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L2 Thinking

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    • 1.
        • Patrick Sturt (patrick.sturt@ed.ac.uk)
        • [email_address]
      Psychology of Thinking & Language
    • 2.
      • Review of categorical perception
      • Introduce to the mental lexicon, and the problem of lexical access.
      • Introduce some factors that affect lexical access.
      • Introduce models of context effects in recognising ambiguous words.
      • Introduce experimental techniques:
        • Lexical decision
        • Cross modal priming
        • Eye-movement recording
      Aims of the lecture
    • 3.
      • Eg. consonants can be classified as :
        • voiced (eg. b/d/g VOT 0 ms ) voiceless (eg. p/t/k VOT 60 ms )
      Review: categorical perception perceiving things that lie along a continuum as belonging to one distinct category or another. VOT 5 ms VOT 15 ms VOT 35 ms VOT 25 ms VOT 45 ms VOT 55 ms d o VOT 0 ms t o VOT 60 ms ‘ perceptual boundary’ of 30ms all sound voiced all sound voiceless
    • 4. categorical perception
      • methodology reminder
        • subjects hear pairs of consonants . Eg.
        • say whether pairs sound the same or different
      VOT 0 ms VOT 10 ms VOT 25 ms VOT 35 ms VOT 50 ms VOT 60 ms same different same crosses category threshold (30ms)
    • 5. categorical perception found that small differences between sounds within a category can still be perceived Pisoni & Nash (1974): same same … the category boundary still exists! VOT 0 ms VOT 10 ms VOT 10 ms VOT 10 ms FASTER VOT 5 VOT 15 VOT 35 VOT 25 VOT 45 VOT 55 d o VOT 0 t o VOT 60 all sound voiced all sound voiceless Nonetheless…
    • 6.
      • approx 75,000 words in memory
        • just 250 msec to find each one
      Understanding words
      • stored in mental lexicon
        • mental storehouse of words (in LTM)
      • mental lexicon contains lexical entries
        • one per word
        • contains all info about the word
          • spelling/ pronunciation/ meaning etc.
      ‘ cat’ [kæt] noun
    • 7. Lexical access
      • lexical access : retrieving a word from the mental lexicon
        • accessing its lexical entry
      HOUSE
      • seeing/hearing a word starts to activate its lexical entry
      • when the activation is high enough, lexical access takes place
      • threshold : the level of activation needed for lexical access
      ‘ house’ [haws] noun ‘ toast’ [towst] noun
    • 8. Random organisation? cloth snooker marathon chair hillside telephone chop monkey horse cheese ballroom cake rain cliff floor slide bomb concert cleaner pullover television piano
    • 9.
      • We can find out how words are organised by looking at things that make lexical access easy or hard
      word organisation
      • How do we know whether a word is easy or hard to access?
        • Lexical decision task
    • 10.
      • Non-words (BRUKE) are ‘fillers’
        • to check the subject is paying attention
        • we only look at real words
      lexical decision task HOUSE NOIK SLEEP NURSE BRUKE (400 msec) (450 msec)
      • Press YES or NO for whether the following is a real word in English:
      • FAST response = easy to access
      • SLOW response = hard to access
      • task variant: lexical naming
        • measures time taken to pronounce the word aloud
    • 11.
      • 1. Word Length
      • short words are faster to access than long words
            • E.g. chaos vs. confusion
      what affects lexical access time?
          • in lexical decision (Chumbley & Balota, 1984)
          • in word naming (Weekes, 1997)
            • strongest for 5-12 letter words
      • also when saying numbers (Klapp, 1974)
        • faster to start saying 91 vs. 77 (syllables: 3 vs. 5)
    • 12.
      • 2. Word Frequency
          • High frequency words = common words ( cat, mother, house )
          • Low frequency words = uncommon words ( czech, compass )
      what affects lexical access time?
      • High frequency are faster to access than Low frequency
          • even when they’re balanced on other features (e.g. length)
            • E.g. Pen vs. Pun
            • Rubenstein et al. (1970)
    • 13. what affects lexical access time?
