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SeminarNeuroscience

Computational Mechanisms of Predictive Processing in Brains and Machines

Dr. Antonino Greco
Hertie Institute for Clinical Brain Research, Germany
Dec 9, 2025

Predictive processing offers a unifying view of neural computation, proposing that brains continuously anticipate sensory input and update internal models based on prediction errors. In this talk, I will present converging evidence for the computational mechanisms underlying this framework across human neuroscience and deep neural networks. I will begin with recent work showing that large-scale distributed prediction-error encoding in the human brain directly predicts how sensory representations reorganize through predictive learning. I will then turn to PredNet, a popular predictive coding inspired deep network that has been widely used to model real-world biological vision systems. Using dynamic stimuli generated with our Spatiotemporal Style Transfer algorithm, we demonstrate that PredNet relies primarily on low-level spatiotemporal structure and remains insensitive to high-level content, revealing limits in its generalization capacity. Finally, I will discuss new recurrent vision models that integrate top-down feedback connections with intrinsic neural variability, uncovering a dual mechanism for robust sensory coding in which neural variability decorrelates unit responses, while top-down feedback stabilizes network dynamics. Together, these results outline how prediction error signaling and top-down feedback pathways shape adaptive sensory processing in biological and artificial systems.

Position

Prof. Jason Corso

University of Michigan
University of Michigan
Dec 5, 2025

The Corso Group (COG) at the University of Michigan is recruiting 2-3 talented, self-motivated, and creative PhD students for the 2024-2025 academic year. Led by Prof. Jason Corso, COG has been pioneering advances in physical AI and visual AI for the last two decades. We've contributed seminal work in areas such as machine learning foundations, video understanding (including the first paper on video captioning), human-in-the-loop computer vision, and interactive physical systems.

SeminarNeuroscience

Generation and use of internal models of the world to guide flexible behavior

Antonio Fernandez-Ruiz
Cornell University, USA
Oct 26, 2025
SeminarNeuroscience

AutoMIND: Deep inverse models for revealing neural circuit invariances

Richard Gao
Goethe University
Oct 1, 2025
SeminarNeuroscience

Understanding reward-guided learning using large-scale datasets

Kim Stachenfeld
DeepMind, Columbia U
Jul 8, 2025

Understanding the neural mechanisms of reward-guided learning is a long-standing goal of computational neuroscience. Recent methodological innovations enable us to collect ever larger neural and behavioral datasets. This presents opportunities to achieve greater understanding of learning in the brain at scale, as well as methodological challenges. In the first part of the talk, I will discuss our recent insights into the mechanisms by which zebra finch songbirds learn to sing. Dopamine has been long thought to guide reward-based trial-and-error learning by encoding reward prediction errors. However, it is unknown whether the learning of natural behaviours, such as developmental vocal learning, occurs through dopamine-based reinforcement. Longitudinal recordings of dopamine and bird songs reveal that dopamine activity is indeed consistent with encoding a reward prediction error during naturalistic learning. In the second part of the talk, I will talk about recent work we are doing at DeepMind to develop tools for automatically discovering interpretable models of behavior directly from animal choice data. Our method, dubbed CogFunSearch, uses LLMs within an evolutionary search process in order to "discover" novel models in the form of Python programs that excel at accurately predicting animal behavior during reward-guided learning. The discovered programs reveal novel patterns of learning and choice behavior that update our understanding of how the brain solves reinforcement learning problems.

SeminarPsychology

Digital Traces of Human Behaviour: From Political Mobilisation to Conspiracy Narratives

Lukasz Piwek
University of Bath & Cumulus Neuroscience Ltd
Jul 6, 2025

Digital platforms generate unprecedented traces of human behaviour, offering new methodological approaches to understanding collective action, polarisation, and social dynamics. Through analysis of millions of digital traces across multiple studies, we demonstrate how online behaviours predict offline action: Brexit-related tribal discourse responds to real-world events, machine learning models achieve 80% accuracy in predicting real-world protest attendance from digital signals, and social validation through "likes" emerges as a key driver of mobilization. Extending this approach to conspiracy narratives reveals how digital traces illuminate psychological mechanisms of belief and community formation. Longitudinal analysis of YouTube conspiracy content demonstrates how narratives systematically address existential, epistemic, and social needs, while examination of alt-tech platforms shows how emotions of anger, contempt, and disgust correlate with violence-legitimating discourse, with significant differences between narratives associated with offline violence versus peaceful communities. This work establishes digital traces as both methodological innovation and theoretical lens, demonstrating that computational social science can illuminate fundamental questions about polarisation, mobilisation, and collective behaviour across contexts from electoral politics to conspiracy communities.

SeminarNeuroscience

“Brain theory, what is it or what should it be?”

