Cracking the Orthographic code

What is word superiority effect

evidence that letters are recognised more easily in words than in isolation

Letters in words are recognised more … than in word contexts than either pseudo-word contexts or when presented in isolation

more accurately

What is the Reicher-Wheeler task

• provides clear evidence for the word superiority effect

• stimulus is displayed briefly then masked, after which the participants make a forced choice between two options for a specific letter display

  • letters are identified more accurately in word than non-word displays or when presented alone

    • evidence that word context facilitates letter recognition

What is the Interactive Activation model (McClelland & Rumelhart, 1981)

provides mechanisms for both bottom-up and top-down influences on letter recognition

• bottom-up input provides one source for letter identification

  • but input is brief and masked, so its degraded

• top-down evidence from lexical level when the letter appears in a real word provides a further source

  • these two sources combined provides stronger evidence for letter identification than one source alone - hence the effect

What is the lexical frequency effect

evidence that words are encoded in terms of frequency of exposure

What indicates that the brain keeps track of of word exposure statistics

that readers are quicker to recognise common words than rare words

What is orthographic neighbour effects

evidence that similarity between words, in terms of their letter composition, can affect reading

The IAM model includes the assumption that…

letter input will activate all words that share these letters in the same locations

• e.g. input like WAVE will activate WAKE, SAVE, and WIRE, etc.

• these words are called orthographic “neighbours” (only differ by one letter when word length and letter position are preserved)

Is there a faster response for words in a large neighbourhood or small neighbourhood

large neighbourhood

What are letter transportation effects

evidence for flexibility in the encoding of letter position information

What evidence supports flexible letter position encoding

priming studies show that words and non-words with transposed letters still facilitate recognition, indicating flexible letter position encoding

Give an example of priming of words in action

Andrews showed priming of words like “slat” by transposed letter counterparts like “salt: compared to control condition

What did Velan & Frost (2007) do

assessed reading of transposed text in English and Hebrew

What did Velan & Frost (2007) find

transposed text read easily in English but not in Hebrew

• semitic languages (Arabic, Hebrew) have a non-concatenative morphology (words formed by interleaving root with word pattern)

What must the word recognition system encode

both the identity and position of letters in words

• letter position appears to be encoded flexibly, so that misspelled words can be easily read as the correct word

Why does IAM model not allow for flexibility in misspelled words

assumes letters are encoded in set channels

• modern models based on IAM have introduced flexibility in letter position encoding

Letter position dyslexia provides evidence for difficulty in…

encoding letter position