John S. Pezaris - US grants

DESCRIPTION (provided by applicant): The AREADNE 2010 Conference on Research on Encoding and Decoding of Neural Ensembles is the third in a series of meetings about interactions amongst multiple neurons from a systems perspective. The field of neural ensembles is fundamental to the pursuit of theoretical, experimental, and applied systems neuroscience, as it embodies the core issues that have been revealed through the ability to monitor the signals from multiple neurons simultaneously. This is a relatively new field that has been enabled by recent advances in recording technology, from multiple simultaneous extracellular recordings, to high-resolution fMRI, to single- and multi-photon imaging techniques. The primary goal of the AREADNE Conference Series is to provide a focal point for interactions between US, European, and Eastern Mediterranean researchers whose work involves understanding how networks of neurons encode information and the tools we might use to decode ongoing activity. Every organizational aspect of this meeting has been carefully selected to achieve this goal by fostering discussion and exchange in an informal setting that provides a fertile environment for the development of professional relationships. As a result, after only two instances it has become one of the preeminent conferences in the field. The agenda for the 2010 meeting will be to discuss advances in olfaction, hippocampus and dentate gyrus, stimulation techniques, two-photon techniques that measure neural function, connectomics, visual systems, and motor systems. By drawing from disparate fields, we create a hybridizing environment where rather than being exceptional, cross-disciplinary discussions are the norm. Scientific presentations at AREADNE Conferences span four days with 22 oral presentations split between two daily sessions, and poster sessions on the first three days with about 20 posters per day. Speakers are invited from the list of world experts in neural ensembles from a wide range of fields. Posters are contributed from a similarly broad cut across Neuroscience with relevance to the focus of understanding neural ensembles from any part of the central or peripheral system. PUBLIC HEALTH RELEVANCE: It is important to understand how the neurons that make up the brain encode information, and how to decode the signals neurons use to communicate. This conference brings together experts and students from across the world who are using new and powerful tools to explore neural encoding and decoding. Topics of discussion include basic experimental and theoretical knowledge as well as applications like visual prostheses for the blind, motor prostheses for the paralyzed, and similar devices that provide restoration of function following neural disease.

DESCRIPTION (provided by applicant): This proposal is part of an ongoing effort to restore sight to the blind with a thalamic visual prosthesis. The proposed research will lay the groundwork for the next major step in the project by demonstrating artificial sight in an animal model, and building tools to design, analyze, and test the performance of a visual prosthesis device that uses thalamic microstimulation. This device has microelectrodes placed in the lateral geniculate nucleus of the thalamus, part of the brain that relays signals from the eye to the rest of the visual system. With results from this proposal we will have in hand a prototype prosthesis in an animal model and be able to predict how experimental designs will perform in blind human subjects. Specific Aim 1 is to measure the visual acuity of normal sighted human volunteers using a virtual reality (VR) simulation of sight as it might appear to a blind patient through an implanted thalamic visual prosthesis. Acuity under various device parameters such as contact count and distribution will be assessed using a letter identification task analogous to standard optometry eye charts and expressed in standard 20/xx notation. We expect to find that a relatively simple device will provide reasonable levels of restoration of function. Specific Aim 2 is to make the same measurements with normal, sighted non-human primates (NHP), creating a foundation for comparing visual prosthesis designs between humans and NHP. We expect to find that non-human primates will perform nearly identically to humans on this task. Specific Aim 3 is to construct prototype prosthesis by adapting the output phase of the VR simulation to multichannel stimulators driving multicontact electrodes, and implant them in NHPs. Importantly; the implants will not affect normal sight so that visual prostheses can be readily calibrated. To evaluate implanted devices, we will use the same letter identification task. We expect to find that the VR models will do a good job of predicting performance with an actual device. With the results of these Specific Aims, we will be prepared to create a prototype visual prosthesis suitable for implanting in a blind volunteer. PUBLIC HEALTH RELEVANCE: Blindness is faced by millions of people due to diseases of the eye like glaucoma, retinitis pigmentosa and macular degeneration, or trauma to the eye from accidents or military combat. A visual prosthesis device to restore sight to these millions of people could be made by sending the output of a digital camera to the visual part of the brain. As proposed here, an important step in making a device like that is to understand how complicated it needs to be in order to be useful and to test a prototype in an animal model.

1005436
Pezaris

This project will support AREADNE 2010 Research in Encoding and Decoding of Neural Ensembles, to be held 17-20 June 2010, at the Nomikos Conference Centre, in Santorini, Greece. This is the third conference in the biennial AREADNE series that provides unparallelled opportunities for US students and scientists studying neural ensembles to interact with their international peers and develop long-term professional relationships.

