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)

Confirmed Speakers

May 8

• Speaker: Lokendra Shastri
• Affiliation: ICSI
• Host: Bruno
• Title: Micro-circuits of Episodic Memory: Structure Matches Function in the Hippocampal System
• Abstract:

We readily remember events and situations in our daily lives and acquire memories of specific facts by watching a telecast or reading a newspaper. This one-shot mnemonic ability poses a challenge for computational neuroscience: How does the brain carry out this remarkable memorization task so rapidly and effortlessly? There is a broad consensus that the hippocampal system (HS), consisting of the hippocampal formation and neighboring cortical areas plays a critical role in encoding and retrieving such “episodic” memories. Furthermore, a great deal is known about the anatomy, local circuitry, and plasticity of the HS, including quantitative data about cell counts and connectivity. But how the HS supports episodic memory function, and what constitutes an “episodic memory trace” is not well understood. I will describe a circuit-level computational model (SMRITI*) that demonstrates how a cortically expressed pattern of rhythmic activity representing an event can be transformed rapidly (~500 msec.) into a robust and functionally adequate memory trace in the HS. This memory trace consists of a complex neuronal circuit having several functional components. A quantitative analysis of the model indicates that memory traces are sparse and specific but, at the same time, they are highly redundant and physically dispersed. The model suggests a striking correspondence between the functional requirements of encoding episodic memories and the idiosyncratic architecture of the HS. Recent empirical findings show that the match between the model and the HS extends to the level of detailed micro-circuits identified in the HS. Time remaining, I will also discuss some of the model’s predictions about the nature of memory deficits resulting from insult to various regions and pathways of the HS.

May 15, 2007

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

In many contemporary studies and textbooks perceptual processing is treated as a ‘pure sensory’ phenomenon, one that can be understood on the basis of pathways passing information from the sensory periphery to the cerebral cortex, for processing within the cortex and subsequent passage to motor centers or memory stores. However, many physiologists, psychologists and philosophers have recognized perceptual processing as closely dependent upon action (e.g. the ‘sensorimotor contingencies’ of O’Regan and Noë, 2001), although the anatomical nature of the functional links is generally left unresolved.

A survey of pathways that pass messages through the thalamus to the cerebral cortex (visual, tactile etc.) shows that these are not ‘pure sensory’ pathways. They are generally branching axons that convey messages through one branch to lower, motor centers and to the thalamus through the other. That is, since the two branches will be transmitting the same message, the thalamic relay receives information not only about sensory events, but also, concurrently, information about instructions that are on the way to motor centers. This dual information, about sensory events and motor instructions, is an implicit part of the message that the thalamus passes to cortex. The axonal branching patterns reveal an anatomical basis of sensorimotor contingencies, which cortical mechanisms are not likely to ignore even when experimental studies do not reveal them.

Reference: O’Regan JK and Noë, (2001) A sensorimotor approach to vision and visual consciousness. Behav. & Brain Sciences 24, 939-973)

Previous Seminars

April 24

• Speaker: Jeff Johnson
• Affiliation: UC Davis
• Host: Bruno
• Title: What does EEG tell us about the timecourse of object recognition?

April 17, 2007

• Speaker: Steve Waydo
• Affiliation: Control & Dynamical Systems, California Institute of Technology
• Host: Bruno
• Title: Explicit Object Representation by Sparse Neural Codes

April 10

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

April 3

• Speaker: Robert Miller
• Affiliation: Department of Anatomy and Structural Biology, Otago University
• Host: Fritz
• Title: Axonal conduction time and human cerebral laterality

March 20, 2007

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

March 13, 2007

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

March 6

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

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