Seminars

CBMM Special Seminar: Self-Learning Systems

Mar 20, 2019 - 4:00 pm
Photo of Dr. Demis Hassabis
Venue:  MIT Lecture Hall 34-101 Address:  50 Vassar Street, Cambridge MA 02139 Speaker/s:  Demis Hassabis, Co-Founder & CEO, DeepMind

This talk is co-hosted by the Center for Brains, Minds, and Machines (CBMM) and MIT Quest for Intelligence.

Demis Hassabis and Tomaso PoggioAbstract: Demis Hassabis will discuss the capabilities and power of self-learning systems. He will illustrate this with reference to some of DeepMind's recent breakthroughs, and talk about the implications of cutting-edge AI research for scientific and philosophical discovery.

Speaker Biography: Demis is a former child chess prodigy, who finished his A-levels two years early before coding the multi-million selling simulation game Theme Park aged 17. Following graduation from Cambridge University with a Double First in Computer Science he founded the pioneering videogames company Elixir Studios producing award winning games for global publishers such as Vivendi Universal. Demis Hassabis presenting at MITAfter a decade of experience leading successful technology startups, Demis returned to academia to complete a PhD in cognitive neuroscience at UCL, followed by postdocs at MIT and Harvard, before founding DeepMind. His research into the neural mechanisms underlying imagination and planning was listed in the top ten scientific breakthroughs of 2007 by the journal Science. Demis is a 5-times World Games Champion, a Fellow of the Royal Society of Arts, and the recipient of the Royal Society’s Mullard Award and the Royal Academy of Engineering's Silver Medal.

Organizer:  Tomaso Poggio Antonio Torralba Organizer Email:  cbmm-contact@mit.edu

CBMM Special Seminar: The State of Autonomous Driving

Mar 19, 2019 - 4:30 pm
Photo of Prof. Amnon Shashua
Venue:  MIT 10-250, Huntington Hall Address:  222 Memorial Drive, Cambridge MA 02139 Speaker/s:  Dr. Amnon Shashua, President and CEO Mobileye, an Intel company; Senior Vice President, Intel Corporation; Sachs Professor of Computer Science | Hebrew University

Please note change of location - this talk will be held in MIT 10-250.

This talk is co-hosted by the Center for Brains, Minds, and Machines (CBMM) and MIT Quest for Intelligence.

Speaker Biography: Professor Amnon Shashua is senior vice president at Intel Corporation and president and chief executive officer of Mobileye, an Intel company. He leads Intel’s global organization focused on advanced driving assist systems (ADAS), highly autonomous and fully autonomous driving solutions and programs.

Professor Shashua holds the Sachs Chair in computer science at the Hebrew University of Jerusalem. Prof. Shashua’s field of expertise is computer vision and machine learning. Prof. Shashua received the MARR Prize Honorable Mention in 2001, the Kaye Innovation Award in 2004, and the Landau Award in Exact Sciences in 2005. Since 2010 Prof. Shashua is the co-founder, Chief Technology Officer and Chairman of OrCam, an Israeli company that recently launched an assistive product for the visually impaired based on advanced computerized visual interpretation capabilities.

Organizer:  Tomaso Poggio Antonio Torralba Organizer Email:  cbmm-contact@mit.edu

Brains, Minds + Machines Seminar Series: Probing memory circuits in the primate brain: from single neurons to neural networks

Mar 22, 2019 - 4:00 pm
Venue:  Singleton Auditorium (46-3002) Address:  MIT Brain and Cognitive Sciences Complex (MIT Bldg 46), 43 Vassar Street, Cambridge MA 02139 Speaker/s:  Julio Martinez-Trujillo

Abstract: The brain’s memory systems are like time machines for thought: they transport sensory experiences from the past to the present, to guide our current decisions and actions. Memories have been classified into long-term, stored for time intervals of days, months, or years, and short-term, stored for shorter intervals of seconds or minutes. There is a consensus that these two types of memories involve different brain systems and have different underlying mechanisms. In this talk I will present data from different experiments in non-human primates examining brain circuits and mechanisms of both short-term memory and long-term memory.

