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Psycholinguistics Lecture 7

Psycholinguistics Lecture 7. Speech Perception II. Announcements. Midterm, Nov. 1 st ! Covers material up to October 25 th October 25 th (by 11:59pm): submit potential exam questions. Form groups of 1-2 students list 5 major points covered in the course submit 5 short essay questions.

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Psycholinguistics Lecture 7

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  1. PsycholinguisticsLecture 7 Speech Perception II

  2. Announcements • Midterm, Nov. 1st! • Covers material up to October 25th • October 25th (by 11:59pm): submit potential exam questions. • Form groups of 1-2 students • list 5 major points covered in the course • submit 5 short essay questions. • the questions you submit will count for 1/3 of your final midterm grade. • October 30th part new stuff, part review.

  3. Review Frequency (Hz) Time (msec) What is Categorical Perception? ba da ga

  4. Continuation on Categorical Perception Methods for Testing Categorical Perception • Identification • Randomly play the audio clips and asked to identify the phoneme • Discrimination • Randomly play pairs and asked to make Same-different Judgment • Same pairs • Different pairs

  5. Continuation on Categorical Perception Identification • Identification • Randomly play the audio clips and asked to identify the phoneme • If there is CP, what should the graph look like? • X-axis stimuli arranged in a continuum with very small incremental difference between the stimuli • Y-axis % Identification as the tested category

  6. Continuation on Categorical Perception Identification(idealized results) 100 80 60 % Identification as Category X 40 20 0 1 2 3 4 5 6 7 Stimulus #

  7. Continuation on Categorical Perception Discrimination Study Last lecture: • The ba/da/ga study varied transitional state (up, down of F2). • In this example, Varying Voice Onset Time.

  8. Continuation on Categorical Perception Voice Onset Time (VOT) • VOT: time between consonant release and vocal cord vibration [b] [p] • So what is the difference in VOT between VOICELESS [b] and VOICED [p]? • SHORT VOT  voiced • LONG VOT  voiced

  9. Short VOT = ? Long VOT = ? Which one is /di/ and which one is /ti/? Continuation on Categorical Perception Voice Onset Time (VOT) di ti

  10. Continuation on Categorical Perception Discrimination Study Same/Different? 0ms 60ms Same/Different? Why is this pair difficult? 0ms 10ms (i) Acoustically similar? (ii) Same Category? Same/Different? 40ms 40ms

  11. Continuation on Categorical Perception Discrimination A More Systematic Test Same/Different D D 0ms 60ms 0ms 20ms D T 20ms 40ms Same/Different 0ms 10ms T T 40ms 60ms Same/Different Within-Category Discrimination is Hard 40ms 40ms

  12. Continuation on Categorical Perception Categorical Perception(Idealized Discrimination Data) 100 80 60 % Correct Discrimination 40 20 0 1-2 2-3 3-4 4-5 5-6 Pairs by VOT

  13. What researchers found…

  14. Motor Theory vs. Auditory Theory Where did our speech perception abilities come from? • The Motor Theory: – perception is informed by our innate knowledge of articulation • The Auditory Theory: – speech perception is based solely on auditory properties of speech

  15. Motor Theory vs. Auditory Theory Contrasting the two theories (slides adapted from J. Snedeker, C. Phillips)

  16. Motor Theory vs. Auditory Theory Questions to Ask (slides adapted from J. Snedeker, C. Phillips)

  17. Motor Theory vs. Auditory Theory Question 1 Question 1 • Is speech perception innate? • Do newborns have categorical perception? • If CP requires exposure to language (e.g., knowledge of minimal pairs in one’s language), then NO. • If CP is innate, then YES. • How do we test newborns?

