Multimodal SP
Neuroanatomy of SP
Categorical SP
Methods in SP
SP Potpourri
100
In the audio-visual perception experiment you see a person articulating /ga/ while you hear an auditory /ba/. What sound are you most likely to perceive?
You are most likely to perceive /da/ as a fusion version between the auditory and visual stimuli. This phenomenon is known as 'McGurk Effect'
100
What is dual stream processing?
Dual stream processing refers to two simultaneous neuroanatomical paths in speech perception. The first path is ventral pathway. The ventral pathway converts phonological representations to the lexical representations. The dorsal pathway takes the sensory or phonological stimuli and transfer them into an articulatory-motor representations
100
Chinchillas respond to abrupt changes on the voice onset timing continuum at precisely the place where many languages separate two phonemic categories. These findings present a challenge to one of the major pillars of motor theory. Which one?
Speech is processed by a specialized speech-processing module in humans
100
Why are Event Related Potentials (ERPs) used in speech perception testing?
ERPs provide information about timing of the brain events that happen after stimulus onset and before a behavioral response. ERPs allow direct correlations between the brain measures and behavior that reflect processing in time at the millisecond level
100
Cochlear implantation does not provide optimum hearing for all implantees. Name the 3 factors that predispose implantees optimum hearing.
1. Young age (less than 3YOA) 2. Shorter period of deprivation 3. Rich and early sensory and linguistic experience
200
In an aero-tactile identification test, a subject hears 50 /ba/-stimuli and 50 /pa/-stimuli, presented in noise in a random order. Half % of the time, each stimulus is presented with a puff air (duration of puff is roughly corresponding to VOT of the /p/ in /pa/) applied to their neck. Discuss two conditions that will yield the highest accuracy in the subject's responses
/ba/ with no puff and /pa/ with a puff will generate highest accuracy since the brain effectively integrates the auditory information with the supplemental tactile information
200
BACKWARDS QUESTIONS In conduction aphasics this fibrous connector is said to be damaged. The speech task is known to be particularly difficult.
What is arcuate fasciculus. What is speech repetition
200
What is the main principle of the categorical perception?
Listeners can only discriminate between sounds that they would identify as belonging to different categories
200
What is the experimental paradigm most often used in ERP studies of speech perception? Describe the stimuli and what to look for in the brain wave.
Oddball paradigm is one of the most widely used approaches the in ERP sudies. Oddball train consists of the 80% standard stimuli (repetitive ones) and 20% of deviant stimuli: S S S S D S S S S D S S S S. Negative deflection of the ERP to the deviant stimulus compared to the standard is known as mismatch negativity (MMN). Auditory MMN occurs ~150-250 ms after the onset of the deviant stimulus.
200
From the perspective of SP, why do L2 speakers have an accent?
Due to the complex interaction between L1 and L2 phonology, L2 speakers have an 'accent' when listening to the foreign speech
300
What benefit for speech perception can be provided by the audio-visual (AV) speech in children with cochlear implants compared to the auditory-only speech?
AV speech improves accuracy of speech perception. A few years after implantation children's performance on a battery of speech perception tests is significantly higher in AV-condition than in the auditory-only condition
300
What methods can be used to study frequency perception in the cochlea, brainstem, and cortex?
The methods that can be used to study frequency processing in cochea. brainstem and cortex are otoacoustic emissions, ABR and ERP, correspondingly
300
In categorical perception of consonants, at what point on the discrimination function graph, is there a drastic change and why?
The discrimination function shows a peak in accuracy at the boundary between categories, with performance at or near chance within category
300
What do evoked potential waveforms show? What are the things to look for in the ERP waveform?
Evoked potential waveforms reflect changes in brain activity over time during stimulus processing. Such changes are reflected in the amplitude (μV height of the wave at different points) or in the latency (time lapsed in milliseconds – ms – since stimulus onset) of certain peaks within the ERP
300
What are the three main claims that the motor theory of speech perception makes?
1. Speech perception is perceived via a specialized module in the brain. 2. Listeners perceive intended articulatory gestures. 3. Speech perception is driven by speech production.
400
What can be said about the audio-visual speech perception in the autistic children?
Autistic children are worse at lipreading than TD indicating deficit in audiovisual integration. They benefit less from the addition of visual information to the auditory-only condition compared to TD age-matched controls.
400
What are mirror neurons? What can be said about their distribution in the left and right hemispheres?
A mirror neuron is a neuron that fires both when we produce speech ourselves and when we observe speech being produced by someone else. The right hemisphere has only visual mirror neurons, the left hemisphere has both, auditory and visual motor neurons
400
Why would you have categorical perception (CP)? Example of clinical population with affected CP
Allows listeners to “ignore” irrelevant variations in speech signal, e.g. individual differences in the exemplars of the same phoneme. E.g, SLI show lower peak discrimination values. CP is weaker in children affected by dyslexia
400
How can transcranial magentic stimulation be used to study speech perception? Where is the stimulation applied to?
There are two approaches: (1) Using TMS to temporary disrupt speech perception (2) Using TMS to measure motor excitability during speech perception? In both approaches, TMS is applied over the motor cortex.
400
BACKWARDS QUESTION! Single category assimilation, Category Goodness, Two-category discrimination
What are the three possible possible patterns of foreign sound discrimination according to Perceptual Assimilation Model
500
How does AV speech help second language learners? Example?
AV speech helps L2 learners discriminate contrasts that are challenging in the auditory only condition. Example: Adding visual speech to the auditory speech helps Spanish speakers discriminate /ɛ/-/e/ contrast in Catalan
500
In the dichotic listening experiment, describe the ascending path from the left ear to the Heschel's gyrus
L cochlea ->L cochlear nuclei ->L superior olivary complex in the brainstem --> CROSSING TO THE RIGHT SIDE R inferior colliculus in the midbrain ->thalamus (R medial geniculate body-->R Heschl's gyrus -> Corpus Callosum -> CROSSING TO THE LEFT SIDE L language centers in the left hemispheres
500
What do we mean by 'CATEGORIAL' discrimination (CD)? Give an example
CD is a task that require listens ignore irrelevant acoustic differences in the target language, while responding on the basis of the acoustic differences that differentiate the phonetic categories in L2. CD require phonetic processing of the stimuli rather than only the detection of acoustic differences. EXAMPLE. ba(speaker -1) vs ba (speaker -2)
500
What change in MMN latency can be expected when discriminating between pairs of speech sounds crossing a phonemic boundary rather than pairs of speech sounds within a phonemic category?
The MMN will occur earlier for a pair of speech sounds crossing a phonemic boundary when compared with a pair of speech sounds within a phonemic boundary.
500
What is tonotopic organizastion and what parts of the auditory system are tonotopically organized?
Tonotopy in the auditory system begins at the cochlea. Nerves that transmit information from different regions of the basilar membrane encode frequency tonotopically. This tonotopy then projects through the auditory nerve and associated midbrain structures to the primary auditory cortex
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