weeks 4.1 to 5.2 Flashcards
closure vs. release/burst (types of stops)
closure: fully blocking airflow at a point of constriction to build up air pressure (shown as a period of silence on the waveform and spectrogram)
release/burst: release the constriction to let the air out (shown as a spike on the waveform and spectrogram)
fricatives
formed by friction; air passing through a tight pathway (constriction) in the oral cavity
aspirated vs. unaspirated stop (p example)
aspirated: [p^h] as in “pet”
unaspirated: [p] as in “spin”
voice onset time (VOT)
a quantitative measure for stop consonants; the duration (in milliseconds) between the stop burst/release and the beginning of voicing (vocal fold vibration)
VOT positive versus negative numbers
0 or negative = voiced
positive = voiceless
phonology and phonetics
phonology: patterning and sequencing of sounds
phonetics: physical properties of sounds (i.e., IPA)
broca’s area region and Brodmann area
left inferior frontal gyrus; Brodmann area 44/45
wernicke’s area region and Brodmann area
left posterior superior temporal gyrus; Brodmann area 22
Broca’s area
first discovered by Paul Broca in 1861 in aphasic patients; language production, both linguistic and non-linguistic rule learning, processing of syntactic structure, abstract sequence processing
BA44 versus BA45 (Broca’s area)
BA44: pars Opercularis; for structure/syntactic processing (i.e., noun-verb agreement)
BA45: pars Triangularis; for semantic processing (i.e., extra verbs)
Wernicke’s area
discovered by Carl Wernicke in 1874 in aphasic patients; language comprehension, reading and visual word recognition, speech perception, pre-articulatory phonological retrieval
arcuate fasciculus (AF)
the connection between Broca’s and Wernicke’s area; crucial in relaying information in both comprehension and production (in dorsal (up) stream)
damage to the arcuate fasciculus
possible difficulties in reading aloud or repeating sentences
diffusion tensor imaging (DTI)
fiber tracking of arcuate fasciculus; diffusion of water molecules in white matter
Wernicke-Geschwind model
based on the assumption of left-hemisphere dominance in language processing; ignores the role of right-hemisphere in language processing (i.e., prosody/rhythm processing); actual language network is more distributed than this model (!)
basal ganglia
motor function, control articulation, produce sequences of sounds and words (sentences)
interpreting fMRI results
a contrast between two conditions (seen in colored blobs on the brain); condition A shows larger activation in X region than condition B
interpreting EEG results
neural response to a stimulus (waveforms); timing and effect size of the cognitive event (ERP)
ERP naming conventions (P, N, number)
P: positive
N: negative
number: either the latency (the duration from the stimulus onset to the peak of the ERP) or the peak order
ERPs (N400 and P600)
N400 (semantic anomaly): a negative-going waveform peaked at 400ms after stimulus onset
P600 (syntactic anomaly): a positive-going waveform peaked at 600ms after stimulus onset
mismatch negativity (ERP)
a negative waveform peaked at ~200ms post-stimulus onset; shows sensitivity to small frequency change
Broca’s vs. Wernicke’s aphasia
Broca’s (non-fluent): impaired fluent speech production; agrammatism (sentence construction deficit, content words preserved more than function words, impaired parsing of complex sentences)
Wernicke’s (fluent/jargon): impaired comprehension; production OK; word-finding difficulties; content-word substitutions; made-up words (neologism)
conduction aphasia (and short-term memory conduction aphasia)
conduction: damage to the arcuate fasciculus; impaired repetition but comprehension OK
STM: impaired auditory short-term memory
evidence from Goschke et al. (2001)
evidence of sequential learning (experiment 1); intact motor sequence learning, but domain-specific (auditory) impairment in Broca’s aphasics (experiment 2)