 

Biography: Julio Martinez-Trujillo is Professor in the Department of Physiology and Pharmacology and Scientist at the Robarts Research Institute. He holds an Academic Chair in Autism. Prior to joining Western University in 2014, he was Associate Professor in the Department of Physiology and Canada Research Chair in Neuroscience at McGill University.

Organizer:  Hector Penagos Frederico Azevedo Organizer Email:  cbmm-contact@mit.edu

Brains, Minds + Machines Seminar Series: Apical dendrites as a site for gradient calculations

Apr 26, 2019 - 4:00 pm
Photo of Blake Richards
Venue:  Singleton Auditorium(46-3002) Address:  MIT Bldg 46-3002, 43 Vassar Street, Cambridge MA 02139 Speaker/s:  Blake Richards, Assistant Professor, Associate Fellow of the Canadian Institute for Advanced Research (CIFAR)

Abstract: 

Theoretical and empirical results in the neural networks literature demonstrate that effective learning at a real-world scale requires changes to synaptic weights that approximate the gradient of a global loss function. For neuroscientists, this means that the brain must have mechanisms for communicating loss gradients between regions, either explicitly or implicitly. Here, I describe our research into potential means of communicating loss gradients using the unique properties of apical dendrites in pyramidal neurons. I will present modelling work showing that, in principle, ensembles of pyramidal neurons could using the temporal derivative of their activity to estimate cost gradients. I will also show how this can be learned using the discontinuities that spikes induce. Finally, I will discuss specific experimental predictions that arise from these theories.

 

This event is co-organized by the CBMM Trainee Leadership Council.

Organizer:  Hector Penagos Frederico Azevedo Martin Schrimpf Organizer Email:  cbmm-contact@mit.edu

Brains, Minds + Machines Seminar Series: Perceiving what we cannot sense: Insights from 3D vision

Nov 30, 2018 - 4:00 pm
Photo of Dr. Ari Rosenberg
Venue:  Singleton Auditorium(46-3002) Address:  43 Vassar Street, Cambridge MA 02139 Speaker/s:  Ari Rosenberg, University of Wisconsin - Madison

Abstract: Our sensory systems are unable to directly sense all the aspects of the world we perceive. For example, our perception of the world as three-dimensional (3D) is compelling, but our eyes only detect two-dimensional (2D) projections of our surroundings. Creating accurate and precise 3D percepts is critical for successful interactions with our environment, but how does the brain solve this inverse problem? Using 3D vision in the macaque monkey as the model system, I will show behavioral, neuroimaging, and electrophysiological data that together reveal a hierarchical, cortical pathway specialized for implementing the 2D-to-3D visual transformation. The results of these experiments reveal roles of little explored brain areas in the dorsal visual pathway, including V3A and CIP, and have broader implications for our understanding of how the brain solves nonlinear optimization problems required to perceive what we cannot sense.

Organizer:  Frederico Azevedo Hector Penagos Organizer Email:  cbmm-contact@mit.edu

Brains, Minds + Machines Seminar Series: What are the computational functions of feedback to early visual cortex?

Oct 19, 2018 - 4:00 pm
Photo of Prof. Daniel J. Kersten
Venue:  Singleton Auditorium (MIT 46-3002) Address:  43 Vassar Street, Cambridge MA 02139 Speaker/s:  Prof. Daniel J. Kersten, University of Minnesota

Abstract: The existence of feedforward and feedback neural connections between areas in the primate visual cortical hierarchy is well known.  While there is a general consensus for how feedforward connections support the sequential stages of visual processing for tasks such as object recognition, the computational functions of feedback for recognition and other tasks are less well understood. I will discuss several proposals for the functions of feedback including resolving local ambiguity using high-level predictive knowledge, binding information across levels of abstraction in the visual hierarchy, and engaging lower-level "expertise" as the task requires it. Several human behavioral and neuroimaging results will be described that support these proposals: the first showing how the larger spatial context modulates local activity in the visual system, the second how cortical activity in human V1/V2 depends on whether shape information is extracted in the presence or absence of clutter, and the third how tasks requiring the analysis of spatial detail influence responses in foveal cortex.

