Do Cats and Dogs Remember Their Past?猫狗记得过去吗？

When I met my cat Pearlita， she lived in an alley between my apartment building and a gas station. She drank from puddles polluted by engine leaks and ate whatever she could find. Ten years later， with Pearlita curled up on my lap， making it hard to type， I can still remember how she wolfed down the food I put in the alley and how easy it was to lure her inside with more.

我是在公寓楼和加油站间的一条小巷里遇见我的爱猫小珍珠的。她喝那些因机油泄露而被污染的水坑里的水，能找到什么就吃什么。10年后，小珍珠蜷缩在我的大腿上，我几乎无法敲字，但我仍记得她曾如何狼吞虎咽掉我放在巷子里的食物，我又曾怎样轻易地用更多吃食将她诱入家门。

But does she remember her life on the streets？ And if so， which parts of it？

但她是否还记得自己在街边流浪的生活？如果记得，记住的又是其中哪些过往？

This question has probably occurred to almost anyone with an animal friend， but for simplicity’s sake， we’ll limit this discussion to our feline and canine companions. Certainly they behave as though they have memories—after all， your special furball doesn’t treat you like a stranger each time you walk through the door—and evolutionary theory suggests as much： It behooves any long-lived animal to have long-lasting recollections. There have been rigorous scientific experiments， too， not enough to fully understand our dogs’ and cats’ memories， but enough to confirm their existence and to raise some interesting questions about how they compare to our own.

几乎所有与动物为友的人都可能有过此类疑问，但简单起见，我们这次的讨论仅限于陪伴我们的猫和狗。当然，它们表现得就像是有记忆——毕竟，你的毛孩子不会在你每次进门时都当你是陌生人——而且进化理论也如此说明：任何长寿的动物都应当具备长期记忆。也有些严格的科学实验，尽管还不足以让我们完全了解狗和猫的记忆究竟是怎么回事，但也足以证实这种记忆是存在的，并让人好奇猫狗的记忆与我们人类的记忆有何异同。

“It is tricky， because we can’t directly ask them，” says Mikel Delgado， an animal psychology researcher from the University of California， Davis who now dispenses advice on cat behavior with the company Feline Minds. “The way I think about it is： What’s important for animals to remember？”

“这很棘手，因为我们不能直接询问它们。”加州大学戴维斯分校的动物心理学研究员迈克尔·德尔加多说，她现在为“猫科思维”公司提供关于猫行为的咨询服务。“我思考的方向是：对动物们来说，什么才是它们要记住的重要内容？”

For a cat or dog—or human—to remember events from way back， they must first be able to recall what happened just a few moments ago. To study this in controlled settings， scientists devise experiments in which animals are rewarded for correctly identifying objects they previously saw， asked to avoid obstacles without looking at them， or monitored while searching for food they saw being hidden. These methods don’t capture everything that cats and dogs can recall， of course; they’re intended to tease out the basics of their cognition.

对于猫狗甚或人类而言，要记住很久以前的事，必须首先能够回忆起几分钟前刚发生的事。为了在受控环境下研究这一点，科学家们设计了一些实验，内容是如果动物能正确识别它们之前看到的物体，就会得到奖励；让它们在不去看的前提下避开障碍物，或者观察它们寻找曾被当面藏起来的食物。当然，这些方法无法涵盖猫和狗所能回忆起的一切；实验的目的是一窥它们认知的基本情况。

A few decades’ worth of data have shown that the species do indeed have short-term recall， and they convert certain events and interactions into long-term memories as they sleep and， crucially， dream. “Dreaming is often connected to the reorganization of memory，” says Ádám Miklósi， an ethologist and canine cognition specialist at Hungary’s Eötvös Loránd University. Both dogs and cats display the telltale neurological signatures of REM， short-wave sleep， and other patterns of snoozing that， in human and rat brains， are linked to the sorting of a day’s experiences.

数十年来的数据表明，猫狗确实有短期记忆，而且它们在睡觉时，尤其是做梦时，还会将某些事件和互动转化为长期记忆。匈牙利厄特沃什·罗兰大学的动物行为学者、犬类认知专家亚当·米克洛希说：“做梦通常与记忆的重组有关。”狗和猫都表现出快速眼动睡眠、短波睡眠和其他打盹类型的诸多神经特征；对人类和鼠类来说，这些神经特征意味着大脑在对一天的经历进行整理。

One of the best-documented examples of long-term memories in dogs involves Chaser， a border collie famous for learning the names of more than 1，000 objects in three years. Impressive as that is， however， such semantic feats don’t necessarily mean that Chaser， who died in 2019 at the ripe old age of 15， could remember his puppyhood. That requires so-called episodic memories containing the details of an experience， the who-what-when-where.

关于狗的长期记忆，记录最完善一例是一只名叫追猎者的边境牧羊犬。它以在3年内学会了1000多种物体的名称而闻名。追猎者在2019年时以15岁的高龄去世，尽管它在语义的记忆方面令人惊叹，然而这并不一定意味着它能记起自己的童年。那需要所谓的情景记忆，其中包含每次经历的诸多细节：人、事、时间和地点。

Until recently， scientists thought the canine mind was limited to associative memories： recollections of the relationships between experiences or events， but not the intricacies of the experiences and events themselves. Were that the case， then every time my dearly departed dog Comet climbed into our car the moment my parents started packing it， she wouldn’t have remembered the canoe rides， swims， and roasted marshmallows of past trips. Comet would simply have learned to identify the preparations with fun.

直到最近，科学家们还认为犬类的思维仅限于关联记忆：能回忆起经历之间或事件之间的关系，但无法记忆错综复杂的经历和事件本身。如果是这样的话，当我那已逝的爱犬彗星每每在我父母开始收拾行李时爬进车里，并不是因为她还记得过去旅行中的独木舟漂流、游泳和烤棉花糖。她只是把准备工作和快乐联系在了一起。

But in recent years， research conducted by Miklósi and his colleague Claudia Fugazza has shaken the idea that canines are restricted to such Pavlovian recall. In 2016 they confirmed， by way of an experiment in which they asked dogs to imitate actions modeled by a human minutes earlier， that the pooches did remember specific elements of what they’d experienced. In follow-up experiments， dogs repeated their own actions long after they first performed them， a finding that added an autobiographical layer to their episodic memories. Their thoughts didn’t just contain a jumble of disparate details， but were woven together by a sense of self.