Michelle L Hughes
Father Flanagan´s Boys´ Home
Project start date: 2009-02-06
Project end date: 2014-01-31
Sponsored Links Excellgen http://Excellgen.com
PHYSIOLOGY AS A POTENTIAL PREDICTOR OF PERCEPTION IN COCHLEAR IMPLANTS
Michelle L Hughes, Coor., Cochlear Implant Prog.
Father Flanagan´s Boys´ Home, Boys Town, Ne 68010
Grant 5R01DC009595-02 from National Institute On Deafness And Other Communication Disorders
Abstract: The overall goal of this research project is to better understand the relation between physiological measures of temporal and spatial interaction in cochlear implants (CIs) and performance on psychophysical and speech-perception tasks. Speech-processor program parameters such as stimulation rate, number of electrodes, or stimulus timing (i.e., simultaneous or sequential stimulation) can be manipulated to some extent to reduce interaction in either the temporal or spatial domain. However, it is not clear what the relative contributions of temporal and spatial interaction are to speech-perception ability and how these effects vary across individual CI users. It is possible that interaction affects CI recipients in different ways based on differences in peripheral physiology. Further, differences in peripheral physiology may account for differences in performance as a function of programming choices across individual CI recipients. It is anticipated that research findings from this project may translate into objective methods that can be used to choose specific CI speech-processor programming parameters to maximize performance on an individual basis. This research project consists of three specific aims. The first aim is to evaluate the extent to which physiological measures of auditory-nerve temporal response properties relate to psychophysical measures of temporal integration and performance with different rates of stimulation. These studies will evaluate temporal response properties of the auditory nerve, temporal integration ability, and speech-perception performance with different rates of stimulation. We hypothesize that neural measures such as refractory-recovery and stochastic independence will aid in predicting an optimal stimulation rate for individual CI users. The second aim is to examine the extent to which physiological measures of spatial selectivity are related to pitch ranking and electrode discrimination for intermediate (or virtual) channels. These studies will evaluate the relation between physiological measures of spatial selectivity using actual and virtual channels versus pitch ranking and electrode discrimination tasks. We hypothesize that measures of auditory-nerve spatial selectivity will aid in predicting whether intermediate pitches can be perceived for individual CI users. These measures may lead to objective ways to determine whether an individual subject may benefit from a strategy that employs expanded spectral representation through intermediate or virtual channels. The third aim is to examine the relative effects of physiological and psychophysical channel interaction for simultaneous and sequential stimulation. These studies will evaluate the relative contribution of each type of interaction to determine whether the potential benefits of increased stimulation rate outweigh potential disadvantages of electrical field interaction with simultaneous stimulation. We hypothesize that physiological measures may aid in predicting whether better performance is achieved with a fully sequential strategy versus a partially simultaneous strategy. The goal of this research is to find objective ways to choose speech-processor programming parameters for cochlear implant recipients. The benefits are that recipients would be fit with an optimal program from the beginning of implant use. This is especially important for very young congenitally deafened children who cannot actively participate in formal speech-perception testing or sound-quality judgments, which are traditionally used to determine the best program for an individual
Keywords: 0-11 years old; Accounting; Acoustic Nerve; Affect; Auditory Prosthesis; Behavioral; Child; Child Youth; Children (0-21); Cochlear Implants; Cochlear Prosthesis; Cognitive Discrimination; Cranial Nerve Eight; Cranial Nerve VIII; Disadvantaged; Discrimination; Discrimination (Psychology); Eighth Cranial Nerve; Electrodes; Generations; Goals; Human, Child; Implant; Individual; Judgment; Lead; Location; Measures; Methods; Nervous; Pattern; Pb element; Perception; Performance; Peripheral; Physiologic; Physiological; Physiology; Process; Programs (PT); Programs [Publication Type]; Property; Property, LOINC Axis 2; Psychology, Physiologic; Psychology, Physiological; Psychophysiological; Psychophysiology; R01 Mechanism; R01 Program; RPG; Recovery; Refractory; Relative; Relative (related person); Research; Research Grants; Research Project Grants; Research Projects; Research Projects, R-Series; Sound; Sound - physical agent; Speech; Speech Perception; Stimulus; Testing; Time; Translating; Translatings; VIIIth Cranial Nerve; Vestibulocochlear Nerve; Work; auditory nerve; base; children; computerized data processing; data processing; heavy metal Pb; heavy metal lead; language translation; neural; preference; programs; psycho-physiological; relating to nervous system; response; signal processing; sound; speech processing; virtual; youngster
Relevance: The goal of this research is to find objective ways to choose speech-processor programming parameters for cochlear implant recipients. The benefits are that recipients would be fit with an optimal program from the beginning of implant use. This is especially important for very young congenitally deafened children who cannot actively participate in formal speech-perception testing or sound-quality judgments, which are traditionally used to determine the best program for an individual
Project start date: 2009-02-06
Project end date: 2014-01-31
Budget start date: 1-FEB-2010
Budget end date: 31-JAN-2011
PFA/PA: PA-07-070
5R01DC009595-02 (2010): $289080
Grants awarded to Michelle L Hughes
PHYSIOLOGY AS A POTENTIAL PREDICTOR OF PERCEPTION IN COCHLEAR IMPLANTS
Michelle L Hughes
Father Flanagan´s Boys´ Home
Grant 1R01DC009595-01A1 from National Institute On Deafness And Other Communication Disorders IRG: AUD