Organizer:  Frederico Azevedo Hector Penagos Organizer Email:  cbmm-contact@mit.edu

Brains, Minds + Machines Seminar Series: Modal-Set Estimation using kNN graphs, and Applications to Clustering

Oct 12, 2018 - 4:00 pm
Photo of Prof. Samory Kpotufe, Princeton University
Venue:  Singleton Auditorium (MIT 46-3002) Address:  43 Vassar Street, Cambridge MA 02139 Speaker/s:  Prof. Samory Kpotufe, Princeton University

Abstract:  Estimating the mode or modal-sets (i.e. extrema points or surfaces) of an unknown density from sample is a basic problem in data analysis. Such estimation is relevant to other problems such as clustering, outlier detection, or can simply serve to identify low-dimensional structures in high dimensional-data (e.g. point-cloud data from medical-imaging, astronomy, etc).  Theoretical work on mode-estimation has largely concentrated on understanding its statistical difficulty, while less attention has been given to implementable procedures. Thus, theoretical estimators, which are often statistically optimal, are for the most part hard to implement. Furthermore for more general modal-sets (general extrema of any dimension and shape) much less is known, although various existing procedures (e.g. for manifold-denoising or density-ridge estimation) have similar practical aim. I’ll present two related contributions of independent interest: (1) practical estimators of modal-sets – based on particular subgraphs of a k-NN graph – which attain minimax-optimal rates under surprisingly general distributional conditions; (2) high-probability finite sample rates for k-NN density estimation which is at the heart of our analysis. Finally, I’ll discuss recent successful work towards the deployment of these modal-sets estimators for various clustering applications.  

 

Much of the talk is based on a series of work with collaborators S. Dasgupta, K. Chaudhuri, U. von Luxburg, and Heinrich Jiang. 

Speaker Biography:  Samory Kpotufe graduated with a PhD, in Sept 2010, from Computer Science at the University of California, San Diego; his advisor was Dr. Sanjoy Dasgupta. Dr. Kpotufe then joined Max Planck Institute for Intelligent Systems as a research in the department of Bernhard Schoelkopf, in the learning theory group of Ulrike von Luxburg. Following his work at MPI, Dr. Kpotufe was an Assistant Research Professor at the Toyota Technological Institute at Chicago. Prof. Kpotufe is now the Assistant Professor of Operations Research and Financial Engineering at Princeton University.

Speaker's research interests:  I work in machine learning, with an emphasis on nonparametric methods and high-dimensional statistics. Generally, I’m interested in understanding the inherent difficulty of high-dimensional problems, under practical constraints from real-world application domains. The nonparametric setting is attractive in that it captures scenarios where we have little domain knowledge, which is important as data sciences reach into a diverse range of applications.

My main practical aim is to design adaptive procedures, i.e., practical procedures that can self-tune to unknown structure in data (e.g., manifold, sparsity, clusters), while at the same time meeting the various constraints (e.g., time, space, labeling cost) of modern applications.

For more, here is a recent research statement.

Organizer:  Frederico Azevedo Hector Penagos Organizer Email:  cbmm-contact@mit.edu

Brains, Minds + Machines Seminar Series: Linking the statistics of network activity and network connectivity

Sep 21, 2018 - 4:00 pm
Venue:  Singleton Auditorium (MIT 46-3002) Address:  43 Vassar Street, Cambridge MA 02139 Speaker/s:  Eric Shea-Brown, University of Washington

Abstract:  There is an avalanche of new data on the brain’s activity, revealing the collective dynamics of vast numbers of neurons.  In principle, these collective dynamics can be of almost arbitrarily high dimension, with many independent degrees of freedom — and this may reflect powerful capacities for general computing or information.  In practice, datasets reveal a range of outcomes, including collective dynamics of much lower dimension — and this may reflect the structure of tasks or latent variables.  For what networks does each case occur? Our contribution to the answer is a new framework that links tractable statistical properties of network connectivity with the dimension of the activity that they produce.  I’ll describe where we have succeeded, where we have failed, and the many avenues that remain.

