Humans and animals have the ability to continually acquire, fine-tune, and transfer knowledge and skills throughout their lifespan. This ability, referred to as lifelong learning, is mediated by a rich set of neurocognitive mechanisms that together contribute to the development and specialization of our sensorimotor skills as well as to long-term memory consolidation and retrieval. Consequently, lifelong learning capabilities are crucial for computational systems and autonomous agents interacting in the real world and processing continuous streams of information. However, lifelong learning remains a long-standing challenge for machine learning and neural network models since the continual acquisition of incrementally available information from non-stationary data distributions generally leads to catastrophic forgetting or interference. This limitation represents a major drawback for state-of-the-art deep neural network models that typically learn representations from stationary batches of training data, thus without accounting for situations in which information becomes incrementally available over time. In this review, we critically summarize the main challenges linked to lifelong learning for artificial learning systems and compare existing neural network approaches that alleviate, to different extents, catastrophic forgetting. Although significant advances have been made in domain-specific learning with neural networks, extensive research efforts are required for the development of robust lifelong learning on autonomous agents and robots. We discuss well-established and emerging research motivated by lifelong learning factors in biological systems such as structural plasticity, memory replay, curriculum and transfer learning, intrinsic motivation, and multisensory integration.

人类和其他动物的先天能力学习多样化，经常干扰，在整个寿命中的知识和技能范围是自然智能的标志，具有明显的进化动机。同时，人工神经网络（ANN）在一系列任务和域中学习的能力，组合和重新使用所需的学习表现，是人工智能的明确目标。这种能力被广泛描述为持续学习，已成为机器学习研究的多产子场。尽管近年来近年来深度学习的众多成功，但跨越域名从图像识别到机器翻译，因此这种持续的任务学习已经证明了具有挑战性的。在具有随机梯度下降的序列上训练的神经网络通常遭受代表性干扰，由此给定任务的学习权重有效地覆盖了在灾难性遗忘的过程中的先前任务的权重。这代表了对更广泛的人工学习系统发展的主要障碍，能够以类似于人类的方式积累时间和任务空间的知识。伴随的选定论文和实施存储库可以在https://github.com/mccaffary/continualualuallning找到。

人类的持续学习（CL）能力与稳定性与可塑性困境密切相关，描述了人类如何实现持续的学习能力和保存的学习信息。自发育以来，CL的概念始终存在于人工智能（AI）中。本文提出了对CL的全面审查。与之前的评论不同，主要关注CL中的灾难性遗忘现象，本文根据稳定性与可塑性机制的宏观视角来调查CL。类似于生物对应物，“智能”AI代理商应该是I）记住以前学到的信息（信息回流）; ii）不断推断新信息（信息浏览:); iii）转移有用的信息（信息转移），以实现高级CL。根据分类学，评估度量，算法，应用以及一些打开问题。我们的主要贡献涉及I）从人工综合情报层面重新检查CL; ii）在CL主题提供详细和广泛的概述; iii）提出一些关于CL潜在发展的新颖思路。

尽管人工神经网络（ANN）取得了重大进展，但其设计过程仍在臭名昭著，这主要取决于直觉，经验和反复试验。这个依赖人类的过程通常很耗时，容易出现错误。此外，这些模型通常与其训练环境绑定，而没有考虑其周围环境的变化。神经网络的持续适应性和自动化对于部署后模型可访问性的几个领域至关重要（例如，IoT设备，自动驾驶汽车等）。此外，即使是可访问的模型，也需要频繁的维护后部署后，以克服诸如概念/数据漂移之类的问题，这可能是繁琐且限制性的。当前关于自适应ANN的艺术状况仍然是研究的过早领域。然而，一种自动化和持续学习形式的神经体系结构搜索（NAS）最近在深度学习研究领域中获得了越来越多的动力，旨在提供更强大和适应性的ANN开发框架。这项研究是关于汽车和CL之间交集的首次广泛综述，概述了可以促进ANN中充分自动化和终身可塑性的不同方法的研究方向。

