Lecture 2 - Phonological Development Flashcards
Why should we care about language development?
- Fascinating = complexity of human development
- Important: practitioners can help diagnose difficulties in disorders and there is an impact beyond psychology
Define Language
- System of symbols and rules that enable us to communicate
How do infants learn languages?
- Listening
What are problems when learning a language?
- Segmentation: speech is continuous not broken up
- Lack of invariance: Different signals should be perceived as the same sound
- Speaker Variability: Each speaker sounds a bit different
What is sound?
Waves of increasing/decreasing in air pressure
How is speech turned into a spectrogram?
- Caused by waves of many diff frequencies
- Each has its own energy level
- Ear decomposes the sound wave into frequency & energy
- Can see this through a spectrogram
How is lack of segmentation seen on a spectrogram?
- Boundaries are not clear
How is lack of invariance seen on a spectrogram?
The same sounds have different patterns
What are darker areas on a spectrogram?
- Higher energy areas
How do adult listeners make sense of adult speech?
- Despite speech being continuous, listeners perceive it as discrete sounds
- Each language has phonemes & listeners perceive phonemes through phoneme identification tasks
What is Voice Onset Time
- Delay between the start of a speech sound and the vibration of the vocal cords
What does word bias do? (Phoneme identification)
- Phoneme identification helps adults make sense out of speech
What is phoneme restoration?
- Phoneme replaced by something and you replace it with a phoneme you expect to hear
E.g cough covers up word, use context to make word fit in sentence
What are the three types of infant phoneme recollection?
- High amplitude sucking: younger children = suck more if they recognise
- Head turn preference
- Preferential looking
What is a study that shows newborn language discrimination?
- Their language vs others
- Babies were read stories and were either French/American
- French babies could discriminate French vs Russian but not English vs Italian
- American babies could discriminate between English vs Italian but not between French vs Russian
What are prenatal language perceptions?
- 4 Months before birth
- Low frequencies
- Rhythms and prosody (not phonemes)
Phoneme perception in adulthood
- Adults are not good at recognising phonemes we do not hear around us
- Babies can differentiate between them
What are the perception of phonemes as we grow up?
- In adults = non-native phonetic discrimination is very difficult
- As we grow = native phonetic contrasts increase
What is neural plasticity?
- Humans are born early in development = allows for tuning/shaping of neural circuitry in interaction with the environment e.g ability to recognise faces and vowels
What is neural commitment?
- Initial native language learning = neural commitment
- Brain across development = more specialised and more committed to native language
What is the brain shape graph
- Synapses go up, and then are pruned as we specialise in language
- Seen in cortical specialisation between seeing/hearing to receptive language speech production e.g Early deprivation of sight = problems later on in life & long-term consequences
- Higher cognitive functions occur later
- brain is hierarchical
