Biologically Plausible Learning via Bidirectional Spike-Based Distillation

ICLR 2026 Conference SubmissionAnonymous Authors
spiking neural networkslearning algorithms
Abstract:

Developing biologically plausible learning algorithms that can achieve performance comparable to error backpropagation remains a longstanding challenge. Existing approaches often compromise biological plausibility by entirely avoiding the use of spikes for error propagation or relying on both positive and negative learning signals, while the question of how spikes can represent negative values remains unresolved. To address these limitations, we introduce Bidirectional Spike-based Distillation (BSD), a novel learning algorithm that jointly trains a feedforward and a backward spiking network. We formulate learning as a transformation between two spiking representations (i.e., stimulus encoding and concept encoding) so that the feedforward network implements perception and decision-making by mapping stimuli to actions, while the backward network supports memory recall by reconstructing stimuli from concept representations. Extensive experiments on diverse benchmarks, including image recognition, image generation, and sequential regression, show that BSD achieves performance comparable to networks trained with classical error backpropagation. These findings represent a significant step toward biologically grounded, spike-driven learning in neural networks.

Disclaimer
This report is AI-GENERATED using Large Language Models and WisPaper (A scholar search engine). It analyzes academic papers' tasks and contributions against retrieved prior work. While this system identifies POTENTIAL overlaps and novel directions, ITS COVERAGE IS NOT EXHAUSTIVE AND JUDGMENTS ARE APPROXIMATE. These results are intended to assist human reviewers and SHOULD NOT be relied upon as a definitive verdict on novelty.
NOTE that some papers exist in multiple, slightly different versions (e.g., with different titles or URLs). The system may retrieve several versions of the same underlying work. The current automated pipeline does not reliably align or distinguish these cases, so human reviewers will need to disambiguate them manually.
If you have any questions, please contact: mingzhang23@m.fudan.edu.cn

Overview

Overall Novelty Assessment

The paper introduces Bidirectional Spike-based Distillation (BSD), a learning framework that jointly trains feedforward and backward spiking networks to achieve bidirectional transformation between stimulus and concept encodings. Within the taxonomy, BSD resides in the 'Biologically Constrained Backpropagation Alternatives' leaf under gradient-based approaches. This leaf contains four papers total, indicating a moderately populated research direction focused on reconciling gradient-based optimization with biological constraints. The work addresses the longstanding challenge of achieving backpropagation-level performance while respecting biological plausibility constraints in spiking neural networks.

The taxonomy reveals that BSD's leaf sits within a broader branch of gradient-based approaches that includes surrogate gradient methods and spatiotemporal adjustments. Neighboring branches explore purely local Hebbian learning (both unsupervised STDP and error-modulated variants) and integrated meta-learning frameworks. The scope note for BSD's leaf explicitly distinguishes it from standard surrogate gradient methods, positioning it among alternatives that incorporate biological constraints or local learning principles. This placement suggests BSD occupies a middle ground between purely local plasticity rules and conventional backpropagation approximations, attempting to leverage gradient information while maintaining biological realism through bidirectional distillation.

Among thirty candidates examined across three contributions, none were identified as clearly refuting BSD's novelty. The core BSD framework examined ten candidates with zero refutable matches, as did the two additional biological plausibility criteria and the experimental validation contribution. This absence of refutation within the limited search scope suggests that the bidirectional distillation approach—jointly training forward perception and backward reconstruction networks—represents a relatively unexplored mechanism within biologically constrained learning. However, the search examined only top-K semantic matches and citations, not an exhaustive survey of the field's approximately fifty papers across thirty-six topics.

Based on the limited literature search, BSD appears to introduce a distinctive approach within its research direction, though the analysis cannot confirm absolute novelty across all biologically plausible learning methods. The taxonomy structure indicates BSD contributes to a moderately active area where researchers continue exploring diverse mechanisms to bridge biological constraints and gradient-based optimization. The lack of identified prior work overlap within thirty examined candidates suggests potential novelty, but a more comprehensive search would be needed to definitively assess originality across the broader field.

