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Frequency-Following Response (FFR)

Frequency-Following Response (FFR). Instructor: Fuh-Cherng Jeng. Background. Follows the periodicity (i.e., frequency content) of the stimulus. Phase locked to the periodicity of the stimulus f0 and harmonics Originates from the brainstem area. Period = 0.02 sec.

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Frequency-Following Response (FFR)

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  1. Frequency-Following Response (FFR) Instructor: Fuh-Cherng Jeng

  2. Background • Follows the periodicity (i.e., frequency content) of the stimulus. • Phase locked to the periodicity of the stimulus f0 and harmonics • Originates from the brainstem area Period = 0.02 sec Frequency = 1/0.02 sec = 500 Hz Moushegian et al., 1973

  3. Frequency-Following Response

  4. Frequency-Following Response

  5. Frequency-Following Response

  6. FFR to voice pitch

  7. FFR to 4 Mandarin pitch contours Tone 1 衣 Tone 2 姨 Tone 3 椅 Tone 4 意

  8. Musical Training Enhanced FFR • Top, FFR waveforms from a musician (left) and nonmusician (right) elicited by a dipping pitch contour (Tone 3). • Middle, trajectories (yellow line) of brainstem pitch tracking elicited by the same tone from the same subjects. The black line indicates the stimulus (expected) f0 contour. • Bottom, autocorrelograms of the FFR waveforms. Color indicates the degree of correlation, with lighter colors indicating higher correlations. For the musician (left panel), the light band of color closely follows the inverse of the pitch contour of Tone 3. • Wong, Skoe, Russo, Dees & Kraus 2007 • Nature Neuroscience

  9. Project 1: Neonates Dear baby, can you hear me?

  10. Project 1: Neonates Goals and Hypotheses • Goals • Investigate the characteristics of FFR to voice pitch in neonates (1-3 days old). • Examine the relative contributions of the “biological capacity” versus “linguistic experience” influences on pitch processing at the human brainstem. • Hypotheses • Based on the “biological capacity” model, neonates will demonstrate accurate processing of voice pitch during the first few days after birth. • Based on the “linguistic experience” model, enhancement of the FFR to voice pitch will be expected as a result of exposure to a specific language environment.

  11. Project 1: NeonatesMethods: Quantitative analysis /i2/

  12. Project 1: NeonatesFrequency Error Frequency Error

  13. Project 1: NeonatesSlope Error Slope Error is the difference of the slope estimates between the stimulus and response f0 contours Slope of stimulus f0 contour Slope of response f0 contour

  14. Project 1: NeonatesTracking Accuracy Tracking Accuracy is the regression r value between the stimulus and response f0 contours

  15. Project 1: NeonatesPitch Strength Pitch Strength is the peak-to-trough amplitude in the normalized autocorrelation output

  16. Project 1: NeonatesRaw data Stimulus Response Control

  17. Project 1: NeonatesAmerican neonates

  18. Project 1: NeonatesChinese neonates

  19. Project 1: Neonates Cross-linguistic comparison -Jeng et al., Ear and Hearing, 2011a

  20. Project 2: InfantsAny change during the first year?

  21. Project 2: InfantsRaw data Stimulus Response Control

  22. Project 2: InfantsIndividual infants

  23. Project 2: InfantsLongitudinal follow-up

  24. Project 2: InfantsDevelopmental trend -Jeng et al., Perceptual and Motor Skills, 2010

  25. Project 3: AutomationCan we make the procedures automated? Stimulus Response Control

  26. Project 3: AutomationResponse threshold Response threshold Distribution of recordings obtained in experimental condition Distribution of recordings obtained in control condition

  27. Project 3: AutomationTwo algorithms across four tones Short-Term Autocorrelation Narrow-Band Spectrogram

  28. Project 3: AutomationSensitivity & specificity

  29. Project 3: AutomationReceiver operating characteristics (ROC) -Jeng et al., International Journal of Audiology, 2011b

  30. Project 4: ModelingExponential model Time constant () Number of sweeps

  31. Project 4: ModelingNumber of sweeps means TIME!!!

  32. Project 4: ModelingThree different stimulus intensities

  33. Project 4: ModelingFFR trends Number of sweeps Number of sweeps

  34. Project 4: ModelingCurve fitting

  35. Project 4: ModelingFour indices at three stimulus intensities

  36. Project 4: ModelingTime constant () = number of sweeps needed -Jeng et al., International Journal of Audiology, 2011c

  37. Project 5: NoiseHow much noise can the listener tolerate?

  38. Project 5: NoiseRaw data

  39. Project 5: NoiseNoise tolerance at about 0-6 dB SNR -Li & Jeng, JASA EL, 2011d

  40. Project 6: f0-HarmonicsRelative contributions of the f0 and its harmonics?

  41. Project 6: f0-Harmonics American adults

  42. Project 6: f0-Harmonics Chinese adults

  43. Project 7: f0-Harmonics Group comparison -Jeng et al., International Journal of Audiology, 2011e

  44. Future directions • Continue, expand and better define the FFR to voice pitch in normal and pathological populations • Cross-linguistic comparison, longitudinal follow-up • Automation and modeling of the FFR to voice pitch in neonates and infants • Integration with behavioral responses • Establishment of an animal model

  45. Spectral versus Envelope FFR • Is the FFR we recorded following the spectral components of the stimulus or its envelope?

  46. Top left panels (A,B) show two periods of a 200 Hz tone, in opposite polarities. Top right panels (G,H) show a 2 kHz tone, amplitude modulated at 200 Hz, also in opposite polarities. The four centre panels show the expected scalp-recorded FFR for either the 200-Hz tone (C,D) or the 200 Hz envelope (I, J). Nerve fibers are unable to lock to the 2000 Hz carrier of the AM tone but can lock to its 200 Hz envelope, so the right column deals with only envelope FFRs. The average response to stimuli presented in a single polarity (+ +) contains both spectral and envelope FFRs and there are responses in both left and right columns (C, I). However, when spectral FFRs to opposite polarities (C,D) are added (+), the result (E) is small and twice the frequency of the actual responses. Conversely, when spectral FFRs to opposite polarities are subtracted (), the result (F) resembles the original spectral component in the stimulus (A). Aiken & Picton, 2008

  47. Spectral versus Envelope FFR Aiken & Picton, 2008

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