  18. Motor Theory vs. Auditory Theory Question 1 High Amplitude Sucking Procedure • Infant given a pacifier that measures sucking rate • Habituation – Infant sucks to hear sound (e.g. ba) until bored. • Test – Play sound (e.g., ba or pa). Is there dishabituation? • Infants will suck to hear sound if the sound is no longer boring. http://psych.rice.edu/mmtbn/language/sPerception/video/sucking_h.mov http://www.learner.org/vod/vod_window.html?pid=1620 (2:50 min. into videoclip)

  19. Motor Theory vs. Auditory Theory Question 1 60 80 20 40 0 Stimuli for Eimas et. al’s Study • BA vs. PA • Vary Voice Onset Time (VOT): time btw consonant release and vocal cord vibration BA PA VOT in milliseconds

  20. Motor Theory vs. Auditory Theory Question 1 Predictions BA1 = VOT 20ms; BA2 = VOT 0ms; PA = VOT 40ms

  21. Motor Theory vs. Auditory Theory Question 1 dishab no no Results for Eimas et. al’s Study MEAN NUMBER OF SUCKING RESPONSE

  22. Motor Theory vs. Auditory Theory Question 1 Question 1 Answer Q1: Is Speech Perception Innate? • Many other studies since tested: • Infants (Neonates) on other contrasts. • Consensus: Yes to Innate Q. • Infants do not discriminate all physically equal acoustic difference; they show heightened sensitivity to those that are important for language. • BUT… there is language-specific fine-tuning…

  23. Predicted by Motor Theory Speech perception driven by innate knowledge of articulation Consistent with Auditory Theory Speech perception due to innate structure of auditory system Motor Theory vs. Auditory Theory Question 1 Motor vs. Auditory TheoryScore card • Q1: Is Speech Perception Innate? • Answer: YES.

  24. Motor Theory vs. Auditory Theory Question 2 Question 2 • Is speech perception species-specific? • Do other animals show categorical perception on the same speech sounds? • How do we test animals? ?

  25. Motor Theory vs. Auditory Theory Question 2 Avoidance Conditioning Procedure • Kuhl & Miller (1978): test chinchillas and humans with identical stimuli • Human Task: identification (d or t) • Chinchillas: avoidance conditioning

  26. Motor Theory vs. Auditory Theory Question 2 60 80 20 40 0 Avoidance Conditioning Procedure • Speech sound at one end of the continuum paired with shock • Other end paired with safety Safety Shock VOT

  27. Motor Theory vs. Auditory Theory Question 2 60 80 20 40 0 Avoidance Conditioning Procedure • Animals learn to “avoid” shock. • What will they do for between cases? Safety = FLEE ? ? ? ? ? ? Shock = STAY VOT

  28. Motor Theory vs. Auditory Theory Question 2 Predictions Categorical Perception 100 Graded Perception 80 60 % Identification as [d] 40 20 0 1 2 3 4 5 6 7 Stimulus #

  29. Motor Theory vs. Auditory Theory Question 2 Kuhl & Miller (1978)

  30. Contrary to Motor Theory Claim That is, only humans have (innate or learned) knowledge of articulation Consistent with Auditory Theory General auditory abilities adequate for (some aspects of) speech perception Motor Theory vs. Auditory Theory Question 2 Motor vs. Auditory TheoryScore card • Q2: Is Speech Perception Species-Specific? • Answer: NO.

  31. Motor Theory vs. Auditory Theory Question 2 Some species-specific aspects of speech perception • Other primates (e.g., Macaques, vervet monkeys, chimpanzees) • Boundary of ra/la not human like (Sinnott & Brown, 1997) • Fail to make use of vowel length in consonant discrimination (Sinnott, Brown, & Borneman, 1998) • Fail to use formant transitions alone in consonant discrimination (Sinnott & Williamson, 1999) • Fail to categorize two different vowels in the same way infants learn to categorize those two vowels (Kuhl, 1991) • Different similarity space for vowels (Sinnot, Brown, Malik, & Kressley, 1997; Kojima & Kiritani, 1989)

  32. Motor Theory vs. Auditory Theory Question 3 Question 3 • Is speech perception based on our knowledge of articulation? • Would knowledge of: • Visual information of mouth movements • Coarticulation influence our speech perception? • What experiments? • McGurk Effects • Co-articulation Experiments

  33. Motor Theory vs. Auditory Theory Question 3 McGurk Effect http://www.faculty.ucr.edu/~rosenblu/McGurkcompressB1.mov

  34. Motor Theory vs. Auditory Theory Question 3 McGurk Effect • McGurk Finding: phoneme categorization is affected by visual information • audio BA + visual GA = percept DA Q3: Is speech perception based on our knowledge of articulation? • YES. Adult speech perception is affected by visual cues. • Are infants?

