Neuroplasticity and Bilateral Cochlear Implantation Blake C. Papsin Karen A. Gordon

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1 Neuroplasticity and Bilateral Cochlear Implantation Blake C. Papsin Karen A. Gordon

2 Cochlear Implant Clinical Team Blake Papsin Vicky Papaioannou Karen Gordon Sharon Cushing Gina Goulding Naureen Sohail Laurie MacDonald Patt Fuller Adrian James Mary Lynn Feness Pat Di Santos Nancy Greenwald-Hood Susan Druker Valerie Simard Rebecca Malcomson Joelene Huber Gillian Lieberman Stephanie Jewell

3 Cochlear Implant Research Team DIRECTORS Karen Gordon Blake Papsin Sharon Cushing RESEARCH COORDINATORS Stephanie Jewell Carmen McKnight GRADUATE STUDENTS Salima Jiwani Melissa Polonenko Nikolaus Wolter Morrison Steel Michael Deighton Sara Giannantonio Josh Gnanasegaram FUNDING CIHR SickKids Foundation POST-DOCTORAL FELLOWS Vijayalakshmi Easwar William Parkes Shazia Peer COLLABORATORS Local Sick Kids Bob Harrison Susan Blaser Adrian James Paolo Campisi Sam Doesburg Vicky Papaioannou Local - External Sandra Trehub Frank Russo International Robert Cowen Richard van Hoesel

4 Introduction evolution/plasticity genetic facultative feature extraction binaurality assembly of the auditory environment effort

5 Introduction evolution/plasticity genetic facultative feature extraction binaurality John Tyler ( ) Teddy Roosevelt ( ) Chester Arthur ( ) Woodrow Wilson ( ) assembly of the auditory environment effort

6 Evolution/Plasticity Starlings at Otmoor (Dylan Winter)

7 Human = Communicators olfaction vision motor skill audition linguistic ability executive function

8 Feature Extraction pattern recognition learn rules fidelity experience consistency

9 SickKids Bilateral Experience Simultaneous implants n=198 Age at implant = 3.0 ± 3.5 yrs Sequen&al implants n=180 Age at 1st implant = 3.4 ± 3.1 yrs Age at 2 nd implant = 9.6 ± 4.7 yrs Inter- implant delay = 6.1 ± 3.9 yrs

10 Brainstem Asymmetry Simultaneous Sequential Gordon, et al., 2010

11 Studying Binaural Perception

12 Studying Binaural Perception Lateralization Index = (R-L)/(R+L) Wong et al. IEEE (2010)

13 Reorganization of Auditory Cortex Long Delay (> 2 years) * * * Left cortex Right cortex Short Delay (< 1.5 years) Simultaneous Normal Hearing Lateralization of auditory activity (%) * P<0.05 Gordon et al. Brain (2013)

14 Reorganization of Auditory Cortex Long Delay (> 2 years) * * * Left cortex Right cortex Short Delay (< 1.5 years) Simultaneous Normal Hearing Lateralization of auditory activity (%) * P<0.05 Gordon et al. Brain (2013)

15 Spatial Unmasking (noise at 0 ) vs. (noise at 90 )

16 Spatial Unmasking (noise at 0 ) vs. (noise at 90 )

17 Spatial Unmasking Spatial unmasking SNR (db) Noise moved to 1st implanted ear Noise moved to 2nd implanted ear P=0.001 P>0.05 Sequential sequential Simultaneous simultaneous Normal normal Chadha et al., Otol NeuroOtol, 2011

18 Inter-Aural/Implant Level & Timing Differences Normal Response Rate LeG +20 db +10 db 0 db - 10 db - 20 db Right L 0 R L R Sequential Response Rate CI2 +20 CU ILD Condi&on +10 CU 0 CU - 10 CU - 20 CU CI CI1 20 CI2 0 CI2 CI1 Simultaneous Response Rate ILD Condi&on Left +20 CU +14 CU +10 CU +6 CU +2 CU 0-2 CU -6 CU -10 CU -14 CU Right L R L R Intra-Aural/Implant Loudness Difference Condition Intra-Aural/Implant Timing Difference Condition

19 Inter-Aural/Implant Level & Timing Differences Normal Response Rate LeG +20 db +10 db 0 db - 10 db - 20 db Right L 0 R L R Sequential Response Rate CI2 +20 CU ILD Condi&on +10 CU 0 CU - 10 CU - 20 CU CI CI1 20 CI2 0 CI2 CI1 Simultaneous Response Rate ILD Condi&on Left +20 CU +14 CU +10 CU +6 CU +2 CU 0-2 CU -6 CU -10 CU -14 CU Right L R L R Intra-Aural/Implant Loudness Difference Condition Intra-Aural/Implant Timing Difference Condition

20 Inter-Aural/Implant Level & Timing Differences Sequential Month 9, n=29 CI CI1 Rate of Right/CI1 Responses Sequential * Simultaneous Simultaneous (n=20) Sequential R CI1 only (n=10) Normal (n=16) CI2 weighted CI1 weighted left leading right leading Interaural Level Difference (CU) Gordon, Abbasalipour et al., in press Inter-aural/implant Timing Difference (µs)

21 Binaural Fusion Steel et. al., in press

22 Inter-Aural/Implant Level & Timing Differences and Fusion * p< Level Cues 0 T T+10 T+20 L/CI- 2 Level Changing (db/cu) Unilateral control NH Group CI Group ITD = 0 ms Electrode = 20 (n=24) (n=25) Propor=on of 1 Response p< * Timing Cues ITD (ms) p< * NH (n=24) Group (n=25) (Mean ILD = ± 0.9 db)

23 Increased Effort & Increased P2 Amplitude Increased reac=on =me - emo=ons P2 Amplitude in speech aler auditory training Reac=on Time (ms) Cochlear Implant Users (n=24) ** ** p<0.01 P1 Normal Hearing Peers N1 (n=23) P2 Auditory Auditory- Visual Hopyan et al. Child Neuropsychology Tremblay (2009) et al. Clinical Neurophysiology (2009)

24 P2 P2 Jiwani et al. Clinical Neurophysiology (2013) Gordon et al. Fron8ers in Auditory Cogni8ve Neuroscience (2013)

25 Additional Resources Recruited Right S=mula=on CI Experienced Normal Hearing Dipole Differences P1 - P1 N1 - N1 P2 - P2 Jiwani et al., Submi?ed

26 Plasticity/Novel Process? the auditory system makes full use of sensory data novel methods of data processing are employed. precisely because assembling correctly promotes survival

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