1995 — 1998 |
Hsiao, Steven S |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Effects of Attention On Neurons in Si and Sii Cortex @ Johns Hopkins University |
1 |
1999 — 2002 |
Hsiao, Steven S |
P01Activity Code Description: For the support of a broadly based, multidisciplinary, often long-term research program which has a specific major objective or a basic theme. A program project generally involves the organized efforts of relatively large groups, members of which are conducting research projects designed to elucidate the various aspects or components of this objective. Each research project is usually under the leadership of an established investigator. The grant can provide support for certain basic resources used by these groups in the program, including clinical components, the sharing of which facilitates the total research effort. A program project is directed toward a range of problems having a central research focus, in contrast to the usually narrower thrust of the traditional research project. Each project supported through this mechanism should contribute or be directly related to the common theme of the total research effort. These scientifically meritorious projects should demonstrate an essential element of unity and interdependence, i.e., a system of research activities and projects directed toward a well-defined research program goal. |
Neural Mechanisms of Size and Shape Perception in Somatosensory Cortex @ Johns Hopkins University
Funds are requested to study the neural mechanisms underlying three- dimensional (3D) shape and size perception in somatosensory system. While the perception of local surface features is based on the activity in the mechanoreceptive afferents innervating the skin, gross object features such as shape and size are based on hand and finger position and cutaneous information from multiple points of contact with the object. Project 1 concentrates on how information is integrated from the multiple points of contact; This project (3) concentrates on the role of hand and finger position in 3D form processing. The aim is to study how information from tactile and proprioceptors within and between digits are integrated in SI and SII cortex of the awake monkey to provide information about the 3D shape and size of objects. Aim 1 is to investigate the processing of shape information by studying the integration of tactile information across adjacent digits positioned at different combinations of flexion, simulating contact with objects with varying shapes. Aim 2 is to investigate the processing of information about object size by studying how digit spread affects the responses of somatosensory neurons to local patents of stimulation. Two modes of stimulation, active and passive, will be used. In the passive mode stimuli that are or are not consistent with a single curved surface (aim 1) or stimulate an object of a specified size (aim 2) will be applied to the hand while the animal performs a tactile match-to-sample task. In the active mode, the animal actively moves it fingers to contact the stimuli that vary in curvature and size. In this manner we will study neuronal response tuning for object size and shape in various areas in the somatosensory cortex and determine and whether the tuning differs during active and passive touch.
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1 |
2000 — 2014 |
Hsiao, Steven S |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Attention and Tactile Processing in Somatosensory Cortex @ Johns Hopkins University
DESCRIPTION (adapted from applicant's abstract): Attention and tactile processing in the somatosensory system. Funds are requested to continue our studies on understanding how selective attention effects the responses of neurons in the somatosensory system. The broad aim of these studies is to determine the neural mechanisms underlying shape processing in the somatosensory system. In this proposal, we focus our efforts on determining how information about the orientation of edges contacting multiple locations on the two hands interact. The study builds on our previous findings showing that: 1) There is a robust representation in the second somatosensory (SII) cortex of the orientation of edges contacting multiple digits, and 2) Most of the neurons in SII are affected by the animal's focus of attention. The first aim is to determine how single and multiple edges presented within and across finger pads of the same and opposite hands are represented in the somatosensory system. In these studies, we record from neurons in areas 3b, 1, 2 and SII cortex in animals performing a visual discrimination task, while simultaneously stimulating different combinations of the proximal, middle and distal phalanges on digits 2-4 on both hands with single or multiple oriented edges. These experiments will determine how edge information is integrated across digits. The second aim is to determine how selective attention affects the representation of edge information when single and multiple edges are presented to the hands. During the experiment, the edges will be placed both inside and outside the neuron's receptive field while animals perform tactile discrimination tasks. In some experiments, animals will be trained to discriminate the orientation of single edges, and in others, animals will be trained to compare the orientations of two edges presented simultaneously to the hands. These experiments will determine how selective attention modifies the receptive field structures of neurons, and will determine whether neurons at higher levels in the somatosensory cortex are tuned to coherent edges that span multiple digits.