Short Bio: Eric Shea-Brown is a professor at the University of Washington Applied Mathematics Department, an affiliate investigator at the Allen Institute for Brain Science, and is adjunct faculty in the Department of Physiology and Biophysics and a member of the Program in Neuroscience. 

Organizer:  Frederico Azevedo Hector Penagos Organizer Email:  cbmm-contact@mit.edu

Brains, Minds and Machines Seminar Series: Body-Brain Interface: Neuroanatomical and Functional Insights from the Primate Insular Cortex

Oct 26, 2018 - 4:00 pm
Photo of Henry Evrard
Venue:  Singleton Auditorium (MIT 46-3002) Address:  43 Vassar Street, Cambridge MA 02139 Speaker/s:  Henry Evrard , Head of Research Group CIN Functional and Comparative Neuroanatomy, Werner Reichardt Center for Integrative Neuroscience, Max Planck Institute for Biological Cybernetics

Abstract:  Interoception substantiate embodied feelings and shape cognitive processes including perceptual awareness.  My lab combines architectonics, tract-tracing, electrophysiology, direct electrical stimulation fMRI (DES-fMRI), neural event triggered fMRI (NET-fMRI) and optogenetics in the macaque monkey in order to examine the neuroanatomical and functional organization of the insular cortex, one of the key central interface of bodily and brain states. Our anatomical examination revealed that the insular cortex is anatomically organized according to a refined and high-consistent modular Bauplan where architectonics and hodology perfectly overlap. Hodological and functional examinations suggest that the insula contains a granular-to-dysgranular-to-agranular processing flow where interoceptive afferents are progressively integrated with self-agency and socially relevant activities from other parts of the brain, until reaching an ultimate representation of instantaneous physiological states in the anterior insula. The anterior insula contains distinct areas that have each specific projections. One of these areas specifically contains the atypical spindle-shaped von Economo neuron (VEN). A relatively high proportion of VEN projects to distant preautonomic midbrain regions. Recording and stimulation in the 'VEN area' confirmed the connection with these regions and highlighted prominent functional relations to high-order cortical areas, supporting the idea that the VEN area could serve as hub for the simultaneous interoceptive shaping of polymodal perceptual experience and high-order regulation of bodily states.

Organizer:  Frederico Azevedo Hector Penagos Organizer Email:  cbmm-contact@mit.edu

CBMM Special Seminar: What information dynamics can tell us about ... brains

Jul 24, 2018 - 11:00 am
Photo of Dr. Joseph Lizier
Venue:  Singleton Auditorium (MIT 46-3002) Address:  MIT Brain and Cognitive Sciences Complex (MIT Bldg 46), 43 Vassar St., Cambridge MA 02139 Speaker/s:  Dr. Joseph T. Lizier, The University of Sydney

Abstract: 

The space-time dynamics of interactions in neural systems are often described using terminology of information processing, or computation, in particular with reference to information being stored, transferred and modified in these systems. In this talk, we describe an information-theoretic framework -- information dynamics --  that we have used to quantify each of these operations on information, and their dynamics in space and time. Not only does this framework quantitatively align with natural qualitative descriptions of neural information processing, it provides multiple complementary perspectives on how, where and why a system is exhibiting complexity. We will review the application of this framework in computational neuroscience, describing what it can and indeed has revealed in this domain. First, we discuss examples of characterising behavioural regimes and responses in terms of information processing, including under different neural conditions and around critical states. Next, we show how the space-time dynamics of information storage, transfer and modification directly reveal how distributed computation is implemented in a system, highlighting information processing hot-spots and emergent computational structures, and providing evidence for conjectures on neural information processing such as predictive coding theory. Finally, via applications to several models of dynamical networks and human brain images, we demonstrate how information dynamics relates the structure of complex networks to their function, and how it can invert such analysis to infer structure from dynamics.

 

This event is organized by the CBMM Trainee Leadership Council.

Organizer:  Wiktor Młynarski Organizer Email:  cbmm-contact@mit.edu

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