Prof. Guenther Palm
University of Ulm
Jun 26, 2025

n the neurosciences the need for some 'overarching' theory is sometimes expressed, but it is not always obvious what is meant by this. One can perhaps agree that in modern science observation and experimentation is normally complemented by 'theory', i.e. the development of theoretical concepts that help guiding and evaluating experiments and measurements. A deeper discussion of 'brain theory' will require the clarification of some further distictions, in particular: theory vs. model and brain research (and its theory) vs. neuroscience. Other questions are: Does a theory require mathematics? Or even differential equations? Today it is often taken for granted that the whole universe including everything in it, for example humans, animals, and plants, can be adequately treated by physics and therefore theoretical physics is the overarching theory. Even if this is the case, it has turned out that in some particular parts of physics (the historical example is thermodynamics) it may be useful to simplify the theory by introducing additional theoretical concepts that can in principle be 'reduced' to more complex descriptions on the 'microscopic' level of basic physical particals and forces. In this sense, brain theory may be regarded as part of theoretical neuroscience, which is inside biophysics and therefore inside physics, or theoretical physics. Still, in neuroscience and brain research, additional concepts are typically used to describe results and help guiding experimentation that are 'outside' physics, beginning with neurons and synapses, names of brain parts and areas, up to concepts like 'learning', 'motivation', 'attention'. Certainly, we do not yet have one theory that includes all these concepts. So 'brain theory' is still in a 'pre-newtonian' state. However, it may still be useful to understand in general the relations between a larger theory and its 'parts', or between microscopic and macroscopic theories, or between theories at different 'levels' of description. This is what I plan to do.

SeminarNeuroscience

“Development and application of gaze control models for active perception”

Prof. Bert Shi
Professor of Electronic and Computer Engineering at the Hong Kong University of Science and Technology (HKUST)
Jun 11, 2025

Gaze shifts in humans serve to direct high-resolution vision provided by the fovea towards areas in the environment. Gaze can be considered a proxy for attention or indicator of the relative importance of different parts of the environment. In this talk, we discuss the development of generative models of human gaze in response to visual input. We discuss how such models can be learned, both using supervised learning and using implicit feedback as an agent interacts with the environment, the latter being more plausible in biological agents. We also discuss two ways such models can be used. First, they can be used to improve the performance of artificial autonomous systems, in applications such as autonomous navigation. Second, because these models are contingent on the human’s task, goals, and/or state in the context of the environment, observations of gaze can be used to infer information about user intent. This information can be used to improve human-machine and human robot interaction, by making interfaces more anticipative. We discuss example applications in gaze-typing, robotic tele-operation and human-robot interaction.

SeminarNeuroscience

Developmental and evolutionary perspectives on thalamic function

Dr. Bruno Averbeck
National Institute of Mental Health, Maryland, USA
Jun 10, 2025

Brain organization and function is a complex topic. We are good at establishing correlates of perception and behavior across forebrain circuits, as well as manipulating activity in these circuits to affect behavior. However, we still lack good models for the large-scale organization and function of the forebrain. What are the contributions of the cortex, basal ganglia, and thalamus to behavior? In addressing these questions, we often ascribe function to each area as if it were an independent processing unit. However, we know from the anatomy that the cortex, basal ganglia, and thalamus, are massively interconnected in a large network. One way to generate insight into these questions is to consider the evolution and development of forebrain systems. In this talk, I will discuss the developmental and evolutionary (comparative anatomy) data on the thalamus, and how it fits within forebrain networks. I will address questions including, when did the thalamus appear in evolution, how is the thalamus organized across the vertebrate lineage, and how can the change in the organization of forebrain networks affect behavioral repertoires.

SeminarNeuroscience

Understanding reward-guided learning using large-scale datasets

Kim Stachenfeld
DeepMind, Columbia U
May 13, 2025

Understanding the neural mechanisms of reward-guided learning is a long-standing goal of computational neuroscience. Recent methodological innovations enable us to collect ever larger neural and behavioral datasets. This presents opportunities to achieve greater understanding of learning in the brain at scale, as well as methodological challenges. In the first part of the talk, I will discuss our recent insights into the mechanisms by which zebra finch songbirds learn to sing. Dopamine has been long thought to guide reward-based trial-and-error learning by encoding reward prediction errors. However, it is unknown whether the learning of natural behaviours, such as developmental vocal learning, occurs through dopamine-based reinforcement. Longitudinal recordings of dopamine and bird songs reveal that dopamine activity is indeed consistent with encoding a reward prediction error during naturalistic learning. In the second part of the talk, I will talk about recent work we are doing at DeepMind to develop tools for automatically discovering interpretable models of behavior directly from animal choice data. Our method, dubbed CogFunSearch, uses LLMs within an evolutionary search process in order to "discover" novel models in the form of Python programs that excel at accurately predicting animal behavior during reward-guided learning. The discovered programs reveal novel patterns of learning and choice behavior that update our understanding of how the brain solves reinforcement learning problems.

SeminarNeuroscience

Simulating Thought Disorder: Fine-Tuning Llama-2 for Synthetic Speech in Schizophrenia

Alban Elias Voppel
McGill University
Apr 30, 2025
SeminarNeuroscience

Unlocking the Secrets of Microglia in Neurodegenerative diseases: Mechanisms of resilience to AD pathologies

Ghazaleh Eskandari-Sedighi
UC Irvince
Apr 30, 2025
SeminarArtificial IntelligenceRecording

Computational modelling of ocular pharmacokinetics

Arto Urtti
School of Pharmacy, University of Eastern Finland
Apr 21, 2025

Pharmacokinetics in the eye is an important factor for the success of ocular drug delivery and treatment. Pharmacokinetic features determine the feasible routes of drug administration, dosing levels and intervals, and it has impact on eventual drug responses. Several physical, biochemical, and flow-related barriers limit drug exposure of anterior and posterior ocular target tissues during treatment during local (topical, subconjunctival, intravitreal) and systemic administration (intravenous, per oral). Mathematical models integrate joint impact of various barriers on ocular pharmacokinetics (PKs) thereby helping drug development. The models are useful in describing (top-down) and predicting (bottom-up) pharmacokinetics of ocular drugs. This is useful also in the design and development of new drug molecules and drug delivery systems. Furthermore, the models can be used for interspecies translation and probing of disease effects on pharmacokinetics. In this lecture, ocular pharmacokinetics and current modelling methods (noncompartmental analyses, compartmental, physiologically based, and finite element models) are introduced. Future challenges are also highlighted (e.g. intra-tissue distribution, prediction of drug responses, active transport).

