Following recent regulatory approvals for anti-Alzheimer's monoclonal antibodies, this paper considers the contemporary role of cognitivism in defining the ontological commitments of dementia research, as well as movements away from cognitivism under the umbrella of 4E cognitive science. 4E cognitive theories, extending cognition into bodies, their environs, and active relations between the two, share potentially fruitful affinities with new materialisms which focus on the co-constitution of matter in intra-action. These semi-overlapping conceptual positions furnish some opportunity for an ontological alternative to longstanding cognitivist commitments, particularly to the isolated brain as a material catalyst for commercial interventions. After outlining mainstream cognitivism and its shortcomings, I explore 4E and new materialism as possibly transformative conceptual schemas for dementia research, a field for which cognitivist imaginings of cognitive decline in later life have profound and often regrettable ramifications. To realise this new materialist dementia, I sketch out a cognitive ontology based on Barad's agential realism. This facilitates a reassessment of the biggest conundrum in dementia research – the lack of neat correlation between (apparently material) neuropathology and (apparently immaterial) cognitive impairment – alongside the continued failure of efforts to develop effective interventions. It also gives social researchers working on cognitive decline in later life an opportunity to reappraise the nature of social science as a response to such phenomena. If cognition and cognitive ageing are reimagined as an emergent characteristic of intra-acting matter, then new materialist social science might be at least as conducive to salutogenic interventions as the neuropsychiatric technoscience that dominates the contemporary dementia research economy despite continual failures. I argue that a new materialist cognitive ontology could help us think beyond an ageing cognitivism and, by extension, beyond the Alzheimer conundrum.

继最近监管机构批准抗阿尔茨海默病单克隆抗体后，本文探讨了认知主义在定义痴呆症研究本体论承诺方面的当代作用，以及 4E 认知科学框架下远离认知主义的运动。4E认知理论将认知扩展到身体、周围环境以及两者之间的积极关系，与新唯物主义有着潜在的富有成效的亲缘关系，新唯物主义关注的是行动中物质的共同构成。这些半重叠的概念立场为长期认知主义承诺的本体论替代提供了一些机会，特别是作为商业干预的物质催化剂的孤立大脑。在概述了主流认知主义及其缺点之后，我探索了 4E 和新唯物主义作为痴呆症研究可能的变革性概念模式，在这一领域，认知主义对晚年认知衰退的想象产生了深远且常常令人遗憾的后果。为了实现这种新的唯物主义痴呆，我根据巴拉德的主体现实主义勾勒出一个认知本体论。这有助于重新评估痴呆症研究中最大的难题——（显然是实质性的）神经病理学和（显然是非实质性的）认知障碍之间缺乏明确的相关性——以及开发有效干预措施的努力持续失败。它还为研究晚年认知衰退的社会研究人员提供了一个机会，让他们重新评估社会科学的本质，作为对此类现象的回应。如果认知和认知衰老被重新想象为内部作用物质的一个新兴特征，那么新唯物主义社会科学可能至少与主导当代痴呆症研究经济的神经精神病学技术科学一样有利于有益的干预，尽管它不断失败。我认为，新的唯物主义认知本体论可以帮助我们超越衰老的认知主义，进而超越阿尔茨海默氏症难题。