大卫·伊格尔曼（David Eagleman）博士是一位著名的神经科学家、作家和科普传播者，他与安德鲁·休伯曼（Andrew Huberman）一同探讨了广泛的脑科学议题，重点聚焦于神经可塑性、记忆、时间感知和社会动力学。 **神经可塑性：大脑的“绝招”** 伊格尔曼将神经可塑性定义为大脑根据经验持续重塑自身的能力。他强调，人类出生时拥有一个“半成品”的大脑（half-baked brain），这使得环境、文化和语言能够构建剩余的神经网络。这种适应性是“大自然的绝妙把戏”（Mother Nature's "big trick"），它使人类能够吸收代代相传的知识并不断创新。他解释说，大脑皮层是一个“只会一招的小马”（"one-trick pony"）——它的结构是统一的，只有当感官信息接入后，它才变得专门化（例如，视觉、听觉）。这种灵活性通过实验得到证明，这些实验显示，在盲人身上，通常用于视觉的区域可以被重新利用来处理触觉或听觉。 为了终生维持和增强神经可塑性，伊格尔曼建议积极地“寻求新颖”。大脑的目标是建立一个成功的外部世界模型，一旦实现，它就会趋于停止变化。因此，持续用“令人沮丧但又力所能及”（frustrating but achievable）的任务来挑战自己是关键。他引用了“修女研究”（Religious Order Study），其中修女们尽管患有阿尔茨海默病理，但由于持续的智力和社会参与，她们保持了认知功能。简单的行为，如选择新的回家路线或用非惯用手刷牙，可以刺激这一过程，通过创造更多记忆让生活感觉“更长”。 他还提及了神经递质的作用，指出虽然各种神经调节剂都能影响可塑性，但血清素（serotonin）似乎尤其关键，尤其是在早期发育阶段。他警告说，虽然像致幻剂这样的工具可以增强可塑性，但目标是“定向可塑性”（directed plasticity），因为无方向的变化可能有害。 **未来自我与尤利西斯契约** 人类拥有一种独特的能力，可以模拟可能的未来并构想他们的“未来自我”。这种能力主要由前额叶皮层控制，使我们能够做出当下的决定，从而限制未来不希望出现的行为——他称之为“尤利西斯契约”（Ulysses Contracts）。借鉴奥德修斯将自己绑在桅杆上以抵御海妖的诱惑，伊格尔曼提供了现代例子：使用手机锁定盒，与朋友安排健身聚会以互相监督，甚至采取极端措施，比如一名女性发誓如果她吸烟就将钱捐给一个她厌恶的组织。这些契约利用我们对自己易犯错误的未来自我的了解，以确保达到期望的结果。 **个体差异与时间感知** 伊格尔曼讨论了内心体验的范围，例如“内心独白”（inner voice，个体差异很大）以及“心盲症”（aphantasia，无法形成心理图像）与“超忆症”（hyperphantasia，生动的心理图像）之间的对比。他分享了一个令人惊讶的发现：皮克斯（Pixar）的许多成功动画师患有心盲症，这表明内部无法可视化反而可能促使他们付出更大的努力来将想法外部化。 关于时间感知，伊格尔曼揭示它并非由单一的大脑区域控制。他的“坠落实验”（falling experiment）表明，虽然可怕、危及生命的经历并不会减慢我们的感知帧率。相反，它们会触发杏仁核（amygdala）形成更密集的记忆，从而在事后回顾时感觉事件持续得更长。这种“记忆密度”也解释了为什么童年时代的夏天感觉漫长（充满新奇和新记忆），而成年后的夏天却常常转瞬即逝（新奇体验较少）。从事新的活动可以创造更多的记忆锚点，使生活感觉更丰富、更漫长。 **记忆与法律** 将时间感知与记忆联系起来，伊格尔曼强调记忆并非“视频录像”。它们是重建性的，容易漂移，即使是创伤性记忆也是如此，9/11幸存者的研究就证明了这一点。这对法律系统具有深远的影响，尤其是在证人证词方面，证人证词臭名昭著地不可靠且容易受到暗示。他指出儿童尤其容易受到记忆操控。 **两极分化与同理心** 伊格尔曼认为，当代社会的两极分化虽然被现代媒体放大，但在历史上并非没有先例。他的实验室的fMRI研究揭示了内群体/外群体偏见的鲜明神经生物学基础：当观察外群体成员的痛苦时，大脑的同理心反应（疼痛矩阵激活）会显著减弱，即使这些群体是随意划分的（例如，“贾斯汀派” vs. “奥古斯丁派”）。这种机制可以被将“他者”非人化的宣传所利用，从而关闭同理心并助长暴力。 为了对抗这种情况，伊格尔曼提倡“关系的复杂化”（complexification of relationships），即有意地培养多元联系并寻找共同点。他描述了一种提议的社交媒体算法，该算法将优先展示共同兴趣，让人们在遇到引发分歧的话题之前建立融洽关系，从而增加建设性参与的意愿。 伊格尔曼的工作强调了大脑深刻的适应性以及经验在塑造我们的感知、记忆和社会互动中的关键作用。他鼓励积极应对新挑战和接纳多元视角，以优化大脑功能并促进一个更具同理心的社会。

Dr. David Eagleman, a renowned neuroscientist, author, and science communicator, joined Andrew Huberman to discuss a wide range of brain science topics, emphasizing neuroplasticity, memory, time perception, and social dynamics. **Neuroplasticity: The Brain's Master Trick** Eagleman defines neuroplasticity as the brain's continuous ability to reconfigure itself based on experience. He highlights that humans are born with a "half-baked brain," which allows the environment, culture, and language to wire the remaining circuitry. This adaptability is Mother Nature's "big trick," enabling humans to absorb generations of knowledge and constantly innovate. The cortex, he explains, is a "one-trick pony" – its structure is uniform throughout, becoming specialized (e.g., visual, auditory) only based on the sensory information plugged into it. This flexibility is demonstrated by experiments showing how areas typically dedicated to vision can be repurposed for touch or hearing in blind individuals. To maintain and enhance neuroplasticity throughout life, Eagleman advises actively "seeking novelty." The brain's goal is to build a successful model of the outside world, and once it achieves this, it tends to stop changing. Therefore, continuously challenging oneself with tasks that are "frustrating but achievable" is key. He cites the "Religious Order Study" where nuns, despite having Alzheimer's pathology, maintained cognitive function due to constant intellectual and social engagement. Simple acts like taking new routes home or brushing teeth with the non-dominant hand can stimulate this process, making life feel "longer" by creating more memories. He also touches on the role of neurotransmitters, noting