Abstract: The overall goal of this research project is to better understand the relation between physiological measures of temporal and spatial interaction in cochlear implants (CIs) and performance on psychophysical and speech-perception tasks. Speech-processor program parameters such as stimulation rate, number of electrodes, or stimulus timing (i.e., simultaneous or sequential stimulation) can be manipulated to some extent to reduce interaction in either the temporal or spatial domain. However, it is not clear what the relative contributions of temporal and spatial interaction are to speech-perception ability and how these effects vary across individual CI users. It is possible that interaction affects CI recipients in different ways based on differences in peripheral physiology. Further, differences in peripheral physiology may account for differences in performance as a function of programming choices across individual CI recipients. It is anticipated that research findings from this project may translate into objective methods that can be used to choose specific CI speech-processor programming parameters to maximize performance on an individual basis. This research project consists of three specific aims. The first aim is to evaluate the extent to which physiological measures of auditory-nerve temporal response properties relate to psychophysical measures of temporal integration and performance with different rates of stimulation. These studies will evaluate temporal response properties of the auditory nerve, temporal integration ability, and speech-perception performance with different rates of stimulation. We hypothesize that neural measures such as refractory-recovery and stochastic independence will aid in predicting an optimal stimulation rate for individual CI users. The second aim is to examine the extent to which physiological measures of spatial selectivity are related to pitch ranking and electrode discrimination for intermediate (or virtual) channels. These studies will evaluate the relation between physiological measures of spatial selectivity using actual and virtual channels versus pitch ranking and electrode discrimination tasks. We hypothesize that measures of auditory-nerve spatial selectivity will aid in predicting whether intermediate pitches can be perceived for individual CI users. These measures may lead to objective ways to determine whether an individual subject may benefit from a strategy that employs expanded spectral representation through intermediate or virtual channels. The third aim is to examine the relative effects of physiological and psychophysical channel interaction for simultaneous and sequential stimulation. These studies will evaluate the relative contribution of each type of interaction to determine whether the potential benefits of increased stimulation rate outweigh potential disadvantages of electrical field interaction with simultaneous stimulation. We hypothesize that physiological measures may aid in predicting whether better performance is achieved with a fully sequential strategy versus a partially simultaneous strategy. The goal of this research is to find objective ways to choose speech-processor programming parameters for cochlear implant recipients. The benefits are that recipients would be fit with an optimal program from the beginning of implant use. This is especially important for very young congenitally deafened children who cannot actively participate in formal speech-perception testing or sound-quality judgments, which are traditionally used to determine the best program for an individual
Project start date: 2009-02-06
Project end date: 2014-01-31
3R01DC009595-01A1S1 (2009): $146000
CHANNEL INTERACTION IN COCHLEAR IMPLANTS
Michelle L Hughes
Father Flanagan s Boys Home Boys Town, Ne 68010
Grant 5R03DC007017-03 from National Institute On Deafness And Other Communication Disorders IRG: ZDC1
Abstract: Multi-channel cochlear implants (CIs) are designed to provide frequency-specific information to the recipient by stimulating different sites within the cochlea. However, the presence of multiple stimulation sites within the cochlea increases the risk of interaction between these sites. Channel interaction is a phenomenon that can occur when electrodes in a CI stimulate overlapping neural populations. When multiple electrodes are stimulated simultaneously, current fields from each electrode can sum or subtract prior to neural stimulation. The perceptual result can be a stimulus that is either uncomfortably loud or inaudible. When 2 electrodes are stimulated in rapid succession, nerve fibers become refractory in response to the first electrode and are thus unable to respond to the second electrode. As a result, some information in the speech signal may not be adequately encoded by the auditory periphery, which might have negative effects on speech perception performance with the CI. Previous research has shown that channel interaction can be measured both psychophysically and physiologically, but little is known about the extent to which these 2 measures are related. Psychophysical measures of channel interaction may be useful for making decisions about creating optimal speech processor programs for individual CI recipients. Unfortunately, making detailed psychophysical measures is not clinically feasible because it is time consuming and generally not possible with pediatric CI recipients. However, peripheral measures of channel interaction can be made relatively quickly with physiologic techniques. The overall goal of this application is to determine how physiologic measures of channel interaction are related to psychophysical measures of channel interaction, and if either of these measures can aid the clinician in choosing optimal speech processing parameters for individual CI recipients. The proposed experiments are designed to (1) investigate the relation between physiologic and psychophysical measures of channel interaction for non-simultaneous stimulation; (2) investigate the relation between physiologic and psychophysical measures of channel interaction for simultaneous stimulation; and (3) investigate the relation between channel interaction and speech perception performance using speech processing strategies that employ both simultaneous and non-simultaneous stimulation modes.
Keywords: auditory stimulus, cochlear implant, electrical impedance, electrostimulus, neural conduction, neurophysiology, perceptual masking, speech recognition, electrode, evoked potential, neural transmission, neuron, psychophysics, stimulus /response, behavior test, clinical research, data collection methodology /evaluation, human subject, medical implant science
Project start date: 2005-04-01
Project end date: 2009-03-31
5R03DC007017-03 (2007): $68269
5R03DC007017-02 (2006): $70308
1R03DC007017-01A1 (2005): $72000