Current Faculty

Catherine Carr

Professor

UMD Biology
4227 Biology-Psychology Bldg.

Research Interests : When sound reaches one ear before the other, the brain uses the resulting interaural time differences (ITDs) to localize the sound. The barn owl is a nocturnal hunter and a good model for how we localize sound and process temporal information in general. We have shown that ITDs are translated into location in space in the brainstem. Detection of these time differences depends upon two mechanisms of general significance to neurobiology, delay lines and coincidence detection. Incoming axons form delay lines to create maps of ITD in nucleus laminaris. Their postsynaptic targets act as coincidence detectors and fire maximally when the interaural time difference is equal but opposite to the delay imposed by the afferent axons. Current research is focused on models of delay line-coincidence detector circuit, on the assembly of the map of sound localization during development and on how such circuits evolve. All projects develop from initial behavioral observations into systems, cellular and molecular levels of analysis.

Animals : Birds, Reptiles

Lab : Carr Lab

Monita Chaterjee

Assistant Professor

UMD Hearing and Speech
0119E LeFrak Hall

Research Interests : A common problem in hearing impairment is that patients find it very difficult to follow speech in noisy backgrounds. This is also true for cochlear-implant listeners . Although cochlear implants are very successful in quiet surroundings, most cochlear implant users find it very difficult to listen in challenging acoustic environments: the presence of even one competing speaker can pose a significant problem. Part of the problem is that we don't quite understand how the normal auditory system performs this difficult task, or what kind of information about the incoming sound stream is needed for the brain to separate one source of sound from another. The work in my lab attempts to answer some of these questions. Our experiments are designed to quantitatively measure how well cochlear implant users can discriminate between speech-like sounds, both in quiet and in the presence of competing background sounds. These experiments are yielding interesting clues about how the brain separates sounds from each other. We expect that results of these experiments will contribute both to our understanding of how the central auditory system works as well as provide ways to improve cochlear implant speech processors in the future.

Animals : Humans

Lab : Cochlear Implants and Psychophysics Lab

Jonathan Fritz

Research Scientist

UMD Engineering
2202 A.V. Williams Bldg.

Research Interests : Part of the Electrical and Computer Engineering Department and The Institute for System Research, the Neural Systems Laboratory studies the functionality of the mammalian auditory system through a wide range of disciplines and techniques ranging from theoretical models to neurophysiological investigations and psychoacoustical experiments.

Animals : Ferrets, Monkeys

Lab : Neural Systems Laboratory

Sandra Gordon-Salant

Professor

UMD Hearing and Speech
0119L LeFrak Hall

Research Interests : The aging auditory system is characterized by anatomical alterations in peripheral and central structures. Aging is also accompanied by decline in cognitive processes. While many deficits in perception are attributed to peripheral hearing loss, there remain age-related alterations in processing of signals beyond those that are associated with sensitivity loss. The focus of this laboratory is investigation of the consequences of aging and hearing loss on auditory performance. Our work has shown that age-related deficits, independent of hearing loss, are primarily observed on measures of auditory temporal processing. The strategies employed include evaluation of behavioral performance on speech perception and psychoacoustic tasks, as well as electrophysiologic indices that alter stimulus timing or presentation rate.

Animals : Humans

Lab : Lab

Mardi Hastings

Visit Res Prof

Biology
2225 Biology-Psychology Building

Research Interests : Since the 1991 Heard Island feasibility test for acoustic thermometry in the ocean, the public concern about the effects of noise on marine mammals has grown. Recent news articles have reported potential effects of Navy sonar on marine mammals in Hanalei Bay, Hawaii, and in the Haro Strait of the Pacific Northwest. To determine how best to prevent harm to marine mammals while still training and operating at sea, we must understand the sound energy source characteristics and propagation paths, the location and movement of marine mammal populations, and the biological effects of sound on individual animals. The Marine Mammal Program at the Office of Naval Research has supported studies to determine the effects of human-generated underwater sound on the health, hearing, and behavior of these animals since 1992. We have learned a great deal about the effects of sound on hearing and some about the effects of sound on behavior, but there is still much to learn.