that while various neuromodulators can influence plasticity, serotonin seems particularly central, especially in early development. He cautions that while tools like psychedelics can boost plasticity, "directed plasticity" is the goal, as undirected change can be detrimental. **The Future Self and Ulysses Contracts** Humans possess a unique ability to simulate possible futures and contemplate their "future self." This capacity, largely governed by the prefrontal cortex, allows us to make present decisions that constrain future undesirable behaviors – a concept he calls "Ulysses Contracts." Drawing from Odysseus lashing himself to the mast to resist the sirens, Eagleman provides modern examples: using phone lockboxes, arranging gym meet-ups with a friend for accountability, or even extreme measures like a woman pledging money to an abhorrent organization if she smoked. These contracts leverage our wisdom about our fallible future selves to ensure desired outcomes. **Individual Differences and Time Perception** Eagleman discusses the spectrum of internal experiences, such as the "inner voice" (which varies greatly among individuals) and aphantasia (the inability to form mental images) versus hyperphantasia (vivid mental imagery). He shares the surprising finding that many successful animators at Pixar are aphantasic, suggesting that the inability to visualize internally can drive greater effort in externalizing ideas. Regarding time perception, Eagleman reveals it's not governed by a single brain region. His "falling experiment" demonstrated that while terrifying, life-threatening experiences *do not* slow down our perceptual frame rate. Instead, they trigger the amygdala to lay down *denser* memories, making the event feel longer in retrospect. This "memory density" also explains why childhood summers seem long (full of novelty and new memories), while adult summers often fly by (fewer novel experiences). Engaging in new activities can create more memory anchors, making life feel richer and longer. **Memory and the Law** Connecting time perception to memory, Eagleman highlights that memories are not "video recordings." They are reconstructive and prone to drift, even traumatic ones, as shown by studies on 9/11 survivors. This has profound implications for the legal system, especially concerning eyewitness testimony, which is notoriously unreliable and susceptible to suggestion. He notes that children are particularly vulnerable to memory manipulation. **Polarization and Empathy** Eagleman suggests that contemporary societal polarization, while amplified by modern media, is not historically unprecedented. His lab's fMRI studies reveal a stark neurobiological basis for in-group/out-group biases: the brain's empathic response (pain matrix activation) is significantly diminished when observing suffering in out-group members, even if the groups are arbitrarily assigned (e.g., "Justinians" vs. "Augustinians"). This mechanism can be exploited by propaganda that dehumanizes "the other," turning off empathy and facilitating violence. To counteract this, Eagleman advocates for "complexification of relationships," meaning intentionally fostering diverse connections and finding common ground. He describes a proposed social media algorithm that would prioritize surfacing shared interests, allowing people to build rapport before encountering divisive topics, thus increasing willingness to engage constructively. Eagleman's work underscores the brain's profound adaptability and the critical role of experience in shaping our perception, memory, and social interactions. He encourages active engagement with new challenges and diverse perspectives to optimize brain function and promote a more empathetic society.