SeminarNeuroscience

Impact of High Fat Diet on Central Cardiac Circuits: When The Wanderer is Lost

Carie Boychuk
University of Missouri
Mar 19, 2025

Cardiac vagal motor drive originates in the brainstem's cardiac vagal motor neurons (CVNs). Despite well-established cardioinhibitory functions in health, our understanding of CVNs in disease is limited. There is a clear connection of cardiovascular regulation with metabolic and energy expenditure systems. Using high fat diet as a model, this talk will explore how metabolic dysfunction impacts the regulation of cardiac tissue through robust inhibition of CVNs. Specifically, it will present an often overlooked modality of inhibition, tonic gamma-aminobuytric acid (GABA) A-type neurotransmission using an array of techniques from single cell patch clamp electrophysiology to transgenic in vivo whole animal physiology. It also will highlight a unique interaction with the delta isoform of protein kinase C to facilitate GABA A-type receptor expression.

SeminarNeuroscienceRecording

Rethinking Attention: Dynamic Prioritization

Sarah Shomstein
George Washington University
Jan 6, 2025

Decades of research on understanding the mechanisms of attentional selection have focused on identifying the units (representations) on which attention operates in order to guide prioritized sensory processing. These attentional units fit neatly to accommodate our understanding of how attention is allocated in a top-down, bottom-up, or historical fashion. In this talk, I will focus on attentional phenomena that are not easily accommodated within current theories of attentional selection – the “attentional platypuses,” as they allude to an observation that within biological taxonomies the platypus does not fit into either mammal or bird categories. Similarly, attentional phenomena that do not fit neatly within current attentional models suggest that current models need to be revised. I list a few instances of the ‘attentional platypuses” and then offer a new approach, the Dynamically Weighted Prioritization, stipulating that multiple factors impinge onto the attentional priority map, each with a corresponding weight. The interaction between factors and their corresponding weights determines the current state of the priority map which subsequently constrains/guides attention allocation. I propose that this new approach should be considered as a supplement to existing models of attention, especially those that emphasize categorical organizations.

SeminarNeuroscience

Decision and Behavior

Sam Gershman, Jonathan Pillow, Kenji Doya
Harvard University; Princeton University; Okinawa Institute of Science and Technology
Nov 28, 2024

This webinar addressed computational perspectives on how animals and humans make decisions, spanning normative, descriptive, and mechanistic models. Sam Gershman (Harvard) presented a capacity-limited reinforcement learning framework in which policies are compressed under an information bottleneck constraint. This approach predicts pervasive perseveration, stimulus‐independent “default” actions, and trade-offs between complexity and reward. Such policy compression reconciles observed action stochasticity and response time patterns with an optimal balance between learning capacity and performance. Jonathan Pillow (Princeton) discussed flexible descriptive models for tracking time-varying policies in animals. He introduced dynamic Generalized Linear Models (Sidetrack) and hidden Markov models (GLM-HMMs) that capture day-to-day and trial-to-trial fluctuations in choice behavior, including abrupt switches between “engaged” and “disengaged” states. These models provide new insights into how animals’ strategies evolve under learning. Finally, Kenji Doya (OIST) highlighted the importance of unifying reinforcement learning with Bayesian inference, exploring how cortical-basal ganglia networks might implement model-based and model-free strategies. He also described Japan’s Brain/MINDS 2.0 and Digital Brain initiatives, aiming to integrate multimodal data and computational principles into cohesive “digital brains.”

SeminarNeuroscience

Sensory cognition

SueYeon Chung, Srini Turaga
New York University; Janelia Research Campus
Nov 28, 2024

This webinar features presentations from SueYeon Chung (New York University) and Srinivas Turaga (HHMI Janelia Research Campus) on theoretical and computational approaches to sensory cognition. Chung introduced a “neural manifold” framework to capture how high-dimensional neural activity is structured into meaningful manifolds reflecting object representations. She demonstrated that manifold geometry—shaped by radius, dimensionality, and correlations—directly governs a population’s capacity for classifying or separating stimuli under nuisance variations. Applying these ideas as a data analysis tool, she showed how measuring object-manifold geometry can explain transformations along the ventral visual stream and suggested that manifold principles also yield better self-supervised neural network models resembling mammalian visual cortex. Turaga described simulating the entire fruit fly visual pathway using its connectome, modeling 64 key cell types in the optic lobe. His team’s systematic approach—combining sparse connectivity from electron microscopy with simple dynamical parameters—recapitulated known motion-selective responses and produced novel testable predictions. Together, these studies underscore the power of combining connectomic detail, task objectives, and geometric theories to unravel neural computations bridging from stimuli to cognitive functions.