Animals : Marine mammals

Timothy Horiuchi

Associate Professor

Electrical and Computer Enginnering; Institute for Systems Research
2215 A.V. Williams Building

Research Interests : The lab's vision is to develop real-time neural models of the brain to understand how animals perceive, interact with, and learn about their environment. We are pursuing this by developing models of brains at the cellular, network, systems, and behavioral levels of abstraction and by testing these models in realistic sensory environments. Our current research is focused on the bat echolocation system, a system rich in interesting scientific questions and potential for commercial, industrial, and other applications. This is called the "Microchipoptera Project"

Animals : bats, robots!

Lab : Computational Sensorimotor Systems Laboratory

Patrick Kanold

Assistant Professor

UMD Biology
1116 Bioscience Research Bldg.

Research Interests : "The human brain is a very complex neuronal circuit. How does this circuit wire up during development? The major focus in the lab is to understand the circuits present in the developing brain and their influence of brain development and plasticity. One focus is on probing the response of the developing brain to sensory stimuli and the other is to record from small sub-circuits and study their responses and circuit behavior in great detail. We are particularly interested in the relationships of mechanisms and circuits that underlie developmental plasticity and circuits and mechanisms that underlie memory and plasticity in adults. We are addressing these issues by studies in the primary auditory and visual cortex."

Lab : The Kanold Lab

Hey-Kyoung Lee

Assistant Professor

College of Chemical and Life Sciences
1112 Bioscience Research Building

Research Interests : Our daily experience can trigger lasting memories, which are stored in our brains. Memories are stored ultimately by changing the way neurons convey information. More precisely, they are stored as changes in the function of synapses: the structures by which neurons contact and transmit signals to each other. My laboratory is interested in exploring the cellular and molecular changes that happen at the synapses to allow memory storage. Combining various techniques, such as electrophysiological recording, biochemical/molecular analysis, and imaging, we are aiming to understand the cellular and molecular changes that happen during synaptic plasticity. It is well established that neural activity can trigger synaptic changes, such as long-term potentiation (LTP) and long-term depression (LTD), which are cellular models of learning and memory. Currently we are looking at postsynaptic mechanisms of LTP and LTD. We found that synaptic plasticity is associated with changes in postsynaptic glutamate receptors. LTP and LTD are associated with changes in phosphorylation of the GluR1 subunit of AMPA type glutamate receptors. Using genetically altered mice that lack phosphorylation sites on GluR1, we found that LTP and LTD are both impaired. One line of research involves elucidating the downstream events that follow AMPA receptor phosphorylation changes. In addition to understanding the basic mechanisms of memory formation, we are also interested in elucidating the events that occur in diseased brains. Alzheimer's disease is a devastating memory disorder that affects the social well-being of affected individuals. In collaboration with Dr. Philip Wong at Johns Hopkins School of Medicine, we are analyzing various mouse models of Alzheimer's disease, especially focusing on the possible alterations in synaptic plasticity mechanisms.

Animals : humans, mice

Lab : The Lee Lab

Marjorie Leek

C-CEBH Investigator, NACS Adjunct Professor

Portland (OR) VA Med Ctr
NCRAR (Portland VA Med Ctr)

Research Interests : Research focus is on auditory perception of complex sounds and speech by normal-hearing and hearing-impaired individuals; speech recognition in noise; modeling of the auditory system; auditory attentional mechanisms; comparative auditory processes across species.

Animals : Birds, humans

Lab : Lab

Cynthia F. Moss

Professor

UMD Psychology
2123M Biology-Psychology Bldg.

Research Interests : Research in the Auditory Neuroethology Lab includes studies of auditory information processing, spatial perception, memory and sensorimotor integration. Using the echolocating bat as a model system, our work combines acoustical, psychophysical, theoretical and neurophysiological research, with the goal of developing integrative theories on brain-behavior relations.

