LCDS Seminar

Monday, January 27, 2019
4:00pm
Room 108, 170 Hope Street

Stanislav Shvartsman , Princeton University and Flatiron Institute

Title: Embryogenesis: a cascade of dynamical systems

Abstract : I will present our work on the formulation, analysis, and experimental validation of mathematical models of embryogenesis. While the foundation of this research is based on models of isolated developmental events, the ultimate challenge is to formulate and understand dynamics encompassing multiple stages of development and multiple levels of regulation. These range from specific chemical reactions in single cells to coordinated dynamics of multiple cells during morphogenesis. Examples of our dynamical systems models of embryogenesis – from the events in the Drosophila egg to the early stages of gastrulation – will be presented. Each of these will demonstrate what had been learned from model analysis and model-driven experiments, and what further research directions are guided by these models.

“From Synchrotrons to Microwires – a broad view on sensory processing”

Andreas Schaefer Ph.D.

Group Leader at the Crick Institute in London

Host: Alexander Fleischmann, Ph.D.

Dr. Jenny Tung- Duke University

Talk Title: “Social interactions in primate genomics, life history, and evolution”

EEG Core Initiative Seminar Series

“Selective Modulation of Cortico-Cortical Connectivity in the Human Brain”

Tommi Raij, Ph.D.

Associate Professor, Northwestern University, Chicago, IL

Many neurological and psychiatric symptoms arise from network-level derangements where the structural and/or functional connectivities between specific brain areas have been altered by the disease. Therefore, techniques that would allow selective up- or downregulation of specific connections between brain areas would be valuable. Here, we used MRI-navigated two-channel transcranial magnetic stimulation (TMS) in a paired associative stimulation (PAS) paradigm to activate two cortical regions at different millisecond-level asynchronies. We hypothesized that this would selectively increase (long asynchronies) or decrease (short asynchronies) effective connectivity between the stimulated areas via spike-timing dependent plasticity (STDP). To observe the connectivity changes, we used short-latency (onset at 5 ms) TMS-evoked electroencephalography (EEG) evoked potentials with source analysis. The results supported the hypothesis, as effective connectivity between the stimulated cortical areas increased or decreased as a function of the TMS asynchrony in a manner consistent with STDP mechanisms. In conclusion, PAS allow non-invasive manipulation of brain interregional connectivity in humans, therefore laying the foundation for network-level multi-channel brain stimulation therapies.

Coffee and cookies will be served. Please RSVP using the link below, as seating is limited. 

Organized by the EEG Core Initiative, Brown University. Co-sponsored by the VA CfNN and the Carney Institute for Brain Science.

Michael S. Goodman ’74 Memorial Seminar Series.  Speaker: Joanna Morris, Hampshire College & RISD.  Title: Is there a ‘moth’ in mother? How we read complex words (and those that are just pretending to be). Abstract: Skilled readers identify words with remarkable speed and accuracy, and fluent word identification is a prerequisite for comprehending sentences and longer texts. Although research on word reading has tended to focus on simple words, models of word recognition must nevertheless also be able to account for complex words with multiple parts or morphemes. One theory of word reading is that we break complex words into their component parts depending on whether the meaning of the whole word can be figured out from its components. For example, a ‘pay-ment’ is something (the ‘-ment’ part) that is paid ( the ‘pay-’ part); a ‘ship-ment’ is something that is shipped. However a ‘depart-ment’ is not something that departs! Thus ‘payment’ and ‘shipment’ are semantically transparent, while ‘department’ is semantically opaque. One model of word reading holds that only semantically transparent words are broken down. Other models claim that not only are all complex words —both transparent and opaque—decomposed, but so are words that are not even really complex but only appear to be, i.e. pseudo-complex words such as ‘mother’. My research examines the circumstances under which we break complex words into their component parts and in this talk I will address how this process may be instantiated in the brain.

Aging and Dementia Research Presentation

 Sponsored by: The Norman Prince Neurosciences Institute

In Association with:

The Rhode Island Hospital Alzheimer’s Disease & Memory Disorders Center

 “Mind-Body Interventions for Mild Cognitive Impairment”

Geoffrey Tremont, PhD

Associate Professor of Psychiatry

Alpert Medical School of Brown University

January 29, 2019

1 to 2 PM

Rhode Island Hospital

Ambulatory Patient Center (APC) Building

Leone Conference 1st floor, Room 133

Speaker: Brian Nosek, University of Virginia. Title: What is replication? Abstract: Reproducibility is a core feature of accumulating scientific knowledge. If evidence for a claim cannot be obtained independently of its originator, then it loses credibility as a scientific claim. The concept of replication seems simple—repeat the study with the same methodology and see if the same result is observed. This conception of replication is intuitive, easy to apply and incorrect. The reality of replication is more central to advancing theory and evidence.

Michael S. Goodman ’74 Memorial Seminar Series. Speaker: Dagmar Sternad, Northeastern University.  Title: Stability, Variability and Predictability: Dynamic Primitives in the Control of Complex Actions.  Abstract: Everyday behavior is a complex flow of actions, combining rhythmic and discrete movement elements and flexibly interacting with objects in the environment. In contrast to real-life behavior, research in human motor control has studied isolated, highly controlled experimental tasks, resulting in focused models that may not scale up to actions with full complexity. The premise of our research is that complex functional behaviors should be understood as the manifestation of a hierarchy of dynamic primitives, robust modules that overcome delays and noise in the neuromotor system and thereby simplify control. Discrete and rhythmic movements are generated by fixed-point and limit-cycle dynamics, attractors that are stable in the face of perturbations and that grant predictability, required for fast and complex actions; impedance is necessary to enable physical interactions. To test this framework, our research pursues both analytic and synthetic approaches using a suite of interactive skills as testbeds: from throwing and bouncing a ball to a target, to transporting a cup of coffee and cracking a whip. Starting with a model of the task that is implemented in a virtual environment, mathematical analyses of the task’s solution space create hypotheses for the experimental studies. Key concepts in our analysis are stability, variability, and predictability. Results show that humans develop skill by: 1) finding error-tolerant strategies that permit variability, 2) exploiting solutions with dynamic stability, 3) optimizing predictability of object dynamics. Simulations based on dynamic primitives generate critical features of these experimental findings. This framework can guide our understanding of pathological behaviors in clinical populations.

Genome-wide in vivo CNS Screening Identifies Genes that Modify CNS Neuronal Survival and Mutant Huntingtin Toxicity

Nonsense-mediated mRNA Decay is Mis-regulated in Fragile X Syndrome

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