Neurological disorders affecting cognition, sensation and motor behaviors
We are investigating the neurobiological bases of clinical disorders of the nervous system that affect sensation, motor performance, and cognition. Our studies employ electrophysiological and behavioral methods to define functional mechanisms underlying clinical syndromes relevant for specific research question. The current interests are two fold:
1) Hearing disorder called Auditory Neuropathy: This form of deafness is due to disordered function of the auditory nerve while cochlea sensory receptors are normal. Patients with this disorder have impaired abilities to utilize temporal features of auditory signals that are essential for proper speech comprehension and sound localization. The disorder is likely due to disordered auditory nerve function that affects synchrony and rate of discharge. The mechanisms underlying the auditory deficits, central auditory pathway changes accompanying the hearing loss, the genetic bases of auditory neuropathy, and the effects of cochlear implants are areas under investigation.
2) Memory changes in Aging and Dementia: We are studying brain activity involved in alterations of memory that accompany both aging and Alzheimer’s dementia. We draw our subjects from the Center for Aging and Dementia that include normal subjects up to 100+ years. Memory functions are well characterized by neuropsychological tests and are related to results from our experiments measuring brain potentials (evoked potentials) and brain blood flow (fMRI) recorded during memory and behavioral tasks. We have identified alterations in auditory cortical activity with both aging and disease that reflects changes in cortical-cortical connections. The role of treatments in modifying changes in both memory and brain activity is under study.
Publications 1-10 below are selected recent publications.
STARR, A, PICTON, TW, SININGER, Y, HOOD, LF, BERLIN, CW. Auditory Neuropathy, Brain, 1996, 119:741-53.
STARR A, SININGER Y, WINTER M, DEREBERY MJ, OBA S, MICHALEWSKI H, Transient deafness due to temperature-sensitive auditory neuropathy. in press Ear and Hearing; 1998, 19:169-179
BUTINAR D, ZIDAR J, LEONARDIS L, POPOVIC M, KALAYDJIEVA L, ANGELICHIVA D, SININGER Y, KEATS B, STARR A. Hereditary Auditory, Vestibular, Motor and Sensory Neuropathy in a Slovenian Roma (Gypsy) Kindred, Annals of Neurology, 1999, 46:36-44
ZENG FG, OBA S, GARDE S, SININGER S, STARR A. Temporal and Speech Processing Deficits in Auditory Neuropathy. Neuroreports, 1999, 10:3429-35.
CONLEY EM, MICHALEWSKI HJ, STARR A. The N100 auditory cortical evoked potential indexes scanning of auditory short-term memory. Clinical Neurophysiology 1999, 110:2086-2094
GOLOB E, STARR A. Effects of stimulus sequence on event-related potentials and reaction time during target detection in Alzheimer’s Disease. Clinical Neurophysology, 2000, 111: 1438-1449.
GOLOB E, STARR A. Age-related qualitative differences in auditory cortical responses during short-term memory. Clinical Neurophysiology,1999,.111:2234-44
GOLOB EJ, MIRANDA GG, JOHNSON JK, STARR A. Sensory cortical interactions in aging, mild cognitive impairment, and Alzheimer’s disease. Neurobiology of Aging, 2001, 22: 755-763
GOLOB EJ, JOHNSON JK, STARR A. Auditory event-related potentials during target detection are abnormal in mild cognitive impairment. Clinical Neurophysiology . 2002;113:151-61.
Starr, A, Picton, T, Kim, R. Pathophysiology of Auditory Neuropathy. In, Y. Sininger and A. Starr (Eds.), Auditory Neuropathy. Singular: San Diego, CA, 2001