Animals : Bats

Lab : Auditory Neuroethology Laboratory (BATLAB)

Rochelle Newman

Associate Professor

UMD Hearing and Speech
0141BB LeFrak Hall

Research Interests : One of the first tasks facing an infant is learning his or her native language. This is a difficult enough task in a quiet learning environment; yet infants often are exposed to speech in noisy environments. For example, a caregiver may be talking to an infant while other siblings are playing in the next room. In order to learn speech in these settings, the infant must first separate that speech from background noise such as that provided by TV shows and siblings. How do infants acquire their native language in such settings? This question has been one of the fundamental topics of our lab's research. We found that infants do have some capacity to understand speech even in the presence of other talkers. However, infant listeners are far more sensitive to background noise than we expected. They can recognize well-known words (such as their own name) in quiet settings, but fail to do so in noise levels comparable to those found in many day care centers. These findings are particularly important given concerns over the quality of childcare environments, and the impact such environments might have on language acquisition. Our lab is currently conducting follow-up research, exploring the types of noise that are most detrimental to infants, and things parents can do to make it easier for infants to attend to their voice. We are also exploring how infant hearing in noise changes with development, testing older children's ability to listen to one voice in a multi-talker setting.

Animals : Humans

Lab : Language development and perception laboratories

Brenda Ryals

C-CEBH Investigator

James Madison University (Communication Sciences and Disorders)
MSC 4304 HHS Building CISAT

Research Interests : "Research currently being conducted in the Auditory Research Lab is concerned primarily with issues involving plasticity (the ability to accomodate change) in the auditory system. We are especially concerned with plasticity as it impacts the system's responds to cochlear injury and hair cell regeneration. Over the past 10 years we have specifically been studying the functional and anatomical consequences of regeneration of auditory hair cells during development and after trauma. Understanding the impact of hair cell regeneration on central auditory connections and on hearing in birds has substantial reference to enhancing our knowledge of human hearing. by understanding the consequences (both antatomical and functional) of sensory cell replacement in birds we can better predict the structural and functional consequences of deafness and auditory restoration (either electronic - cochlear implants, or biochemical - human hair cell replacement) in humans.

Animals : Birds, Humans

Lab : Auditory Research Laboratory

Shihab Shamma

Professor

UMD Engineering
2203 A.V.Williams Bldg.

Research Interests : Part of the Electrical and Computer Engineering Department and The Institute for System Research, the Neural Systems Laboratory studies the functionality of the mammalian auditory system through a wide range of disciplines and techniques ranging from theoretical models to neurophysiological investigations and psychoacoustical experiments.

Animals : Ferrets, Humans

Lab : Neural Systems Laboratory

Jonathan Simon

Assistant Professor

UMD Biology, Electrical and Computer Engineering
2209 A.V.Williams Bldg.

Research Interests : I am active in a number of research areas, all under the general headings of Auditory Neural Computations and Representations,Computational and Theoretical Neuroscience, and Signal Processing in Biological Systems. My specific research areas are: Magnetoencephalography (MEG): Experimental Research, Analysis, and Signal Processing of Large Scale Neural Data. Coincidence Detection and Neural Coding of Temporal Information in Auditory Brainstem: Modeling. Neural Processing of Spectrotemporal Auditory Information in Mammals: Physiology and Modeling. Signal Processing and Neural Data.

Animals : Birds

Lab : Computational Sensorimotor systems lab

David Yager

Associate Professor

UMD Psychology, Biology
2123G Biology-Psychology Bldg.

Research Interests : The overarching goal of our laboratory is to find out how insect auditory systems are able to acquire and process acoustic information to yield complex, adaptive behaviors. We are especially interested in the evolution of hearing in insects, and have chosen the very unusual praying mantis ear as a model system.

Animals : Insects

Lab : The Yager Lab