L&C, W3 Flashcards
What is visual word recognition
• First stage in reading things > see letters on page + combine them to reach a meaning of the word
• A small set of symbols in combination makes up an infinite set of words. E.g. How many words can you make out of the 4 letters “C” “A” “T” “S”?
• What representations are used to access the mental lexicon? > mental lexicon = mental dictionary that contains information regarding a word’s meaning, pronunciation, syntactic characteristics (depending on age/language, usually have 60,000 to 70,000 words in mental lexicon)
- What are the units, calculated from the visual input, that are used to address the mental dictionary? Is it single letters? Grapheme (clusters)? Syllables? Morphemes? > essentially, when you see the word, what do you use from it (Visual input) to find the word in the mental lexicon
Q1. Are graphemes used to access visual words?
• The name grapheme is given to the letter or combination of letters that represents a phoneme. For example, the word ‘ghost’ contains five letters and four graphemes (‘gh,’ ‘o,’ ‘s,’ and ‘t’), representing four phonemes.
• Graphemes are letters and letter groups that correspond to one sound (phoneme). Hence, they act as a ‘functional bridge’ between phonology (sound of word) and orthography (conventional spelling of word).
• Bread has 4 graphemes: B R EA D = 4
So do you use EACH letter (5) to go to your mental lexicon and decide it is a word OR do you use the graphemes (4) to decide what word it is
Task detection: was the target letter present?
• Ppts were shown target letter A, ppts had to say very quickly when presented with a word whether there was an A in the word
• Ppt sees target letter (700ms), brief pause (1000 ms) and then the word is presented for only 33 ms (almost below conscious perception) > then mask + response
2 conditions: Condition 1: had the word BOARD, where OA is 1 grapheme. Condition 2: had the word BRASH where A is it on it’s own
Q1. Possible outcomes + results
• If graphemes ARE perceptual units: Finding A should take longer in the condition 1 aka BROAD than in condition 2 aka BRASH > this is because the OA will need to be split up within BROAD
• If there are no perceptual grapheme units, the time taken to find A in BROAD and BRASH should be equal > this is because there is not a grapheme to split up
Are grapheme access units to the lexicon?
• The result shows that multi-letter graphemes aka OA in BOARD took longer than the single target letter A in BRASH to be detected
• Graphemes are processed as perceptual reading units > to get to the A in BOARD you need to break apart OA
Q2. Are morphemes access units in reading?
• Morphemes are the smallest meaningful unit of a language
○ can be a word itself (e.g. deck) or part of a word (de-brief)
○ morpheme – roots and affixes (prefixes & suffixes)
○ “unreal” has two morphemes “un” (prefix -word/letter placed before another) and “real” (root - the main meaning of the word)
- “teaspoon” has two morphemes “tea” and “spoon” > each has individual meaning, no prefix + root > Do we read “unreal” / “teaspoon” as a single word, or through its parts “un”+”real” / “tea” + “spoon”?
• Pseudo-affix words are words which look like an affix but they are not actually one
• “swing”? Is this “sw” + “ing” > running + carrying are an affix but swing is not because sw on it’s own is not meaningful
• “seed” vs. “look” + “ed”
“deter” vs. “de” + “press” > de = pre-fix and press = root but this is not the case with deter because ter is not a verb
Task: primed lexical decision (Lima & Pollatsek, 1983)
• Ppts are shown letters on a screen + they have to decide whether the presented letters are a real word or random letters > they were also primed so they could have been primed with TEA for 90 ms then show teaspoon + they say whether teaspoon is a real word OR they would be primed with TEA but shown TEGSPOON + they say whether tegspoon is a real word or not > You then measure reaction time and accuracy
• 3 conditions (if the prime overlaps w/ the target, you should recognise the target faster, more overlap = more fast)
○ Condition 1: prime was TE + target was teaspoon
○ Condition 2: prime was TEA + target was teaspoon
Condition 3: prime was TEASP + target was teaspoon
Q2. Possible outcomes + results
Possible outcomes:
• If morphemes are not access units + the most important thing was how much of the prime overlaps with the target, then condition 3 would have the quickest response, then 2 then 1.
• If morphemes are access units, then condition 2 (tea) corresponds to a morpheme in the target word (teaspoon) > shared unit so response would be faster > 2 would be faster than 3 and 1
Results
• When presented with TEA (c2) before seeing teaspoon + saying whether it was a real word > results show that ppts were both faster at saying teaspoon was a real word when primed with the morpheme and they had made less errors compared to the other conditions
• This happens even though there is less overlap compared to C3 which suggests we do not see the word as one whole but access in terms of morphemes
Therefore, morphemes are also access units to the mental lexicon
What about pseudo-affixes?
