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Word Recognition (Sereno, 4/04)

Word Recognition (Sereno, 4/04). How long does it take to recognise a visual word?. What is meant by “recognition” or “lexical access”? Can lexical access be accurately measured? What factors affect lexical access and when?. The “magic moment” (Balota, 1990) of lexical access:

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Word Recognition (Sereno, 4/04)

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  1. Word Recognition (Sereno, 4/04) How long does it take to recognise a visual word? • What is meant by “recognition” or “lexical access”? • Can lexical access be accurately measured? • What factors affect lexical access and when? The “magic moment” (Balota, 1990) of lexical access: “At this moment, presumably there is recognition that the stimulus is a word, and access of other information (such as the meaning of the word, its syntactic class, its sound, and its spelling) would be rapid if not immediate.” (Pollatsek & Rayner, 1990)

  2. Background: Basic Units of Language A. ~5,000 languages phonemes  morphemes  sentences  conversations (sounds) & words B. Phonemes = elementary sounds of speech • phonemes are not letters... to, too, two, through, threw, shoe, clue, view • vowel & consonant phonemes • 11-144 phonemes in any given language English has ~ 40; Hawaiian has ~16 • combining phonemes is rule-governed

  3. Wordness: For each row of 3 possible new words, which one will probably never make it : ( blick splunge rlight sbarm wumple turl mancer nserht crelurious inther iwhucr neen shace fring ngout

  4. “free” { { “bound” Basic Units of Language C. Morphemes = smallest meaningful unit of lang. • can be a word, word stem, or affix (prefix, suffix) word: help, love word stem: spir, ceive, duce prefix/suffix: re-, dis-, un- / -less, -ful, -er • derivational & inflectional morphemes derivational – change the grammatical class V + -able = Adj (adorable, believable) V + -er = N (singer, runner) inflectional – grammatical markers V + -ed = past tense (walked) N + -s = plural (cows)

  5. Basic Units of Language C. Words • Content vs. function (open- vs. closed-class) words Content words = carry the main meaning nouns, verbs, adjectives, adverbs Function words = grammatical words articles (a, the, this), conjunctions (and, but), prepositions (in, above) Psychological reality of the content-function word distinction in aphasia selective impairment of content (Wernicke’s) or function words (Broca’s aphasia) • Cattell (1886) & Stroop (1925)

  6. d k  word --- d k  d Word superiority effect (Cattell, 1886) • Reicher (1969); Wheeler (1970) • tachistoscopic presentation • more accurate identification of the letter when stimulus is a word • pseudoword superiorty effect

  7. GREEN RED RED BLUE BLUE GREEN BLACK BLACK BLUE GREEN RED BLUE BLACK GREEN BLACK RED RED BLUE BLUE GREEN NAME THE COLOUR OF THE INK

  8. homographs homophones Basic Units of Language C. Words • Ambiguity 1 word form, but 2 (or more) word meanings Ex: bank (N-N, “money” vs. “river”) watch (N-V, “clock” vs. “look”) bass (N-N, “guitar” vs. “fish”) 2 word forms, but 1 pronunciation Ex: sail/sale, right/write Generally unaware of ambiguity... even though it is quite pervasive even though it affects behaviour (RT, etc)

  9. Basic Units of Language D. Sentences • Syntax = the rule-governed system for grouping words together into phrases and sentences • Sentences introduce a concept that they are about, the subject (or noun phrase), and then propose something about that concept, the predicate (or verb phrase). Ex: “The boy hit the ball.” doeractdone-to (thematic roles) subjectpredicate

  10. Basic Units of Language D. Sentences • Same deep structure, different surface structure “The boy hit the ball.” (active) “The ball was hit by the ball.” (passive) • Same surface structure, different deep structure [The French bottle]NP [smells.]VP [The French]NP [bottle smells.]VP THEY are boring. VISITING THEM is boring. cf. ambig. figures in perception: 1 form, 2 interpretations “The French bottle smells.” “Visiting relatives can be boring.”

  11. Necker cube

  12. Headlines New obesity study looks for larger test group Reagan wins on budget, but more lies ahead Man struck by lightening faces battery charge Enraged Cow Injures Farmer with Axe Milk Drinkers Are Turning to Powder Local High School Dropouts Cut in Half British Left Waffles on Falklands Dealers Will Hear Car Talk at Noon Miners Refuse to Work after Death Beating Witness Provides Names Squad Helps Dog Bite Victim Kids Make Nutritious Snacks

  13. Headlines Stolen Painting Found by Tree Prostitutes Appeal to Pope Red Tape Holds up Bridge Deer Kill 17,000 Teenage Prostitution Problem is Mounting Child Stool Great for Use in Garden Shouting Match Ends Teacher’s Hearing Man Robs then Kills Himself Lung Cancer in Women Mushrooms Mondale’s Offensive Looks Hard to Beat Tuna Biting off Washington Coast Chinese Apeman Dated

  14. Basic Units of Language D. Sentences • Syntactic ambiguities “She hit the boy with the big stick.” “She hit the boy with the runny nose.” Interpretation depends on structural preferences (certain constructions used more often, favoured), as well as the prior discourse context.