SeminarNeuroscience

LLMs and Human Language Processing

Maryia Toneva, Ariel Goldstein, Jean-Remi King
Max Planck Institute of Software Systems; Hebrew University; École Normale Supérieure
Nov 28, 2024

This webinar convened researchers at the intersection of Artificial Intelligence and Neuroscience to investigate how large language models (LLMs) can serve as valuable “model organisms” for understanding human language processing. Presenters showcased evidence that brain recordings (fMRI, MEG, ECoG) acquired while participants read or listened to unconstrained speech can be predicted by representations extracted from state-of-the-art text- and speech-based LLMs. In particular, text-based LLMs tend to align better with higher-level language regions, capturing more semantic aspects, while speech-based LLMs excel at explaining early auditory cortical responses. However, purely low-level features can drive part of these alignments, complicating interpretations. New methods, including perturbation analyses, highlight which linguistic variables matter for each cortical area and time scale. Further, “brain tuning” of LLMs—fine-tuning on measured neural signals—can improve semantic representations and downstream language tasks. Despite open questions about interpretability and exact neural mechanisms, these results demonstrate that LLMs provide a promising framework for probing the computations underlying human language comprehension and production at multiple spatiotemporal scales.

SeminarNeuroscience

Brain-Wide Compositionality and Learning Dynamics in Biological Agents

Kanaka Rajan
Harvard Medical School
Nov 12, 2024

Biological agents continually reconcile the internal states of their brain circuits with incoming sensory and environmental evidence to evaluate when and how to act. The brains of biological agents, including animals and humans, exploit many evolutionary innovations, chiefly modularity—observable at the level of anatomically-defined brain regions, cortical layers, and cell types among others—that can be repurposed in a compositional manner to endow the animal with a highly flexible behavioral repertoire. Accordingly, their behaviors show their own modularity, yet such behavioral modules seldom correspond directly to traditional notions of modularity in brains. It remains unclear how to link neural and behavioral modularity in a compositional manner. We propose a comprehensive framework—compositional modes—to identify overarching compositionality spanning specialized submodules, such as brain regions. Our framework directly links the behavioral repertoire with distributed patterns of population activity, brain-wide, at multiple concurrent spatial and temporal scales. Using whole-brain recordings of zebrafish brains, we introduce an unsupervised pipeline based on neural network models, constrained by biological data, to reveal highly conserved compositional modes across individuals despite the naturalistic (spontaneous or task-independent) nature of their behaviors. These modes provided a scaffolding for other modes that account for the idiosyncratic behavior of each fish. We then demonstrate experimentally that compositional modes can be manipulated in a consistent manner by behavioral and pharmacological perturbations. Our results demonstrate that even natural behavior in different individuals can be decomposed and understood using a relatively small number of neurobehavioral modules—the compositional modes—and elucidate a compositional neural basis of behavior. This approach aligns with recent progress in understanding how reasoning capabilities and internal representational structures develop over the course of learning or training, offering insights into the modularity and flexibility in artificial and biological agents.

SeminarNeuroscience

Contribution of computational models of reinforcement learning to neurosciences/ computational modeling, reward, learning, decision-making, conditioning, navigation, dopamine, basal ganglia, prefrontal cortex, hippocampus

Khamasi Mehdi
Centre National de la Recherche Scientifique / Sorbonne University
Nov 7, 2024
SeminarNeuroscienceRecording

On finding what you’re (not) looking for: prospects and challenges for AI-driven discovery

André Curtis Trudel
University of Cincinnati
Oct 9, 2024

Recent high-profile scientific achievements by machine learning (ML) and especially deep learning (DL) systems have reinvigorated interest in ML for automated scientific discovery (eg, Wang et al. 2023). Much of this work is motivated by the thought that DL methods might facilitate the efficient discovery of phenomena, hypotheses, or even models or theories more efficiently than traditional, theory-driven approaches to discovery. This talk considers some of the more specific obstacles to automated, DL-driven discovery in frontier science, focusing on gravitational-wave astrophysics (GWA) as a representative case study. In the first part of the talk, we argue that despite these efforts, prospects for DL-driven discovery in GWA remain uncertain. In the second part, we advocate a shift in focus towards the ways DL can be used to augment or enhance existing discovery methods, and the epistemic virtues and vices associated with these uses. We argue that the primary epistemic virtue of many such uses is to decrease opportunity costs associated with investigating puzzling or anomalous signals, and that the right framework for evaluating these uses comes from philosophical work on pursuitworthiness.

SeminarPsychology

How Generative AI is Revolutionizing the Software Developer Industry

Luca Di Grazia
Università della Svizzera Italiana
Sep 30, 2024

Generative AI is fundamentally transforming the software development industry by improving processes such as software testing, bug detection, bug fixes, and developer productivity. This talk explores how AI-driven techniques, particularly large language models (LLMs), are being utilized to generate realistic test scenarios, automate bug detection and repair, and streamline development workflows. As these technologies evolve, they promise to improve software quality and efficiency significantly. The discussion will cover key methodologies, challenges, and the future impact of generative AI on the software development lifecycle, offering a comprehensive overview of its revolutionary potential in the industry.

SeminarNeuroscience

Top-down models of learning and decision-making in BG

Rafal Bogacz & Michael Frank
University of Oxford Resp. Brown University
Sep 26, 2024
SeminarArtificial IntelligenceRecording

Llama 3.1 Paper: The Llama Family of Models

Vibhu Sapra
Jul 28, 2024

Modern artificial intelligence (AI) systems are powered by foundation models. This paper presents a new set of foundation models, called Llama 3. It is a herd of language models that natively support multilinguality, coding, reasoning, and tool usage. Our largest model is a dense Transformer with 405B parameters and a context window of up to 128K tokens. This paper presents an extensive empirical evaluation of Llama 3. We find that Llama 3 delivers comparable quality to leading language models such as GPT-4 on a plethora of tasks. We publicly release Llama 3, including pre-trained and post-trained versions of the 405B parameter language model and our Llama Guard 3 model for input and output safety. The paper also presents the results of experiments in which we integrate image, video, and speech capabilities into Llama 3 via a compositional approach. We observe this approach performs competitively with the state-of-the-art on image, video, and speech recognition tasks. The resulting models are not yet being broadly released as they are still under development.

