the ____ from the light
closest to the light, farthest
This type of photoreceptor is
* Light sensitive (not color)
* Found in periphery of retina
* Low activation threshold
Rods
This type of photoreceptor are
* color sensitive
* Found mostly in fovea (center of retina)
Cones
This is where photopigments are located…
in the membrane of the outer segment of rods and cones
Each pigment consists of an ____ and ____
opsin (protein), retinal (a lipid)
Why is light important to seeing?
The effect of light is to hyperpolarize the photoreceptors and reduce the release of NT
- light hits photoreceptor becomes deactivated in response, inhibit the bipolar cell less (release less NT), cause the bipolar cell to become relatively activated causing action potentials (rate law) releasing NT
the relationship between the photoreceptor and the bipolar cell is ____
ihibitory
the relationship between the bipolar cell to the ganglion cell is ___
excitatory
Meyers loop processes:
superior vision (upper half)
What happens if we lesion the parvocellular layers of the LGN in the right hemisphere?
their left visual field would be without color
Horizontal cells perform “___” which is…
lateral inhibition
when a neuron is stimulated, it actively suppresses the activity of its neighboring neurons, essentially creating a sharper contrast between stimulated and non-stimulated areas, allowing for better distinction between different stimuli; example fall of a cliff
Trichromatic theory argued there are…
there are 3 different receptors in the eye, with each sensitive to a single hue, blue, green, red,
If you stare at the colors red and green for a while, after you look a way you would see blue and yellow. This is a example of ____
Opponent Theory
This is an inherited form of defective color vision in which red and green hues are confused; “red” cones are filled with “green” cone opsin
- See the world in shades of yellow and blue; both red and green look yellowish to them
Protonopia
An inherited form of defective color vision in which hues with short wavelengths are confused; blue cones are lacking or faulty
tritanopia
_____ can be used to record the firing activity of a single sensory neuron
microelectrodes
This is called _____ when some cells fire best to a stimulus
of a particular orientation and fire less when orientation
is shifted
Orientation sensitivity:
_____ cells vary firing rate according to the
sine wave frequency of the stimulus
Spatial frequency
Visual neurons respond to a ____
sine wave grating:
A lesion in the temporal lobe would affect what
affect identifying objects by sight (though touch would help only visual)
A lesion in the parietal lobe would affect
location/movement of objects, grasping problems
This is the inability to recognize faces, even of close friends or family…
prosopagnosia
These are the 3 Divisions of the Ear
Outer Ear (Channel to the tympanic membrane)
Middle Ear (Ossicles)
Inner Ear (Cochlea)
These are the three subsections of the ossicles
Malleus, Incus, Stapes (you can’t MIS these)
Describe how the Cochlear works
Stapes presses against oval window to create force in cochlea
Cochlea is filled with liquid, which transmits energy
the Round window helps the liquid move in the closed system
Where’s the organ of Corti?
Inside the cochlea
What does the organ of Corti do?
Transduces sound waves into nerve impulses (sound in mental thought)
The organ of Corti consists of 3 parts
- Basilar Membrane (forms the base) with hair cells
- Tectorial membrane (forms the roof)
- Hair cells in between
This is one of the types of hair cells in the Corti
- single line cells along the basilar membrane (they do not touch tectorial membrane, but move with movement of liquid)
destruction of which eliminates hearing,
inner hair cells
This is one of the types of hair cells in the Corti
- are arranged in three rows along the basilar membrane
- Serve a structural function, as they actually connect the basilar and tectorial membranes
outer hair cells
Which is more important to hearing, inner or outer hair cells
inner hair cells
____ project from the top of each hair cell
____ attach adjacent cilia at a point known as an _____, which is always on the tallest cilium.
cilia, tip links, insertional plaque
Cilia arranged due to height, insertional plaque is just what you call the biggest Cilia tip link
The cilia moves due to sound, the cilia are connected by tip links, these tip links open and release ions. CA and K ions flow into the cilia and produce depolarization
Afferent pathways:
Through cochlear nuclei
- To ____
- To ____
- To ____
- To ____
superior olivary nuclei (medulla)
inferior colliculus (dorsal midbrain, near cerebellum)
Medial Geniculate (thalamus)
Auditory cortex (superior temporal lobe)
80% of the pathways are contralateral, 20% are ipsilateral
Cortical Auditory Divisions (The cortex can be divided into three divisions with regard to hearing
core region (contains the primary auditory cortex)
Belt region (the secondary association area (receives information from the PAC and the medial geniculate nucleus)
parabelt region (tertiary regions (receives information from the belt region and medial geniculate nucleus
Two auditory streams
Dorsal stream
Ventral Stream
Dorsal stream does what
determines sound location
Ventral Stream does what
Helps determine meaning
This type of frequency is near the base of basilar membrane
high
this type of frequency is near the apex of the basilar membrane
moderate frequency
tonotopic organization means
essentially the higher pitches are represented by deeper cortex
loudness is determined by the ____ of hair cell firing
rate
more intense vibrations produce more intense shearing force on cilia -> cells release more NT -> more firing
Sounds are coded by ___ of firing
intensity coded by the ____ of hair cells depolarized
rate, number
what is place coding theory?
refers to the theory that the brain deciphers sound frequencies based on the location of the hair cells activated in the cochlea, with high-frequency sounds stimulating cells at the base and low-frequency sounds at the tip.
Location of sound is detected first by
olives
______ have coincidence detectors which can determine which sound the side hit first
Medial Superior Olives
the _____ have intensity detectors which can determined the intensity of sound
The Lateral Superior Olives
