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Sense and nonsense: The contributions of spectral and amplitude modulations to speech perception. Carolyn McGettigan 1 , Stuart Rosen 2 , Zarinah Agnew 1 , Sophie Scott 1 1 UCL Institute of Cognitive Neuroscience 2 UCL Speech, Hearing and Phonetic Sciences. Background
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Sense and nonsense: The contributions of spectral and amplitude modulations to speech perception Carolyn McGettigan1, Stuart Rosen2, Zarinah Agnew1, Sophie Scott1 1UCL Institute of Cognitive Neuroscience 2UCL Speech, Hearing and Phonetic Sciences
Background In PET: Rosen, Wise, Chadha & Scott (in prep)investigated lateral asymmetries in auditory perception (and speech perception) using speech-derived acoustic modulations • SØAØ • SmodAØ • SØAmod • SmodAmod • intSmodAmod
Flat AM SpM SpMAM Flat AM SpM SpMAM Flat AM SpM SpMAM Additive Effects Effect size SØAØ SØAmod SmodAØ SmodAmod N=13, p<0.0001, 40 voxels Intelligibility Response Effect size SØAØ intSmodAmod SØAmod SmodAØ SmodAmod N=6, p<0.001, 40 voxels
Proposed study in fMRI • - A replication of the PET study, with all 5 conditions • Subjects • 16 participants (18-40yrs) • Procedure • Pretraining to criterion on intSmodAmod • Passive listening in scanner; 40 items from each of the five conditions; 40 silent trials; pseudorandomized condition order • Memory probe post-test • Protocol • 1 functional run; sparse sampling (TR 8 sec, TA 3 sec), flip angle 90 degrees, 35 axial slices; 1 video per TR; jittered stimulus onset (4.3 seconds before acquisition ± 500ms) • HIRes MP-RAGE (160 sagittal slices; 1mm3 resolution) • Total approx. 45 mins in the scanner • Analysis in SPM5 • Predictions: • Right anterior STS peak for additive response to modulated sounds • Left ant. STS for intelligible sounds