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93 Cards in this Set
- Front
- Back
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What is the Opponent Process Theory of Color Vision?
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Proposed by Herin (1800's)
Color vision is caused by opposing responses Behavioral evidence: color afterimages |
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What are Opponent Neurons?
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Respond in a excitatory manner to one wavelength and in an inhibitory manner to another.
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What causes afterimages?
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Chromatic adaptation
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What is Color Constancy?
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Perception of color as relatively constant in spite of changing light sources.
Activating receptors differently by we still perceive it as the same color. |
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What are possible causes of color constancy?
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Chromatic Adaptation
Memory and Color Comparison to surrounding colors |
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What is Chromatic adaptation?
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Caused by prolonged exposure to chromatic color.
Adaptation "readjusts the color" |
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What is simultaneous color contrast?
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By surounding an area with color you can change the perception of the appearance of that color
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Explain a "Trichromat"
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Someone with normal color vision
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What is an anamalous trichromat?
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One of the systems has abnormal absorption
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Explain "Monochromat"
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Someone who is truly color blind.
Usually has no functioning cones, only rods. Does affect Acuity, and people are often light sensitive. |
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Explain "Dichromat"
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3 Types:
Protanope: red/green mixups, most commonly missing an L cone. Deuteranope: red/green mixups, most commonly missing an M cone. Tritanope: blue/yellow mixups, most commonly missing an S cone (this is very rare) |
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Explain Cerebral Achromatopsia
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Cortical loss of color vision
Damage to the "what" pathway or the ventral pathway. |
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Explain Synesthesia
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A mixture of the senses.
Each has his/her own unique association. Most often "chromatic" |
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What are the two definitions of sound?
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Perceptual: sound is the experience we have when we hear.
Physical: sound is pressure changes (vibrations) |
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Explain Sound waves
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alternating high/low pressure regions through the air.
Occurs when you have some movement that causes pressure changes through the air. |
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What is a pure tone?
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A simple sine wave.
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What is amplitude:
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difference in pressure between high and low peaks of a wave.
Loudness |
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What is the measurement of sound?
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decible (dB)
Computed from the log of the pressure ratio. |
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What is frequency?
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The number of cycles within a given time period.
measured in Hz, 1Hz= I cycle per second Pitch |
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What is complexity?
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A mixture of many pure tones
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Explain phase angle
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What phase of the sound wave cycle your in when the sound reaches your ear.
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What are the parts of the Outer Ear?
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The Pinna
The Auditory Canal |
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What is the Pinna?
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The part of the ear that we see.
Involved in localization of sound and some sound amplification. |
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What is the auditory Canal?
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Protects the tympanic membrane using wax, from bugs and dust
Keeps a consistent temperature. Resonates sound |
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What ar the parts of the middle ear?
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The Eustachian Tube
The 3 Ossicles |
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What does the Eustachian Tube do?
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Connects ear to the throat
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What are the 3 ossicles?
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Malleus (mallot)
Incus (anvil) Stapes (stirrup) |
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What does the Malleus do?
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Moves due to vibrations of the tympanic membrane.
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What does the Stapes do?
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Transmits vibrations to the inner ear via the oval window.
"BANGS ON THE OVAL WINDOW" |
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Explain Acoustic Reflex
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Involves the middle ear muscles.
With loud sound, the muscles tense up and dampen the vibrations to reduce damage. Can lower sound by 30dB Also kicks in when talking/chewing |
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What is the Impedence mismatch
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sound waves can't be transmitted from one medium to another.
Pressure changes transmit poorly into denser medium |
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What are the two functions of the ossicles?
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1. Concentrates pressure changes onto a small surface area.
2. Lever action: small movement of ossicles allows bigger action. |
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What are the structures of the Inner ear?
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The Semicircular canal
The cochlea |
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What does the semicircular canal do?
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Responsible for balance (vestibular system)
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Explain the cochlea
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Fluid-filled snake-like structure.
Main structure for hearing Set into vibration by the stapes. |
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Explain the Organ of Corti
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3 major structures: basilar membrane, hair cells, tectorial membrane
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What are the key auditory nerve fibers?
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The hair cells
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What is the role of inner hair cells?
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Primary transducers, most of the afferent fibers in the auditory nerve.
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What is the role of outer hair cells?
