【TED】What would happen if you lost your

In 1971, Ian Waterman suddenly collapsed from a severe case of what seemed to be gastric flu. His illness passed after a few days, but a stranger set of symptoms lingered. Although his muscles and joints remained healthy, Waterman was unable to move. In fact, he was unable to feel anything from the neck down. Eventually, he was diagnosed with a rare and extreme form of deafferentation, a neurological condition in which certain signals from the nervous system are interrupted or impaired. Without his body's constant feedback on how his limbs were moving, Waterman was unable to sit up, stand, or walk. But over time, he taught himself to use sight to judge the distance of his limbs from other objects. And eventually he regained complete control of his body— so long as he could see it.

1971 年，伊恩·沃特曼突然病倒， 他以为是肠胃炎导致的。 几天后，症状消退了， 但他感到身体有些异样。 尽管沃特曼的肌肉 和关节状况良好， 但他无法移动身体了。 实际的状况是： 他从脖子以下没有任何感知。 最后，他被诊断患了一种极其罕见 的传入神经阻滞疾病， 这是一种神经系统疾病， 这意味着神经系统中的部分 传输信号中断或受到了损伤。 由于沃特曼失去了 四肢活动时惯常的感知， 他无法坐、无法站、 也无法走路。 但多年后，他逐渐学会了 使用目光来判断 自己的肢体与其他物体之间的距离。 最终，他又重新获得了 自由移动身体的能力， 前提是他能看见周围的事物。

We often don’t think of touch as being a vital part of movement. But touch is just one part of the somatosensory system, a network that oversees all the sensations arising from the surface and interior of our bodies. Touch, pain, temperature, and our awareness of our bodies in space— also known as proprioception— are regulated by this system. And when something goes wrong, the effects can be dramatic.

我们一般不会认为触觉 在日常生活中起到多大作用。 虽然触觉仅仅只是 躯体感觉系统的一部分， 呈网络状， 但统筹着身体表面 与身体内部产生的所有感觉。 我们的触觉、痛感、体温 和空间感知 统称为本体感觉， 也是由躯体感觉系统来调节的。 当哪个部分出了问题时， 会对人体产生巨大的影响。

All these sensations are processed by millions of tiny receptor cells embedded in our skin, muscles, tendons, and organs. Every square centimeter of our skin is packed with hundreds of these cells, and their shape, size, and depth determine what kind of stimuli they respond to.

成千上万微小的受体细胞 处理着所有这些感觉， 深入我们的皮肤、肌肉、 肌腱和各个器官。 我们身上每平方厘米皮肤 都充满了成百上千个这样的细胞， 这些细胞的形状、大小和厚度 决定了这些细胞对哪种刺激有反应。

Mechanoreceptors sense mechanical deformation of the skin. This could be triggered by low or high frequency vibrations, a stretch, or simply light, static pressure. Thermoreceptors respond to temperature changes, while nociceptors sense pain. And propriocepters sit deep in your muscles and tendons, continually detecting and relaying information about the position of your body. Your brain then combines this information with other sensory data to move through space without needing to see your limbs.

机械感受器会检测并记录 皮肤机械变形的情况。 这可能会由低频或高频的感受、 拉伸，或仅仅由轻微 的静态压力所引发。 温度感受器对温度变化有反应， 而伤害感受器会感知到疼痛。 本体感受器存在于肌肉和肌腱底层， 持续不断地探测传递 与身体位置相关的信息。 然后，大脑就会将 这类信息与其他感官数据结合， 让人可以在空间中自由移动， 而不用看见肢体的位置。

All of these receptors work by sending electrical signals to the brain through fibers they’re attached to. And the speed of those signals varies with the fiber’s thickness. For example, some nociceptors are attached to fibers with slightly more conductive, fatty myelin than others. So when you get hurt, the electrical impulses from thicker nociceptors trigger sharp, intense pain, while thin, unmyelinated nociceptors are responsible for the dull, aching pain that follows. And since the fibers carrying tactile information are much thicker than those carrying nociceptive signals, rubbing an injury can produce temporary relief from the pain

所有这些感受器通过 向大脑发送电信号来工作， 经由所依附的神经纤维。 这些信号的速度 与神经纤维的厚度有关。 例如，有些伤害感受器 依附于神经纤维， 就会更具有传导作用， 髓磷脂所富含的脂肪也更多一些。 所以当你受伤时， 具有更厚质的伤害感受器 所传导的电脉冲 就会引发强烈的剧痛， 而薄质且无髓鞘的伤害感受器 则会产生隐隐的酸痛。 而且由于带有触觉信息的神经纤维 比带有损伤性信号 的纤维要更厚一些， 摩擦伤口反而可能暂时不会那么疼。

These receptors generate a constant flood of signals that travel through the nervous system to the brain. But if this process is disrupted— either by damage to the skin, the nerves, or the brain— the network breaks down. And since it underpins so many bodily functions, damage to the somatosensory system can manifest in a wide variety of ways.

