Keith A Johnson
University Of California Berkeley
Project start date: 2011-02-01
Project end date: 2014-01-31
Sponsored Links Excellgen http://Excellgen.com
Grants awarded to Keith A Johnson
PROCESSES OF SPEAKER NORMALIZATION IN SPEECH PERCEPTION
Keith A Johnson, Professor
Ohio State University 1960 Kenny Road Columbus, Oh 43210
Grant 5R29DC001645-05 from National Institute On Deafness And Other Communication Disorders IRG: CMS
Abstract: This project will investigate the listener s ability to understand speech produced by different talkers. This perceptual ability (which is called speaker normalization) is one example of the adaptiveness of speech perception, and so a better understanding of how listeners adapt to different talkers may lead to a better understanding of the adaptive perceptual processes which take place in response to hearing impairment. In spite of its intrinsic and practical importance, speaker normalization has not been a focus of interest for most speech perception researchers. The project will compare two models of speaker normalization. The mediated normalization model holds that the perception of speech is cognitively mediated by information about the speaker, whereas the immediate normalization model holds that information in the speech signal resulting from acoustic differences between speakers is auditorily integrated with linguistic acoustic cues in such a way that differences between speakers are eliminated. These two models will be contrasted in 13 experiments involving tests of (1) the role of familiarity with particular speakers in speech perception, (2) the role of secondary acoustic cues for speaker identity (such as breathiness) and visual information about the speaker, and (3) speaker normalization effects for plosive consonants and nasals. The proposed experiments make use of synthetic speech or digitally processed natural speech and involve manipulating acoustic cues for speaker identity, interstimulus interval, and presentation type (randomly mixing speakers or blocking stimuli by speaker) while observing the impact of these manipulations on the perception of vowels, fricatives, stops, and nasals. In addition to the experiments, the proposed program of research involves the construction of mathematical models of speech perception. Exemplar-based implementations of both the mediated and immediate normalization models will be constructed and tested against the data generated by the experiments.
Project start date: 1992-07-01
Project end date: 1997-06-30
5R29DC001645-05 (1995): $99029
5R29DC001645-04 (1994): $94043
5R29DC001645-02 (1993): $90634
Cross Linguistic Studies On Spoken Language Processing
Keith A Johnson, Professor
University Of California Berkeley 2150 Shattuck Avenue, Room 313 Berkeley, Ca 947045940
Grant 5R01DC004421-06 from National Institute On Deafness And Other Communication Disorders IRG: ZRG1
Abstract: The long-term objective of this project is to understand spoken language processing (particularly speech perception and auditory word recognition) in linguistic context. Speech signals are unique in human experience because they are highly familiar, and have great practical significance in daily life. Therefore, it is not too surprising to find that people develop optimized processing strategies tuned specifically for speech (cf. Werker and Tees, 1984; Kuhl et al., 1992). In this project, we study how this tuning process may be sensitive to linguistic structure. Two key questions are addressed in the proposed work. (1) What in the speech perception mechanism is altered by linguistic experience? and (2) how is linguistic/phonetic information encoded for speech processing? These questions will be addressed in a set of nine studies that address four specific aims. (1) Distinguish between language-specific perceptual processing and language-universal auditory sensitivity for speech sounds. (2) Determine whether language-specific speech processing is tied to the lexicon. (3) Test the claim that phonetic/perceptual knowledge is oriented toward handling distinctive phonological features. (4) Model the experimental results in an explicit theory of speech perception.
Keywords: auditory discrimination, phonology, semantics, sensory feedback, speech, speech recognition, adult human (21+), nonEnglish language, psychophysics, behavior test, behavioral /social science research tag, clinical research, human subject
Project start date: 2000-04-01
Project end date: 2009-01-30
5R01DC004421-06 (2007): $167242
5R01DC004421-05 (2006): $135762
2R01DC004421-04A1 (2005): $178093
5R01DC004421-02 (2001): $73000
1R01DC004421-01 (2000): $106510
CHARACTERIZING THE EVOLUTION OF AMYLOID DEPOSITION IN NORMAL ELDERLY
Keith A Johnson
Massachusetts General Hospital, Partners Research Management, Boston, Ma 02199
Grant 1R01AG037497-01 from National Institute On Aging
