研究大脑如何在无外部信号时实现状态稳定转换,发现拓扑结构决定学习成败。
Learning Discrete Successor Transitions in Continuous Attractor Networks: Emergence, Limits, and Topological Constraints
- 用训练让连续吸引子网络自主学习状态转移,测试不同环路结构表现
- 短期评估下网络依赖瞬时刺激获得高准确率,但无持续动态;长期评估才出现真实吸引子行为
- 环形结构可长期稳定,折叠蛇形结构在断点处失效,且难以通过训练改善
连续吸引子网络(CANs)是表征头向、空间位置等低维连续变量的经典模型。在典型空间域中,吸引子流形上的转移由外部提供的连续位移信号(如角速度)驱动。当缺乏此类显式位移输入时,吸引子电路能否可靠学习到支持稳定状态转移的循环动态尚不明确。本文构建实验框架,训练CANs在无外部位移信号条件下完成类后继转移。对比环形与折叠蛇形两种递归拓扑,在不同时间尺度下评估稳定性。结果表明:在短评估窗口下,网络普遍收敛至脉冲驱动的关联解,虽准确率高但缺乏持续吸引子动态;仅当稳定性要求覆盖长自由运行周期时,真正的吸引子转移动态才出现。这表明局部学习默认产生捷径解,而吸引子动态属于受约束的特殊状态。此外,拓扑严格限制学习能力:环形结构可在长时程保持完美稳定,折叠蛇形结构在流形不连续处达到几何极限,即使采用课程学习或基底节启发的门控机制也难以克服。
原文摘要 · Abstract (English)
Continuous attractor networks (CANs) are a well-established class of models for representing low-dimensional continuous variables such as head direction, spatial position, and phase. In canonical spatial domains, transitions along the attractor manifold are driven by continuous displacement signals, such as angular velocity-provided by sensorimotor systems external to the CAN itself. When such signals are not explicitly provided as dedicated displacement inputs, it remains unclear whether attractor-based circuits can reliably acquire recurrent dynamics that support stable state transitions, or whether alternative predictive strategies dominate. In this work, we present an experimental framework for training CANs to perform successor-like transitions between stable attractor states in the absence of externally provided displacement signals. We compare two recurrent topologies, a circular ring and a folded snake manifold, and systematically vary the temporal regime under which stability is evaluated. We find that, under short evaluation windows, networks consistently converge to impulse-driven associative solutions that achieve high apparent accuracy yet lack persistent attractor dynamics. Only when stability is explicitly enforced over extended free-run periods do genuine attractor-based transition dynamics emerge. This suggests that shortcut solutions are the default outcome of local learning in recurrent networks, while attractor dynamics represent a constrained regime rather than a generic result. Furthermore, we demonstrate that topology strictly limits the capacity for learned transitions. While the continuous ring topology achieves perfect stability over long horizons, the folded snake topology hits a geometric limit characterized by failure at manifold discontinuities, which neither curriculum learning nor basal ganglia-inspired gating can fully overcome.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。