Transcript The role of phonology in visual word recognition and reading

The role of phonology in visual
word recognition and reading
Marc Brysbaert
Reading silently
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Recent skill (not before IX century;
may require spaces between words)
Takes some time in the development
(children first read aloud; also high
degree of learning problems and
failure, certainly in English)
Reading silently (cont.)
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Silent reading goes faster than
reading aloud (250-300 words per
minute, depending on reader, text,
and goal)
People remember more after silent
reading than after reading aloud.
Once mastered very powerful skill,
because then reading becomes
automatic (cf. Stroop effect)
Reading silently (cont.)
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Not purely based on visual
information
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inner voice
phonological loop in working memory
errors in proofreading particularly
frequent for homophones and mute
letters
tongue-twister effect (e.g., “Boris
burned the brown bread badly.”). Also
in Chinese (Zhang & Perfetti, 1993)
Addressed phonology vs. assembled
phonology
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Given that phonological coding plays an
important part in reading, where does
the coding take place: before or after
the word is recognised?
Originally (1970s) many researchers
thought “before” (implicit speech in
reading)
Gradually, shift to “after” or “a
combination”.
Addressed phonology vs. assembled
phonology
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Important element: the development
of the dual-route theory (Coltheart,
1978, 1993, 2001)
Latest version: the DRC-model
(Coltheart et al., 2001)
DRC
print
Feature
Representations
Letter
Representations
Semantic
Representations
Orthographic
Lexicon
Phonological
Lexicon
Phoneme
Representations
speech
Rule-Based
Translation
Addressed phonology vs. assembled
phonology
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DRC = a weak phonological theory
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bulk of visual word recognition is
orthographically based
GPC-route is slow and serial (from the word
beginning to the word end)
GPC-route activates the wrong phonology for
irregular words (e.g., “pint”)
The position of irregularity effect (e.g.,
Roberts et al., 2003: more difference in
naming times between “bind” and “bluff”
(2nd position) than between “beige” and
“bless” (3rd position)
Addressed phonology vs. assembled
phonology
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Addressed phonology = phonology
activated on the basis of word
representations in the orthographic
lexicon
Assembled phonology = phonology
activated on the basis of direct lettersound correspondences (graphemephoneme conversions)
Evidence for the importance of phonology
in isolated visual word recognition
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Rubenstein et al. (1971): it takes longer
to reject a pseudohomophone (“brane”)
in a lexical decision task
Van Orden (1987): many false alarms
with homophones in semantic decision
(e.g., “rows” is a flower), in particular
with brief presentation duration
(prevents spelling check)
Evidence for the importance of phonology
in isolated visual word recognition
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Lesch & Pollatsek (1993): it takes longer
to decide that “sand-beech” are
unrelated than that “sand-bench” are
unrelated
Same finding with “pillow-bead”
Evidence for the importance of assembled
phonology in visual word recognition
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Many of the findings thus far might be
explained on the basis of addressed
phonology.
If we want to show the importance of
assembled phonology, we have to work
with non-words, that do not have a
lexical representation
Perfetti & Bell (1991): masked priming
Perfetti & Bell (1991)
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three types of primes for target RATE:
rait (pseudohomophone), ralt
(graphemic control), busk (unrelated
control)
Procedure:
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prime in lower case (25, 35, 45, 55, or 65
ms)
TARGET in upper case (30 ms)
XXXXXX mask
task = perceptual identification “which word
was presented in capitals?”
