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Spoken Language Biomarkers for Detecting Cognitive Impairment Tuka - - PowerPoint PPT Presentation

Spoken Language Biomarkers for Detecting Cognitive Impairment Tuka Alhanai Advisor: James Glass Spoken Language Systems Group Computer Science & Artificial Intelligence Lab Massachusetts Institute of Technology 3 rd May 2018 tuka@mit.edu


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Spoken Language Biomarkers for Detecting Cognitive Impairment

Tuka Alhanai

Advisor: James Glass Spoken Language Systems Group Computer Science & Artificial Intelligence Lab Massachusetts Institute of Technology 3rd May 2018

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tuka@mit.edu talhanai talhanai.com

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Objective: Automatically detect cognitive conditions using spoken language.

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Cognitive impairment

Definition: decline in mental abilities that is severe enough to interfere with daily life.

  • Alzheimer’s
  • Vascular Dementia
  • Lewy Body Dementia

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Cognitive impairment

Definition: decline in mental abilities that is severe enough to interfere with daily life.

2nd

to spinal cord injuries in terms of its debilitating

  • effects. [WHO, (2003)]

$200B

expenditure in USA.

[Alzheimer’s Association, (2015])

equivalent value as:

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Why detect it?

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Pathological load Cognitive function Normal MCI Dementia

Nestor et al. 2004

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Plan

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$80K a year Hospital in the home: 35% hosp. visits. 4% mortality rates. 50% suffer from depression.

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Delay onset by 2 months Delay onset by 7 months Delay onset by 4 years Fish meal a week, 70% lower risk 3 times a week, 45% lower risk

Lifestyle

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Prevention

Alzheimer’s Parkinson’s Lewy Body Vascular

SIRT3 protein protects brain cells against degeneration. AD alone less damaging than mixed pathologies. Non-steroidal Anti- inflammatory Drugs lowers risk

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Data: Audio recordings of neuropsychological exams at the Framingham Heart Study.

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Framingham Heart Study

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15,000+

subjects since

1948

recording

audio

neuropsychological exams since

2006

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Outcome

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recall details describe scene recall verbal pair associates

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Outcome

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reviewed

  • severity
  • onset
  • cause
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Study: 92 subjects (21 impaired)

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Data statistics

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N Subjects 92 N Impaired 21 (22.8%) Age 68 years (+/- 17) Gender 47 male (51 female) Duration 65 minutes (+/- 18) Vocabulary Size 527 words (+/- 181) Transcript Size 2,496 words (+/- 1,508)

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Outcome of interest

  • Binary cognitive impairment
  • According to dementia review panel assessment
  • Pathology:
  • 14 Alzheimer’s
  • 5 Vascular Dementia
  • Severity:
  • 10 < mild
  • 6 mild
  • 5 moderate

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Assessment

  • AUC: Area Under the Receiver Operating Curve
  • TPR: True Positive Rate
  • FPR: False Positive Rate
  • HL-test: Hosmer-Lemeshow Test for statistical

calibration

  • LOOCV: Leave-one-out cross-validation

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Modeling

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Inside the box

Models:

  • Support vector machine (SVM)
  • Discriminant analysis
  • Decision tree
  • K-nearest neighbor
  • Logistic regression

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Inside the box

Models:

  • Support vector machine (SVM)
  • Discriminant analysis
  • Decision tree
  • K-nearest neighbor
  • Logistic regression

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  • Interpretable
  • Best performing
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Baseline model

  • Output: binary cognitive impairment
  • Model: logistic regression
  • Features: age, education, employment, gender

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age high school some college college part-time retired unemployed disability never volunteer

  • ther

female

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(modeled on N = 6,258, evaluated on the 92 subjects)

age high school some college college part-time retired unemployed disability never volunteer

  • ther

female Age Education Employment Gender

Model Coefficients *** *** *** *** *** *

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age high school some college college part-time retired unemployed disability never volunteer

  • ther

female Age Education Employment Gender

Model Coefficients *** *** *** *** *** * 26

(modeled on N = 6,258, evaluated on the 92 subjects)

More likely with:

  • Increasing age
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age high school some college college part-time retired unemployed disability never volunteer