SeminarPsychology

Error Consistency between Humans and Machines as a function of presentation duration

Thomas Klein
Eberhard Karls Universität Tübingen
Jun 30, 2024

Within the last decade, Deep Artificial Neural Networks (DNNs) have emerged as powerful computer vision systems that match or exceed human performance on many benchmark tasks such as image classification. But whether current DNNs are suitable computational models of the human visual system remains an open question: While DNNs have proven to be capable of predicting neural activations in primate visual cortex, psychophysical experiments have shown behavioral differences between DNNs and human subjects, as quantified by error consistency. Error consistency is typically measured by briefly presenting natural or corrupted images to human subjects and asking them to perform an n-way classification task under time pressure. But for how long should stimuli ideally be presented to guarantee a fair comparison with DNNs? Here we investigate the influence of presentation time on error consistency, to test the hypothesis that higher-level processing drives behavioral differences. We systematically vary presentation times of backward-masked stimuli from 8.3ms to 266ms and measure human performance and reaction times on natural, lowpass-filtered and noisy images. Our experiment constitutes a fine-grained analysis of human image classification under both image corruptions and time pressure, showing that even drastically time-constrained humans who are exposed to the stimuli for only two frames, i.e. 16.6ms, can still solve our 8-way classification task with success rates way above chance. We also find that human-to-human error consistency is already stable at 16.6ms.

SeminarNeuroscience

Transcranial magnetic stimulation in animal models: Using small coils in small brains to investigate biological and therapeutic mechanisms

Jennifer Rodger
University of Western Australia, Perth
Jun 19, 2024
SeminarNeuroscience

Neural mechanisms governing the learning and execution of avoidance behavior

Mario Penzo
National Institute of Mental Health, Bethesda, USA
Jun 18, 2024

The nervous system orchestrates adaptive behaviors by intricately coordinating responses to internal cues and environmental stimuli. This involves integrating sensory input, managing competing motivational states, and drawing on past experiences to anticipate future outcomes. While traditional models attribute this complexity to interactions between the mesocorticolimbic system and hypothalamic centers, the specific nodes of integration have remained elusive. Recent research, including our own, sheds light on the midline thalamus's overlooked role in this process. We propose that the midline thalamus integrates internal states with memory and emotional signals to guide adaptive behaviors. Our investigations into midline thalamic neuronal circuits have provided crucial insights into the neural mechanisms behind flexibility and adaptability. Understanding these processes is essential for deciphering human behavior and conditions marked by impaired motivation and emotional processing. Our research aims to contribute to this understanding, paving the way for targeted interventions and therapies to address such impairments.

SeminarNeuroscience

Trends in NeuroAI - Brain-like topography in transformers (Topoformer)

Nicholas Blauch
Jun 6, 2024

Dr. Nicholas Blauch will present on his work "Topoformer: Brain-like topographic organization in transformer language models through spatial querying and reweighting". Dr. Blauch is a postdoctoral fellow in the Harvard Vision Lab advised by Talia Konkle and George Alvarez. Paper link: https://openreview.net/pdf?id=3pLMzgoZSA Trends in NeuroAI is a reading group hosted by the MedARC Neuroimaging & AI lab (https://medarc.ai/fmri | https://groups.google.com/g/medarc-fmri).

SeminarNeuroscience

Updating our models of the basal ganglia using advances in neuroanatomy and computational modeling

Mac Shine
University of Sydney
May 28, 2024
SeminarPsychology

The Role of Cognitive Appraisal in the Relationship between Personality and Emotional Reactivity

Livia Sacchi
University of Lausanne
May 12, 2024

Emotion is defined as a rapid psychological process involving experiential, expressive and physiological responses. These emerge following an appraisal process that involves cognitive evaluations of the environment assessing its relevance, implication, coping potential, and normative significance. It has been suggested that changes in appraisal processes lead to changes in the resulting emotional nature. Simultaneously, it was demonstrated that personality can be seen as a predisposition to feel more frequently certain emotions, but the personality-appraisal-emotional response chain is rarely fully investigated. The present project thus sought to investigate the extent to which personality traits influence certain appraisals, which in turn influence the subsequent emotional reactions via a systematic analysis of the link between personality traits of different current models, specific appraisals, and emotional response patterns at the experiential, expressive, and physiological levels. Major results include the coherence of emotion components clustering, and the centrality of the pleasantness, coping potential and consequences appraisals, in context; and the differentiated mediating role of cognitive appraisal in the relation between personality and the intensity and duration of an emotional state, and autonomic arousal, such as Extraversion-pleasantness-experience, and Neuroticism-powerlessness-arousal. Elucidating these relationships deepens our understanding of individual differences in emotional reactivity and spot routes of action on appraisal processes to modify upcoming adverse emotional responses, with a broader societal impact on clinical and non-clinical populations.