Continual Learning (CL) is a field dedicated to devise algorithms able to achieve lifelong learning. Overcoming the knowledge disruption of previously acquired concepts, a drawback affecting deep learning models and that goes by the name of catastrophic forgetting, is a hard challenge. Currently, deep learning methods can attain impressive results when the data modeled does not undergo a considerable distributional shift in subsequent learning sessions, but whenever we expose such systems to this incremental setting, performance drop very quickly. Overcoming this limitation is fundamental as it would allow us to build truly intelligent systems showing stability and plasticity. Secondly, it would allow us to overcome the onerous limitation of retraining these architectures from scratch with the new updated data. In this thesis, we tackle the problem from multiple directions. In a first study, we show that in rehearsal-based techniques (systems that use memory buffer), the quantity of data stored in the rehearsal buffer is a more important factor over the quality of the data. Secondly, we propose one of the early works of incremental learning on ViTs architectures, comparing functional, weight and attention regularization approaches and propose effective novel a novel asymmetric loss. At the end we conclude with a study on pretraining and how it affects the performance in Continual Learning, raising some questions about the effective progression of the field. We then conclude with some future directions and closing remarks.

在流行媒体中，人造代理商的意识出现与同时实现人类或超人水平智力的那些相同的代理之间通常存在联系。在这项工作中，我们探讨了意识和智力之间这种看似直观的联系的有效性和潜在应用。我们通过研究与三种当代意识功能理论相关的认知能力：全球工作空间理论（GWT），信息生成理论（IGT）和注意力模式理论（AST）。我们发现，这三种理论都将有意识的功能专门与人类领域将军智力的某些方面联系起来。有了这个见解，我们转向人工智能领域（AI），发现尽管远未证明一般智能，但许多最先进的深度学习方法已经开始纳入三个功能的关键方面理论。确定了这一趋势后，我们以人类心理时间旅行的激励例子来提出方式，其中三种理论中每种理论的见解都可以合并为一个单一的统一和可实施的模型。鉴于三种功能理论中的每一种都可以通过认知能力来实现这一可能，因此，具有精神时间旅行的人造代理不仅具有比当前方法更大的一般智力，而且还与我们当前对意识功能作用的理解更加一致在人类中，这使其成为AI研究的有希望的近期目标。

Recent progress in artificial intelligence (AI) has renewed interest in building systems that learn and think like people. Many advances have come from using deep neural networks trained end-to-end in tasks such as object recognition, video games, and board games, achieving performance that equals or even beats humans in some respects. Despite their biological inspiration and performance achievements, these systems differ from human intelligence in crucial ways. We review progress in cognitive science suggesting that truly human-like learning and thinking machines will have to reach beyond current engineering trends in both what they learn, and how they learn it. Specifically, we argue that these machines should (a) build causal models of the world that support explanation and understanding, rather than merely solving pattern recognition problems; (b) ground learning in intuitive theories of physics and psychology, to support and enrich the knowledge that is learned; and (c) harness compositionality and learning-to-learn to rapidly acquire and generalize knowledge to new tasks and situations. We suggest concrete challenges and promising routes towards these goals that can combine the strengths of recent neural network advances with more structured cognitive models.

Many theories, based on neuroscientific and psychological empirical evidence and on computational concepts, have been elaborated to explain the emergence of consciousness in the central nervous system. These theories propose key fundamental mechanisms to explain consciousness, but they only partially connect such mechanisms to the possible functional and adaptive role of consciousness. Recently, some cognitive and neuroscientific models try to solve this gap by linking consciousness to various aspects of goal-directed behaviour, the pivotal cognitive process that allows mammals to flexibly act in challenging environments. Here we propose the Representation Internal-Manipulation (RIM) theory of consciousness, a theory that links the main elements of consciousness theories to components and functions of goal-directed behaviour, ascribing a central role for consciousness to the goal-directed manipulation of internal representations. This manipulation relies on four specific computational operations to perform the flexible internal adaptation of all key elements of goal-directed computation, from the representations of objects to those of goals, actions, and plans. Finally, we propose the concept of `manipulation agency' relating the sense of agency to the internal manipulation of representations. This allows us to propose that the subjective experience of consciousness is associated to the human capacity to generate and control a simulated internal reality that is vividly perceived and felt through the same perceptual and emotional mechanisms used to tackle the external world.