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1 |
2005 — 2012 |
Hsiao, Steven S |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Cortical Processing of Tactual Spacial Information @ Johns Hopkins University
[unreadable] DESCRIPTION (provided by applicant): The broad, long-term aim of this study is to understand the neural mechanisms of tactile spatial perception in the human hand. Impaired tactile acuity leads to the inability to perform simple tasks such as buttoning and unbuttoning a button. Tactile spatial acuity is impaired in advanced age and in many neurological conditions. Understanding the underlying mechanisms is an essential first step in any treatment. The long-term aim of the study proposed here is to understand the neural mechanisms of tactile spatial perception in primary somatosensory (SI) cortex. A basic problem is that the functional organization of SI cortex is not well understood and this makes it difficult to formulate and test specific hypotheses. Combined psychophysical and neurophysiological studies over the last forty years have lead us to understand that the human hand is innervated by four types of mechanoreceptors and that each is responsible for a distinctly different aspect of tactile perception. Despite the distinct functional division evident in the peripheral nerve and despite the widespread, and justified belief that the information conveyed by the four afferent groups remains segregated within the central nervous system, the division of function within SI cortex is understood only in very broad terms. One reason is the lack of flexible, controlled stimuli with which to study the functions of neurons in St cortex, which we believe we have overcome with the development of a tactile stimulator with 400 independently controlled probes. Experiments proposed in Aim 1 examine the response properties of neurons in areas 3a, 3b, 1, and 2 of macaque SI cortex with temporal and spatial stimuli selected to span a wide range of tactile function. Experiments proposed in Aim 2 examine differences in the mechanisms underlying neuronal response properties in these areas using random stimuli and regression analyses. Experiments proposed in Aim 3 examine the neural mechanisms of tactile spatial perception with stimuli that have been particularly effective in previous studies (square-wave gratings) and with a new class of stimuli that combine the spatial and temporal properties of tactile function in a single framework (spatiotemporal sinusoids). [unreadable] [unreadable]
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1 |
2007 |
Hsiao, Steven S |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Cortical Processing of Tactual Spatial Information @ Johns Hopkins University
[unreadable] DESCRIPTION (provided by applicant): The broad, long-term aim of this study is to understand the neural mechanisms of tactile spatial perception in the human hand. Impaired tactile acuity leads to the inability to perform simple tasks such as buttoning and unbuttoning a button. Tactile spatial acuity is impaired in advanced age and in many neurological conditions. Understanding the underlying mechanisms is an essential first step in any treatment. The long-term aim of the study proposed here is to understand the neural mechanisms of tactile spatial perception in primary somatosensory (SI) cortex. A basic problem is that the functional organization of SI cortex is not well understood and this makes it difficult to formulate and test specific hypotheses. Combined psychophysical and neurophysiological studies over the last forty years have lead us to understand that the human hand is innervated by four types of mechanoreceptors and that each is responsible for a distinctly different aspect of tactile perception. Despite the distinct functional division evident in the peripheral nerve and despite the widespread, and justified belief that the information conveyed by the four afferent groups remains segregated within the central nervous system, the division of function within SI cortex is understood only in very broad terms. One reason is the lack of flexible, controlled stimuli with which to study the functions of neurons in St cortex, which we believe we have overcome with the development of a tactile stimulator with 400 independently controlled probes. Experiments proposed in Aim 1 examine the response properties of neurons in areas 3a, 3b, 1, and 2 of macaque SI cortex with temporal and spatial stimuli selected to span a wide range of tactile function. Experiments proposed in Aim 2 examine differences in the mechanisms underlying neuronal response properties in these areas using random stimuli and regression analyses. Experiments proposed in Aim 3 examine the neural mechanisms of tactile spatial perception with stimuli that have been particularly effective in previous studies (square-wave gratings) and with a new class of stimuli that combine the spatial and temporal properties of tactile function in a single framework (spatiotemporal sinusoids). [unreadable] [unreadable]
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1 |
2011 — 2013 |
Etienne-Cummings, Ralph [⬀] Hsiao, Steven |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Learning Shape Representation in Somatosensory Cortex and Their Applications to Upper Limb Prosthetics @ Johns Hopkins University
Project Abstract: 1057644 The human hand, wrist and arm make up one of the most complex portions of the human body. Using our arms and hands, humans are able to perform extremely complex functions, ranging from the delicate and dexterous tasks involved in artistic design, through dynamic ones involved in playing musical instruments, to forceful ones involved in sports and labor. Scientific studies demonstrate that, even without seeing our hands, a person can effortlessly recognize hundreds of objects with his hands. Unfortunately, none of the arm and hand prosthetics that have been developed to-date are remotely capable of providing touch sensation that approaches that of the natural limbs. Yet, it is known that the touch sensation is indispensable for humans to effectively manipulate and explore objects. So it is a challenge is to assimilate amputees into society and provide them the tools to contribute to the workforce unless they are provided prosthetics limbs that move by thought, as well as feel what the prosthetic hand touches. This EAGER proposal specifically aims to improve our scientific knowledge of how touch is represented and learned by the brain, develop electronic systems that can be implanted to communicate touch directly to the brain, and to test the effectiveness of providing the sensation of touch to a monkey by circumventing its arm and communicating directly to the brain. If successful, this high-risk/high-pay-off project could make Luke Skywalker's replacement arm in Star Wars: The Empire Strikes Back a reality. This project will develop new transdisciplinary knowledge involving neuroscience and engineering. The goal is to record and stimulate directly from the parts of the brain where the sense of touch is normally represented. Current research shows that normal perception of touch is provided by the activity of large groups of brain cells (i.e. neurons). The Investigators will study the possibility of using electrical stimulation to restore the sense of touch to amputees in the same way that cochlear implants restore hearing to the deaf or visual implants the sense of vision to the blind. They plan to exploit the natural representations of the brain and to stimulate, using new electronic circuitry, large groups of neurons that represent movement and from in the animals brain. Ultimately this research will lead to an understanding of how to recreate the feel of objects. Throughout this work, the investigators will train students to have unique neuroscience, biomedical, and engineering skills, a combination of which is invaluable to the modern high-tech health related workforce. They plan to train both undergraduate and graduate students and expose K-12 students who regularly rotate through their laboratories to the research.
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0.915 |