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Primary amplifiers, all of the efferent fibers in the auditory nerve.
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Explain how sound travels to the cortex, after the ear.
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1. Cochlear Nucleus (ear specific)
2. Superior Olivary Nucleus (brainstem) (bineural) 3. Inferior Colliculli (midbrain) 4. Medial Geniculate Nucleus (thalamus) 5. Auditory Cortex |
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What is conductive hearing loss
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problems delivering the sound stimulus to the receptors.
mechanical problems |
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What is sensorineural hearing loss
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damage to the cochlea or auditory nerve, usually damage to the receptors (hair cells)
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What is conductive hearing loss?
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Vibrations are not conducted from the outer ear to the cochlea
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What is Otitis Media?
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Middle ear infection
Bacteria growning in the middle ear, build up of fluid so that the ossicles can't vibrate. |
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What is Otosclerosis?
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Hereditary.
Calcification of bones in the middle ear, mostly effects the stapes |
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What is Presbycusis?
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"old-hearing"
Loss of sensitivity of high frequencies with old age |
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How do drugs affect hearing?
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Nicotine: reduced blood flow to the cochlea
Apirin: blocks amplification of outer hair cells, temporary hearing loss. |
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What is acoustic trauma?
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Can result from on loud explosive noise, causes hearing damage.
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Explain noise induced hearing loss
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loud noises causes degeneration of hair cells.
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What is temporary threshold shift?
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Shift in dB (20 dB) for hours to days.
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Explain Neural Hearing loss
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Also called Cortical Deafness
Tumors or injuries Damage to the auditory nerve= neural hearing loss. Damage to the auditory cortex= cortical deafness |
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What are cochlear implants?
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For damage to the hair cells but the rest of the auditory system is intact.
1. Microphone 2. Sound processor: breaks up complex sounds to frequencies. 3. Transmitter (along the mastoid bone) 4. Receiver (surgically implanted) 5. Cochlea, stimulating locations along the basilar membrane This can help people who are deaf to hear some sounds and to understand language. The work best for people who receive them early in life or for those who have lots their hearing later in life. |
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What are the two typical "paths" of communication for deafness?
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1. Lip reading and oral skills.
2. Sign language |
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Explain Deaf vs. deaf
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deaf (audiologically): problems in hearing processing but may/may not be in deaf culture.
Deaf (culturally deaf): may function only in Deaf culture and not have oral skills. |
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What are the two ways that nerve fibers signal frequency?
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1. Which fibers are responding (place theory)
2. How fibers are firing (rate of pattern of firing) |
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What is Bekey's theory of hearing?
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Place theory
Which fibers are firing? Different frequencies of vibration disturb different regions of the basilar membrane. Activate different hair cells and therefore activate different auditory nerve fibers Shape made by connecting of maximum points of the traveling wave. |
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How is the cochlea organized?
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Tonotopically
Apex responds best to low frequencies Base responds best to high frequencies |
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What is Broad Displacement?
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Frequencies below 1000 Hz have broad displacement, and no specific place of peak
Therefore, place theory is less effective for low frequency sounds |
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Explain noise induced hearing loss
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loud noises causes degeneration of hair cells.
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What is temporary threshold shift?
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Shift in dB (20 dB) for hours to days.
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Explain Neural Hearing loss
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Also called Cortical Deafness
Tumors or injuries Damage to the auditory nerve= neural hearing loss. Damage to the auditory cortex= cortical deafness |
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What are cochlear implants?
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For damage to the hair cells but the rest of the auditory system is intact.
1. Microphone 2. Sound processor: breaks up complex sounds to frequencies. 3. Transmitter (along the mastoid bone) 4. Receiver (surgically implanted) 5. Cochlea, stimulating locations along the basilar membrane This can help people who are deaf to hear some sounds and to understand language. The work best for people who receive them early in life or for those who have lots their hearing later in life. |
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What are the two typical "paths" of communication for deafness?
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1. Lip reading and oral skills.
2. Sign language |
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Explain Deaf vs. deaf
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deaf (audiologically): problems in hearing processing but may/may not be in deaf culture.
Deaf (culturally deaf): may function only in Deaf culture and not have oral skills. |
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What are the two ways that nerve fibers signal frequency?
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1. Which fibers are responding (place theory)
2. How fibers are firing (rate of pattern of firing) |
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What is Bekey's theory of hearing?
