The role of phonology in visual word recognition and reading

The role of phonology in visual word recognition and reading

Marc Brysbaert

Reading silently

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.)

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.)

Not purely based on visual information 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

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

Important element: the development of the dual-route theory (Coltheart, 1978, 1993, 2001)

Latest version: the DRC-model (Coltheart et al., 2001)

print

speech

Feature Representations

Letter Representations

Orthographic Lexicon

Phonological Lexicon

Phoneme Representations

Rule-Based Translation

Semantic Representations

DRC

Addressed phonology vs. assembled phonology

DRC = a weak phonological theory 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

Addressed phonology = phonology activated on the basis of word representations in the orthographic lexicon

Assembled phonology = phonology activated on the basis of direct letter-sound correspondences (grapheme-phoneme conversions)

Evidence for the importance of phonology in isolated visual word recognition

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

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

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)

three types of primes for target RATE: rait (pseudohomophone), ralt (graphemic control), busk (unrelated control)

Procedure: 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)

Findings: 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)

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)

Procedure: ###### (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) 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) 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 First replicated Lukatela & Turvey (57 ms)

Drieghe & Brysbaert, 2002 Extended it to LDT (57 ms)

Drieghe & Brysbaert, 2002 LDT( 258 ms)

Strong phonological theories

“. . .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.)

“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.)

“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.)

Brysbaert (2001) “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) “ 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.)

Coltheart, Rastle, Perry, Langdon, & Ziegler (2001) “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)

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

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.)

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 msprime 58 msTARGET until response

First new Lexical Decision Experiment (cont.)

Results:phon contr effect

603 ms 617 ms 14 ms5.8% 7.5% 1.7%

No effect of orthographic similarity prime - target

Second new Lexical Decision Experiment (rationale)

In Experiment 1 (and all published experiments) only word trials preceded by pseudohomophones of existing words

pharmFARM

gharmFARM

whoneWONE

sowdGOWD

pharmFARM

gharmFARM

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.)

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.)

Results:phon contr effect

634 ms 643 ms 9 ms5.8% 6.4% 0.6%

No effect of orthographic similarity prime - target

Conclusions Rastle & Brysbaert (2006)

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)

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)

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)

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

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

Will “relubocion” then also prime “REVOLUCION”?

50 ms priming, LDT results

reloducion-REVOLUCION 585 ms reluvocion-REVOLUCION 570 ms relubocion-REVOLUCION 585 ms

Conclusion: TL-effect is orthographic

A new challenge: The transposed letter priming effect

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)

33 ms prime duration slne-SILENCE: 577 ms brma-SILENCE: 597 ms

83 ms prime duration slne-SILENCE: 613 ms brma-SILENCE: 610 ms

Reading list

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.