  15. Word Recognition (Sereno, 4/04) • Measures • Components • Models • Eye movements (EMs) • Event-related potentials (ERPs) • Word frequency & lexical ambiguity

  16. controlled endogenous top-down cost & benefit unconscious exogenous bottom-up benefit Measures • Standard behavioural techniques • lexical decision, naming, categorisation; also RSVP, self-paced reading • priming, masking, lateralised presentation • Donders (1868): subtractive method • assumes strictly serial stages of processing • additive vs. interactive effects • automatic vs. strategic(Posner & Snyder, 1975)

  17. Measures • Eye movements • Neuroimaging • “Electrical”: EEG, MEG • “Blood flow”: PET, fMRI

  18. Standard word recognition paradigms (± priming, ± masking): naming ~500 ms lexical decision RT ~600 ms categorisation ~800 ms TASK MEASURE TIME RES. GOOD various word tasks “electrical” imaging: EEG, MEG ms-by-ms fixation duration (as well as location and sequence of EMs) Normal reading ~250 ms various word tasks “blood flow” imaging: fMRI, PET seconds POOR

  19. Components • Orthography of language • English vs. Hebrew or Japanese • Language skill • beginning (novice) vs. skilled (expert) reader • easy vs. difficult text

  20. Components • Intraword variables • word-initial bi/tri-grams clown vs. dwarf • spelling-to-sound regularity hint vs. pint • neighborhood consistency made vs. gave • morphemes • prefix vs. pseudoprefix remind vs. relish • compound vs. pseudocompound cowboy vs. carpet

  21. Components • Word variables • word length duke vs. fisherman • word frequency student vs. steward • AoA dinosaur vs. university • ambiguity bank vs. edge, brim • syntactic class open vs. closed; A,N,V • concreteness tree vs. idea • affective tone love vs. farm vs. fire • etc.

  22. Components • Extraword variables • contextual predictability The person saw the... moustache. The barber trimmed the... • syntactic complexity Mary took the book. *Mary took the book was good. Mary knew the book. Mary knew the book was good. *Mary hoped the book. Mary hoped the book was good. • discourse factors (anaphora, elaborative inferences) He assaulted her with his weapon.... knife... stabbed

  23. semantics phonology orthography Models • Dual-route account (Coltheart, 1978) Direct route (addressed) Indirect route (assembled)

  24. meaning context phonology orthography Models • Interactive (Morton, 1969; Seidenberg & McClelland, 1989) M A K E /m A k/

  25. Lexical processor Syntactic processor Message processor General Problem Solver Models • Modular (Forster, 1979; Fodor, 1983) input features decision output

  26. Models • Hybrid • 2-stage: generate candidate set  selection • (Becker & Killion; Norris; Potter)

  27. Word Recognition (Sereno, 4/04) • Measures • Components • Models • Eye movements (EMs) • Event-related potentials (ERPs) • Word frequency & lexical ambiguity

  28. Standard word recognition paradigms (± priming, ± masking): naming ~500 ms lexical decision RT ~600 ms categorisation ~800 ms TASK MEASURE TIME RES. GOOD various word tasks “electrical” imaging: EEG, MEG ms-by-ms fixation duration (as well as location and sequence of EMs) Normal reading ~250 ms various word tasks “blood flow” imaging: fMRI, PET seconds POOR

  29. Tools of choice: • Recording eye movements in reading • Recording ERPs in language tasks

  30. Eye Movements (EMs) Best on-line measure of visual word recognition in the context of normal reading: • Fast (avg fixation time ≈ 250 ms) • Ecologically valid task • Eye-mind span is tight

  31. Number of trials EEG 1 2 4 8 P300 P1 ERP 16 N400 N1

  32. ERPs Best real-time measure of brain activity associated with the perceptual and cognitive processing of words: • Continuous ms-by-ms record of events • Early, exogenous components (before 200 ms) should reflect lexical processing

  33. (Sereno & Rayner, Trends in Cognitive Sciences, 2003)

  34. High-density ERP Analysis:A case of “too many notes”? DIVERSION

  35. High-density ERP Analysis:Typical approaches for space & time • Pick ‘n choose favourite electrode and ERP component

  36. High-density ERP Analysis:Typical approaches for space & time • Pick ‘n choose favourite electrode and ERP component • Hunt down where/when the effect is strongest and gather data from those electrodes/time window

  37. High-density ERP Analysis:Typical approaches for space & time • Pick ‘n choose favourite electrode and ERP component • Hunt down where/when the effect is strongest and gather data from those electrodes/time window • Procrustean regions analysis (turtle shell) or series of pre-set time windows (eg, 50, 100, 200 ms)

  38. High-density ERP Analysis:Typical approaches for space & time • Pick ‘n choose favourite electrode and ERP component • Hunt down where/when the effect is strongest and gather data from those electrodes/time window • Procrustean regions analysis (turtle shell) or series of pre-set time windows (eg, 50, 100, 200 ms) • Spatial and/or temporal principal component analysis (PCA)

  39. Scalp topography of the N1 @ 132-192 ms SF1 loadings Voltages (Sereno, Brewer, & O’Donnell, Psychological Science, 2003)

  40. Word frequency • Word frequency effect represents the differential response to commonly used high-frequency (HF) words versus low-frequency (LF) words that occur much less often. • Presence of word frequency effects is used as a marker of successful word recognition or lexical access.

  41. 490 ms 553 ms 259 ms 275 ms 280 ms 293 ms (Sereno & Rayner, Trends in Cognitive Sciences, 2003)

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