1 00:00:02,040 --> 00:00:07,160 Speaker 1: Welcome to brain stuff. From how stuff Works, Hey, brain Stuff, 2 00:00:07,200 --> 00:00:10,200 Speaker 1: Loring Vogel Bomb. Here the human brain is a mysterious 3 00:00:10,200 --> 00:00:13,280 Speaker 1: little ball of gray matter. After all these years, researchers 4 00:00:13,280 --> 00:00:15,840 Speaker 1: are still baffled by many aspects of how and why 5 00:00:15,880 --> 00:00:19,200 Speaker 1: it operates like it does. Scientists have been performing sleep 6 00:00:19,200 --> 00:00:21,760 Speaker 1: and dream studies for decades now, and we still aren't 7 00:00:21,800 --> 00:00:24,360 Speaker 1: a hundred percent sure about the function of sleep or 8 00:00:24,400 --> 00:00:27,479 Speaker 1: exactly how and why we dream. We do know that 9 00:00:27,520 --> 00:00:30,320 Speaker 1: our dream cycle is typically most abundant and best remembered 10 00:00:30,400 --> 00:00:32,760 Speaker 1: during the R E M stage of sleep. It's also 11 00:00:32,760 --> 00:00:36,280 Speaker 1: pretty commonly accepted among the scientific community that we all dream, 12 00:00:36,400 --> 00:00:38,879 Speaker 1: though the frequency in which dreams are remembered varies from 13 00:00:38,920 --> 00:00:42,239 Speaker 1: person to person. The question of weather dreams actually have 14 00:00:42,400 --> 00:00:46,839 Speaker 1: a physiological, biological, or psychological function has yet to be answered, 15 00:00:47,080 --> 00:00:50,440 Speaker 1: but that hasn't stopped scientists from researching and speculating. There 16 00:00:50,440 --> 00:00:53,600 Speaker 1: are several theories as to why we dream. One is 17 00:00:53,640 --> 00:00:56,240 Speaker 1: that dreams work hand in hand with sleep to help 18 00:00:56,280 --> 00:00:59,320 Speaker 1: the brain sort through everything it collects. During the waking hours. 19 00:00:59,720 --> 00:01:02,400 Speaker 1: Your brain is met with hundreds of thousands, if not millions, 20 00:01:02,400 --> 00:01:05,560 Speaker 1: of inputs every day. Some are minor sensory details like 21 00:01:05,600 --> 00:01:07,959 Speaker 1: the color of a passing car, while others are far 22 00:01:08,040 --> 00:01:10,600 Speaker 1: more complex, like the big presentation you're putting together for 23 00:01:10,640 --> 00:01:13,560 Speaker 1: your job or class. During sleep, the brain works to 24 00:01:13,600 --> 00:01:15,959 Speaker 1: plow through all of this information to decide what to 25 00:01:15,959 --> 00:01:18,920 Speaker 1: hang onto and what to forget. Some researchers think that 26 00:01:19,000 --> 00:01:21,760 Speaker 1: dreams play a role in this process. It's not just 27 00:01:21,800 --> 00:01:24,000 Speaker 1: a stab in the dark, though. There is some research 28 00:01:24,040 --> 00:01:26,319 Speaker 1: to back up the ideas that dreams are tied to 29 00:01:26,400 --> 00:01:29,800 Speaker 1: how we form memories. Studies indicate that as we're learning 30 00:01:29,840 --> 00:01:32,640 Speaker 1: new things in our waking hours, our dreams increase while 31 00:01:32,640 --> 00:01:35,440 Speaker 1: we sleep. Participants in a dream study who are taking 32 00:01:35,480 --> 00:01:38,119 Speaker 1: a language course showed more dream activity than those who 33 00:01:38,160 --> 00:01:40,880 Speaker 1: were not. In light of such studies, the idea that 34 00:01:40,920 --> 00:01:43,240 Speaker 1: we use our dreams to sort through and convert short 35 00:01:43,360 --> 00:01:46,320 Speaker 1: term memories into long term memories has gained some momentum 36 00:01:46,319 --> 00:01:50,560 Speaker 1: in recent years. Another theory is that dreams typically reflect 37 00:01:50,560 --> 00:01:53,520 Speaker 1: our emotions during the day, our brains are working hard 38 00:01:53,600 --> 00:01:56,800 Speaker 1: to make connections to achieve certain functions. When posed with 39 00:01:56,840 --> 00:02:00,120 Speaker 1: a tough math problem, your brain is incredibly focused on 40 00:02:00,120 --> 00:02:03,240 Speaker 1: one thing, and the brain doesn't only serve mental functions. 