这些感受器会产生持续的信号流， 通过神经系统传输到大脑。 但如果这个过程受到干扰， 不管是皮肤受伤， 还是神经或大脑受到了损伤， 这种信号传输的过程就无法进行。 而且由于很多身体功能都依赖于 这种信号传输， 躯体感觉系统会产生 各种不同的损伤。

In Waterman’s case, an autoimmune reaction attacked a large swath of his nervous system, leaving him with no tactile or proprioceptive sensations from the neck down. But deafferentation is just one of many somatosensory disorders. Individuals can receive damage to a specific brain area or a section of skin, resulting in the loss of certain sensations in particular locations. And the impact of this loss can be significant. Losing tactile sensations makes it difficult to gauge how much strength to use in a situation. Without the warning signals provided by thermal and pain stimuli, we don’t react when our bodies are damaged. And, being deprived of social touch can cause a condition known as touch starvation, characterized by anxiety, depression, high blood pressure, and even a weakened immune system.

在沃特曼这个案例中， 自身免疫反应 攻击了他大部分的神经系统， 使他从脖子以下 就失去了触觉或本体感觉。 但传入神经阻滞仅仅只是 许多躯体感觉失调的情况之一。 个体的脑部区域或部分皮肤 可能受到损伤， 导致丧失特定部位的感觉。 这种感觉的丧失 会对人体产生非常大的影响。 丧失触觉会让人在具体情境中 判断使用多少力气变得非常困难。 如果没有体温或痛感的刺激 来提醒我们引起注意， 身体在受到损伤时， 我们就不会做出相应的反应。 并且，由于缺乏与他人的社会交往， 导致“触摸匮乏”的情况发生， 主要表现为焦虑、抑郁、 高血压，甚至还会出现 免疫力下降这样的情况。

Many individuals who face these realities have found innovative ways to adapt. But it’s undeniable that all these invisible sensations play a vital role in how we navigate the world— even if they can be difficult to put your finger on.

In 1971, Ian Waterman suddenly collapsed from a severe case of what seemed to be gastric flu. His illness passed after a few days, but a stranger set of symptoms lingered. Although his muscles and joints remained healthy, Waterman was unable to move. In fact, he was unable to feel anything from the neck down. Eventually, he was diagnosed with a rare and extreme form of deafferentation, a neurological condition in which certain signals from the nervous system are interrupted or impaired. Without his body's constant feedback on how his limbs were moving, Waterman was unable to sit up, stand, or walk. But over time, he taught himself to use sight to judge the distance of his limbs from other objects. And eventually he regained complete control of his body— so long as he could see it.

1971 年，伊恩·沃特曼突然病倒， 他以为是肠胃炎导致的。 几天后，症状消退了， 但他感到身体有些异样。 尽管沃特曼的肌肉 和关节状况良好， 但他无法移动身体了。 实际的状况是： 他从脖子以下没有任何感知。 最后，他被诊断患了一种极其罕见 的传入神经阻滞疾病， 这是一种神经系统疾病， 这意味着神经系统中的部分 传输信号中断或受到了损伤。 由于沃特曼失去了 四肢活动时惯常的感知， 他无法坐、无法站、 也无法走路。 但多年后，他逐渐学会了 使用目光来判断 自己的肢体与其他物体之间的距离。 最终，他又重新获得了 自由移动身体的能力， 前提是他能看见周围的事物。

We often don’t think of touch as being a vital part of movement. But touch is just one part of the somatosensory system, a network that oversees all the sensations arising from the surface and interior of our bodies. Touch, pain, temperature, and our awareness of our bodies in space— also known as proprioception— are regulated by this system. And when something goes wrong, the effects can be dramatic.

我们一般不会认为触觉 在日常生活中起到多大作用。 虽然触觉仅仅只是 躯体感觉系统的一部分， 呈网络状， 但统筹着身体表面 与身体内部产生的所有感觉。 我们的触觉、痛感、体温 和空间感知 统称为本体感觉， 也是由躯体感觉系统来调节的。 当哪个部分出了问题时， 会对人体产生巨大的影响。

All these sensations are processed by millions of tiny receptor cells embedded in our skin, muscles, tendons, and organs. Every square centimeter of our skin is packed with hundreds of these cells, and their shape, size, and depth determine what kind of stimuli they respond to.