• Rastle et al (2004) > the broth in my brother’s brothel study > looked at pseudo-suffixes + compared processing of pseudo-affixes compared to another word which is not a pseudo-suffix but controlled for by length etc
○ Corner = pseudo-suffix because corn = stand alone word and er = usually used like farmer but a corner does not corn, it is the corner of something (corner of room)
○ Brothel = not a pseudo-suffix because broth = stand alone word but el is not usually used (don’y usually have “el” at the end of things”
• First showed corner or brothel as a prime, then they saw corn or broth then say whether it is a real word or not
Possible outcomes:
• If pseudo-affixes are not seen as separate units (corn + er) then the priming+ RT should be comparable between both conditions (corner + brothel) > don’t split corner into corn + er because then you would react faster to corn
• If pseudo-affixes are used to divide words then you would expect greater priming for corner than brothel due to the above
Result
• Results show this is the case, RT is faster for the pseudo-suffix than the non pseudo-suffix
This means that both suffixes and pseudo-suffixes are extracted as access units early in word recognition
Q3. Are letters processed at the same time (parallel) or one at a time (serial) during word recognition?
• Usually the longer the word is, the longer it takes to recognise the word > this is expected if you process the letters one at a time. > long word = long RT and short word = short RT
• However, if words are processed in parallel, all at once, then the RT to recognise a long word should equal to a short word’s RT
Task: reading aloud/word-naming
• Present a word, and you pronounce it out loud as quickly as possible + measure onset RT (as soon as you begin speaking, this is the RT + accuracy is considered)
The word presented can either be a non-word (sep, snutch), low frequency word (cot, crunch) or high frequency word (box, branch)
q3. Results
• Found that the more letters a non-word has, the longer it takes to pronounce that word
• High frequency words (words occurring often) showed that ppts consistently responded fast regardless of length
• Low frequency words were a bit longer than high but shorter than non-word RT, there was only a slight factor of length but this was weak
○ No word length effect for HF word
○ Weak word length effect for LF words
○ Strong word length effect for non-words
• There is a strong word length effect for non-words because these words do not exist in your mental lexicon, so you need serial grapheme-phoneme conversion (coverts letter-by-letter into sound > more letters = more time needed)
• LF words showed a weak effect but it’s not clear whether this is due to word length, could just be that long LF words have fewer similar looking words so there is less “help” from them (neighbourhood effect)
• So it is not clear whether there is a length effect for LF words
• If reading proceeds letter-by-letter, we expect to see a length effect for BOTH LF and HF words.
This means that letters must be processed in parallel > to some extent because eye-tracking research shows people use the first letters most then the last letters + middle letter in the word matter least
Q4. Are words that share letters activated during the search of a target?
• When you look for a word, will you activate words which look similar to the target?
• Evidence suggests that during recognition, we do not activate just one word (target), but a set of words which are similar looking > this is called Colheart’s N: orthographic neighbourhood of a word = how many other words overlap w/ the letters in the target word
• The words which activate together are those which are coded in a similar way aka words which share similar letters or syllables
- If we use form-based priming or orthographic priming and we present a non-word like LOUP before presenting target word LOUD, will ppts be quicker to detect the word LOUD? (because the similar form + overlap is meant to pre-activate loud)
Task: four field mask priming + results
• First you see a mask, then a prime very quickly for 15ms, then the target for 35ms + you have to say whether the target is an existing word or not
• The prime is usually in a different case (lowercase vs uppercase) than the target, this may be because we pay more attention to things in uppercase than lowercase? More attention-grabbing
• So prime is loup (lowercase) and target is LOUD (uppercase) > is the word in uppercase real?
Results:
• Results showed that when you presented loud as a prime and LOUD as the target, you got the maximum priming effect + max accuracy in this condition
• When presenting a similar form, loup (prime) and LOUD (target) > you still get priming but it is not as strong as the condition where prime + target were the same (Bit less strong) > better than control condition where there is no overlap
• Control condition where prime was ship and target was LOUD, there was much less priming
• So a prime that shares letters with the target leads to faster recognition > this is true for words AND non-word primes
• Words that share letters are connected in the lexicon but this is negatively > if a prime is consciously recognised + it IS a word, then you will slower to react to a similar word (e.g. proud and loud)
• But if the prime is a non-word like loup, then there is facilitation > faster to recognise loud
Q5. How does information flow in the system? Are there feedback connections between letters + words?
Task: letter detection task
• Ppts were shown were shown a fixation point first then 1 of 3 conditions
○ Condition 1: word condition > shown an existing word like work
○ Condition 2: non-word condition > RWOK
○ Condition 3: single word condition > K
• Task is to say what was the last letter you saw > was it K or D?
The words shown and options given (k and d) make up a word (work and word) > was there a k or not?
Q5. Results
• Results show that there was better performance for detecting the letter in a word vs a non-word > they are even better at detecting letters in a word than when a letter is by itself
This suggests that info from the word helps letter identification > there is some kind of feedback from the word level to the letter level > this is the word superiority effect
How do models of word recognition differ?
Two key dimensions of difference
• How are words searched in the mental lexicon
○ Word entries are searched one at a time (in a series or serially)
○ Word entries are searched all at once (in parallel).
• How does information flow?
○ Strictly one way: letters ® words (bottom-up, left to right)
Interactive: letters « words. (can feedback)