1 00:00:02,240 --> 00:00:04,760 Speaker 1: Welcome to brain Stuff, a production of I Heart Radio, 2 00:00:07,200 --> 00:00:11,320 Speaker 1: Hey brain Stuff Lauren Vogelbaum. Here, most dogs and cats 3 00:00:11,360 --> 00:00:14,480 Speaker 1: are never late for a meal. They know exactly where 4 00:00:14,520 --> 00:00:17,440 Speaker 1: to be at the same time every day. They also 5 00:00:17,480 --> 00:00:20,759 Speaker 1: know their owner's schedules, and, like clockwork, will join you 6 00:00:20,800 --> 00:00:24,080 Speaker 1: in or even anticipate your daily movements, like waiting by 7 00:00:24,079 --> 00:00:26,600 Speaker 1: the door when you usually get home from work, or 8 00:00:26,640 --> 00:00:29,560 Speaker 1: complaining if it's bedtime and you're still up. When you 9 00:00:29,600 --> 00:00:32,040 Speaker 1: witness this behavior, you might assume that your pet has 10 00:00:32,040 --> 00:00:36,000 Speaker 1: a sophisticated understanding of time, But what is time really 11 00:00:36,080 --> 00:00:39,400 Speaker 1: like for a dog or cat. To understand how animals 12 00:00:39,440 --> 00:00:44,680 Speaker 1: perceive time, we first need to understand how humans perceive time. Arguably, 13 00:00:44,760 --> 00:00:47,800 Speaker 1: each person experiences the passing of time in different ways 14 00:00:47,840 --> 00:00:51,519 Speaker 1: at different times. Albert Einstein once explained the principle of 15 00:00:51,560 --> 00:00:54,320 Speaker 1: relativity by saying, when a man sits with a pretty 16 00:00:54,360 --> 00:00:56,600 Speaker 1: girl for an hour, it seems like a minute. But 17 00:00:56,680 --> 00:00:58,400 Speaker 1: let him sit on a hot stove for a minute, 18 00:00:58,520 --> 00:01:02,360 Speaker 1: and it's longer than any hour. That's relativity. Even though 19 00:01:02,400 --> 00:01:05,760 Speaker 1: the experience of time is relative for every individual, all 20 00:01:05,880 --> 00:01:09,679 Speaker 1: humans probably think about time in similar ways. For instance, 21 00:01:09,800 --> 00:01:13,080 Speaker 1: our memories are inextricably tied to how we understand the 22 00:01:13,080 --> 00:01:15,880 Speaker 1: passing of time. Our ability to remember events in a 23 00:01:15,880 --> 00:01:18,840 Speaker 1: particular order plays a large part in our perception of time. 24 00:01:19,440 --> 00:01:22,800 Speaker 1: We're also able to predict things not in a psychic way. 25 00:01:23,160 --> 00:01:26,200 Speaker 1: Each of us makes educated assumptions about certain events in 26 00:01:26,200 --> 00:01:28,840 Speaker 1: the future, even as simple as assuming that the sun 27 00:01:28,840 --> 00:01:33,600 Speaker 1: will come up tomorrow. These abilities have important implications. For instance, 28 00:01:33,720 --> 00:01:36,000 Speaker 1: memory and prediction allow us to have a sense of 29 00:01:36,040 --> 00:01:40,959 Speaker 1: continuity of personal history and self awareness. So do dogs, 30 00:01:41,080 --> 00:01:44,160 Speaker 1: Cats and other animals have the same abilities. If you 31 00:01:44,200 --> 00:01:46,800 Speaker 1: climbed inside of a dog's mind, would you be presented 32 00:01:46,840 --> 00:01:49,520 Speaker 1: with the memory of eating a raw hide bone earlier 33 00:01:49,520 --> 00:01:53,320 Speaker 1: this morning. Research on how dogs and cats in particularly 34 00:01:53,360 --> 00:01:56,360 Speaker 1: perceived time is limited, but we can learn more about 35 00:01:56,400 --> 00:01:58,440 Speaker 1: it when we look at the extensive research that's been 36 00:01:58,480 --> 00:02:01,400 Speaker 1: done with other animals, such as broad birds and primates. 37 00:02:02,120 --> 00:02:06,120 Speaker 1: Animal cognition researcher William Roberts has made some remarkable conclusions 38 00:02:06,120 --> 00:02:10,359 Speaker 1: regarding animal memories and anticipation. He says that animals are 39 00:02:10,480 --> 00:02:14,240 Speaker 1: stuck in time. By this, he means that without the 40 00:02:14,280 --> 00:02:18,320 Speaker 1: sophisticated abilities it takes to perceive time, like truly forming memories, 41 00:02:18,639 --> 00:02:22,320 Speaker 1: animals only live in the present. Roberts thinks animals are 42 00:02:22,320 --> 00:02:25,760 Speaker 1: stuck in time because they can't mentally time travel backward 43 00:02:25,840 --> 00:02:29,400 Speaker 1: or forward. Humans can consciously and willfully think back to 44 00:02:29,440 --> 00:02:34,880 Speaker 1: specific memories and anticipate new events. Animals cannot, too many. 45 00:02:34,919 --> 