The AREADNE Conference series serves an important role, providing a unique forum in the developing field of neural ensembles where investigators from a wide variety of subfields can exchange ideas and interact in an intensive, focused environment. Under the leadership of the two co-founders who serve as co-chairs, the AREADNE Organizing Committee has successfully run the conference in 2006 and 2008; the 2010 session will be the third in the series. Many novel mechanisms are employed to ensure complete engagement from the speakers and attendees that result not only in successful, invigorating meetings, but in a strengthening of the field.
Many cutting-edge and provocative results have been premiered at the first two AREADNE Conferences, a pattern that is expected to continue in the third.

The conference sessions focus on either experimental or analytical/theoretical approaches to understanding neural ensemble processing, or combine presentations from different approaches on the same brain area. Sessions are currently planned as (1) olfactory systems, (2) hippocampus and dentate gyrus, (3) stimulation techniques, (4) advanced functional labeling techniques, (5) network dynamics, (6) visual systems, and (7) motor systems. For each theme, presentations emphasize how sensory, cognitive, and motor states are encoded in the interaction of multiple neurons and in turn how these states can be reconstructed from neuronal ensembles.

About half of the attendees from previous meetings have been from the United States, and half from Europe and the Eastern Mediterranean. Across all attendees, one-third are students, one-third post-docs or junior faculty, and the remainder senior faculty. Speakers are selected from the world experts in the field, and include one-third women, reflective of the general attendance.

The Organizing Committee consists of systems neuroscientists with wide and varied backgrounds. Hybridization within the committee is reflected in the range of invited speakers and thus at the conference itself where cross-disciplinary discussions among attendees, rather than being exceptional, are the norm. Feedback forms from attendees are overwhelmingly positive, including specifically on the aspect of discussion and interaction.

The conference proceedings are provided to attendees in printed form and on CD-ROM, and shortly after the end of each meeting, are published on the conference web site. In the 12 months ending on 1 October 2009, slightly more than 4,500 copies have been downloaded, demonstrating a very broad impact.

1205468
Pezaris

This project will support AREADNE 2012 Research in Encoding and Decoding of Neural Ensembles, to be held 21-24 June 2012, at the Nomikos Conference Centre, in Santorini, Greece. This will be the fourth conference in the biennial AREADNE series that provides unparalleled opportunities for US students and scientists studying neural ensembles to interact with their international peers and develop long-term professional relationships.

The AREADNE Conference series serves an important role, providing a unique forum in the developing field of neural ensembles where investigators from a wide variety of subfields can exchange ideas and interact in an intensive, focused environment. Under the leadership of the two co-founders who serve as co-chairs, the AREADNE Organizing Committee has successfully run the conference in 2006, 2008, and 2010; the 2012 session will be the fourth. Many novel mechanisms are employed to ensure complete engagement from the speakers and attendees that result not only in successful, invigorating meetings, but in a strengthening of the field. Many cutting-edge and provocative results have been premiered at the AREADNE Conferences this far, a pattern that is expected to continue in the future.

About half of the attendees from previous meetings have been from the United States, and half from Europe and the Eastern Mediterranean. Across all attendees, one-third are students, one third post-docs or junior faculty, and the remainder senior faculty. Speakers are selected from the world experts in the field, and include one-third women, reflective of the general attendance. The Organizing Committee consists of systems neuroscientists with wide and varied backgrounds. Hybridization within the committee is reflected in the range of invited speakers and thus at the conference itself where cross-disciplinary discussions among attendees, rather than being exceptional, are the norm. Feedback forms from attendees are overwhelmingly positive, including specifically on the aspect of discussion and interaction. The conference proceedings are provided to attendees in printed form and on CD-ROM, and shortly after the end of each meeting, are published on the conference web site. In the 24 months ending on 1 October 2011, more than 3,000 copies have been downloaded from the web site, demonstrating a very broad impact.

PI: Pezaris, John S.
Proposal Number: 1403636
Institution: Massachusetts General Hospital
AREADNE 2014 Conference, Santorini, Greece, June 26-29, 2014

This proposal seeks support for travel awards and registration support to US students and post-docs to attend the AREADNE 2014 Research in Encoding and Decoding of Neural Ensembles conference to be held June 26-29, 2014, at the Nomikos Conference Centre, in Santorini, Greece. This will be the fifth conference in the biennial AREADNE series that provides opportunities for US students and scientists studying neural ensembles to be informed on the latest advances in the field, interact with their international peers and develop long-term professional relationships. The primary goals of the AREADNE conference include: 1. To provide an open, interactive forum to foster discussion of cutting-edge results from scientific leaders in the field of neural ensembles. 2. To enable the development of lasting professional relationships by creating an informal environment that predisposes attendees to free interaction. 3. To create a scientific venue that offers US investigators exposure to their European and Eastern Mediterranean peers in the field. Additionally, the conference will provide a forum to foster interactions of established investigators with students, post-docs and other young scientists in the field.

