Theme 3A Flashcards
Name and explain how the 3 scripts represent speach
o Universal for becoming literate
o Logographic scripts
o Alphabetec scripts
Universal for becoming literate: learning how the visual symbols of a script represent speech
Logographic scripts: representation at level of meaningful units (morphemes)
Alphabetic scripts: representation at abstract level of speech sounds (phonemes), represented by letters (graphemes)
Letter-sound mappings & reading (2 steps)
1: Learning the speech sounds (phonemes) in a word
2: Learning the mappings between phonemes and letter symbols
Letter-sound mappings & dyslexia (3 steps)
Chicken or egg?
- Impaired phonological processing
- Impaired learning of letter-speech sound mappings
- Reading deficit
Evolutionary brain for reading?
Basic code for reading?
Brain not evolutionary shaped to learn to read -Basic code for reading (letter/sound mappings) is not intuitive, nor universal
Neuronal recycling hypothesis question + answer of Dehaene & Cohen
- Letters/number symbols activate very consistent parts of visual cortex
- How is this possible, if there are no hardwired mechanisms?
Dehaene & Cohen (2007):
•Cultural inventions (literacy) partially “recycle” evolutionary older brain circuits
•Recycled brain circuits have been evolutionarily shaped to process similar information > e.g. visual shape processing / discriminating small shapes
Neuronal recycling hypothesis: recycling
Recycling: reading is constrained by preexisting brain architectures for language and vision
How does literacy change the brain?
Reading interacts with naturally evolved brain mechanisms:
•Visual shape recognition: “invaded” by letter symbols
•Speech processing and audiovisual integration: become fine-tuned by learning letters & letter-sound mappings
•Literacy increases ability to isolate and use phonemes (speech sounds) > phonemic awareness
•Literates vs. illiterates: increased phonemic awareness in literates
•Example Elias: from ELS to ELIAS is the step of acquiring phonemic awareness
How does literacy change the brain? Visual cortex:
Gains and losses in the Visual Word Form Area
•Literates (LB1/LB2/LP), illiterates (ILB)
•Literacy: stronger responses to written words, but weaker responses to faces/houses > competition
(How) does literacy change the brain? Auditory cortex: speech sound processing
- Stronger activation to speech in Platum Temporale
* Probably related to improved speech processing at behavioral level (phoneme awareness)
(How does literacy change speech sound processing?)
Is this a different process in transparent vs. opaque orthographies?
- Transforming speech sound processing by literacy should be adaptive;
- Flexible to accommodate the differences in how symbols are mapped to sounds and meanings
Modulation of speech processing by letters depends on orthography ENG vs NL
Dutch readers:
•Modulation of speech processing in auditory cortex (superior temporal cortex, STC)
•Depending on learned letter-sound (LS) congruency & individual development
English readers:
•Do not learn reliable LS mappings > how is speech processing in STC modulated by letters?
Speech processing system is transformed during reading acqusition:
- Response to speech sounds modulated when presented in letter-sound pairs
- Modulation depends on learned associations > effect of education
Precise tuning of letter-speech processing in STC during reading acquisition adaptive to:
- Individual differences (reading skills; dyslexia)
* Orthography (tuning to regular mappings)
Literacy is constrained by the brain:
Learning LS associations does not connect well to natural phonological processing > extra attention to e.g. phoneme awareness
Literacy changes brain function:
- Visual cortex (VWFA): universal, gains as well as losses
- Auditory/speech processing: STC tunes to learned LS associations; depending on language and development
