Join the Presentation: https://mit.zoom.us/s/96797510492 Webinar ID 967 9751 0492

Presenter: Anna Ivanova, Fedorenko Lab

Anna Ivanova is a 4th year PhD student working with Ev Fedorenko and Nancy Kanwisher. She uses neuroimaging tools to investigate the language network in the human brain. She enjoyed snowy weather in Boston this year because it reminded her of winters in her hometown, Moscow. Anna is part of a peer support program for grad students in the department, so feel free to reach out at any time.

Title: The role of language in broader human cognition

Abstract: Many prominent thinkers have argued that language serves as a foundation for the human mind. But does language indeed underpin various aspects of human cognition or is it just one tool in our cognitive toolbox? In this talk, I will present two studies that test whether the language brain network supports cognitive functions that resemble language in important ways. In the first study, we use neuroimaging to investigate whether the language network responds to computer code, an input that is structurally similar to natural language. In the second study, we combine neuroimaging and evidence from patients to ask whether the language network supports a task that requires access to world knowledge, namely, evaluating plausibility of event drawings. In both cases, we find a dissociation between linguistic and non-linguistic processing. Overall, this work supports the view that most processes within an adult human mind can function independently of language.

Presenter: Dimitra Vardalaki, Harnett Lab

Dimitra is a graduate student in Brain and Cognitive Sciences at MIT, where she works with Prof. Mark Harnett since 2019. Her doctoral work focuses on plasticity of cortical synapses and involves single cell electrophysiology and proteomic imaging. She got her M.D from the University of Athens, Greece. Dimitra is a Boehringer Ingelheim Fonds PhD fellow.

Title: Filopodia in adult cortex contain recruitable silent synapses

Abstract: Memory formation requires a balance between flexibility and stability: flexibility establishes memory acquisition and stability ensures memory retention. Learning and memory is thought to occur at the level of the synapse, or the connection between neurons, where the modification of synaptic strength is known as plasticity. Do the processes governing stability versus flexibility operate at the synaptic level? Theoretical work has proposed that differential synaptic plasticity thresholds could orchestrate these conflicting processes. One candidate for flexibility is filopodia, identified by their long, thin structure and lack of a “head”, where the synapse is formed. While filopodia are notably present in the juvenile cortex during widespread experience-dependent plasticity, it is unclear how plasticity mechanisms transform filopodia into functional synapses and if this occurs in the adult brain. Here I use a super-resolution proteomic imaging technique to resolve synaptic content relative to morphology, which I then relate to functional plasticity thresholds tested in acute slices in adult mouse cortex. My results show that filopodia have distinct synaptic receptor content that cannot be directly activated, rendering them “silent synapses”. Furthermore, synapses on filopodia can be unsilenced by plasticity mechanisms to facilitate new active connections. Thus, filopodia have a low plasticity threshold and represent an important locus of plasticity in the adult cortex. This mechanism may permit the stability of acquired information stored in mature synapses while allowing for the acquisition of new information by filopodia

Presenter: Francisco Garcia, Heiman Lab

Francisco graduated from MIT in 2017 with a dual bachelors in Materials Science and Engineering and Chemistry. As an undergraduate, he worked in the lab of Polina Anikeeva synthesizing magnetic nanoparticles for neuronal stimulation. He joined MIT BCS as a graduate student in the fall of 2017 and the Heiman Lab in the spring of 2018. Outside of lab, he is an active contemporary/ballet dancer in the greater Boston area

Title: Molecular Profiling of the Human Cerebrovasculature in Health and Neurodegeneration

Abstract: Despite the importance of the cerebrovasculature in maintaining normal brain function and known cerebrovasculature dysfunction in several neurodegenerative disorders, the molecular and cellular properties of the human cerebrovasculature remain poorly characterized. Here, I discuss our recent work to develop the first comprehensive single-cell molecular atlas of human cerebrovasculature cells from healthy ex vivo and post mortem brain tissue, as well as to elucidate molecular mechanisms associated with their dysfunction in Huntington's disease.

Presenter: Halie Olson, Gabrieli Lab

Halie Olson is a fourth year graduate student in BCS working with John Gabrieli and Rebecca Saxe. She is interested in how the developing brain supports language and reading, and how individual differences in children’s experiences and environments impact brain development and behavior. In her research, she uses neuroimaging tools like functional magnetic resonance imaging (fMRI) and functional near-infrared spectroscopy (fNIRS), as well as cognitive and behavioral measures.

Title: Let’s talk about trains: Using special interests to study the language network in children

Abstract: In this talk, I will describe an ongoing study investigating how the brain’s language network is modulated by personal interest in children with and without autism. Traditional neuroimaging studies tend to rely on measuring the brain’s response to the same set of stimuli across many different people. But what if some people find the stimuli much more engaging than others? Here we ask - how does interest modulate the brain’s response to language? We compare 7-12 year old children’s neural responses to generic, neutral stories to their response to individualized stories written based on their  special interests. Special interests (also called circumscribed interests or affinities) are highly prevalent in autism (ASD), a neurodevelopmental disorder characterized by impairments in social communication and the presence of repetitive patterns of behavior or restricted/special interests. These special interests are present in most children with ASD, and are characterized by specificity, focus, and intensity. While prevalent, these highly focused interests are not unique to autism, however - many children and adults without autism also exhibit strong passions or interests. Thus, in this study, we are recruiting a sample of children with and without ASD who all exhibit strong special interests. We aim to determine whether special interests modulate the language response in all children, as well as whether that modulation is particularly strong for individuals with ASD. 

Presenter: Andrew Bahle, Fee Lab

Andrew Bahle is a fifth year BCS PhD student in Michale Fee’s lab. Before coming to MIT Andrew received  undergraduate degrees in music performance and neuroscience from the University of Michigan and performed research as a Fulbright fellow in Trondheim, Norway.

Title: A neural mechanism for the storage and recall of an auditory memory

Abstract: The songbird has emerged as a powerful model system in which to develop a mechanistic understanding of how neural circuit dynamics control the learning and production of complex sequential behaviors. Songbirds are an ideal model in which to study this phenomenon as they acquire their songs through an imitation process reminiscent of speech acquisitions in humans; juvenile songbirds form a memory of the song of an adult male and gradually refine their own vocalizations until they form a close match to this tutor song. Previous work in our lab and others has made great strides in understanding the brain regions that support the gradual learning of the imitation as well as the production of mature song, however the mechanisms underlying the formation and recall of the tutor memory that guide learning have remained obscure. In this talk we will present a new model for how the tutor memory is formed and retrieved during song learning and discuss ongoing experiments designed to test key predictions of this model.