SeminarNeuroscience

Investigating dynamiCa++l mechanisms underlying cortical development and disease

Georgia Panagiotakos
Icahn School of Medicine at Mount Sinai
May 7, 2024
SeminarArtificial IntelligenceRecording

Improving Language Understanding by Generative Pre Training

Amgad Hasan
Apr 22, 2024

Natural language understanding comprises a wide range of diverse tasks such as textual entailment, question answering, semantic similarity assessment, and document classification. Although large unlabeled text corpora are abundant, labeled data for learning these specific tasks is scarce, making it challenging for discriminatively trained models to perform adequately. We demonstrate that large gains on these tasks can be realized by generative pre-training of a language model on a diverse corpus of unlabeled text, followed by discriminative fine-tuning on each specific task. In contrast to previous approaches, we make use of task-aware input transformations during fine-tuning to achieve effective transfer while requiring minimal changes to the model architecture. We demonstrate the effectiveness of our approach on a wide range of benchmarks for natural language understanding. Our general task-agnostic model outperforms discriminatively trained models that use architectures specifically crafted for each task, significantly improving upon the state of the art in 9 out of the 12 tasks studied. For instance, we achieve absolute improvements of 8.9% on commonsense reasoning (Stories Cloze Test), 5.7% on question answering (RACE), and 1.5% on textual entailment (MultiNLI).

SeminarNeuroscience

Roles of inhibition in stabilizing and shaping the response of cortical networks

Nicolas Brunel
Duke University
Apr 4, 2024

Inhibition has long been thought to stabilize the activity of cortical networks at low rates, and to shape significantly their response to sensory inputs. In this talk, I will describe three recent collaborative projects that shed light on these issues. (1) I will show how optogenetic excitation of inhibition neurons is consistent with cortex being inhibition stabilized even in the absence of sensory inputs, and how this data can constrain the coupling strengths of E-I cortical network models. (2) Recent analysis of the effects of optogenetic excitation of pyramidal cells in V1 of mice and monkeys shows that in some cases this optogenetic input reshuffles the firing rates of neurons of the network, leaving the distribution of rates unaffected. I will show how this surprising effect can be reproduced in sufficiently strongly coupled E-I networks. (3) Another puzzle has been to understand the respective roles of different inhibitory subtypes in network stabilization. Recent data reveal a novel, state dependent, paradoxical effect of weakening AMPAR mediated synaptic currents onto SST cells. Mathematical analysis of a network model with multiple inhibitory cell types shows that this effect tells us in which conditions SST cells are required for network stabilization.

SeminarNeuroscience

Investigating activity-dependent processes during cortical neuronal assembly in development and disease

Simona Lodato
Humanitas University
Mar 19, 2024
SeminarArtificial IntelligenceRecording

A Comprehensive Overview of Large Language Models

Ivan Leo
Mar 14, 2024

Large Language Models (LLMs) have recently demonstrated remarkable capabilities in natural language processing tasks and beyond. This success of LLMs has led to a large influx of research contributions in this direction. These works encompass diverse topics such as architectural innovations, better training strategies, context length improvements, fine-tuning, multi-modal LLMs, robotics, datasets, benchmarking, efficiency, and more. With the rapid development of techniques and regular breakthroughs in LLM research, it has become considerably challenging to perceive the bigger picture of the advances in this direction. Considering the rapidly emerging plethora of literature on LLMs, it is imperative that the research community is able to benefit from a concise yet comprehensive overview of the recent developments in this field. This article provides an overview of the existing literature on a broad range of LLM-related concepts. Our self-contained comprehensive overview of LLMs discusses relevant background concepts along with covering the advanced topics at the frontier of research in LLMs. This review article is intended to not only provide a systematic survey but also a quick comprehensive reference for the researchers and practitioners to draw insights from extensive informative summaries of the existing works to advance the LLM research.

SeminarNeuroscience

Learning produces a hippocampal cognitive map in the form of an orthogonalized state machine

Nelson Spruston
Janelia, Ashburn, USA
Mar 5, 2024

Cognitive maps confer animals with flexible intelligence by representing spatial, temporal, and abstract relationships that can be used to shape thought, planning, and behavior. Cognitive maps have been observed in the hippocampus, but their algorithmic form and the processes by which they are learned remain obscure. Here, we employed large-scale, longitudinal two-photon calcium imaging to record activity from thousands of neurons in the CA1 region of the hippocampus while mice learned to efficiently collect rewards from two subtly different versions of linear tracks in virtual reality. The results provide a detailed view of the formation of a cognitive map in the hippocampus. Throughout learning, both the animal behavior and hippocampal neural activity progressed through multiple intermediate stages, gradually revealing improved task representation that mirrored improved behavioral efficiency. The learning process led to progressive decorrelations in initially similar hippocampal neural activity within and across tracks, ultimately resulting in orthogonalized representations resembling a state machine capturing the inherent struture of the task. We show that a Hidden Markov Model (HMM) and a biologically plausible recurrent neural network trained using Hebbian learning can both capture core aspects of the learning dynamics and the orthogonalized representational structure in neural activity. In contrast, we show that gradient-based learning of sequence models such as Long Short-Term Memory networks (LSTMs) and Transformers do not naturally produce such orthogonalized representations. We further demonstrate that mice exhibited adaptive behavior in novel task settings, with neural activity reflecting flexible deployment of the state machine. These findings shed light on the mathematical form of cognitive maps, the learning rules that sculpt them, and the algorithms that promote adaptive behavior in animals. The work thus charts a course toward a deeper understanding of biological intelligence and offers insights toward developing more robust learning algorithms in artificial intelligence.

