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Alex H Williams

14 accepted papers

2026

Quasi-Monte Carlo Methods Enable Extremely Low-Dimensional Deep Generative Models

ICLR 2026poster

This paper introduces *quasi-Monte Carlo latent variable models* (QLVMs): a class of deep generative models that are specialized for finding extremely low-dimensional and interpretable embeddings of high-dimensional datasets. Unlike standard approaches, which rely on a learned encoder and variationa…

Cited by 0SourcecodeScholar
2026

Unbalanced Soft-Matching Distance For Neural Representational Comparison With Partial Unit Correspondence

ICLR 2026poster

Representational similarity metrics typically force all units to be matched, making them susceptible to noise and outliers common in neural representations. We extend the soft-matching distance to a partial optimal transport setting that allows some neurons to remain unmatched, yielding rotation-sen…

Cited by 0SourceScholar
2025

Comparing noisy neural population dynamics using optimal transport distances

ICLR 2025oral

Biological and artificial neural systems form high-dimensional neural representations that underpin their computational capabilities. Methods for quantifying geometric similarity in neural representations have become a popular tool for identifying computational principles that are potentially shared…

Cited by 2SourcePDFScholar
2025

Discriminating image representations with principal distortions

ICLR 2025poster

Image representations (artificial or biological) are often compared in terms of their global geometric structure; however, representations with similar global structure can have strikingly different local geometries. Here, we propose a framework for comparing a set of image representations in terms…

Cited by 1SourcePDFScholar
2025

Disentangling 3D Animal Pose Dynamics with Scrubbed Conditional Latent Variables

ICLR 2025poster

Methods for tracking lab animal movements in unconstrained environments have become increasingly common and powerful tools for neuroscience. The prevailing hypothesis is that animal behavior in these environments comprises sequences of discrete stereotyped body movements ("motifs" or "actions"). How…

Cited by 0SourcePDFScholar
2025

Modeling Neural Activity with Conditionally Linear Dynamical Systems

NeurIPS 2025poster

Neural population activity exhibits complex, nonlinear dynamics, varying in time, over trials, and across experimental conditions. Here, we develop *Conditionally Linear Dynamical System* (CLDS) models as a general-purpose method to characterize these dynamics. These models use Gaussian Process prio…

Cited by 0SourcecodeScholar
2025

Scalable inference of functional neural connectivity at submillisecond timescales

NeurIPS 2025poster

The Poisson Generalized Linear Model (GLM) is a foundational tool for analyzing neural spike train data. However, standard implementations rely on discretizing spike times into binned count data, limiting temporal resolution and scalability. Here, we develop stochastic optimization methods and polyn…

Cited by 0SourceScholar
2024

Estimating Shape Distances on Neural Representations with Limited Samples

ICLR 2024poster

Measuring geometric similarity between high-dimensional network representations is a topic of longstanding interest to neuroscience and deep learning. Although many methods have been proposed, only a few works have rigorously analyzed their statistical efficiency or quantified estimator uncertainty…

2024

Vocal Call Locator Benchmark (VCL) for localizing rodent vocalizations from multi-channel audio

NeurIPS 2024poster

Understanding the behavioral and neural dynamics of social interactions is a goal of contemporary neuroscience. Many machine learning methods have emerged in recent years to make sense of complex video and neurophysiological data that result from these experiments. Less focus has been placed on unde…

Cited by 0SourcePDFScholar
2023

Estimating Noise Correlations Across Continuous Conditions With Wishart Processes

NeurIPS 2023poster

The signaling capacity of a neural population depends on the scale and orientation of its covariance across trials. Estimating this "noise" covariance is challenging and is thought to require a large number of stereotyped trials. New approaches are therefore needed to interrogate the structure of ne…

2023

Representational Dissimilarity Metric Spaces for Stochastic Neural Networks

ICLR 2023poster

Quantifying similarity between neural representations---e.g. hidden layer activation vectors---is a perennial problem in deep learning and neuroscience research. Existing methods compare deterministic responses (e.g. artificial networks that lack stochastic layers) or averaged responses (e.g., trial…

2022

Distinguishing discrete and continuous behavioral variability using warped autoregressive HMMs

NeurIPS 2022accept

A core goal in systems neuroscience and neuroethology is to understand how neural circuits generate naturalistic behavior. One foundational idea is that complex naturalistic behavior may be composed of sequences of stereotyped behavioral syllables, which combine to generate rich sequences of actions…

Cited by 21SourcePDFScholar
2021

Explaining heterogeneity in medial entorhinal cortex with task-driven neural networks

NeurIPS 2021spotlight

Medial entorhinal cortex (MEC) supports a wide range of navigational and memory related behaviors. Well-known experimental results have revealed specialized cell types in MEC --- e.g. grid, border, and head-direction cells --- whose highly stereotypical response profiles are suggestive of the role t…

2021

Generalized Shape Metrics on Neural Representations

NeurIPS 2021poster

Understanding the operation of biological and artificial networks remains a difficult and important challenge. To identify general principles, researchers are increasingly interested in surveying large collections of networks that are trained on, or biologically adapted to, similar tasks. A standard…