Seminars

Instructions

1. Check the internal calendar for a free seminar slot. If the seminar is not at the booked time of Tueday noon, you have to call or email Sharyn [510-643-4971, climons@berkeley.edu] to book a room. You have to do this as early as possible or she will be pissed. It is not easy for them to find rooms. The 3 rooms they can get are 5101 Tolman, the Beech Room (3rd floor Tolman), and the Barker seminar room (no more than 20 people...). They can also book the LSA large seminar room through MCB if given enough warning.
2. Make a note on this page in the Tentative Speakers section that you are going to invite a speaker. Please include your name and email as host in case somebody wants to contact you.
3. Invite a speaker.
4. As soon as the speaker confirms, put the information in the Confirmed Speakers section.
5. Put the date into the internal calendar
6. Notify kilian [1] that we have a confirmed speaker so that I can update the web page. Please include title and abstract.
7. Notify Sharyn [2] about the seminar date.

--Kilian 21:48, 4 November 2005 (PST)

Tentative Speakers

March 27 - (spring recess)

Confirmed Speakers

March 6

• Speaker: Pietro Perona
• Affiliation: Caltech
• Host: Bruno
• Title: An exploration of visual recognition

March 13, 2007

• Speaker: Chris Wiggins
• Affiliation: Columbia University, NY
• Host: Tony
• Title: Optimal signal processing in small stochastic biochemical networks

March 20, 2007

• Speaker: Jeff Hawkins
• Affiliation: Numenta
• Host: Bruno
• Title: Hierarchical Temporal Memory

March 27, 2007

• Speaker: Steve Waydo
• Affiliation: Control & Dynamical Systems, California Institute of Technology
• Host: Bruno
• Title: Explicit Object Representation by Sparse Neural Codes
• Abstract: Highly sparse representations of objects in the visual environment in which individual neurons display a strong selectivity for only one or a few stimuli (such as familiar individuals or landmark buildings) out of on the order of 100 presented to a test subject have been observed in the human medial temporal lobe (MTL), a brain area believed to be crucial to the formation of new semantic memories. The process by which more distributed representations earlier in the visual pathway are transformed to produce such highly selective and invariant units results in information represented only implicitly by the pattern of light impinging on the retina and in the firing of neurons in early visual areas being made explicit at the level of MTL. This “sparsification” may be an important design principle underlying the structure of this brain region. We apply a modified version of the model of Olshausen and Field, in which a network of nonlinear neurons generates a sparse representation of its inputs through an unsupervised learning process, to the outputs of a biologically plausible model of the human ventral visual pathway. We train this system on real-world images from multiple categories taken from the Caltech-256 dataset. This training is carried out in an entirely unsupervised manner, without specifying image categories or even the number of categories present. Although the underlying constraint in the model is merely to produce a sparse representation of its input set, units emerge that respond selectively to specific image categories such as faces and airplanes. The sparseness constraint thus facilitates the formation of explicit representations of image categories, despite the category information being represented only implicitly in the input images.

April 3

• Speaker: Robert Miller
• Affiliation: Department of Anatomy and Structural Biology, Otago University
• Host: Fritz
• Title: Axonal conduction time and human cerebral laterality
• Abstract: The idea of asymmetry of cerebral functions is well established, and depends mainly on psychological evidence. Hitherto there have been few ideas proposed to explain this evidence in terms of lower-level postulates, e.g. about differences between hemispheres in cellular poperties or biochemistry. In 1996 I published a book ("Axonal conduction time and human cerebral laterality",[Gordon and Breach]). The "central hypothesis" of this work is that cortico-cortical axons connecting different parts of the right hemisphere are relatively rapidly conducting, while those in the left hemisphere are on average slower conducting, constituting a "repertoire of delay lines". This talk is based on the 1996 book, but brings the story up to date. It starts with empirical evidence about conduction times in cortico-cortical axons in animals, and then shows how the central hypothesis explains various psychological findings (asymmetry in perception, motor control, vigilance), evidence of directional asymmetry in conduction time between hemispheres, as well as evidence of morphological asymmetry. Lastly, I mention one area of function (some aspects of the representation of speech sounds), where the original hypothesis requires modification, and the difference between right and left in axon properties seems to be the reverse of that originally proposed. Evidence based on diffusion tensor imaging suggests that, while the reasoning in the 1996 book still holds, the pattern of asymmetry of axonal properties is probably more complex than originally proposed.