这篇理论文章研究了如何在计算机中构建类似人类的工作记忆和思维过程。应该有两个工作记忆存储，一个类似于关联皮层中的持续点火，另一个类似于大脑皮层中的突触增强。这些商店必须通过环境刺激或内部处理产生的新表示不断更新。它们应该连续更新，并以一种迭代的方式进行更新，这意味着在下一个状态下，应始终保留一组共同工作中的某些项目。因此，工作记忆中的一组概念将随着时间的推移逐渐发展。这使每个状态都是对先前状态的修订版，并导致连续的状态与它们所包含的一系列表示形式重叠和融合。随着添加新表示形式并减去旧表示形式，在这些更改过程中，有些保持活跃几秒钟。这种持续活动，类似于人工复发性神经网络中使用的活动，用于在整个全球工作区中传播激活能量，以搜索下一个关联更新。结果是能够朝着解决方案或目标前进的联想连接的中间状态链。迭代更新在这里概念化为信息处理策略，一种思想流的计算和神经生理决定因素以及用于设计和编程人工智能的算法。

预测性编码提供了对皮质功能的潜在统一说明 - 假设大脑的核心功能是最小化有关世界生成模型的预测错误。该理论与贝叶斯大脑框架密切相关，在过去的二十年中，在理论和认知神经科学领域都产生了重大影响。基于经验测试的预测编码的改进和扩展的理论和数学模型，以及评估其在大脑中实施的潜在生物学合理性以及该理论所做的具体神经生理学和心理学预测。尽管存在这种持久的知名度，但仍未对预测编码理论，尤其是该领域的最新发展进行全面回顾。在这里，我们提供了核心数学结构和预测编码的逻辑的全面综述，从而补充了文献中最新的教程。我们还回顾了该框架中的各种经典和最新工作，从可以实施预测性编码的神经生物学现实的微电路到预测性编码和广泛使用的错误算法的重新传播之间的紧密关系，以及对近距离的调查。预测性编码和现代机器学习技术之间的关系。

Graph learning is a popular approach for performing machine learning on graph-structured data. It has revolutionized the machine learning ability to model graph data to address downstream tasks. Its application is wide due to the availability of graph data ranging from all types of networks to information systems. Most graph learning methods assume that the graph is static and its complete structure is known during training. This limits their applicability since they cannot be applied to problems where the underlying graph grows over time and/or new tasks emerge incrementally. Such applications require a lifelong learning approach that can learn the graph continuously and accommodate new information whilst retaining previously learned knowledge. Lifelong learning methods that enable continuous learning in regular domains like images and text cannot be directly applied to continuously evolving graph data, due to its irregular structure. As a result, graph lifelong learning is gaining attention from the research community. This survey paper provides a comprehensive overview of recent advancements in graph lifelong learning, including the categorization of existing methods, and the discussions of potential applications and open research problems.

在基于人工神经网络的终身学习系统中，最大的障碍之一是在遇到新信息时无法保留旧知识。这种现象被称为灾难性遗忘。在本文中，我们提出了一种新型的连接主义架构，即顺序的神经编码网络，在从数据点流中学习时忘记了，并且与当今的网络不同，它不会通过流行的错误反向传播来学习。基于预测性处理的神经认知理论，我们的模型以生物学上可行的方式适应了突触，而另一个神经系统学会了指导和控制这种类似皮层的结构，模仿了一些基础神经节的某些任务连续控制功能。在我们的实验中，我们证明了与标准神经模型相比，我们的自组织系统经历的遗忘大大降低，表现优于先前提出的方法，包括基于排练/数据缓冲的方法，包括标准（SplitMnist，SplitMnist，Split Mnist等） 。）和定制基准测试，即使以溪流式的方式进行了训练。我们的工作提供了证据表明，在实际神经元系统中模仿机制，例如本地学习，横向竞争，可以产生新的方向和可能性，以应对终身机器学习的巨大挑战。