Perfetti & Bell (1991)
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Findings:
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Phonological priming is possible with
pseudohomophones; so, it is non-lexical (i.e.,
assembled phonology)
It takes some time before the phonological
code is computed (45 ms)
Ferrand & Grainger (1994)
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A further look at the time course of
phonological activation and see whether
this is the same for orthographic
information
French language: has many
homophones, that can be written
differently
mert-MERE vs. mair-MERE vs. toul-MERE
Ferrand & Grainger (1994)
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Procedure:
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###### (500 ms)
prime (14, 29, 43, 57 ms)
TARGET (until lexical decision)
Lexical decision is better than perceptual
identification, because a more on-line
task
orthographic priming: mert vs. mair
phonological priming: mair vs. toul
Brysbaert (2001)
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To show that phonological priming is
automatic, you have to create conditions
where the use of the phonological code is
negative
Procedure of Perfetti & Bell (1991) with
perceptual identification; 43 ms prime
Two conditions with 60% fillers for which
the targets were either preceded by
pseudohomophonic primes (ieb-IEP) or
by pseudohomophones of another word
(gad-IEP)
Lukatela & Turvey (1994)
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Phonological priming is not limited to
form priming, you also find it for
associative priming
Prime duration 50 ms, word naming
toad-FROG = towed-FROG = tode-FROG
< tolled-FROG or tord-FROG
Drieghe & Brysbaert, 2002
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First replicated Lukatela & Turvey (57 ms)
Drieghe & Brysbaert, 2002
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Extended it to LDT (57 ms)
Drieghe & Brysbaert, 2002
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LDT( 258 ms)
Strong phonological theories
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“. . .we take the primary and initial source
of lexical activation in English to be
phonological. The role of orthographic
codes is then taken to be that of refining
the lexical activation begun by phonology”
(Lukatela & Turvey, 1994a, p. 108).
Strong phonological theories (cont.)
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“Over the last two decades, a number of
studies using brief-stimulus-presentation
and masked-stimulus-presentation
paradigms have reported phonological
effects in visual word identification. . ..
These effects have been taken as major
evidence for a rapid, automatic, and
obligatory phonological process during
lexical access.” (Xu & Perfetti, 1999, p.
26).
Strong phonological theories (cont.)
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“The consistent evidence for phonological
computation, its role in lexical access when
the minimality constraint is taken into
account, the manner in which phonology is
assembled from print and shaped into a
detailed representation, and the basic role of
phonological structures in conveying meaning
all suggest that the role of phonology is more
important than dual-route models have
assumed.” (Frost, 1998, p.95)
Strong phonological theories
(cont.)
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Brysbaert (2001)
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“Now that the existence of mandatory
prelexical phonology assembly has been
demonstrated, the logical next question is
what this code looks like.”
Drieghe & Brysbaert (2002)
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“ Our data add further support to the strong
phonological theory of visual word recognition,
which claims that the stored lexico-semantic
information requires a phonological access
code.”
Strong phonological theories
(cont.)
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Coltheart, Rastle, Perry, Langdon, & Ziegler
(2001)
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“Potential problems for the DRC model: Masked
phonological priming effects”
“… there currently exist some difficulties
concerning exactly what the effects are that would
need to be simulated. …”
“Hence the implementation of a computational
account of masking effects in the DRC would need
to be accompanied by considerable further
empirical work…”
Rastle & Brysbaert (2006)
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Despite the previous evidence many
researchers still not convinced about
the importance of phonological coding
in English
Rastle & Brysbaert: meta-analysis of
previous research in English + two
new, fully controlled studies
Task = lexical decision (stronger than
naming + can be modelled in DRC)
First new
Lexical Decision Experiment
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Two types of primes : phonological (pharm FARM; korce - COARSE) and graphemic controls
(gharm - FARM; roipe - COARSE)
Selected from the ARC Nonword Database
(Rastle et al., 2002)
Same number of overlapping letters both on
matching and non-matching positions
phonological primes do not activate the targets
to a higher degree in any component of DRC
First new Lexical Decision
Experiment (cont.)
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112 word trials and 112 non-word trials (also
with phononological and graphemic control
primes)
42 participants
presentation with DMDX (Forster & Forster,
2003)
trial :
########
500 ms
prime
58 ms
TARGET
until response
First new Lexical Decision
Experiment (cont.)
