Association-sensory spatiotemporal hierarchy and functional gradient-regularised recurrent neural network with implications for schizophrenia
- URL: http://arxiv.org/abs/2511.02722v1
- Date: Tue, 04 Nov 2025 16:45:55 GMT
- Title: Association-sensory spatiotemporal hierarchy and functional gradient-regularised recurrent neural network with implications for schizophrenia
- Abstract summary: This study characterises the AS hierarchy of patients with schizophrenia in a comparison with controls.<n>We found that schizophrenia compresses the AS hierarchy indicating reduced functional differentiation.<n>By modelling neural timescale with the Ornstein-Uhlenbeck process, we observed that the most specialised, locally cohesive regions at the gradient extremes exhibit dynamics with a longer time constant.
- Score: 1.7711010795772193
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: The human neocortex is functionally organised at its highest level along a continuous sensory-to-association (AS) hierarchy. This study characterises the AS hierarchy of patients with schizophrenia in a comparison with controls. Using a large fMRI dataset (N=355), we extracted individual AS gradients via spectral analysis of brain connectivity, quantified hierarchical specialisation by gradient spread, and related this spread with connectivity geometry. We found that schizophrenia compresses the AS hierarchy indicating reduced functional differentiation. By modelling neural timescale with the Ornstein-Uhlenbeck process, we observed that the most specialised, locally cohesive regions at the gradient extremes exhibit dynamics with a longer time constant, an effect that is attenuated in schizophrenia. To study computation, we used the gradients to regularise subject-specific recurrent neural networks (RNNs) trained on working memory tasks. Networks endowed with greater gradient spread learned more efficiently, plateaued at lower task loss, and maintained stronger alignment to the prescribed AS hierarchical geometry. Fixed point linearisation showed that high-range networks settled into more stable neural states during memory delay, evidenced by lower energy and smaller maximal Jacobian eigenvalues. This gradient-regularised RNN framework therefore links large-scale cortical architecture with fixed point stability, providing a mechanistic account of how gradient de-differentiation could destabilise neural computations in schizophrenia, convergently supported by empirical timescale flattening and model-based evidence of less stable fixed points.
Related papers
- When Brain Networks Travel: Learning Beyond Site [19.116206481048224]
Graph-based learning on functional magnetic resonance imaging (fMRI) has shown strong potential for brain network analysis.<n>Existing methods degrade under cross-site out-of-distribution (OOD) settings because site-conditioned confounders induce non-pathological shortcuts.<n>We propose Cross-site OOD Robust brain nEtwork (CORE), a unified framework for brain network learning across unseen sites.
arXiv Detail & Related papers (2026-05-07T11:35:34Z) - Unleashing Temporal Capacity of Spiking Neural Networks through Spatiotemporal Separation [67.69345363409835]
Spiking Neural Networks (SNNs) are considered naturally suited for temporal processing, with membrane potential propagation widely regarded as the core temporal modeling mechanism.<n>We design Non-Stateful (NS) models progressively removing membrane propagation to its stage-wise role. Experiments reveal a counterintuitive phenomenon: moderate removal in shallow layers improves performance, while excessive removal causes collapse.
arXiv Detail & Related papers (2025-12-05T07:05:53Z) - Moving Beyond Diffusion: Hierarchy-to-Hierarchy Autoregression for fMRI-to-Image Reconstruction [65.67001243986981]
We propose MindHier, a coarse-to-fine fMRI-to-image reconstruction framework built on scale-wise autoregressive modeling.<n>MindHier achieves superior semantic fidelity, 4.67x faster inference, and more deterministic results than the diffusion-based baselines.
arXiv Detail & Related papers (2025-10-25T15:40:07Z) - Fractional Spike Differential Equations Neural Network with Efficient Adjoint Parameters Training [63.3991315762955]
Spiking Neural Networks (SNNs) draw inspiration from biological neurons to create realistic models for brain-like computation.<n>Most existing SNNs assume a single time constant for neuronal membrane voltage dynamics, modeled by first-order ordinary differential equations (ODEs) with Markovian characteristics.<n>We propose the Fractional SPIKE Differential Equation neural network (fspikeDE), which captures long-term dependencies in membrane voltage and spike trains through fractional-order dynamics.
arXiv Detail & Related papers (2025-07-22T18:20:56Z) - Fractional-order spike-timing-dependent gradient descent for multi-layer spiking neural networks [18.142378139047977]
This paper proposes a fractional-order spike-timing-dependent gradient descent (FOSTDGD) learning model.