00:02:38,040 Speaker 1: This might seem like a faulty theory. After all, can't 46 00:02:38,080 --> 00:02:41,520 Speaker 1: we train animals and doesn't this training depend on animals 47 00:02:41,520 --> 00:02:45,360 Speaker 1: own memories? Well, not necessarily, at least not in the 48 00:02:45,400 --> 00:02:49,320 Speaker 1: way we usually think of memories. According to Roberts, animals 49 00:02:49,360 --> 00:02:51,160 Speaker 1: might be trained to do things in the same way 50 00:02:51,160 --> 00:02:54,040 Speaker 1: that young children are trained to do things. According to 51 00:02:54,080 --> 00:02:56,600 Speaker 1: studies with children, by the age of four, kids have 52 00:02:56,720 --> 00:03:00,160 Speaker 1: learned lots of things crawling, walking, but without them toll 53 00:03:00,200 --> 00:03:03,400 Speaker 1: ability to remember where or how they learned them. In 54 00:03:03,440 --> 00:03:06,360 Speaker 1: other words, they don't have the power of episodic memory, 55 00:03:06,760 --> 00:03:09,480 Speaker 1: or the ability to remember particular events in the past. 56 00:03:10,280 --> 00:03:12,480 Speaker 1: A dog can know how to respond to the command 57 00:03:12,560 --> 00:03:15,320 Speaker 1: sit without having a memory of the specific event in 58 00:03:15,360 --> 00:03:18,440 Speaker 1: which it learned that command. And that's not all that's 59 00:03:18,480 --> 00:03:20,560 Speaker 1: at work in a dog or cat's brain to help it, 60 00:03:20,720 --> 00:03:24,840 Speaker 1: for example, impeccably predict the arrival of its owner. Internal 61 00:03:24,880 --> 00:03:29,080 Speaker 1: biological rhythms also play their part. According to Robert's researchers 62 00:03:29,080 --> 00:03:32,359 Speaker 1: have discovered from experiments on pigeons that an internal clock 63 00:03:32,600 --> 00:03:35,240 Speaker 1: allowed the birds to learn where and when food would 64 00:03:35,240 --> 00:03:40,000 Speaker 1: be available. Similarly, our furry friends might use circadian oscillators, 65 00:03:40,320 --> 00:03:43,840 Speaker 1: that is, daily fluctuations of hormones, body temperature, and neural 66 00:03:43,880 --> 00:03:46,840 Speaker 1: activity to know when food is likely to hit the 67 00:03:46,840 --> 00:03:50,480 Speaker 1: bowl or when owners are likely to return home. Instead 68 00:03:50,480 --> 00:03:53,520 Speaker 1: of remembering how much time passes between meals or what 69 00:03:53,760 --> 00:03:57,000 Speaker 1: time meals are given, dogs and cats react to a 70 00:03:57,000 --> 00:03:59,600 Speaker 1: biological state that they reach at a particular time of day, 71 00:04:00,000 --> 00:04:01,920 Speaker 1: and they react the same way at the same time 72 00:04:01,960 --> 00:04:05,600 Speaker 1: every day to the stimulus. So if they can't store 73 00:04:05,640 --> 00:04:08,680 Speaker 1: memories like humans can, can they plan for the future. 74 00:04:09,600 --> 00:04:12,360 Speaker 1: In his work, Roberts argues that time is a human 75 00:04:12,400 --> 00:04:15,800 Speaker 1: construction created to keep track of such things as days 76 00:04:15,840 --> 00:04:20,520 Speaker 1: and significant events. A timekeeping devices from sundials and precise 77 00:04:20,560 --> 00:04:24,560 Speaker 1: clocks to smartphones have revolutionized how humans perceived time, and 78 00:04:24,680 --> 00:04:28,520 Speaker 1: animals don't have the advantage of these tools. Human beings 79 00:04:28,520 --> 00:04:32,000 Speaker 1: have two important abilities to help us understand time. We 80 00:04:32,040 --> 00:04:34,599 Speaker 1: are able to remember a sequence of events, and we 81 00:04:34,640 --> 00:04:38,719 Speaker 1: are able to anticipate future needs or events. Studies show 82 00:04:38,760 --> 00:04:41,960 Speaker 1: that animals may have these abilities, but to a lesser extent. 83 00:04:42,680 --> 00:04:46,680 Speaker 1: Scientists have tested animals working memories and reference memories, that is, 84 00:04:46,760 --> 00:04:50,159 Speaker 1: their short term and long term memory, respectively. They did 85 00:04:50,160 --> 00:04:53,320 Speaker 1: this to see how well the animals recall sequences of events. 