        • the prior context lowers the threshold for the word’s activation
        • interacts with frequency
          • low frequency words are facilitated (speeded up) more
      • 3. Priming
        • when word-reading is ‘ facilitated ’ (speeded up) by prior context
      • a) repetition priming (Scarborough et al., 1977)
        • a repeated word is read faster second time round
          • eg. pen … pen
            • pen 1st (‘context’) speeds up pen 2nd
            • pun speeds up pun more than pen speeds up pen
    • 14.
          • subject sees 2 words
          • must say (YES/NO) whether both are real words
            • doctor grass
            • doctor nurse
      what affects lexical access time? b) Semantic Priming (Meyer & Schvandeveldt, 1971)
      • suggests …
        • reading doctor somehow speeds up nurse
          • doctor & nurse are linked in our minds (but NOT doctor & grass )
      priming : when language processing (eg. reading nurse ) is ‘facilitated’ (speeded up) by prior context (e.g., reading doctor ) SLOW FAST
    • 15.
      • accounts for priming effects
      • words in memory represented in a ‘network’
      • each word is a ‘node’
      • nodes (words) are connected to other nodes related in meaning
      • accessing a word causes activation
      • activation spreads to connected nodes
      spreading activation model
    • 16. canary bird animal ostrich mammal Spreading Activation Model yellow doctor dentist fever green baby cradle bed hospital sun rain heat grass nurse delirium
    • 17. canary bird animal ostrich mammal Spreading Activation Model yellow doctor dentist fever green baby cradle bed hospital sun rain heat grass nurse delirium
    • 18.
          • like semantic priming, but for word related in sound (not meaning)
            • trail chute
            • shoot chute
      what affects lexical access time? … because chute is already ‘warmed up’ by having just activated shoot
      • c) Phonological (sound) Priming
        • (Evett & Taylor, 1982)
          • What does this tell us about how the lexicon is organised?
            • not only a semantic network but also an phonological network
      SLOW FAST
    • 19. canary bird animal ostrich mammal Semantic Network yellow doctor dentist fever green baby cradle bed hospital sun rain heat grass nurse delirium
    • 20. poor pour shorn prawn pawn Phonological Network shin shoot chute shore sharp door dirt shirt short chin ship gin harp sure court
    • 21.
      • Bruce (1958)
          • participants heard words against background noise
          • better recognition for words in context vs. out of context
      what affects lexical access time? priming : when language processing is facilitated by prior context
      • 4. context
      • words are recognised better in sentence contexts
        • Lieberman (1963)
          • participants heard words either in isolation or in sentences
          • in isolation, take almost twice as long to recognise
    • 22. what affects lexical access time?
      • 5. lexical ambiguity
        • Which we will look at in detail in the rest of the lecture…
        • What is the first sentence that comes to mind given the word:
          • BANK
          • COACH
          • BEAM
          • PORT
    • 23. lexical ambiguity
        • WRITTEN word: ‘lead’
          • lead [lid] vs. lead [led]
          • homographs : written the same but have different meanings
      • lexical ambiguity : when a word has more than one meaning
        • = polysemous words:
          • bank; straw; letter
      • ambiguity might be only in written or spoken language
        • SPOKEN word: [najt]
          • knight vs. night
          • homophones : sound the same but have different meanings
    • 24. lexical ambiguity
      • many many words are ambiguous
      • coach, straw, bank, chick, tea/tee, bug, tie, here/hear, mail, you/ewe, bread, letter, plane, eye/I, pound, score, watch, house, table, phone, plate, trip, branch, shore/sure, bed, two/too/to, top, cite/sight, fork, pan, …………..
      • How do people choose the right meaning?
    • 25. Effect of context on meaning
      • … but how?
          • is the relevant meaning selected immediately?
          • or do we first consider all meanings?
      • contexts helps select the relevant meaning
        • The fisherman sat down on the bank
        • The businessman put his money in the bank
    • 26. 3 models of context effects
      • Autonomous access model
        • All of a word’s meanings are accessed from the lexicon, regardless of context.
        • Contextually appropriate meaning is selected later in an integration phase.