成千上万微小的受体细胞 处理着所有这些感觉， 深入我们的皮肤、肌肉、 肌腱和各个器官。 我们身上每平方厘米皮肤 都充满了成百上千个这样的细胞， 这些细胞的形状、大小和厚度 决定了这些细胞对哪种刺激有反应。

Mechanoreceptors sense mechanical deformation of the skin. This could be triggered by low or high frequency vibrations, a stretch, or simply light, static pressure. Thermoreceptors respond to temperature changes, while nociceptors sense pain. And propriocepters sit deep in your muscles and tendons, continually detecting and relaying information about the position of your body. Your brain then combines this information with other sensory data to move through space without needing to see your limbs.

机械感受器会检测并记录 皮肤机械变形的情况。 这可能会由低频或高频的感受、 拉伸，或仅仅由轻微 的静态压力所引发。 温度感受器对温度变化有反应， 而伤害感受器会感知到疼痛。 本体感受器存在于肌肉和肌腱底层， 持续不断地探测传递 与身体位置相关的信息。 然后，大脑就会将 这类信息与其他感官数据结合， 让人可以在空间中自由移动， 而不用看见肢体的位置。

All of these receptors work by sending electrical signals to the brain through fibers they’re attached to. And the speed of those signals varies with the fiber’s thickness. For example, some nociceptors are attached to fibers with slightly more conductive, fatty myelin than others. So when you get hurt, the electrical impulses from thicker nociceptors trigger sharp, intense pain, while thin, unmyelinated nociceptors are responsible for the dull, aching pain that follows. And since the fibers carrying tactile information are much thicker than those carrying nociceptive signals, rubbing an injury can produce temporary relief from the pain

所有这些感受器通过 向大脑发送电信号来工作， 经由所依附的神经纤维。 这些信号的速度 与神经纤维的厚度有关。 例如，有些伤害感受器 依附于神经纤维， 就会更具有传导作用， 髓磷脂所富含的脂肪也更多一些。 所以当你受伤时， 具有更厚质的伤害感受器 所传导的电脉冲 就会引发强烈的剧痛， 而薄质且无髓鞘的伤害感受器 则会产生隐隐的酸痛。 而且由于带有触觉信息的神经纤维 比带有损伤性信号 的纤维要更厚一些， 摩擦伤口反而可能暂时不会那么疼。

These receptors generate a constant flood of signals that travel through the nervous system to the brain. But if this process is disrupted— either by damage to the skin, the nerves, or the brain— the network breaks down. And since it underpins so many bodily functions, damage to the somatosensory system can manifest in a wide variety of ways.

这些感受器会产生持续的信号流， 通过神经系统传输到大脑。 但如果这个过程受到干扰， 不管是皮肤受伤， 还是神经或大脑受到了损伤， 这种信号传输的过程就无法进行。 而且由于很多身体功能都依赖于 这种信号传输， 躯体感觉系统会产生 各种不同的损伤。

In Waterman’s case, an autoimmune reaction attacked a large swath of his nervous system, leaving him with no tactile or proprioceptive sensations from the neck down. But deafferentation is just one of many somatosensory disorders. Individuals can receive damage to a specific brain area or a section of skin, resulting in the loss of certain sensations in particular locations. And the impact of this loss can be significant. Losing tactile sensations makes it difficult to gauge how much strength to use in a situation. Without the warning signals provided by thermal and pain stimuli, we don’t react when our bodies are damaged. And, being deprived of social touch can cause a condition known as touch starvation, characterized by anxiety, depression, high blood pressure, and even a weakened immune system.

在沃特曼这个案例中， 自身免疫反应 攻击了他大部分的神经系统， 使他从脖子以下 就失去了触觉或本体感觉。 但传入神经阻滞仅仅只是 许多躯体感觉失调的情况之一。 个体的脑部区域或部分皮肤 可能受到损伤， 导致丧失特定部位的感觉。 这种感觉的丧失 会对人体产生非常大的影响。 丧失触觉会让人在具体情境中 判断使用多少力气变得非常困难。 如果没有体温或痛感的刺激 来提醒我们引起注意， 身体在受到损伤时， 我们就不会做出相应的反应。 并且，由于缺乏与他人的社会交往， 导致“触摸匮乏”的情况发生， 主要表现为焦虑、抑郁、 高血压，甚至还会出现 免疫力下降这样的情况。

Many individuals who face these realities have found innovative ways to adapt. But it’s undeniable that all these invisible sensations play a vital role in how we navigate the world— even if they can be difficult to put your finger on.

许多患者采用了一些新 的方式来适应这种情况。 但不可否认的是， 所有这些无形的感觉 在我们探索世界的过程中， 起到了非常重要的作用， 即使这些感觉可能很难说清楚。