Goto

Collaborating Authors

 functional organization



Brain Diffusion for Visual Exploration: Cortical Discovery using Large Scale Generative Models

Neural Information Processing Systems

A long standing goal in neuroscience has been to elucidate the functional organization of the brain. Within higher visual cortex, functional accounts have remained relatively coarse, focusing on regions of interest (ROIs) and taking the form of selectivity for broad categories such as faces, places, bodies, food, or words. Because the identification of such ROIs has typically relied on manually assembled stimulus sets consisting of isolated objects in non-ecological contexts, exploring functional organization without robust a priori hypotheses has been challenging. To overcome these limitations, we introduce a data-driven approach in which we synthesize images predicted to activate a given brain region using paired natural images and fMRI recordings, bypassing the need for category-specific stimuli. Our approach -- Brain Diffusion for Visual Exploration (BrainDiVE) -- builds on recent generative methods by combining large-scale diffusion models with brain-guided image synthesis. Validating our method, we demonstrate the ability to synthesize preferred images with appropriate semantic specificity for well-characterized category-selective ROIs. We then show that BrainDiVE can characterize differences between ROIs selective for the same high-level category. Finally we identify novel functional subdivisions within these ROIs, validated with behavioral data. These results advance our understanding of the fine-grained functional organization of human visual cortex, and provide well-specified constraints for further examination of cortical organization using hypothesis-driven methods.



Brain Diffusion for Visual Exploration: Cortical Discovery using Large Scale Generative Models

Neural Information Processing Systems

A long standing goal in neuroscience has been to elucidate the functional organization of the brain. Within higher visual cortex, functional accounts have remained relatively coarse, focusing on regions of interest (ROIs) and taking the form of selectivity for broad categories such as faces, places, bodies, food, or words. Because the identification of such ROIs has typically relied on manually assembled stimulus sets consisting of isolated objects in non-ecological contexts, exploring functional organization without robust a priori hypotheses has been challenging. To overcome these limitations, we introduce a data-driven approach in which we synthesize images predicted to activate a given brain region using paired natural images and fMRI recordings, bypassing the need for category-specific stimuli. Our approach -- Brain Diffusion for Visual Exploration ("BrainDiVE") -- builds on recent generative methods by combining large-scale diffusion models with brain-guided image synthesis.


A Mechanistic Explanatory Strategy for XAI

Rabiza, Marcin

arXiv.org Artificial Intelligence

Despite significant advancements in XAI, scholars note a persistent lack of solid conceptual foundations and integration with broader scientific discourse on explanation. In response, emerging XAI research draws on explanatory strategies from various sciences and philosophy of science literature to fill these gaps. This paper outlines a mechanistic strategy for explaining the functional organization of deep learning systems, situating recent advancements in AI explainability within a broader philosophical context. According to the mechanistic approach, the explanation of opaque AI systems involves identifying mechanisms that drive decision-making. For deep neural networks, this means discerning functionally relevant components -- such as neurons, layers, circuits, or activation patterns -- and understanding their roles through decomposition, localization, and recomposition. Proof-of-principle case studies from image recognition and language modeling align these theoretical approaches with the latest research from AI labs like OpenAI and Anthropic. This research suggests that a systematic approach to studying model organization can reveal elements that simpler (or ''more modest'') explainability techniques might miss, fostering more thoroughly explainable AI. The paper concludes with a discussion on the epistemic relevance of the mechanistic approach positioned in the context of selected philosophical debates on XAI.


Brain-like Functional Organization within Large Language Models

Sun, Haiyang, Zhao, Lin, Wu, Zihao, Gao, Xiaohui, Hu, Yutao, Zuo, Mengfei, Zhang, Wei, Han, Junwei, Liu, Tianming, Hu, Xintao

arXiv.org Artificial Intelligence

The human brain has long inspired the pursuit of artificial intelligence (AI). Recently, neuroimaging studies provide compelling evidence of alignment between the computational representation of artificial neural networks (ANNs) and the neural responses of the human brain to stimuli, suggesting that ANNs may employ brain-like information processing strategies. While such alignment has been observed across sensory modalities--visual, auditory, and linguistic--much of the focus has been on the behaviors of artificial neurons (ANs) at the population level, leaving the functional organization of individual ANs that facilitates such brain-like processes largely unexplored. In this study, we bridge this gap by directly coupling sub-groups of artificial neurons with functional brain networks (FBNs), the foundational organizational structure of the human brain. Specifically, we extract representative patterns from temporal responses of ANs in large language models (LLMs), and use them as fixed regressors to construct voxel-wise encoding models to predict brain activity recorded by functional magnetic resonance imaging (fMRI). This framework links the AN sub-groups to FBNs, enabling the delineation of brain-like functional organization within LLMs. Our findings reveal that LLMs (BERT and Llama 1-3) exhibit brain-like functional architecture, with sub-groups of artificial neurons mirroring the organizational patterns of well-established FBNs. Notably, the brain-like functional organization of LLMs evolves with the increased sophistication and capability, achieving an improved balance between the diversity of computational behaviors and the consistency of functional specializations. This research represents the first exploration of brain-like functional organization within LLMs, offering novel insights to inform the development of artificial general intelligence (AGI) with human brain principles.


Why it pays to be a chatty mum: Babies start learning language BEFORE birth, study finds

Daily Mail - Science & tech

If you're an expectant mother, chatting as much as possible could give your baby a headstart when it comes to learning to talk. That's because new research has found your unborn son or daughter will start learning the language you speak before they're even born. In experiments, researchers discovered heightened activity in the brains of newborns when they heard the language they were exposed to most often in utero. The study didn't look at exactly when babies become receptive to spoken language while they are still in the womb, although it's well known that a foetus starts hearing sounds in the later stages of the second trimester and the start of the third. Therefore, expectant mothers – and fathers too – should not be afraid to chat away, and even talk directly to their baby bump.


Modeling Ecological Integrity with Bayesian Belief Networks

Barrios, Juan M. (National Commission for Knowledge and Use of Biodiversity) | Sierra-Alcocer, Raúl (National Commission for Knowledge and Use of Biodiversity) | González-Salazar, Constantino (National Commission for Knowledge and Use of Biodiversity) | Mora, Franz E. (National Commission for Knowledge and Use of Biodiversity) | Munguía, Mariana (National Commission for Knowledge and Use of Biodiversity) | Pérez-Maqueo, Octavio M. (National Commission for Knowledge and Use of Biodiversity) | Trejo, Isabel (National Commission for Knowledge and Use of Biodiversity)

AAAI Conferences

Although the concept of ecological integrity is referred in many country legislations there is no consensus on how to formalize and implement it. One possible definition is as the capacity of an ecosystem to support and maintain a balanced, integrated, and adaptive community of organisms having a species composition, diversity, and functional organization comparable to that of a natural habitat of the region. Our objective is to model this interpretation of ecological integrity from a set of ecological measures that can be estimated from ecological inventory data.