      • Re-ordered access model
        • All of a word’s meanings are accessed from the lexicon
        • Context can increase the speed with which a meaning becomes available
      • Direct access model:
        • Only contextually appropriate meaning is accessed in the first place.
    • 27. Understanding ambiguous words
      • Swinney (1979)
        • bugs : insects / listening devices
        • The man wasn’t surprised when he found several spiders, roaches and other bugs in the corner of the room
      • context supports insects
        • but do people still instantly consider both meanings?
    • 28. Cross-modal lexical decision (Swinney, 1979)
        • target word appears after subjects hear bugs
          • ant (related to “insect”)
          • spy (related to “listening device”)
          • sew (unrelated to either meaning)
      • Participants listen to sentences, and look at a screen
        • words appear on screen
        • lexical decision task
        • … he found several spiders, roaches and other bugs in the corner…
      AMBIGUOUS CONDITION Slow FAST FAST
    • 29. Cross-modal lexical decision
        • target word appears after subjects hear insects
          • ant (related to “insect”)
          • spy (related to “listening device”)
          • sew (unrelated to either meaning)
      • Participants listen to sentences, and look at a screen
        • words appear on screen
        • lexical decision task
        • … he found several spiders, roaches and other insects in the corner…
      UNAMBIGUOUS CONDITION Slow FAST SLOW
    • 30. Cross-modal lexical decision
      • So both meanings were available immediately after bugs
        • context had no immediate effect
      AMBIGUOUS CONDITION
          • ant (related to “insect”)
          • spy (related to “listening device”)
          • sew (unrelated to either meaning)
      • But Swinney also tested 3 syllables downstream
        • … several spiders, roaches and other bugs in the corner…
      baseline FAST SLOW
    • 31.
      • only relevant meaning remains (3 syllables) downstream
      Cross-modal lexical decision
      • So both meanings were available immediately after bugs
        • context had no immediate effect
      UNAMBIGUOUS CONDITION
          • ant (related to “insect”)
          • spy (related to “listening device”)
          • sew (unrelated to either meaning)
      • But Swinney also tested 3 syllables downstream
        • … several spiders, roaches and other insects in the corner…
      SLOW FAST SLOW
    • 32. Discussion
      • suggests lexical access makes available all meanings instantly
        • independently of context:
      • but context rapidly “kicks in”: (“integration”)
        • selects the appropriate meaning
        • screens out irrelevant meanings
        • process happens quickly (at least within 3 syllables)
      • Supports Autonomous Access model
      • but is this always true?
    • 33.
      • in fact, processing can vary, depending on …
        • the particular ambiguous word
        • the particular prior context
      • All Swinney’s words were “balanced” (each meaning occurs roughly equally.
      • What happens with “ biased” words (one meaning occurs more often than another)?
      Understanding ambiguous words
    • 34. biased vs. balanced words
      • port
        • harbour
        • wine
      • bark
        • part of tree
        • dog noise
      BIASED BALANCED more common less common roughly balanced
    • 35.
          • biased words:
            • common meaning is always accessed
            • uncommon meaning is only sometimes accessed
      Understanding ambiguous words
      • in fact, processing can vary, depending on …
        • the particular ambiguous word
        • Depends on the particular prior context
    • 36. Effect of context: Rayner & Duffy (1986); Duffy et al. (1988)
      • eye-tracking ambiguous words
        • balanced (eg. bark) vs. biased (eg. port )
      Eye-movements in reading: -difficulty of lexical access can be measured from “ gaze duration” (time spent first fixating a word before moving to another word). To their surprise, the bark was unusual 1 2 3 4 5 6 7 8
    • 37. Effect of bias: Basic finding (Rayner & Duffy; 1986)
      • eye-tracking ambiguous words
        • balanced (eg. bark) vs. biased (eg. port )
      slower gaze duration than control same as control
      • neutral context:
        • He found the bark was…
      • both meanings accessed
        • 2 meanings competing
      • 1 meaning accessed
        • no competition
      control: howl control: soup
        • Last night the port was…
    • 38. Effect of context: Duffy et al. (1988)
      • Manipulated whether the disambiguating context came before or after the critical word:
        • CONTEXT BEFORE:
        • CONTEXT AFTER
      Because they heard it from so far away , the bark/howl was difficult to identify Unfortunately, the bark/howl was difficult to identify, because they heard it from so far away .