Taxonomy

Core-task Taxonomy Papers
50
3
Claimed Contributions
30
Contribution Candidate Papers Compared
0
Refutable Paper

Research Landscape Overview

Core task: biologically plausible learning in spiking neural networks. The field organizes around several major branches that reflect different emphases in reconciling biological realism with computational performance. Learning Rule Design and Theoretical Foundations explores how to derive training algorithms that respect constraints such as locality and spike timing, ranging from gradient-based methods with biological constraints to purely local plasticity rules like STDP. Network Architecture and Structural Mechanisms examines how dendritic computation, recurrent connectivity, and modular organization can support learning without global error signals. Application Domains and Task-Specific Learning demonstrates these principles on concrete problems—from sensory processing to robotics—while Hardware Implementation and Neuromorphic Systems addresses the practical realization of bioplausible algorithms on specialized substrates. Finally, Theoretical Analysis and Computational Modeling provides the mathematical underpinnings that link spiking dynamics to learning theory. Representative works such as Biologically Plausible Learning[1] and Local Backprop Spiking[5] illustrate efforts to bridge the gap between backpropagation and local synaptic rules. Within the gradient-based approaches that impose biological constraints, a central tension emerges between leveraging powerful supervised signals and maintaining strict locality or causality. Some methods approximate backpropagation through time using feedback alignment or layer-wise credit assignment, while others rely on local error signals derived from dendritic compartments or neuromodulatory cues. Bidirectional Spike Distillation[0] sits squarely in this landscape of biologically constrained backpropagation alternatives, proposing a mechanism that distills knowledge bidirectionally to respect synaptic locality while still harnessing gradient information. This contrasts with purely unsupervised approaches like Unsupervised Dendritic Spiking[3], which forgoes any global error signal, and with works such as Precise Timing Training[18] that focus on exact spike-time targets under supervised regimes. The ongoing challenge across these lines is to balance the expressiveness needed for complex tasks against the biological and hardware constraints that make spiking networks attractive in the first place.

Claimed Contributions

Bidirectional Spike-Based Distillation (BSD) learning framework

The authors propose BSD, a learning framework inspired by the brain's bidirectional architecture of perception and recall. The feedforward network maps sensory stimuli to conceptual representations for perception and decision-making, while the backward network reconstructs stimuli from concepts to support memory recall. Both networks are jointly trained by mutually distilling spiking feature representations.

10 retrieved papers
Two additional biological plausibility criteria

The authors extend existing biological plausibility criteria by adding two new requirements: neurons should communicate using discrete binary spikes for both learning and inference (C4), and learning should rely on unsigned spiking signals only (C5). Together with three prior criteria, BSD satisfies all five principles for biologically plausible learning.

10 retrieved papers
Extensive experimental validation across diverse tasks and architectures

The authors conduct comprehensive experiments demonstrating that BSD achieves performance comparable to error backpropagation across multiple tasks including image classification, text character prediction, time-series forecasting, and image generation, using diverse architectures such as MLPs, CNNs, RNNs, and autoencoders.

10 retrieved papers

Core Task Comparisons

Comparisons with papers in the same taxonomy category

Contribution Analysis

Detailed comparisons for each claimed contribution

Contribution

Bidirectional Spike-Based Distillation (BSD) learning framework

The authors propose BSD, a learning framework inspired by the brain's bidirectional architecture of perception and recall. The feedforward network maps sensory stimuli to conceptual representations for perception and decision-making, while the backward network reconstructs stimuli from concepts to support memory recall. Both networks are jointly trained by mutually distilling spiking feature representations.

Contribution

Two additional biological plausibility criteria

The authors extend existing biological plausibility criteria by adding two new requirements: neurons should communicate using discrete binary spikes for both learning and inference (C4), and learning should rely on unsigned spiking signals only (C5). Together with three prior criteria, BSD satisfies all five principles for biologically plausible learning.

Contribution

Extensive experimental validation across diverse tasks and architectures

The authors conduct comprehensive experiments demonstrating that BSD achieves performance comparable to error backpropagation across multiple tasks including image classification, text character prediction, time-series forecasting, and image generation, using diverse architectures such as MLPs, CNNs, RNNs, and autoencoders.