Study of Neural Correlates of Mandarin Tonal Production with Neural Network Model Department of Electrical Engineering, National Central University, Jhongli 320, Taiwan, ROC Chairman:Hung-Chi Yang Presenter: Yue-Fong Guo Advisor: Dr. Yeou-Jiunn Chen Date: Chao-Min Wu* Tao-Wei Wang Received 6 May 2011; Accepted 15 July 2011; doi: /jmbe.934

Outline Introduction Overview of the DIVA model Method Results Discussion Conclusion 2

Introduction Population ages Communicative disorders Improve the diagnosis and treatment of speech problems Analyzing Mandarin speech production Neural correlates of Mandarin tonal production 3

Introduction Physiological model To Examine speech articulation A neural-network-based direction into DIVA models （ Directions Into Velocities Articulator ） Simulate neural correlates of speech production To determine the neural correlates of Mandarin tonal production 4

Introduction The DIVA model Originally design Fixed preset pitch Tonal production was not considered The modified DIVA model Produce four types of Mandarin tones Simulate brain activity regions 5

Overview of the DIVA model Adaptive neural network model The steps A word or a syllable input Generate articulatory movement commands Shape of the vocal tract required to produce Speech synthesizer produce speech sound Produces a sequence of number Represent the brain activity regions and levels 6

Overview of the DIVA model 7

Method DIVA model Mandarin tonal production is described and incorporated Simulating brain activity are presented 8

Method Mandarin tonal production Chao proposed a five-point-scale 9

Method Pitch scaling function Approximated with the fourth-order polynomials Multiplied by the pitch periods of the first tone 10

Method To modify the motor commands Corresponding articulator to generate The tonal speech The corresponding brain activity regions 11

Method Simulation of brain activity Baseline condition Speaking condition Corresponding brain areas 12

Method In the first simulation Given vowel with different tones(/a/, /á/, /ã/, and /à/) Were analyzed Verify whether capable of tone production In the second simulation The brain activity regions of two different vowels with a given tone(/a/-/u/) The difference of the corresponding vowel brain activity regions Determine whether the original function maintained 13

Method In the third simulation Give vowel with different tones A comparison among brain activity regions 14

Results In the first experiment According to the first two formant frequencies The produced f0 contours Capable of Mandarin tonal production 15

Results In the second experiment motor cortex, pre-motor cortex, auditory cortex, SMA, and cerebellum (a) the vowel /a/ and (b) the vowel /u/ 16

Results Difference between the production of different vowels Difference in the activation in the lip and laryngeal areas and the SSM area 17

Results In the third experiment Difference in the larynx area and the somatosensory cortex 18

Discussion Previous study find the tone-relate activity regions Prefrontal cortex Pitch judgment tasks Left middle temporal Word-level comprehension Right inferior frontal gyri Precentral gyri 19

Discussion The DIVA model simulating brain activity Motor cortex Auditory Somatosensory Cerebellum The differences between simulation and study 20

Conclusion Because these regions are not included in the DIVA model. Future study Focus on the tone-related brain region Needed to include these region in the DIVA model To investigate the role The frontal and temporal lobes 21

The end 22