人类和其他动物学会从感觉体验中提取一般概念，没有大量的教学。这种能力被认为是睡眠的离线状态，如睡眠，以前的经验在全身重放。然而，梦想的特征创造性本质表明，学习语义表示可能超越仅仅重播以前的经历。我们通过实施由生成的对冲网络（GANS）启发的皮质架构来支持这一假设。我们模型中的学习是在三种不同的全球脑状态下组织，模仿清醒，NREM和REM睡眠，优化不同但互补的客观功能。我们在自然图像的标准数据集上培训模型，并评估学习符号的质量。我们的结果表明，通过对抗睡眠期间通过对抗梦想产生新的虚拟感官输入对于提取语义概念至关重要，同时通过在NREM睡眠期间通过扰动梦想重放剧集的集更记忆，提高了潜在表示的鲁棒性。该模型在睡眠状态，记忆重放和梦想中提供了一种新的计算透视，并提出了GAN的皮质实施。

本文回顾了概念，建模方法和最新发现，沿着不同级别的神经网络模型的抽象范围，包括跨（1）样本跨（2）分布，（3）域，（4）任务，（5）模态的概括，（2） ，和（6）范围。 （1）样品概括的结果表明，对于ImageNet而言，几乎所有最近的改进都减少了训练误差，而过度拟合则保持平坦。几乎消除了所有训练错误，未来的进度将需要专注于减少过度拟合。统计数据的观点突出显示了（2）分布概括如何交替地视为样本权重的变化或输入输出关系的变化。总结了（3）域概括的转移学习方法，以及最新的进步和域适应性基准数据集的财富。在（4）任务概括中调查的最新突破包括很少的元学习方法和BERT NLP引擎以及最近（5）个模态概括研究，这些研究整合了图像和文本数据，并应用了跨嗅觉的生物学启发的网络，视觉和听觉方式。回顾了最近（6）个范围泛化结果，将知识图嵌入深度NLP方法中。此外，讨论了关于大脑的模块化结构以及多巴胺驱动的条件导致抽象思维的步骤。

Artificial neural networks thrive in solving the classification problem for a particular rigid task, acquiring knowledge through generalized learning behaviour from a distinct training phase. The resulting network resembles a static entity of knowledge, with endeavours to extend this knowledge without targeting the original task resulting in a catastrophic forgetting. Continual learning shifts this paradigm towards networks that can continually accumulate knowledge over different tasks without the need to retrain from scratch. We focus on task incremental classification, where tasks arrive sequentially and are delineated by clear boundaries. Our main contributions concern (1) a taxonomy and extensive overview of the state-of-the-art; (2) a novel framework to continually determine the stability-plasticity trade-off of the continual learner; (3) a comprehensive experimental comparison of 11 state-of-the-art continual learning methods and 4 baselines. We empirically scrutinize method strengths and weaknesses on three benchmarks, considering Tiny Imagenet and large-scale unbalanced iNaturalist and a sequence of recognition datasets. We study the influence of model capacity, weight decay and dropout regularization, and the order in which the tasks are presented, and qualitatively compare methods in terms of required memory, computation time and storage.

建立一种人类综合人工认知系统，即人工综合情报（AGI），是人工智能（AI）领域的圣杯。此外，实现人工系统实现认知发展的计算模型将是脑和认知科学的优秀参考。本文介绍了一种通过集成元素认知模块来开发认知架构的方法，以实现整个模块的训练。这种方法是基于两个想法：（1）脑激发AI，学习人类脑建筑以构建人类级智能，（2）概率的生成模型（PGM）基础的认知系统，为发展机器人开发认知系统通过整合PGM。发展框架称为全大脑PGM（WB-PGM），其根本地不同于现有的认知架构，因为它可以通过基于感官电机信息的系统不断学习。在这项研究中，我们描述了WB-PGM的基本原理，基于PGM的元素认知模块的当前状态，与人类大脑的关系，对认知模块的整合的方法，以及未来的挑战。我们的研究结果可以作为大脑研究的参考。随着PGMS描述变量之间的明确信息关系，本说明书提供了从计算科学到脑科学的可解释指导。通过提供此类信息，神经科学的研究人员可以向AI和机器人提供的研究人员提供反馈，以及目前模型缺乏对大脑的影响。此外，它可以促进神经认知科学的研究人员以及AI和机器人的合作。

