NeuroScience of Lang Week 4 + Week 3

Sine-wave speech

pseudo speech (non-biological) that has some of the characteristics of actual speech

Fundamental frequency

Source Filter theory

source - air from lungs vibrates vocal folds

filter - vocal tract filters frequencies to pass through based on shape/vocal tract

Articulators

Formants

spectogram

Marler, 1990.

Swamp vs. Song sparrow and whether they can learn conspecific songs when

exposed during critical period

Vouloumanous et al., 2001.

Speech registers in unique brain regions but shares some regions

with sine-wave speech

Ramus et al., 2000

. Infants and cotton-top Tamarins prefer forward to backward speech.

Vouloumanous et al., 2010.

Neonates like human and Rhesus calls equally. They like both of these better than sine-wave speech. By 3 mos., they prefer human speech to Rhesus calls

Perceptual Magnet effect

or native-like sounds, whereby linguistic experience allows infants to group native language phonemic variants as more similar than non-native phonemic variants

Native Language Neural Commitment Hypothesis

the brains early coding of language effects our subsequent abilities to learn phonetic structure of a new language

• synaptic pruning - loss of excess neural synapses as brain matures to increase network efficiency from infancy to childhood to adolescence (too little pruning is correlated with ASD and epilepsy, too much pruning linked to associated with schizophrenia)

Kuhl and Miller - 1975

/ba/ /ga/ /da/ sound accompanied by electric shock on side with water, chinchillas would run away if they heard the sound accompanied by the shock

• animals can categorize sounds by VOT same as humans

Best Mcroberts and Sithole (1998)

tested infant perception of Zulu clicks - theorizing that categorical perception is not only influenced by meaning but also by phonlogical category

3 experiments:

• adults - discriminated above chance

• infants - above chance discrimination

• acoustic controls

adults retain ability to differentiate non native sounds that cannot be mapped onto out language

Evidence speech as a domain general ability

• neural responses for categorizing/discriminating non speech sounds is extremely similar to speech sounds

• animals have categorical perception for speech (kuhl and Miller 1975)

universal selection theory

• prenatal - babies are born universal listeners (developed in utero)

• postnatal - maintenance loss theory - maintain sound distinctions relevant to lannguage(s) and lose irrelevant distinctions

Perceptual learning theory

babies are born “blank slate”

• prenatal - undeveloped

• postnatal - sounds are learned entirely through postnatal exposure which shapes abilities

attachment theory

“fine tuning”

• prenatal - partial development abilities (sound contrasts)

• postnatal - experiences facilitate abilites like stress detection, maintaining contrasts, or loss of irrelevant contrasts

perceptual magnet hypothesis

how ambient language experience (sounds used in environment) changes infants perception of phonetic categories

• Phase 1: infants differentiate all speech sounds

• Phase 2: environment of sound warps perception

• phase 3: native phonetic abilites can be strengthened

start state

• babies like listening to mothers voice

• babies remember stories read in the womb

• like listening to language heard in the womb

articulators

formant

distinctive