April 10

• Speaker: Andrew Ng
• Affiliation: Stanford University
• Host: Bruno
• Title: Unsupervised discovery of structure for transfer learning

April 24

• Speaker: Jeff Johnson
• Affiliation: UC Davis
• Host: Bruno
• Title: EEG studies of object recognition

May 15, 2007

• Speaker: Ray Guillery
• Affiliation: University of Madisson, WI
• Host: Fritz
• Title: Thalamus and Sensorimotor Aspects of Perception

Previous Seminars

March 1

• Speaker: Hiroki Asari
• Affiliation: CSL
• Host: Fritz
• Title: Sparse Representations for the Cocktail Party Problem
• Abstract: A striking feature of many sensory processing problems is that there appear to be many more neurons engaged in the internal representations of the signal than in its transduction. For example, humans have about 30,000 cochlear neurons, but at least a thousand times as many neurons in the auditory cortex. Such apparently redundant internal representations have sometimes been proposed as necessary to overcome neuronal noise. We instead posit that they directly subserve computations of interest. Here we provide an example of how sparse overcomplete linear representations can directly solve difficult acoustic signal processing problems, using as an example monaural source separation using solely the cues provided by the differential filtering imposed on a source by its path from its origin to the cochlea (the head-related transfer function, or HRTF). In contrast to much previous work, the HRTF is used here to separate auditory streams rather than to localize them in space. The experimentally testable predictions that arise from this model--- including a novel method for estimating a neuron's optimal stimulus using data from a multi-neuron recording experiment---are generic, and apply to a wide range of sensory computations.

February 20, 2007

• Speaker: Yair Weiss
• Affiliation: Hebrew University, Jerusalem
• Host: Tony
• Title: What makes a good model of natural images?

February 13, 2007

• Speaker: Tobi Delbruck
• Affiliation: Inst of Neuroinformatics, UNI-ETH Zurich
• Host: Bruno
• Title: Building a high-performance event-based silicon retina leads to new ways to compute vision
• URL: http://siliconretina.ini.uzh.ch

Jan 23, 2007

• Speaker: Giuseppe Vitiello
• Affiliation: Department of Physics “E.R.Caianiello”, Salerno University
• Host: Fritz
• Title: Relations between many-body physics and nonlinear brain dynamics

Jan 9, 2007

• Speaker: Boris Gutkin
• Affiliation: University of Paris
• Host: Fritz
• Title: TBA

Dec 5

• Speaker: Tanya Baker
• Affiliation: U Chicago
• Host: Kilian
• Title: What Forest Fires Tell Us About the Brain

December 1, 2006 1.30pm

• Informal visit: Nancy Kopell
• Affiliation: Boston University
• Host: Fritz
• Title: No talk: Informal visit in the afternoon

Nov 28

• Speaker: Thomas Dean
• Host: Bruno
• Affiliation: Brown University/Google
• Title: TBA

Nov 21

• Speaker: Urs Koster
• Host: Bruno
• Affiliation: University of Helsinki
• Title: Towards Multi-Layer Processing of Natural Images

Nov 14

• Speaker: Andrew D. Straw
• Affiliation: Bioengineering, California Institute of Technology
• Host: Kilian
• Title: Closed-Loop, Visually-Based Flight Regulation in a Model Fruit Fly

Nov 7

• Speaker: Mitya Chklovskii
• Host: Bruno
• Title: What determines the shape of neuronal arbors?

Oct 31

• Speaker: Matthias Kaschube
• Host: Kilian
• Title: A mathematical constant in the design of the visual cortex

Oct 3

• Speaker: Jay McClelland
• Affiliation: Mind, Brain & Computation/MBC, Psychology Department, Stanford
• Host: Evan
• Title: Graded Constraints in English Word Forms (video)

Sept 25

• Speaker: Peter Latham
• Affiliation: Gatsby Unit, UCL
• Host: Bruno
• Title: Requiem for the spike (video)

Sept 19

• Speaker: Jerry Feldman
• Affiliation: ICSI/UC Berkeley
• Host: Bruno
• Title: From Molecule to Metaphor: Towards a Unified Cognitive Science (video)

Sept 5

• Speaker: Tom Griffiths
• Affiliation: Cogsci/UC Berkeley
• Host: Bruno
• Title: Natural Statistics and Human Cognition (video)

