Cogs 101a- Lectures 13-16 2 Flashcards
** What are the three components to the somatosensory system?
Proprioception, Kinesthesis, Cutaneous senses
** What is proprioception?
It is the ability to sense the POSITION of the body and the limbs. (is our perception of our bodies caused by feedback from the skin, muscles and joints.)
** What is kinesthesis?
It is the ability to sense MOVEMENT in the body and limbs.(tracking of our body as it is in motion)
**What is cutaneous senses?
It is the perception of touch and pain from stimulation of the skin.
Who is Ian Waterman and what is unique about him?
- No sensory input from the PROPRIOCEPTORS in his muscles and joints.
- No information from the MECHANORECEPTORS in his skin that would respond to physical objects in his environment.
How did Ian Waterman cope with his condition?
able to compensate by using his VISUAL INFORMATION to update his brain on his body’s positon. – This shows underlying multimodal nature or proprioception
What is proprioceptors?
When information is sent to the spinal cord and brain from the golgi tendon organ and muscle spindles.
What are the 4 mechanoreceptors listed in lecture?
Merkel receptors, meissner corpuscles, ruffini cylinders and pacinian corpuscles
What does the Merkle receptor in charge of?
Fine detail
What does the meissner corpuscles in charge of?
Handgrip
What is the ruffini cylinders in charge of?
stretching
What is the pacinian corpuscles in charge of?
rapid vibration, fine texture.
What are the two types of mechanoreceptors located CLOSE to the surface of the skin? What do they have in common?
Merkle and Meissner corpuscle. They both have SMALL response fields and HIGH acuity.
How does the merkle receptor fire?
It fires continuously while stimulus is present.
How does the meissner corpus receptor fire?
Fires only when a stimulus is first applied and when it is removed.
What are the two types of mechanoreceptors DEEPER in the skin and what do they have in common?
Ruffini cyliners and pacinian corpuscle. Both have a LARGE receptive field with LOW acuity
How does the ruffini cylinders fire?
Fires continuously
How does the pacinian corpuscle fire?
fires only when a stimulus is first applied and when it is removed.
What is the duplex theory of texture proposed by David Katz?
That two receptors acting together may be responsible for this process (Merkle and pacinian corpuscle) (spatial cues and temporal cues)
What are the two major pathways in the spinal cord?
Spinothamalic pathway and Medial lemniscal pathway
What is the spinothalamic pathway?
consist of small fibers that carry temperature and pain information.
What is the medial lemniscal pathway?
consist of large fibers that carry proprioceptive and touch information.
What do both pathways pass through?
The ventral posterolateral nucleus in the thalamus.
How are signals pass through(skin to cortex)
signals travel from the thalamus to somatosenory receiving area (S1) and the secondary receiving area (S2) in the parietal lobe.
What is homunculi?
Body maps
What has high acuity in the sensory homunculus
- Body area with high acuity have larger areas of cortical tissue
- Area with higher acuity also have smaller receptive fields on the skin
What is focal dystonia
when areas responsible for controlling a certain area is fused with the other area in the homunculus area
What is the Haptic perception, what are its three distinct systems?
The haptic perception is the active exploration of 3-D objects with the hands. It uses three distinct systems,
What EXPLORATORY PROCEDURES did Klatzky discovered that people use?
- Lateral motion
- pressure
- encolsure
- contour following
What does the monkey example of somatosensory demonstrate?
- As signals move forward from the mechanoreceptor they are more comples
- single cell recording show that some cells respond maximally to orientations of stimuli and direction and movement.
- neurons respond best to grasping specific objects
- paying attention to task increases firing rate of somatosensory cell
How similar are music and speech?
- Rule based systems
- require specific knowledge
- innate to humans
- composed of sequential events that extend in time
- involve the development of expectations over time
- results from the combination of the same types of frequency, amplitude and timbre combinations.
Is music and speech perceived the same way in the brain?
No
In the Van petten and Rehinfelder experiment what did they discover about the left and right ear?
The right ear (left hemisphere) has an advantage for speech sounds.
** What are steps 1 and 2 for producing a speech stimulus?
- Push air from the lungs with a certain force. (this will be the stimulus amplitude)
** What are steps 3 and 4 for producing a speech stimulus?
- Air then goes into vocal tract (mouth and nasal cavity)
How are vowel sounds produced? (articulators)
changing the shape of the vocal tract.
What in the vocal tract alters the resonance of the chamber?
articulators
What is formants?