SeminarPsychology

Are integrative, multidisciplinary, and pragmatic models possible? The #PsychMapping experience

Alexander Latinjak
University of Suffolk
Mar 3, 2024

This presentation delves into the necessity for simplified models in the field of psychological sciences to cater to a diverse audience of practitioners. We introduce the #PsychMapping model, evaluate its merits and limitations, and discuss its place in contemporary scientific culture. The #PsychMapping model is the product of an extensive literature review, initially within the realm of sport and exercise psychology and subsequently encompassing a broader spectrum of psychological sciences. This model synthesizes the progress made in psychological sciences by categorizing variables into a framework that distinguishes between traits (e.g., body structure and personality) and states (e.g., heart rate and emotions). Furthermore, it delineates internal traits and states from the externalized self, which encompasses behaviour and performance. All three components—traits, states, and the externalized self—are in a continuous interplay with external physical, social, and circumstantial factors. Two core processes elucidate the interactions among these four primary clusters: external perception, encompassing the mechanism through which external stimuli transition into internal events, and self-regulation, which empowers individuals to become autonomous agents capable of exerting control over themselves and their actions. While the model inherently oversimplifies intricate processes, the central question remains: does its pragmatic utility outweigh its limitations, and can it serve as a valuable tool for comprehending human behaviour?

SeminarNeuroscience

Trends in NeuroAI - Unified Scalable Neural Decoding (POYO)

Mehdi Azabou
Feb 21, 2024

Lead author Mehdi Azabou will present on his work "POYO-1: A Unified, Scalable Framework for Neural Population Decoding" (https://poyo-brain.github.io/). Mehdi is an ML PhD student at Georgia Tech advised by Dr. Eva Dyer. Paper link: https://arxiv.org/abs/2310.16046 Trends in NeuroAI is a reading group hosted by the MedARC Neuroimaging & AI lab (https://medarc.ai/fmri | https://groups.google.com/g/medarc-fmri).

SeminarNeuroscience

Unifying the mechanisms of hippocampal episodic memory and prefrontal working memory

James Whittington
Stanford University / University of Oxford
Feb 13, 2024

Remembering events in the past is crucial to intelligent behaviour. Flexible memory retrieval, beyond simple recall, requires a model of how events relate to one another. Two key brain systems are implicated in this process: the hippocampal episodic memory (EM) system and the prefrontal working memory (WM) system. While an understanding of the hippocampal system, from computation to algorithm and representation, is emerging, less is understood about how the prefrontal WM system can give rise to flexible computations beyond simple memory retrieval, and even less is understood about how the two systems relate to each other. Here we develop a mathematical theory relating the algorithms and representations of EM and WM by showing a duality between storing memories in synapses versus neural activity. In doing so, we develop a formal theory of the algorithm and representation of prefrontal WM as structured, and controllable, neural subspaces (termed activity slots). By building models using this formalism, we elucidate the differences, similarities, and trade-offs between the hippocampal and prefrontal algorithms. Lastly, we show that several prefrontal representations in tasks ranging from list learning to cue dependent recall are unified as controllable activity slots. Our results unify frontal and temporal representations of memory, and offer a new basis for understanding the prefrontal representation of WM

SeminarNeuroscienceRecording

Reimagining the neuron as a controller: A novel model for Neuroscience and AI

Dmitri 'Mitya' Chklovskii
Flatiron Institute, Center for Computational Neuroscience
Feb 4, 2024

We build upon and expand the efficient coding and predictive information models of neurons, presenting a novel perspective that neurons not only predict but also actively influence their future inputs through their outputs. We introduce the concept of neurons as feedback controllers of their environments, a role traditionally considered computationally demanding, particularly when the dynamical system characterizing the environment is unknown. By harnessing a novel data-driven control framework, we illustrate the feasibility of biological neurons functioning as effective feedback controllers. This innovative approach enables us to coherently explain various experimental findings that previously seemed unrelated. Our research has profound implications, potentially revolutionizing the modeling of neuronal circuits and paving the way for the creation of alternative, biologically inspired artificial neural networks.

SeminarNeuroscience

Visual mechanisms for flexible behavior

Marlene Cohen
University of Chicago
Jan 25, 2024

Perhaps the most impressive aspect of the way the brain enables us to act on the sensory world is its flexibility. We can make a general inference about many sensory features (rating the ripeness of mangoes or avocados) and map a single stimulus onto many choices (slicing or blending mangoes). These can be thought of as flexibly mapping many (features) to one (inference) and one (feature) to many (choices) sensory inputs to actions. Both theoretical and experimental investigations of this sort of flexible sensorimotor mapping tend to treat sensory areas as relatively static. Models typically instantiate flexibility through changing interactions (or weights) between units that encode sensory features and those that plan actions. Experimental investigations often focus on association areas involved in decision-making that show pronounced modulations by cognitive processes. I will present evidence that the flexible formatting of visual information in visual cortex can support both generalized inference and choice mapping. Our results suggest that visual cortex mediates many forms of cognitive flexibility that have traditionally been ascribed to other areas or mechanisms. Further, we find that a primary difference between visual and putative decision areas is not what information they encode, but how that information is formatted in the responses of neural populations, which is related to difference in the impact of causally manipulating different areas on behavior. This scenario allows for flexibility in the mapping between stimuli and behavior while maintaining stability in the information encoded in each area and in the mappings between groups of neurons.

ePoster

Building internal models during periods of rest and sleep

Helen Barron

Bernstein Conference 2024

ePoster

Computing mutual-information rates by maximum-entropy-inspired models

Tobias Kühn, Gabriel Mahuas, Ulisse Ferrari

Bernstein Conference 2024

ePoster

Conditions for sequence replay in recurrent network models of CA3

Gaspar Cano, Richard Kempter

Bernstein Conference 2024

ePoster

Diffusion Tempering Improves Parameter Estimation with Probabilistic Integrators for Hodgkin Huxley Models

Jonas Beck, Nathanael Bosch, Michael Deistler, Kyra Khadim, Jakob Macke, Philipp Hennig, Philipp Berens

Bernstein Conference 2024

ePoster

Effects of global inhibition on models of neural dynamics

Antonio de Candia, Silvia Scarpetta, Ludovico Minati

Bernstein Conference 2024

ePoster

Evolutionary algorithms support recurrent plasticity in spiking neural network models of neocortical task learning

Ivyer Qu, Huaze Liu, Jiayue Li, Yuqing Zhu

Bernstein Conference 2024

ePoster

Excitatory and inhibitory neurons exhibit distinct roles for task learning, temporal scaling, and working memory in recurrent spiking neural network models of neocortex.