Encoding and decoding of neural ensembles is a developing field in neuroscience. The biennial AREADNE conference meets an important need in this field, as there is no other similar conference that provides a tight, focused, and intensive presentation of the subject and topics. Single-track morning and evening sessions with invited speakers and evening poster presentations will be used to disseminate the latest advances in the field and promote interactions among the attendees. Planned sessions include (1) early visual systems, (2) decision making, (3) patterns and network synchronization, (4) connectomics, (5) learning and plasticity, (6) molecular mechanisms, and (7) visuo-motor integration. For each theme, presentations will emphasize how sensory, cognitive, and motor states are encoded in the interaction of multiple neurons and in turn how these states can be reconstructed from neuronal ensembles. After the meeting, proceedings will be published on the web for wide dissemination to the scientific community.

1637127-Pezaris

NSF has made an award in support of travel and registration fees for US students and post-docs to attend the AREADNE 2016 Research in Encoding and Decoding of Neural Ensembles conference to be held June 22-26, 2016, at the Nomikos Conference Centre, in Santorini, Greece. This will be the sixth conference in the biennial AREADNE series that provides opportunities for US students and scientists studying neural ensembles to be informed on the latest advances in the field, interact with their international peers and develop long-term professional relationships. The primary goals of the AREADNE conference include: 1)To provide an open, interactive forum to foster discussion of cutting-edge results from scientific leaders in the field of neural ensembles. 2) To enable the development of lasting professional relationships by creating an informal environment that predisposes attendees to free interaction. 3)To create a scientific venue that offers US investigators exposure to their European and Eastern Mediterranean peers in the field. Additionally, the conference will provide a forum to foster interactions of established investigators with students, post-docs and other young scientists in the field.

Encoding and decoding of neural ensembles is a developing field in neuroscience. The biennial AREADNE conference meets an important need in this field, as there is no other similar conference that provides a tight, focused, and intensive presentation of the subject and topics. Single-track morning and evening sessions with invited speakers and evening poster presentations will be used to disseminate the latest advances in the field and promote interactions among the attendees. Planned sessions include: 1) early visual systems, 2) decision making, 3) patterns and network synchronization, 4) connectomics, 5) learning and plasticity, 6) molecular mechanisms, and 7) visuo-motor integration. For each theme, presentations will emphasize how sensory, cognitive, and motor states are encoded in the interaction of multiple neurons and in turn how these states can be reconstructed from neuronal ensembles. After the meeting, proceedings will be published on the web for wide dissemination to the scientific community.

PROJECT SUMMARY / ABSTRACT This proposal is part of an ongoing e?ort to restore sight to the blind with a thalamic visual prosthesis. Such devices use microelectrodes placed in the lateral geniculate nucleus of the thalamus (LGN), part of the brain that relays signals from the eye to the rest of the visual system, in order to generate visual images. Each microelectrode creates one pixel-like element of an arti?cial image that is called a phosphene. While phosphene location is predictable, it is not known how their size or color are in?uenced by electrode placement or strength of electrical stimulation for thalamic devices. Some work has been done in retina with humans, and in cortex with both humans and animal models, but we lack a rigorous study for LGN. The LGN architecture, with macroscopic segregation of magno-, parvo-, and koniocellular pathways not found elsewhere, suggests that observations made in other systems may not be applicable. We propose investigating LGN phosphenes to measure size, hue (color), and persistence, and then to unify this knowledge by using phosphenes to present simple visual objects. The work will be done in a behaving non-human primate model, where behavioral reports from simple tasks will convey the animal's perception of phosphenes and synthetic letters. Match-to-sample tasks will be used for size and hue. A memory saccade task will be used for persitence. A match-to-sample task will be used for letter identity. In the match-to-sample tasks, the animals are brie?y shown a cue on a computer screen, and then a choice of targets that vary in size, hue, or letter identity. They must look to the target that matched the cue in order to receive a reward. In the memory saccade task, the animal is shown two targets, and after a delay must look to the one that was illuminated longer. Tasks are presented in blocks of interleaved trials with occasional probes with cues presented through microstimulation rather than on the screen. Responses in probe trials provide insight into animal perceptions when compared with responses to control trials. By the end, we will know how phosphene size, hue, and persistence vary with electrode placement and with strength of microstimulation. We will also have demonstrated an LGN prosthesis conveying simple visual scenes. The knowledge will be critical to development of a device for use in blind humans.