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Place theory
Which fibers are firing? Different frequencies of vibration disturb different regions of the basilar membrane. Activate different hair cells and therefore activate different auditory nerve fibers Shape made by connecting of maximum points of the traveling wave. |
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How is the cochlea organized?
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Tonotopically
Apex responds best to low frequencies Base responds best to high frequencies |
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What is Broad Displacement?
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Frequencies below 1000 Hz have broad displacement, and no specific place of peak
Therefore, place theory is less effective for low frequency sounds |
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Explain Temporal Theory
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Nerve cells fire at a rate that matches the vibration rate of basilar membrane
Based on the frequency of the tone. BUT, neurons rest after firing Not just a single neuron, multiple nerve fibers can fire in synchrony with frequency. This system breaks down at 5,000 Hz. Not good for high frequency tones. |
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What is Fourier Analysis?
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A complex wave can be broken into a number of sine wave components.
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What is Timbre?
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Quality or characteristic of sound
Loudness and pitch can be the same, but the sounds may be perceived differently. |
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What are Harmonics?
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The pure sine-wave components of a complex sound.
Usually multiples of the fundamental frequency "Overtones" |
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What is the fundamental frequency?
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The component of complex tone with the lowest frequency.
The first Harmonic |
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Explain the problem of the missing fundamental.
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Play the fundamental and the harmonics: sounds like the fundamental frequency.
Play all harmonics except the fundamental frequency: still sounds like the un-played fundamental freq. This is a problem for both place and temporal theories. Indicates that some of pitch perception is higher level. |
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What are Binaural cues?
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Comparison of signals received by the left and right ears.
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What is the horizontal plane of sound localization?
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The Azimuth
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What is the vertical plane of sound localization?
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The Elevation
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Explain the Interaural Time difference
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Cues to localization based on different arrival times at the two ears.
Time differences result in: 1. Onset differences 2. Phase differences |
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Explain "Phase differences"
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Sound is at a different phase of cycle when it reaches each ear.
Even sounds without distinct onset, we can localize using phase differences. Much easier with low frequency tones because they will be more out of phase. Higher tones are more difficult because the peaks are closer together. |
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Explain Interaural Intensity Differences
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Difference in sound level reaching the two ears.
Reduction in intensity for the farther ear. Caused by two thing: 1. Distance: intensity decreases over distance. 2. Acoustic shadow: head is a barrier to sound |
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Explain the acoustic shadow
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Head is a barrier to sound.
High frequency tones can't wrap around head easily, they bounce off and cause more intensity differences. Low frequency tones can wrap around head more easily so not as much intensity differences. |
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What is the duplex theory?
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We need to use both interaural time difference (for low frequencies) and the interaural intensity difference (for high frequencies)
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What are Monoaural cues?
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Cues from one ear
Pinna affects the intensity of frequencies |
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Explain how the Pinna helps localize sounds
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sounds bounces around fold of the ear
Waveforms different by elevation |
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What is the tone chroma?
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Similarity of all the tones that share the same name
Pitch Class |
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What is the tone height?
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increase in pitch with an increase in frequency.
Each successive tone height= 1 octave Octaves double in frequency |
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What influences the Timbre of a sound?
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Fundamental Frequency
Harmonics Overtones Missing Fundamental Simultaneous tone combinations |
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Explain Simultaneous tone combinations
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Consonant (simple ratio of tone frequency): pleasant sound
Dissonant (tones close together or not a simple ratio): unpleasant sound |
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Why can't harmonics fully explain timbre?
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Attack (beginning/build up of a tone)
Decay (sustained part before the final release of sound) |
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Explain auditory cues in relation to the Gestalt Laws.
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Our auditory system seems to use salient deatures
Illusionary contours= Missing fundamental Common region: a single sound source tends to come from one location. Similarity: of pitch and timbre: similar sounds are generally grouped together Good Continuation: Sounds that stay constant or change smoothly are usually from the same source |
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Explain the two properties of acoustics
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Direct Sound: reaches ears straight from the source.
Indirect sound: reflected off environmental surfaces |
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Explain architectural acoustics.
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Factors that affect perception in concert halls.
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What is reverberation time?
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The amount and duration of indirect sound produced by a room.
2 second= the perfect acoustics? |