The resonant frequency and produce peaks in pressure at a number of frequencies.
What are sound spectrograms?
measuring device that show changes in frequency and intensity for speech.
**What are step 5 and 6 of producing a speech stimulus
- Consonants are produced by a constriction of the vocal tract (using the articulators)
How is a consonant formed? (formant transitions)
producing constriction of the vocal tract
What is formant transition
Rapid changes in frequency preceding or following consonants.
What is the diagram of the speech stimulus (starting from the bottom up)
- Blow some air
What is a phoneme?
Smallest unit of PERCEIVED speech stimulus that changes meaning of a word.
What is the variability problem?
There is no simple correspondence between the acoustic signal (phones) and individual phonemes.
How do we deal with the variability problem?
Categorical perception
When does categorical perception occur?
When a ride range of acoustic cues result in the perception of a limited number of sound categories.
What is an example of categorical perception?
Voice onset time experiment.
What is voice onset time
time delay between when a sound starts and when voicing begins.
what is the mcGurk effect?
Person see’s a person say ga-ga, but hears ba-ba, he then answers that he heard da-da which is the midpoint between ga and ba
What did Rubin et al discover?
That we have an advantage for recognizing more meaningful stimuli. (people were quicker to answer with meaning then none bat vs baf)
What is the phonemic restoration effect?
Listeners could not correctly identify the position and they also did not notice that a phoneme was missing when they heard a sentence that had a phoneme covered by a cough. ( task was to state where in the sentence the cough occur)
** What is Binural, azimuth?
ITD interneural time difference(low frequencies)
** what is monural, elevation?
Spectral cues andHRTF - Head related transfer function
Why are we best at localizing sounds in front of us?
It appears that ITD and ILD azmuth cues are most effective to the sides, but we have difficulties detecting those on the cone of confusion.
Why is perception and active process?
perception is an active process because no single observation is used to localize a sound. We orient ITD and ILD infront of us.
**What are the two physiological representation of auditory space- (2 approaches)
Narrowly tuned ITD - specificity coding
In broadly tuned ITD where is sound indicated at?
Sound is indicated by the RATIO of responding to TWO TYPES of ITD neurons, left sensitive and right sensitive.
What is related to melody schema?
Effect of past experience (familiarity) . After people hear the normal melody they can hear the modified version and understand it compared to not listening to the normal melody.
What is a complex tone?
additive waveform of 200Hz
What does musical instruments share when they place the same tone (note?
Fundamental frequency
What will differ from the musical instruments?
The timbre (quality) of the tones will differ.
What can the basilar membrane be described as?
Acoustic prism
**What are the auditory grouping principles?
Onset time, location, similarity of timbre and pitch, proximity in time, auditory continuity, effect of past experience
** What is onset time?
sounds that start at different times are likely from difference sources.
** What is location?
A single sound source tends to come from one location and to move continuously
** What is similarity of timbre and pitch?
Similar sounds are grouped together (similarity)
**What is proximity in time?
Sounds that occur in rapid succession usually come from the same source (proximity)
** What is auditory continuity?
Sounds that stay constant or change smoothly are usually from the same source. ( good continuation)
** What is effect of past experience?
Deals with melody schema
**What is auditory stream segregation?
Grouping allows for auditory stream segregation, based of attribution of different qualities/dimensions to multiple sources.
What is the main structure of the inner ear? What sets it into vibration?
Cochlea, stapes
Where does transduction take place?
Transduction takes place by the cilia
What is the cilia?
Cilia is on the end of hair cells bending in response to the movement of organ of Corti and tectorial membrane.
In sending signals to the brain, the auditory nerve fibers synapse in a series of subcortical structures. What does “Co Nuc SON-IC MG- ARA” stand for?
Co Nuc- Cochlear nucleus
In the primary auditory cortex (A1), which is the first cortical region to receive auditory information ?
Temporal lobe
The auditory cortex is hierarchically organized, explain.
Neural signals travel through the core (including A1) then belt, followed by the parabelt area.
What causes activation to the core areas?
Simple sounds (pure tones)
What kind of tones preferentially cause activation to the Belt and parabelt areas?
They respond to more complex stimuli (tones, voices) made up of many frequencies.
**What is the “What pathway” and what is it responsible for?
What, aka ventral streams, begin in the anterior portion of the core and belt and extends to the prefrontal cortex. - It is responsible for identifying sounds.