Abstract: The deposition of amyloid-beta (Ass) deposition is thought to begin many years prior to the onset of clinical Alzheimer´s disease, but until recently it was not possible to track the longitudinal accumulation of Ass in vivo. Cross-sectional autopsy series and recent PET studies using 11CPittsburgh Compound B (PiB) suggest that a large fraction of cognitively normal older individuals harbor amyloid pathology. Our preliminary cross-sectional PiB imaging data in 100 cognitively normal (CN) older individuals have demonstrated significant variability in the level and anatomic distribution of amyloid deposition. It remains unknown whether there is a specific threshold of amyloid pathology in these CN that will predict 1) further amyloid accumulation, 2) the emergence of abnormalities on structural and functional imaging consistent with preclinical AD, and 3) subsequent cognitive decline. This project will acquire longitudinal PiB imaging, FDG-PET, resting fMRI, and detailed neuropsychological assessments in 80 CN subjects every 2 years to investigate the temporal course and anatomic pattern of amyloid accumulation (Aim 1). We will also utilize a recently developed, high-sensitivity PET camera to determine if there is a gradual accumulation of amyloid deposition that is not currently detectable with existing standard cameras (Aim 2). Finally, we will relate longitudinal amyloid accumulation to other indicators of prodromal AD, including regional FDG hypometabolism, functional MRI default network disruption, hippocampal atrophy, cortical thinning, and cognitive decline (Aim 3). This study will capitalize on an existing cohort of well-characterized clinically normal older subjects, a strong multi-disciplinary team of investigators, and state-of-the-art imaging methodology to probe the link between amyloid accumulation and the earliest brain changes associated with preclinical AD. The symptoms of Alzheimer´s disease, a major threat to public health, are preceded by a period of brain amyloid accumulation of at least 10 years duration. The overall aim of this grant proposal is to improve our ability during the presymptomatic period to detect amyloid, to trace its accumulation at low levels, and to assess its impact on the brain, so that treatments may begin at an earlier stage of disease when damage is more limited. To accomplish this, we propose to re-enroll a group of older adults who have already participated in our amyloid research, to now undergo a set of follow-up brain scans and cognitive tests every two years. We propose to measure the buildup of amyloid over time with PiB PET and assess the impact on brain structure with MRI and function with FDG PET. We will also test a powerful new, high-sensitivity PET scanner that we predict will improve our detection of amyloid and permit us to better study it´s earliest consequences
Keywords: Active Follow-up; Age; Aged 65 and Over; Alzheimer; Alzheimer beta-Protein; Alzheimer disease; Alzheimer sclerosis; Alzheimer syndrome; Alzheimer`s; Alzheimer`s Disease; Alzheimer`s amyloid; Alzheimers Dementia; Alzheimers disease; Amyloid; Amyloid Alzeheimer`s Dementia Amyloid Protein; Amyloid Beta-Peptide; Amyloid Fibril Protein (Alzheimer`s); Amyloid Protein A4; Amyloid Substance; Amyloid beta-Protein; Amyloid beta-Protein, Alzheimer`s; Amyloid deposition; Anatomic; Anatomical Sciences; Anatomy; Applications Grants; Arts; Asses; Autopsy; Binding; Binding (Molecular Function); Brain; Brain scan; CH3OCF2CH(CF3)OCH2F; Cell Communication and Signaling; Cell Signaling; Clinical; Clinical Data; Cognitive; Cognitive Disturbance; Cognitive Impairment; Cognitive decline; Cognitive function abnormal; D-Glucose; Data; Dementia, Alzheimer Type; Dementia, Primary Senile Degenerative; Dementia, Senile; Deposit; Deposition; Detection; Dextrose; Diagnosis; Disease; Disorder; Disturbance in cognition; Donkey; Dysfunction; Early Diagnosis; Elderly; Elderly, over 65; Encephalon; Encephalons; Enrollment; Equus asinus; Evaluation; Evolution; FDG PET; Functional Imaging; Functional Magnetic Resonance Imaging; Functional disorder; Glucose; Grant Proposals; Grants, Applications; Head; Image; Impaired cognition; Impairment; Individual; Intracellular Communication and Signaling; Investigators; Lateral; Link; MR Imaging; MR Tomography; MRI; MRI, Functional; Magnetic Resonance Imaging; Magnetic Resonance Imaging Scan; Magnetic Resonance Imaging, Functional; Measures; Medical Imaging, Magnetic Resonance / Nuclear Magnetic Resonance; Medical Imaging, Positron Emission Tomography; Memory; Memory Deficit; Memory impairment; Method LOINC Axis 6; Methodology; Methods; Molecular Interaction; NMR Imaging; NMR Tomography; Nervous System, Brain; Nuclear Magnetic Resonance Imaging; PET; PET Scan; PET imaging; PETSCAN; PETT; Parietal; Pathologic; Patients; Pattern; Performance; Physiologic Imaging; Physiopathology; Pittsburgh Compound-B; Play; Positron Emission Tomography Scan; Positron-Emission Tomography; Price; Primary Senile Degenerative Dementia; Proton Magnetic Resonance Spectroscopic Imaging; Public Health; Rad.-PET; Research; Research Personnel; Researchers; Rest; Risk; Role; Sampling; Science of Anatomy; Series; Signal Transduction; Signal Transduction Systems; Signaling; Staging; Structure; Symptoms; Testing; Time; Zeugmatography; a beta peptide; abeta; advanced age; amyloid beta; amyloid imaging; amyloid pathology; amyloid-b protein; anatomy; beta amyloid fibril; biological signal transduction; cognitive dysfunction; cognitive loss; cognitive reserve; cognitively impaired; cohort; compound B; dementia of the Alzheimer type; design; designing; disease/disorder; early detection; elders; endophenotype; enroll; executive control; executive function; fMRI; fluorodeoxyglucose PET; fluorodeoxyglucose positron emission tomography; follow-up; geriatric; hippocampal atrophy; hippocampal atropy; imaging; imaging modality; improved; in vivo; late life; later life; ligand PIB; necropsy; neuropsychological; novel; older adult; older person; pathophysiology; postmortem; pre-clinical; preclinical; pricing; primary degenerative dementia; public health medicine (field); public health relevance; senile dementia of the Alzheimer type; senior citizen; social role; soluble amyloid precursor protein
