Towards a better understanding of explicit-declarative learning in humans and non-human primates

该奖项全部或部分由《2021年美国救援计划法案》（公法117-2）资助。学习和记忆对教育、智力功能和日常生活的各个方面都至关重要。研究记忆的研究人员已经明确地表明，存在不同的记忆系统（例如，无意识的习惯记忆与有意识的陈述性记忆）。这一认识改变了社会对认知老化、痴呆和健忘症的看法。然而，研究学习基本机制的研究人员并没有参与到这场系统革命中来，这是科学进步的一个障碍。例如，可能存在不同的学习系统，它们具有不同的优势、用途、大脑组织、认知发展轨迹和认知老化期间的保存水平。但是，当学习文献中占主导地位的思维模式保留了对单一学习系统的强调时，这种区分就无法明确地做出来。因此，这个项目为学习研究领域带来了内隐行为学习（即学习自动、习惯性、无意识地做出反应）和外显陈述学习（即概念上、有意识地、可能是可语言化地学习新知识）之间的分离。为此，该项目采用了创新的方法。这些方法有选择地抑制内隐学习，击败可能干扰外显学习形式的基于习惯的学习，从而有选择地促进外显学习。这些方法填补了学习文献中的重要空白。将它们应用于人类和非人类灵长类动物，有可能通过打开一扇研究动物反思思维的新窗口来改变比较心理学，并可能为动物意识提供启发性的见解。所获得的见解也将让研究人员询问语言的使用对显性学习过程的贡献——一个古老的问题。例如：人类的规则和假设一定要用语言来表达，还是只是为了方便？事物之间的抽象关系有可能无声无息地构想出来吗？发展中的语言是为什么幼儿慢慢地达到成熟的类比推理？因此，这项研究将为未来研究幼儿外显学习早期表现的研究人员提供完美的范例。培养显性学习的新方法可以帮助患有发育迟缓、学习障碍和自闭症谱系障碍的儿童——通过教他们基本的学习方法，减少语言限制，减少内省和自我意识。这些方法可以让教育者将学生的学习努力集中在显性/概念层面上，并优化他们的成功。这项研究将产生外显学习的动物模型，以进一步外显认知的神经科学研究，揭示其大脑组织，指出可能降低其功能的因素和可能增强其功能的因素。因此，该项目与人类最高认知能力的进化有关，这是人类出现故事的重要组成部分。无数的人类和动物学习研究为受试者提供了即时的、具体的、一次又一次的强化。这种方法限制了科学的理解，因为它允许低级形式的自动化、习惯性学习来控制学习过程。反过来，这可能会干扰更理想的更高层次的明确概念学习形式的运作。因此，本项目采用替代加固环境——即置换加固——来克服这一障碍并实现其目的。例如，一种方法会要求参与者在收到任何反馈之前完成一组试验。该项目将表明，移位强化打败了内隐程序学习的过程，同时鼓励参与者对手头的任务进行明确和概念性的思考。这将表明参与者必须在这种强化环境中自我监督他们的学习，将总结反馈与他们自己发现的规则或策略联系起来。事实上，这个项目的关键创新之处在于这些效应协同运作，因为内隐程序学习被选择性地禁用，研究人员可以观察到一些其他学习策略的支点，比如使用外显陈述性学习系统。因此，研究人员正在观察有意识的假设和规则，概念知识和类比关系特别加强。具体来说，实验1 （E1）训练人类和动物在研究中使用的改变的强化环境中茁壮成长，这是后续实验的关键初步基础。E2显示，移位强化选择性地促进了基于单一维度的规则学习（例如，大的东西是A，小的东西是B），这是典型的前额叶大脑区域。E3提出的问题是，假设测试形式的学习是否在置换强化下被选择性地保留下来。E4询问移位强化下的外显学习是否具有有意识的规则发现和突然学习（所谓的“AHA体验”）。这可能是一项关于动物思维的革命性发现。E5表明，在移位强化下，参与者可以运用自己的概念框架对自己的学习进行自我监督。E6让猴子第一次在没有得到即时强化的情况下宣布它们自己的概念规则和类别边界。后来的实验表明，明确的陈述性学习在培养更一般化和更概念化的知识方面是独特的。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Learning and memory are crucial to every aspect of education, intellectual functioning, and daily living. Researchers who study memory have definitively shown that there are different systems of memory (e.g., unconscious habit memory vs. conscious declarative memory). This knowledge has changed society’s views of cognitive aging, dementia, and amnesia. However, researchers who study the basic mechanisms of learning have not participated in this systems revolution, and this is a barrier to scientific progress. For example, there might be different systems of learning that have different strengths, uses, brain organizations, cognitive-developmental trajectories, and levels of preservation during cognitive aging. But such differentiations cannot be clearly made while the dominant mode of thinking in the learning literature preserves an emphasis on a unitary learning system. Accordingly, this project brings to the domain of learning research the separation between implicit-behavioral learning (i.e., learning to react automatically, habitually, unconsciously) and explicit-declarative learning (i.e., learning new knowledge conceptually, consciously, perhaps verbalizably). The project uses innovative methods toward this end. These methods selectively suppress implicit learning, defeating habit-based learning that can interfere with explicit forms of learning, and therefore selectively fostering explicit learning. These methods fill important gaps in the learning literature. Applying them across humans and nonhuman primates has the potential to transform comparative psychology by opening a new window on animals’ reflective minds, and possibly providing illuminating insights into animal consciousness. The insights gained will also let researchers ask what contribution the use of language brings to explicit learning processes —an age-old question. For example: Are human rules and hypotheses necessarily couched in language, or only conveniently so? Is it possible