**What is the “Where pathway” and what is it responsible for?
Where pathway aka dorsal stream, starts in the posterior core and belt and extends to the parietal and prefrontal corticies.- it is responsible for locating sound.
What do humans who have brain damage to the auditory cortex have difficulties with?
Pitch
What did Bendor & Wang (2005) do?
They recorded from cells just outside of A1 and found that they responded to COMPLEX TONES with the SAME FUNDAMENTAL FREQUENCY called PITCH NEURONS.
What is auditory space?
space that surrounds and observer and exsist wherever there are sound sources.
What three dimensions of auditory space are there?
Azimuth- Position left to right
People can localize sounds more accurately if…
sounds is directly infront of them
People can localize sounds less accurately if…
sounds is to the sides and behind their heads.
** What are the localization cues in Binaural (using both ears, left and right)?
ITD- Interaural time difference
** What are the localization cues in monaural (using one ear)
HRTF- Head related transfer function and spectral cues.
What is Interarual time difference (ITD)?
ITD is the difference between the times at which sounds reach the two ears.
Explain (ITD) point A, B and does this effect occure for low frequency tones?
Point A- When distance to each ear is the same and there are no differences in time.
What is Interaural level differences (ILD)
ILD it the difference in sound pressure reaching the two ears.
In ILD, when does reduction in intensity occur?
It occurs for high frequency sounds for the far ear.
What is an acoustic shadow in ILD, does ILD effect occur for low frequency sounds?
When there is high frequency, the head casts an acoustic shadow, blocking out (reflecting) and absorbing some of the ihgh frequency pressure waves.
Which between ILD and ITD is largest at locations farther to the side?
The Interaural level difference (ILD)
What are the ILD and ITD not effective of detecting?
The ILD and ITD are not effective of detecting the differences in elevation.
What does HRTF stand for and is it unique to each head?
Head related transfer function, it is unique to each head.
What is a spectral cue?
When information comes from the spectrum of frequencies. (measurements performed by placing small microphone in ears and comparing intensities of frequencies with those
What did the Hoffman study suggest?
The study stuggested that there might be two different sets of neurons- one for each set of spectral cues (new and old)
**In binaural, azimuth, interaural time difference (ITD) are useful for
(ITD) useful for low frequencies
** In binaural, azimuth, interaural level difference (ILD) are useful for
(ILD) useful for high frequencies
** In monaural, elevation are conected to
spectural cues and the head related transfer fuction (HRTF)
How do Binaural and Monaural work together?
Both work together effectively, but are mainly for orientating. In real applications, we move our heads and take many auditory samples with all localization cues.
What are two basic approaches have been proposed using ITD as a model
Narrowly tuned ITD neurons and Broadly tuned ITD neurons
What is narrowly tuned ITD neurons?
narrowly tuned ITD neurons responds to specific time differences only. One neuron gives location- form of SPECIFICITY CODING
What is broadly tuned ITD neurons?
Broadly tuned ITD neurons respond to broad range of time differences. Location is calculated from a range of neural responses. Form of distributed coding.
What ITD neuron did Jeffress Model look at?
Narrowly tuned ITD
What is the Jefress model for narrowly tuned ITD neurons? What is the coincidence detectors?
-Neurons receive signals from both ears,
Which sub cortical area responds to narrowly tuned ITD neurons?
Neurons in the inferior colliculus and superior olivary nuclei responds to a narrow range
What does ITD stand for
Inter-neural time differences
What is auditory scene?
the range of all sound sources in the environment
What is auditory scene analysis?
Process by which sound sources in the auditory scene are separated into individual perception - does not happen on cochlear, occurs in basilar membrane.
** What are the auditory grouping principles?
Onset time, Location, similarity of timbre and pitch, proximity in time, auditory continuity, effect of past experience (familiarity)—- OLSPAE (on love spae)
**What is onset time?
Sounds that start different times are likely to come from different sources ( recall visual synchrony)
**What is location?
A single sound source tends to come from one location and to move continuously.
**What is similarity of timbre and pitch?
Similar sounds are grouped together(flute trills belong to flute, trumpet blares belong to trumpets)
**What is unique about similarity of timbre and pitch?
Similarity of timbre and pitch allows us to perform auditory segregation
**What is auditory segregation?
based on attribution of different timbres or pitch to multiple sources
**What is proximity in time?
sounds that occur in rapid succession usually come from the same source
** what is auditory continuity?
Sounds that stay constant or change smoothly are usually from the same source.
** what is effect of past experience (familiarity)?
deals with melody schema