Relevance: The symptoms of Alzheimer´s disease, a major threat to public health, are preceded by a period of brain amyloid accumulation of at least 10 years duration. The overall aim of this grant proposal is to improve our ability during the presymptomatic period to detect amyloid, to trace its accumulation at low levels, and to assess its impact on the brain, so that treatments may begin at an earlier stage of disease when damage is more limited. To accomplish this, we propose to re-enroll a group of older adults who have already participated in our amyloid research, to now undergo a set of follow-up brain scans and cognitive tests every two years. We propose to measure the buildup of amyloid over time with PiB PET and assess the impact on brain structure with MRI and function with FDG PET. We will also test a powerful new, high-sensitivity PET scanner that we predict will improve our detection of amyloid and permit us to better study it´s earliest consequences
Project start date: 2010-09-01
Project end date: 2015-08-31
Budget start date: 1-SEP-2010
Budget end date: 31-AUG-2011
PFA/PA: PA-07-070
1R01AG037497-01 (2010): $694513
SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY (SPECT)
Keith A Johnson, Associate Professor Of Neurology
Brigham And Women s Hospital Research Administration Boston, Ma 02115
Grant 2P01AG004953-190005 from National Institute On Aging IRG: ZAG1
Abstract: In this project, SPECT perfusion data will be obtained at baseline from controls and non-demented subjects with cognitive impairments who will be recruited through the Clinical Core and followed over time. Subjects will be evaluated longitudinally with SPECT when they cross specific transition boundaries, as defined by the Clinical Core. The overall goal of the SPECT project is to determine whether SPECT data can be used to predict which non-demented individuals with cognitive problems will develop progressive cognitive decline, which will progress to the point where they meet criteria for AD, and which will remain stable. In addition, we will seek to determine the evolution of brain changes that characterize prodromal AD, and how these measures relate to the clinical characteristics of the subjects. Underlying these goals is the assumption that SPECT perfusion data can serve as an indirect measure of the neuronal loss that occurs when neuritic plaques and neurofibrillary tangles accumulate during the development of Alzheimer s disease (AD). In the proposed funding cycle we will analyze the SPECT data with several methods (1) MRI guided regions-of-interest (ROI), (2) a multivariate, voxel-based method known as singular value decomposition (SVD), and (3) a widely used voxel-based unvariate method, statistical parametric mapping (SPM99). Results from the three processing streams will be compared with one another and to variables from other projects and cores. In addition, we will seek to determine the relationship between SPECT measures and other information obtained on the same individuals by the cores and the projects, including clinical data, genotype status, volumetric MRI, and fMRI signal change.
Keywords: Alzheimer s disease, aging, brain imaging /visualization /scanning, pathologic process, single photon emission computed tomography, brain circulation, brain disorder diagnosis, cognition disorder, genetic susceptibility, longitudinal human study, neuroanatomy, neurophysiology, psychological aspect of aging, bioimaging /biomedical imaging, human old age (65+), human subject, image processing, patient oriented research
Project start date: 1984-08-01
Project end date: 2007-07-31
Sponsored Links Excellgen http://Excellgen.com
Keith A Johnson
Massachusetts General Hospital
Project start date: 2012-03-15
Project end date: 2017-02-28
SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY (SPECT)
Keith A Johnson, Associate Professor Of Neurology
Brigham And Women s Hospital Research Administration Boston, Ma 02115
Grant 5P01AG004953-230005 from National Institute On Aging IRG: ZAG1
Keywords: Alzheimer s disease, aging, brain imaging /visualization /scanning, pathologic process, single photon emission computed tomography, brain circulation, brain disorder diagnosis, cognition disorder, genetic susceptibility, longitudinal human study, neuroanatomy, neurophysiology, psychological aspect of aging, bioimaging /biomedical imaging, human old age (65+), human subject, image processing, patient oriented research
PROCESSES OF SPEAKER NORMALIZATION IN SPEECH PERCEPTION
Keith A Johnson, Professor
Ohio State University 1960 Kenny Road Columbus, Oh 43210
Grant 5R29DC001645-06 from National Institute On Deafness And Other Communication Disorders IRG: CMS
Project start date: 1992-07-01
Project end date: 1997-12-31
5R29DC001645-06 (1996): $103136