  35. Motor Theory vs. Auditory Theory Question 3 Three Infant Studies • Do infants make use of visual cues to articulation? • Kuhl & Meltzoff (1982) • Rosenblum, Lawrence, Schmuckler, & Johnson (1997) • Burnham & Dodd (2004)

  36. Familiarlization: [a] and [i] face NO AUDIO Test Phase: [a] and [i] face AUDIO of either [a] or [i] MEASURE: looking time to appropriate face. Motor Theory vs. Auditory Theory Question 3 Experiment 1 Kuhl & Meltzoff (1982) Preferential Looking Paradigm

  37. Motor Theory vs. Auditory Theory Question 3 Kuhl & Meltzoff (1982) Experiment 1 • Do infants know visual cues to articulation? • Kuhl & Meltzoff (1982) • Show that 4-5 months-old infants can match sound with correct mouth shape • But not evidence of visual cues influencing categorization Kuhl & Meltzoff, 1982

  38. Motor Theory vs. Auditory Theory Question 3 Experiment 2 Rosenblum et al. (1997) • Tested 5-months-old infants • Habituated on audio VA & visual VA • Tested on • (1): Audio BA & Visual VA (adults perceive as VA) • (2): Audio DA & Visual VA (adults perceive as DA) • Results • Dishabituate to (1)? (2)? • Infants dishabituate only to (2) • Show? • Infants are like adults! • They are sensitive to visual cues to articulation.

  39. Motor Theory vs. Auditory Theory Question 3 Experiment 3 Burnham & Dodd (2004) • Tested 2 groups of ½ months-old infants Control Group: habituation Audio BA Visual BA Test Group: habituation Audio BA Visual GA • Both groups then tested on: • (1) audio BA; (2) audio DA; (3) audio THA • Results: Dishabituation? (1)? (2)? (3)? • Control Group: • Test Group: Show: Dishabituated to DA, THA, not BA Dishabituated only to BA Again show infants are show the Classic McGurk Effect Audio BA, Visual GA  DA Caveat: DA ≈THA

  40. Motor Theory vs. Auditory Theory Question 3 Frequency (Hz) Time (msec) Coarticulation Coarticulation Revisited

  41. Motor Theory vs. Auditory Theory Question 3 Coarticulation Coarticulation Revisited

  42. Motor Theory vs. Auditory Theory Question 3 Coarticulation Coarticulation Revisited

  43. Motor Theory vs. Auditory Theory Question 3 Coarticulation Coarticulation Revisited • [šu]shoe, [ša]shot • [u] oo F1: 310 F2: 870 • [a] ah F1: 710 F2: 1100 • [š] has lower frication frequency with [u] • [š] has higher frication frequency with [a]

  44. What should the identification curve if there is categorical perception? Motor Theory vs. Auditory Theory Question 3 Coarticulation Coarticulation & Identification Curve

  45. Contextual Effect? (consonant plus vowel) [u] [a] We know: [š] lofreq w/ [u] [š] hi freq w/ [a] Motor Theory vs. Auditory Theory Question 3 Coarticulation Coarticulation & Identification Curve

  46. Contextual Effect? (consonant plus vowel) [u] [a] We know: [š] lofreq w/ [u] [š] hi freq w/ [a] Motor Theory vs. Auditory Theory Question 3 Coarticulation Coarticulation & Identification Curve

  47. Motor Theory vs. Auditory Theory Question 3 Motor vs. Auditory TheoryScore card • Q3: Is Speech Perception based on our knowledge of articulation • Answer: YES. Our compensation for Coarticulation Effects and response to McGurk Stimuli suggest that knowledge of articulation influences speech perception. • Inconsistent with Auditory Theory • Though perhaps perceptual learning might explain these effects • Predicted by Motor Theory • Innate connection btw production and perception

  48. Motor Theory vs. Auditory Theory General Conclusions Provisional Conclusions • Speech Perception makes use of some auditory mechanisms which evolved prior to language • These abilities are innate • Speech Perception also makes use of our knowledge of articulation – These abilities are likely innate

  49. Language Specific Fine Tuning Becoming a Native Listener • Languages differ in their inventories of phonemes. • What develops or changes in our speech perception abilities?

  50. Language Specific Fine Tuning Japanese vs. English(Miyawaki et al. 1975) RA AMERICANS LA

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