Visuomotor Tracking Abilities of Adults who Stutter, Adults with Parkinson’s disease and Normally Fluent Healthy Adults Victoria Tumanova Department of Communication Sciences and Disorders Dissertation project

Introduction Stuttering is a disorder of timing and sequencing of multiple movements Procedural learning Motor Learning Speech is a highly automatized motor behavior Language Phonology Grammar May be less robust in people who stutter Studies of nonsense word learning Studies of finger tapping and tracking

Introduction Procedural learning is dependent on the Basal Ganglia function Studies of people who have abnormal BG function Recent hypothesis that BG may be involved in developmental stuttering Imaging studies of PWS and NS Subcortical mapping and lesion studies Sensitivity to dopamine modulating medication Speech and non-speech (tics) characteristics

Questions Is procedural learning less robust in PWS? Is there any difference in oral vs manual tracking performance (pervasive vs non pervasive deficit) Is it similar to people with abnormal BG function (Parkinson’s disease)?

Method: Participants 15 adults who stutter (13) 15 adults with Parkinson’s disease, mild or moderate stage, on regular medication (13) 15 age-matched to PWS normally fluent healthy adults 15 age-matched to PPD normally fluent healthy adults

Tracking with the jaw and dominant hand Each trial lasts 60 seconds 3 repeated trials for each “predictable” condition

Optotrak – Jaw tracking

Hand tracking

Optotrak camera

User interface

Method: Visuomotor Tracking Conditions Simple repetitive movement sine waves at 0.3, 0.6 and 0.9 Hz Complex repetitive movement combination of sine waves with 3 amplitudes, S-M-L

Method: Visuomotor Tracking Conditions Complex non-repetitive movement combination of sine waves with different amplitudes with constant frequency at 0.3, 0.6 and 0.9 Hz Sine waves that vary both in frequency and in amplitude Tracking by memory Simple sine wave, target disappears after 30 sec

Analysis Learning =increases in speed and accuracy over time Sine wave can be characterized in terms of Amplitude Frequency Phase

Analysis Gain Delay Calculated using amplitude data is the ratio of tracking peak velocity to target peak velocity is expected to be very close to 1 for “good trackers” Delay Calculated using phase data, target phase - tracking phase Negative phase difference – lag Positive phase difference – lead expected to be very close to 0 for “good trackers”

Data points for each measure

GAIN AMPLITUDE DELAY

Results

Data points for Gain/Delay per trail Depending on the frequency of the target 54 points (0.3Hz=18 cycles*3) 108 points (0.6Hz= 36 cycles*3) 162 points (0.9Hz=54 cycles*3)

Subject 1 (gain over t) Subject 2 Subject 3 Subject 4 Subject 5 0.8896 0.6013 0.7569 0.7112 1.2525 0.8355 1.2611 0.861 0.5922 0.1023 0.8807 0.9297 1.1177 0.8719 0.4393 0.1779 0.8165 0.9588 0.9607 0.8755 1.2346 0.4579 0.9283 0.7416 0.8768 0.8995 0.8255 0.3954 0.8266 0.7906 0.8281 0.8982 0.5844 0.5762 0.6696 0.7182 0.9397 0.9737 0.8757 0.5608 0.8207 0.9786 0.9013 0.9163 0.8714 0.7125 0.934 0.8668 0.8946 0.5841 0.9115 0.8895 0.7886 0.7771 0.7878 1.1617 0.7622 0.2118 0.9378 0.6076 0.9532 1.0331 0.7432 0.7403 1.0086 0.6837 1.0221 0.816 0.6075 0.9901 1.2561 0.7922 0.6993 1.042 0.9897 0.3225 0.9301 0.8499 1.2458 1.0671 0.9917 0.6745 1.0104 0.9218 1.6381 0.8826 1.2568 0.9542 0.7527 0.9462

Statistical Analysis Accuracy overall Accuracy over time Divide the tracking trail into 3 segments (initial 20 sec, medial 20sec, final 20sec) Compare trial 1 with trail 2 and trial 3

Thank you!