It is tested on theNIST and DVS128 Gesture datasets and its accuracy under different network structure and fractional orders is analyzed.
arXiv Detail & Related papers (2024-10-20T05:31:34Z) - The Role of Temporal Hierarchy in Spiking Neural Networks [2.0881857682885836]
Spiking Neural Networks (SNNs) have the potential for rich-temporal signal processing thanks to exploiting both spatial and temporal parameters.
Time constants have been recently shown to have computational benefits that help reduce the overall number of parameters required in the network.
To reduce the cost of optimization, architectural biases can be applied, in this case in the temporal domain.
We propose to impose a hierarchy of temporal representation in the hidden layers of SNNs, highlighting that such an inductive bias improves their performance.
arXiv Detail & Related papers (2024-07-26T16:00:20Z) - Understanding the Convergence in Balanced Resonate-and-Fire Neurons [1.4186974630564675]
Resonate-and-Fire (RF) neurons are an interesting complementary model for integrator neurons in spiking neural networks (SNNs)
The recently proposed balanced resonate-and-fire (BRF) neuron marked a significant methodological advance in terms of task performance, spiking and parameter efficiency.
This paper aims at providing further intuitions about how and why these convergence advantages emerge.
arXiv Detail & Related papers (2024-06-01T10:04:55Z) - Interpretable Spatio-Temporal Embedding for Brain Structural-Effective Network with Ordinary Differential Equation [56.34634121544929]
In this study, we first construct the brain-effective network via the dynamic causal model.
We then introduce an interpretable graph learning framework termed Spatio-Temporal Embedding ODE (STE-ODE)
This framework incorporates specifically designed directed node embedding layers, aiming at capturing the dynamic interplay between structural and effective networks.
arXiv Detail & Related papers (2024-05-21T20:37:07Z) - TC-LIF: A Two-Compartment Spiking Neuron Model for Long-Term Sequential
Modelling [54.97005925277638]
The identification of sensory cues associated with potential opportunities and dangers is frequently complicated by unrelated events that separate useful cues by long delays.
It remains a challenging task for state-of-the-art spiking neural networks (SNNs) to establish long-term temporal dependency between distant cues.
We propose a novel biologically inspired Two-Compartment Leaky Integrate-and-Fire spiking neuron model, dubbed TC-LIF.
arXiv Detail & Related papers (2023-08-25T08:54:41Z) - Long Short-term Memory with Two-Compartment Spiking Neuron [64.02161577259426]
We propose a novel biologically inspired Long Short-Term Memory Leaky Integrate-and-Fire spiking neuron model, dubbed LSTM-LIF.
Our experimental results, on a diverse range of temporal classification tasks, demonstrate superior temporal classification capability, rapid training convergence, strong network generalizability, and high energy efficiency of the proposed LSTM-LIF model.
This work, therefore, opens up a myriad of opportunities for resolving challenging temporal processing tasks on emerging neuromorphic computing machines.
arXiv Detail & Related papers (2023-07-14T08:51:03Z) - Temporal Dynamic Synchronous Functional Brain Network for Schizophrenia
Diagnosis and Lateralization Analysis [8.280225660612862]
The study was validated on COBRE and UCLA datasets and achieved 83.62% and 89.71% average accuracies.
Interestingly, this study showed that the lower order perceptual system and higher order network regions in the left hemisphere are more severely dysfunctional than in the right hemisphere in SZ.
arXiv Detail & Related papers (2023-03-31T02:54:01Z) - Spatio-Temporal Graph Convolution for Resting-State fMRI Analysis [11.85489505372321]
We train a-temporal graph convolutional network (ST-GCN) on short sub-sequences of the BOLD time series to model the non-stationary nature of functional connectivity.
St-GCN is significantly more accurate than common approaches in predicting gender and age based on BOLD signals.
arXiv Detail & Related papers (2020-03-24T01:56:50Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.