to wordlessly conceive of abstract relations between things? Is developing language why young children slowly achieve mature analogical reasoning? Thus, this research will provide paradigms perfectly suited to future researchers studying the earliest manifestations of explicit learning in young children. New methods to foster explicit learning could help children with developmental delay, learning disabilities, and autism spectrum disorder—by teaching them basic approaches to that learning that are less language-bound or less introspective and self-conscious. The methods could let educators focus students’ learning effort toward the explicit/conceptual level and optimize their success. The research will produce animal models of explicit learning to further the neuro-scientific study of explicit cognition, revealing its brain organization, pointing to factors that may reduce its functionality and factors that may enhance it. Thus, the project bears on the evolution of humans’ highest cognitive capacities—an important part of the story of human emergence.Myriad human and animal learning studies have provided subjects with immediate, concrete, trial-by-trial reinforcement. This approach limits scientific understanding because it allows low-level forms of automated, habitual learning to control the learning process. In turn, this can interfere with the operation of higher-level forms of explicit-conceptual learning that may be more desirable. Accordingly, this project uses alternative reinforcement environments—that is, displaced reinforcement—to surmount this obstacle and achieve its ends. For example, one method will ask participants to complete a block of trials before receiving any feedback. The project will show that displaced reinforcement defeats the processes of implicit-procedural learning, while encouraging participants to think explicitly and conceptually about the task at hand. It will show that participants must self-supervise their learning in this reinforcement environment, relating the summary feedback to their self-discovered rule or strategy. Indeed, the crucial innovation of this project is that these effects operate synergistically, for with implicit-procedural learning selectively disabled, the investigators can observe a pivot to some other learning strategy such as the use of the explicit-declarative learning system. Thus, the investigators are observing conscious hypotheses and rules, conceptual knowledge, and analogical relationships particularly enhanced. Specifically, Experiment 1 (E1) trains humans and animals to thrive in the altered reinforcement environments used in the research, a key preliminary grounding later experiments. E2 shows that displaced reinforcement selectively fosters the learning of rules based on single dimensions (e.g., big things are A; small things are B) that is typical of pre-frontal brain regions. E3 asks whether a hypothesis-testing form of learning is selectively preserved under displaced reinforcement. E4 asks whether explicit learning under displaced reinforcement features conscious rule discovery and sudden learning (so-called “AHA experiences”). This may be a revolutionary finding about animal minds. E5 demonstrates that participants can self-supervise their own learning under displaced reinforcement, applying their own conceptual framework. E6 lets monkeys – for the first time, without having ever received immediate reinforcement -- declare their own conceptual rules and category boundaries. The later experiments demonstrate that explicit-declarative learning is distinctive for fostering knowledge that is more generalizable and more conceptual.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.