41 00:02:03,640 --> 00:02:05,640 Speaker 1: If you're building a bench, your brain is focused on 42 00:02:05,720 --> 00:02:08,399 Speaker 1: making the right connections to allow your hands to work 43 00:02:08,400 --> 00:02:10,640 Speaker 1: in concert with the saw in the wood to make 44 00:02:10,680 --> 00:02:13,600 Speaker 1: an exact cut. The same goes for simple tasks like 45 00:02:13,680 --> 00:02:16,160 Speaker 1: hitting a nail with a hammer. Have you ever lost 46 00:02:16,200 --> 00:02:18,600 Speaker 1: focus and smashed your finger because your mind was elsewhere. 47 00:02:19,320 --> 00:02:23,080 Speaker 1: Some researchers have proposed that while sleeping, everything slows down. 48 00:02:23,520 --> 00:02:26,320 Speaker 1: We aren't required to focus on anything during sleep, so 49 00:02:26,360 --> 00:02:29,679 Speaker 1: our brains make very loose connections. It's during sleep that 50 00:02:29,720 --> 00:02:31,480 Speaker 1: the emotions of the day battle it out in our 51 00:02:31,520 --> 00:02:34,120 Speaker 1: dream cycle. If something is weighing heavily on your mind 52 00:02:34,200 --> 00:02:36,320 Speaker 1: during the day, chances are you might dream about it, 53 00:02:36,320 --> 00:02:39,840 Speaker 1: either specifically or through some kind of imagery. For instance, 54 00:02:39,840 --> 00:02:42,600 Speaker 1: if you're worried about losing your job due to company downsizing, 55 00:02:42,919 --> 00:02:44,919 Speaker 1: you may dream that you're a shrunken person living in 56 00:02:44,960 --> 00:02:47,639 Speaker 1: a world of giants, or that you're wandering aimlessly through 57 00:02:47,639 --> 00:02:51,720 Speaker 1: a great desert abyss. There's also a theory, definitely the 58 00:02:51,800 --> 00:02:54,480 Speaker 1: least intriguing of the bunch, that dreams don't really serve 59 00:02:54,520 --> 00:02:57,000 Speaker 1: any function at all, that they're just a pointless byproduct 60 00:02:57,040 --> 00:03:00,040 Speaker 1: of the brain firing wallaby slumber. We know that a 61 00:03:00,120 --> 00:03:02,440 Speaker 1: rear portion of our brain gets pretty active during r 62 00:03:02,639 --> 00:03:05,480 Speaker 1: M sleep, when most dreaming occurs. Some think that it's 63 00:03:05,520 --> 00:03:07,600 Speaker 1: just the brain winding down for the night, and that 64 00:03:07,760 --> 00:03:11,040 Speaker 1: dreams are random and meaningless firings that we don't have 65 00:03:11,120 --> 00:03:14,079 Speaker 1: when we're awake at the end of the day. As 66 00:03:14,120 --> 00:03:16,280 Speaker 1: long as the brain remains such a mystery, we probably 67 00:03:16,320 --> 00:03:19,399 Speaker 1: won't be able to pinpoint with absolute certainty exactly why 68 00:03:19,440 --> 00:03:27,560 Speaker 1: we dream. Today's episode was written by Charles W. Bryant 69 00:03:27,600 --> 00:03:30,000 Speaker 1: and produced by Tristan McNeil. For more on this and 70 00:03:30,160 --> 00:03:32,800 Speaker 1: lots of other dreamy topics, visit our home planet, how 71 00:03:32,840 --> 00:03:45,320 Speaker 1: Stuff Works dot com.