Aug 1

• Speaker: Carol Whitney
• Affiliation: U Maryland
• Host: Bruno
• Title: What can Visual Word Recognition Tell us about Visual Object Recognition? (video)

July 18

• Speaker: Evan Smith
• Affiliation: Redwood Center/Stanford
• Host: Bruno
• Title: Efficient auditory coding

June 20

• Speaker: Vincent Bonin
• Affiliation: Smith Kettlewell Institute
• Host: Thomas
• Title:

June 15

• Speaker: Philip Low
• Affiliation: Salk Institute
• Host: Tony
• Title: A New Way To Look At Sleep

May 2

• Speaker: Dileep George
• Affiliation: Numenta
• Host: Bruno
• Title: Hierarchical, cortical memory architecture for pattern recognition

April 18

• Speaker: Risto Miikkulainen
• Affiliation: The University of Texas at Austin
• Host: Bruno
• Title: Computational maps in the visual cortex (video)

April 11

• Speaker: Charles Anderson
• Affiliation: Washington University School of Medicine
• Host: Bruno
• Title: Population Coding in V1 (video)

April 10

• Speaker: Charles Anderson
• Affiliation: Washington University School of Medicine
• Host: Bruno
• Title: A Comparison of Neurobiological and Digital Computation (video)

April 4

• Speaker: Odelia Schwartz
• Affiliation: The Salk Institute
• Host: Bruno
• Title: Natural images and cortical representation

March 21

• Speaker: Mark Schnitzer
• Affiliation: Stanford University
• Host: Amir
• Title: In vivo microendoscopy and computational modeling studies of mammalian brain circuits

March 15

• Speaker: Mate Lengyel
• Affiliation: Gatsby Unit/UCL London
• Host: fritz
• Title: Bayesian model learning in human visual perception (video)

March 14

• Speaker: Mate Lengyel
• Affiliation: Gatsby Unit/UCL London
• Host: fritz
• Title: Firing rates and phases in the hippocampus: what are they good for? (video)

March 7

• Speaker: Michael Wu
• Affiliation: Gallant lab/UC Berkeley
• Host: Bruno
• Title: A Unified Framework for Receptive Field Estimation

February 28

• Speaker: Dario Ringach
• Affiliation: UCLA
• Host: thomas
• Title: Population dynamics in primary visual cortex

February 21

• Speaker: Gerard Rinkus
• Affiliation: Brandeis University
• Host: Bruno
• Title: Hierarchical Sparse Distributed Representations of Sequence Recall and Recognition (video)

February 14

• Speaker: Jack Cowan
• Affiliation: U Chicago
• Host: Bruno
• Title: Spontaneous pattern formation in large scale brain activity: what visual migraines and hallucinations tell us about the brain (video)

February 7

• Speaker: Christian Wehrhahn
• Affiliation: Max Planck Institute for Biological Cybernetics, Tuebingen, Germany
• Host: Tony
• Title: Seeing blindsight: motion at isoluminance?

January 23 (Monday)

• Speaker: Read Montague
• Affiliation: Baylor College of Medicine
• Host: Bruno
• Title: Abstract plans and reward signals in a multi-round trust game

January 17

• Speaker: Erhardt Barth
• Affiliation: Institute for Neuro- and Bioinformatics, Luebeck, Germany
• Host: Bruno
• Title: Guiding eye movements for better communication (video)

January 3

• Speaker: Dan Butts
• Affiliation: Harvard University
• Host: Thomas
• Title: "Temporal hyperacuity": visual neuron function at millisecond time resolution

December 13, 2005

• Speaker: Paul Rhodes
• Affiliation: Stanford University
• Title: Simulations of a thalamocortical column with compartment model cells and dynamic synapses (video)

December 6, 2005

• Speaker: Special debate between Walter J. Freeman and Robert Hecht-Nielsen
• Affiliation: University of California at Berkeley (Walter). University of California at San Diego (Robert)
• Title: Waves or words in neocortex
• Video: Walter, Robert

November 29, 2005

• Speaker: Stanley Klein
• Affiliation: School of Optometry, UC Berkeley
• Title: Limits of Vision and psychophysical methods (video)

November 22, 2005

• Speaker: Scott Makeig
• Affiliation: Swartz Center for Computational Neuroscience, Institute for Neural Computation, UCSD
• Title: Viewing event-related brain dynamics from the top down