AI的一个关键挑战是构建体现的系统，该系统在动态变化的环境中运行。此类系统必须适应更改任务上下文并持续学习。虽然标准的深度学习系统实现了最先进的静态基准的结果，但它们通常在动态方案中挣扎。在这些设置中，来自多个上下文的错误信号可能会彼此干扰，最终导致称为灾难性遗忘的现象。在本文中，我们将生物学启发的架构调查为对这些问题的解决方案。具体而言，我们表明树突和局部抑制系统的生物物理特性使网络能够以特定于上下文的方式动态限制和路由信息。我们的主要贡献如下。首先，我们提出了一种新颖的人工神经网络架构，该架构将活跃的枝形和稀疏表示融入了标准的深度学习框架中。接下来，我们在需要任务的适应性的两个单独的基准上研究这种架构的性能：Meta-World，一个机器人代理必须学习同时解决各种操纵任务的多任务强化学习环境;和一个持续的学习基准，其中模型的预测任务在整个训练中都会发生变化。对两个基准的分析演示了重叠但不同和稀疏的子网的出现，允许系统流动地使用最小的遗忘。我们的神经实现标志在单一架构上第一次在多任务和持续学习设置上取得了竞争力。我们的研究揭示了神经元的生物学特性如何通知深度学习系统，以解决通常不可能对传统ANN来解决的动态情景。

Understanding how biological neural networks carry out learning using spike-based local plasticity mechanisms can lead to the development of powerful, energy-efficient, and adaptive neuromorphic processing systems. A large number of spike-based learning models have recently been proposed following different approaches. However, it is difficult to assess if and how they could be mapped onto neuromorphic hardware, and to compare their features and ease of implementation. To this end, in this survey, we provide a comprehensive overview of representative brain-inspired synaptic plasticity models and mixed-signal CMOS neuromorphic circuits within a unified framework. We review historical, bottom-up, and top-down approaches to modeling synaptic plasticity, and we identify computational primitives that can support low-latency and low-power hardware implementations of spike-based learning rules. We provide a common definition of a locality principle based on pre- and post-synaptic neuron information, which we propose as a fundamental requirement for physical implementations of synaptic plasticity. Based on this principle, we compare the properties of these models within the same framework, and describe the mixed-signal electronic circuits that implement their computing primitives, pointing out how these building blocks enable efficient on-chip and online learning in neuromorphic processing systems.

在过去的几年中，计算机视觉的显着进步总的来说是归因于深度学习，这是由于大量标记数据的可用性所推动的，并与GPU范式的爆炸性增长配对。在订阅这一观点的同时，本书批评了该领域中所谓的科学进步，并在基于信息的自然法则的框架内提出了对愿景的调查。具体而言，目前的作品提出了有关视觉的基本问题，这些问题尚未被理解，引导读者走上了一个由新颖挑战引起的与机器学习基础共鸣的旅程。中心论点是，要深入了解视觉计算过程，有必要超越通用机器学习算法的应用，而要专注于考虑到视觉信号的时空性质的适当学习理论。

Lack of performance when it comes to continual learning over non-stationary distributions of data remains a major challenge in scaling neural network learning to more human realistic settings. In this work we propose a new conceptualization of the continual learning problem in terms of a temporally symmetric trade-off between transfer and interference that can be optimized by enforcing gradient alignment across examples. We then propose a new algorithm, Meta-Experience Replay (MER), that directly exploits this view by combining experience replay with optimization based meta-learning. This method learns parameters that make interference based on future gradients less likely and transfer based on future gradients more likely. 1 We conduct experiments across continual lifelong supervised learning benchmarks and non-stationary reinforcement learning environments demonstrating that our approach consistently outperforms recently proposed baselines for continual learning. Our experiments show that the gap between the performance of MER and baseline algorithms grows both as the environment gets more non-stationary and as the fraction of the total experiences stored gets smaller.