  • ther

female Age Education Employment Gender

Model Coefficients *** *** *** *** *** * 27

(modeled on N = 6,258, evaluated on the 92 subjects)

More likely with:

  • Increasing age
  • Less education
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age high school some college college part-time retired unemployed disability never volunteer

  • ther

female Age Education Employment Gender

Model Coefficients *** *** *** *** *** * 28

(modeled on N = 6,258, evaluated on the 92 subjects)

More likely with:

  • Increasing age
  • Less education
  • Less employment
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age high school some college college part-time retired unemployed disability never volunteer

  • ther

female Age Education Employment Gender

Model Coefficients *** *** *** *** *** * 29

(modeled on N = 6,258, evaluated on the 92 subjects)

More likely with:

  • Increasing age
  • Less education
  • Less employment
  • Male
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Audio pre-processing

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Extracting features

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Extracting features

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Modeling

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Features (inputs)

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Pitch Jitter Spectral Energy Shimmer RMS Energy Segment Duration Speaking Rate Question Mark # Words Lexical Overlap Language Perplexity

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Features (inputs)

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Pitch Jitter Spectral Energy Shimmer RMS Energy Segment Duration Speaking Rate Question Mark # Words Lexical Overlap Language Perplexity

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Spectral Energy Prosody Text M F C C 3 d i f f . M F C C 3 J i t t e r M F C C 8 d i f f . P i t c h M F C C 3 M F C C 6 M F C C 3 d i f f . M F C C 1 Q u e s t i

  • n

M a r k S e g m e n t D u r a t i

  • n

M F C C 1 3

Model Coefficients

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  • Monotonous voice

Spectral Energy Prosody Text M F C C 3 d i f f . M F C C 3 J i t t e r M F C C 8 d i f f . P i t c h M F C C 3 M F C C 6 M F C C 3 d i f f . M F C C 1 Q u e s t i

  • n

M a r k S e g m e n t D u r a t i

  • n

M F C C 1 3

Model Coefficients

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  • Monotonous voice
  • Hesitation

Spectral Energy Prosody Text M F C C 3 d i f f . M F C C 3 J i t t e r M F C C 8 d i f f . P i t c h M F C C 3 M F C C 6 M F C C 3 d i f f . M F C C 1 Q u e s t i

  • n

M a r k S e g m e n t D u r a t i

  • n

M F C C 1 3

Model Coefficients

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  • Monotonous voice
  • Hesitation
  • Limited response

Spectral Energy Prosody Text M F C C 3 d i f f . M F C C 3 J i t t e r M F C C 8 d i f f . P i t c h M F C C 3 M F C C 6 M F C C 3 d i f f . M F C C 1 Q u e s t i

  • n

M a r k S e g m e n t D u r a t i

  • n

M F C C 1 3

Model Coefficients

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Results

Features AUC TPR @ FPR 10% HL-test Text 0.69 0.14 > 0.05 Demographic 0.79 0.38 < 0.05 Audio 0.90 0.71 > 0.05 Text + Audio 0.92 0.76 > 0.05

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  • Text + Audio best performing (better than demographic)
  • Text + Audio also has best recall rate
  • Best performing model is well-calibrated
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Conclusion

  • A method to quantify speech patterns to model

cognitive impairment.

  • Utilize findings without formally deploying the

model.

  • Don’t necessarily need to know exam

structure.

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Future Work

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5,000+

subjects 7,000+ audio recordings

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Details in Publication

“Spoken Language Biomarkers for Detecting Cognitive Impairment”

  • T. Alhanai, R. Au, and J. Glass, IEEE Automatic Speech and

Recognition Workshop, December 2017

[Paper]: https://groups.csail.mit.edu/sls/publications/2017/ASRU17_alhanai.pdf [Source Code]: https://github.com/talhanai/asru2017-method.git

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Spoken Language Biomarkers for Detecting Cognitive Impairment

Tuka Alhanai

Advisor: James Glass Spoken Language Systems Group Computer Science & Artificial Intelligence Lab Massachusetts Institute of Technology 3rd May 2018

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tuka@mit.edu talhanai talhanai.com