    • 39. Effect of context: Duffy et al. (1988)
      • Also manipulated whether the ambiguous word was balanced (e.g. “bark”) or biased (e.g. “port”):
        • BALANCED:
        • BIASED
      Because they heard it from so far away , the bark/howl was difficult to identify Even though it had a strange flavour , the port/soup was a great success.
      • The context always disambiguated to the less common meaning (e.g. “wine” meaning of port).
      • Ambiguous words were compared with unambiguous controls
    • 40. Duffy et al gaze duration results: CONTEXT BEFORE CONTEXT AFTER
    • 41. Summary of Duffy et al
      • When context after the critical word, lexical access was difficult for the balanced ambiguous word
        • lexical access happens before disambiguating context
        • 2 meanings are accessed at the same time, causing competition, and difficulty
      • When context comes before the critical word, lexical access was difficult for the biased ambiguous word
        • The context promoted the less preferred reading, making it accessed earlier than usual. Caused competition between the two readings.
      This pattern of results is called the subordinate bias effect
    • 42. The re-ordered access model
        • most frequent meaning is always accessed ( harbour )
        • but context can “promote” uncommon meaning ( wine )
        • If so, both meanings become available together
          • meanings compete, causing difficulty
    • 43. Subordinate bias effect
        • most frequent meaning is accessed first ( harbour )
        • this is checked with context
          • but it doesn’t make sense! comprehension break-down
        • have to re-access for 2 nd meaning ( wine )
          • break-down & re-analysis causes slow-down
      • slow-down when context biases to uncommon meaning
        • both meanings are accessed, but when? (2 accounts)
      • IN SEQUENCE : Integration account
      ‘ Autonomous/ ordered access’
    • 44.
      • context strongly biases uncommon meaning
        • When she served it to her guests, the port …
      Subordinate bias effect slow-down
      • slowdown could be caused by…
        • competition between 2 concurrent meanings (“Re-ordered access”)
        • 1 st (common) meaning being ruled out (“Integration account”)
    • 45. Dopkins et al (1992)
      • Tried to distinguish between integration account and re-ordered access account, also in an eye-tracking experiment:
      • Positive condition: context highlights a feature of the uncommon meaning, but doesn’t rule out less common:
        • Having been examined by the King, the page was soon marched off to bed. (King highlights “servant” meaning)
      • Negative condition : context rules out common meaning
        • Having been hurt by the bee sting, the page was soon marched off to bed. (Bee-sting rules out “paper” meaning)
      • Neutral condition :
        • Just as Henrietta feared, the page was soon marched off to bed.
    • 46. Results of Dopkins et al Dopkins et al measured time taken to finish reading the final disambiguating region marched off to bed.
    • 47. Summary of Dopkins et al
      • Speed up in disambiguating region, both for positive and for negative conditions
      • Shows that the prior context in the positive condition caused selection of the less common meaning, at least some of the time.
      • Does not support integration account:
        • Having been examined by the king, the page…
        • Still no reason to reject “paper” reading of page at this point, so integration model would select “paper” reading.
        • Therefore “integration” model would predict difficulty at “ was soon marched off to bed ”.
      • Results support the “re-ordered access” account.
        • The phrase the king caused the “servant” meaning to be accessed more quickly
        • Therefore less difficulty at “ was soon marched off to bed”.
    • 48. Summary of Lecture
      • READING:
        • Harley, T. (2001). Psychology of Language . Hove: Psychology Press. Ch 6
      • Lexical access: The process of retrieving details of a word from long-term store (lexicon).
      • Speed of lexical access is affected by:
        • Length
        • Frenquency
        • Priming
      • How do we process ambiguous words?
        • For balanced words (Swinney 1979), all meanings become simultaneously available, and context is used to select.
      • Context can affect the order with which meanings become available (Duffy et al, 1988; Dopkins et al, 1992).