Ulaş Ayyılmaz, Antara Krishnan, Yuqing Zhu

Bernstein Conference 2024

ePoster

Experiment-based Models to Study Local Learning Rules for Spiking Neural Networks

Giulia Amos, Maria Saramago, Alexandre Suter, Tim Schmid, Jens Duru, Sean Weaver, Benedikt Maurer, Stephan Ihle, Janos Vörös, Katarina Vulić

Bernstein Conference 2024

ePoster

Optimal control of oscillations and synchrony in nonlinear models of neural population dynamics

Lena Salfenmoser, Klaus Obermayer

Bernstein Conference 2024

ePoster

Inhibition-controlled Hebbian learning unifies phenomenological and normative models of plasticity

Julian Rossbroich, Friedemann Zenke

Bernstein Conference 2024

ePoster

Integrating activity measurements into connectome-constrained and task-optimized models

Linda Ulmer, Janne Lappalainen, Srinivas Turaga, Jakob Macke

Bernstein Conference 2024

ePoster

Investigating the role of recurrent connectivity in connectome-constrained and task-optimized models of the fruit fly’s motion pathway

Zinovia Stefanidi, Janne Lappalainen, Srinivas Turaga, Jakob Macke

Bernstein Conference 2024

ePoster

Navigating through the Latent Spaces in Generative Models

Antoniya Boyanova, Tahmineh Koosha, Marco Rothermel, Hamidreza Jamalabadi

Bernstein Conference 2024

ePoster

Reverse engineering recurrent network models reveals mechanisms for location memory

Ian Hawes, Matt Nolan

Bernstein Conference 2024

ePoster

Sequence learning under biophysical constraints: a re-evaluation of prominent models

Barna Zajzon, Younes Bouhadjar, Tom Tetzlaff, Renato Duarte, Abigail Morrison

Bernstein Conference 2024

ePoster

Threshold-Linear Networks as a Ground-Zero Theory for Spiking Models

Stefano Masserini, Richard Kempter

Bernstein Conference 2024

ePoster

Unified C. elegans Neural Activity and Connectivity Datasets for Building Foundation Models of a Small Nervous System

Quilee Simeon, Anshul Kashyap, Konrad Kording, Ed Boyden

Bernstein Conference 2024

ePoster

Affine models explain tuning-dependent correlated variability within and between V1 and V2

COSYNE 2022

ePoster

Bayesian active learning for latent variable models of decision-making

COSYNE 2022

ePoster

Do better object recognition models improve the generalization gap in neural predictivity?

COSYNE 2022

ePoster

Disentangling neural dynamics with fluctuating hidden Markov models

COSYNE 2022

ePoster

Fitting recurrent spiking network models to study the interaction between cortical areas

COSYNE 2022

ePoster

Fitting recurrent spiking network models to study the interaction between cortical areas

COSYNE 2022

ePoster

Hypothesis-neutral models of higher-order visual cortex reveal strong semantic selectivity

COSYNE 2022

ePoster

Hypothesis-neutral models of higher-order visual cortex reveal strong semantic selectivity

COSYNE 2022

ePoster

Identifying and adaptively perturbing compact deep neural network models of visual cortex

COSYNE 2022

ePoster

Identifying and adaptively perturbing compact deep neural network models of visual cortex

COSYNE 2022

ePoster

Learning accurate path integration in ring attractor models of the head direction system

COSYNE 2022

ePoster

Learning accurate path integration in ring attractor models of the head direction system

COSYNE 2022

ePoster

Many, but not all, deep neural network audio models predict auditory cortex responses and exhibit hierarchical layer-region correspondence

COSYNE 2022

ePoster

Many, but not all, deep neural network audio models predict auditory cortex responses and exhibit hierarchical layer-region correspondence

COSYNE 2022

ePoster

Normative models of spatio-spectral decorrelation in natural scenes predict experimentally observed ratio of PR types

COSYNE 2022

ePoster

Normative models of spatio-spectral decorrelation in natural scenes predict experimentally observed ratio of PR types

COSYNE 2022

ePoster

Reduced stochastic models reveal the mechanisms underlying drifting cell assemblies

COSYNE 2022

ePoster

Reduced stochastic models reveal the mechanisms underlying drifting cell assemblies

COSYNE 2022

ePoster

Time-warped state space models for distinguishing movement type and vigor

COSYNE 2022

ePoster

Time-warped state space models for distinguishing movement type and vigor

COSYNE 2022

ePoster

Towards using small topologically constrained networks in-vitro in combination with in-silico models

COSYNE 2022

ePoster

Towards using small topologically constrained networks in-vitro in combination with in-silico models

COSYNE 2022

ePoster

Building mechanistic models of neural computations with simulation-based machine learning

Jakob Macke

Bernstein Conference 2024