86 00:04:54,080 --> 00:04:57,599 Speaker 1: In working memory tests, for example, pigeons or primates have 87 00:04:57,680 --> 00:05:00,719 Speaker 1: been encouraged to remember a sequence well enough to pick 88 00:05:00,839 --> 00:05:02,760 Speaker 1: or pick it in the right order again to get 89 00:05:02,800 --> 00:05:06,280 Speaker 1: a reward. The animals did fairly well at these tasks, 90 00:05:06,320 --> 00:05:09,720 Speaker 1: but their memory faded fast. Roberts thinks that they were 91 00:05:09,720 --> 00:05:13,719 Speaker 1: probably learning going from weakest memory to strongest memory, rather 92 00:05:13,760 --> 00:05:17,920 Speaker 1: than actually learning or remembering a sequence. Other researchers found 93 00:05:17,920 --> 00:05:20,760 Speaker 1: that pigeons and monkeys performed well at reference memory tests, 94 00:05:20,760 --> 00:05:22,880 Speaker 1: in which they needed to remember a sequence after a 95 00:05:22,880 --> 00:05:27,080 Speaker 1: delay between learning and testing, but it took extensive training 96 00:05:27,080 --> 00:05:30,120 Speaker 1: for the animals to learn these sequences, suggesting to Roberts 97 00:05:30,160 --> 00:05:33,240 Speaker 1: that the ability did not come naturally to them. From 98 00:05:33,279 --> 00:05:36,120 Speaker 1: these tests, it seems that animals would perceive time differently 99 00:05:36,160 --> 00:05:39,560 Speaker 1: from humans, who have a relatively reliable and sophisticated memory 100 00:05:39,600 --> 00:05:42,920 Speaker 1: of a sequence of events. In addition, animals don't seem 101 00:05:42,960 --> 00:05:46,160 Speaker 1: to anticipate future needs and rewards very well, suggesting to 102 00:05:46,240 --> 00:05:48,839 Speaker 1: researchers that they don't have a concept of the future. 103 00:05:49,720 --> 00:05:53,080 Speaker 1: For instance, when given the choice, pigeons and rats shows 104 00:05:53,120 --> 00:05:57,320 Speaker 1: a smaller immediate reward over a larger future reward. In 105 00:05:57,360 --> 00:06:00,880 Speaker 1: one test, researchers presented primates with a choice between one 106 00:06:00,920 --> 00:06:06,880 Speaker 1: banana and two bananas. Understandably, they chose to bananas consistently. However, 107 00:06:07,279 --> 00:06:10,440 Speaker 1: as the supply of the two choices got larger, they 108 00:06:10,440 --> 00:06:13,720 Speaker 1: started showing less of a preference. They weren't hungry enough 109 00:06:13,720 --> 00:06:16,320 Speaker 1: at that moment to eat ten bananas, so they chose 110 00:06:16,360 --> 00:06:19,960 Speaker 1: five bananas about half the time. Roberts concludes from these 111 00:06:20,000 --> 00:06:23,799 Speaker 1: experiments that these animals sought to satisfy immediate hunger needs 112 00:06:23,960 --> 00:06:28,120 Speaker 1: and weren't planning for future hunger. This is very unlike humans, 113 00:06:28,200 --> 00:06:31,520 Speaker 1: who often use reason and forethought to anticipate future needs, 114 00:06:31,640 --> 00:06:33,720 Speaker 1: from packing a snack and a drink for later to 115 00:06:33,920 --> 00:06:37,479 Speaker 1: investing in a retirement plan. So what about squirrels and 116 00:06:37,560 --> 00:06:40,520 Speaker 1: other animals that hoard food for the impending winter months. 117 00:06:41,279 --> 00:06:44,920 Speaker 1: That behavior seems to imply that the animals anticipate future needs, 118 00:06:45,560 --> 00:06:49,200 Speaker 1: but maybe that's not it studies have found that animals 119 00:06:49,320 --> 00:06:52,800 Speaker 1: don't stop hoarding even when their supplies disappear over and 120 00:06:52,880 --> 00:06:56,560 Speaker 1: over again. This could mean that the animals don't understand 121 00:06:56,720 --> 00:06:59,600 Speaker 1: why they hoard, what it means for their future, or 122 00:07:00,040 --> 00:07:02,800 Speaker 1: in what the future is. They simply do it out 123 00:07:02,800 --> 00:07:06,920 Speaker 1: of instinct. Humans, on the other hand, understand their preparations 124 00:07:07,120 --> 00:07:10,080 Speaker 1: and will quickly change strategies when their plans go awry. 125 00:07:11,000 --> 00:07:14,960 Speaker 1: If animals are stuck in time, as Robert suggests, this 126 00:07:15,000 --> 00:07:19,480 Speaker 1: could mean that understanding time is uniquely and fundamentally human. 127 00:07:25,520 --> 00:07:27,920 Speaker 1: Today's episode was written by Jane McGrath and produced by 128 00:07:27,920 --> 00:07:30,120 Speaker 1: Tyler Clang. For more on this a lot of other 129 00:07:30,160 --> 00:07:33,360 Speaker 1: curious topics, visit how stuff works dot com. Brain Stuff 130 00:07:33,400 --> 00:07:35,920 Speaker 1: is production of iHeart Radio or more podcasts. My Heart 131 00:07:36,000 --> 00:07:39,040 Speaker 1: Radio visit the iHeart Radio app, Apple Podcasts, or wherever 132 00:07:39,080 --> 00:07:40,480 Speaker 1: you listen to your favorite shows.