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Results:
phon
contr
effect
603 ms
5.8%
617 ms
7.5%
14 ms
1.7%
No effect of orthographic similarity prime - target
Second new Lexical Decision
Experiment (rationale)
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In Experiment 1 (and all published experiments)
only word trials preceded by pseudohomophones
of existing words
pharm
FARM
gharm
FARM
whone
WONE
sowd
GOWD
pharm
FARM
gharm
FARM
phite
FITE
biss
BUSS
• Phonology uninformative both for word/non-word decision
and for the target that will follow a particular type of prime
Second new Lexical Decision
Experiment (cont.)
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112 words and 112 pseudo-homophones (both
with phononological and graphemic control
primes)
80 participants
procedure same as in Experiment 1 (SOA = 58
ms)
after the experiment, session run again and this
time participants tried to indicate whether the
prime had been a pseudohomophone or a control
(at chance)
Second new Lexical Decision
Experiment (cont.)
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Results:
phon
contr
effect
634 ms
5.8%
643 ms
6.4%
9 ms
0.6%
No effect of orthographic similarity prime - target
Conclusions Rastle & Brysbaert (2006)
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Despite some justified concerns about
the previous evidence, masked
phonological priming effect in lexical
decision is real
The effect is rather small (d = .30)
The effect does not depend on the
orthographic similarity of prime and
target
Is this evidence against a weak
phonological model like DRC?
Conclusions Rastle & Brysbaert (2006)
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DRC simulates LDT by looking either at
the orthographic activation of the most
active word node or at the total activity
in the orthographic lexicon.
Different simulations show that it is
impossible to find a parameter set that
at the same time predicts phonological
priming and correct reading of irregular
words.
Conclusions Rastle & Brysbaert (2006)
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The situation looks much better when
we look at the activity of the
phonological lexicon.
There we see clear phonological
priming.
However, is it possible to make a word/
pseudohomophone decision on the
basis of this lexicon? (researchers
always assumed this was not possible)
Conclusions Rastle & Brysbaert (2006)
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In a weak phonological model, the
activation of phonology is much
stronger for a word than for a
pseudohomophone, because a word
also activates the phonology via the
orthographic lexicon.
So, the masked phonological priming
effect is not really evidence against a
weak phonological model.
A new challenge: The transposed letter
priming effect
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How to reconcile the findings with
transposed letters (fiary-TALES) with
the use of phonology?
Perea & Carreiras (2006): Is it also
possible to have transposed letter
priming with pseudohomophones?
In Spanish “v” and “b” sound the
same; so “rebolucion” is a
pseudohomophone of “revolucion”
A new challenge: The transposed letter
priming effect
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Will “relubocion” then also prime
“REVOLUCION”?
50 ms priming, LDT
results
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reloducion-REVOLUCION
reluvocion-REVOLUCION
relubocion-REVOLUCION
585 ms
570 ms
585 ms
Conclusion: TL-effect is orthographic
A new challenge: The transposed letter
priming effect
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Grainger et al. (2006)
Letter position effects are part of the
orthographic route (cf. Grainger &
Ferrand’s findings of the time course of
orthography and phonology)
Therefore, letter position effects should
be stronger for short prime durations
than for long prime durations
33 ms prime duration vs. 83 ms
A new challenge: The transposed letter
priming effect (Grainger et al., 2006)
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33 ms prime duration
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slne-SILENCE:
brma-SILENCE:
577 ms
597 ms
83 ms prime duration
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slne-SILENCE:
brma-SILENCE:
613 ms
610 ms
Reading list
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Frost, R. (1998). Toward a strong
phonological theory of visual word
recognition: True issues and false trails.
Psychological Bulletin, 123, 71-99.
Rastle, K. & Brysbaert, M. (2006).
Masked phonological priming effects in
English: Are they real? Do they matter?
Cognitive Psychology, 53, 97-145.