1 00:00:02,080 --> 00:00:04,560 Speaker 1: Welcome to brain Stuff, a production of I Heart Radio, 2 00:00:07,120 --> 00:00:11,200 Speaker 1: Hey brain Stuff Lauren Voglebon here. What if you lost 3 00:00:11,360 --> 00:00:14,640 Speaker 1: all sense of self? You know you have a body, 4 00:00:14,720 --> 00:00:17,040 Speaker 1: You can see it there beneath you, but you can't 5 00:00:17,360 --> 00:00:21,479 Speaker 1: feel it. You aren't paralyzed per se, just unaware that 6 00:00:21,560 --> 00:00:24,360 Speaker 1: your body is moving unless you're looking at it, and 7 00:00:24,480 --> 00:00:28,320 Speaker 1: then only under intense concentration and your own watchful eye 8 00:00:28,560 --> 00:00:31,880 Speaker 1: can you reach out towards something and grasp it. But 9 00:00:31,920 --> 00:00:34,760 Speaker 1: if you don't look or pay close attention, the object 10 00:00:34,840 --> 00:00:37,160 Speaker 1: will either slip out of your hand because you're holding 11 00:00:37,159 --> 00:00:40,080 Speaker 1: it too loosely, or you'll squeeze up with such intensity 12 00:00:40,120 --> 00:00:43,680 Speaker 1: that your knuckles go pale. The ability to feel our 13 00:00:43,720 --> 00:00:47,839 Speaker 1: bodies to unconsciously sense them, is known as propri exception. 14 00:00:48,520 --> 00:00:50,839 Speaker 1: It's sometimes referred to as the secret sense or the 15 00:00:50,920 --> 00:00:55,200 Speaker 1: sixth sense. Unlike our five senses sight, sound, smell, touch, 16 00:00:55,240 --> 00:00:58,120 Speaker 1: and taste, which are obvious to us, the sense of 17 00:00:58,160 --> 00:01:02,520 Speaker 1: controlling and owning our own bodies is hidden. We're usually 18 00:01:02,600 --> 00:01:07,480 Speaker 1: unaware of the sensation unless something goes wrong. Appropriate reception 19 00:01:07,600 --> 00:01:10,000 Speaker 1: is the awareness of where your body is in space. 20 00:01:10,720 --> 00:01:14,279 Speaker 1: For example, while walking, sensor receptors on your skin joints 21 00:01:14,280 --> 00:01:16,760 Speaker 1: and muscles send signals to the brain that make you 22 00:01:16,840 --> 00:01:19,240 Speaker 1: aware of your right foot being in front of you, 23 00:01:19,440 --> 00:01:21,400 Speaker 1: even if your eyes are closed or if you're not 24 00:01:21,440 --> 00:01:25,200 Speaker 1: looking down at your feet. Appropriate reception is sometimes used 25 00:01:25,200 --> 00:01:28,840 Speaker 1: interchangeably with the teram at caynesthesia, but they're actually very 26 00:01:28,880 --> 00:01:33,560 Speaker 1: different perceptions. Canesthesia is the sense of movement of our muscles, tendons, 27 00:01:33,560 --> 00:01:37,480 Speaker 1: and joints. For example, while walking, the brain picks up 28 00:01:37,480 --> 00:01:40,440 Speaker 1: on the sensations of force, velocity, and the propelling of 29 00:01:40,480 --> 00:01:43,959 Speaker 1: your body forward from the inner ear, which oversees balance 30 00:01:44,000 --> 00:01:47,880 Speaker 1: orientation to sense movement. You're aware of the sensation of 31 00:01:47,880 --> 00:01:50,480 Speaker 1: your body being in motion even if you're focused on 32 00:01:50,520 --> 00:01:53,840 Speaker 1: the scenery around you and not on your body. Appropriate 33 00:01:53,880 --> 00:01:57,560 Speaker 1: reception in kinnesthesia, while different work together to make us 34 00:01:57,600 --> 00:02:01,280 Speaker 1: cognizant of our own bodies in space. Combined, they can 35 00:02:01,320 --> 00:02:04,720 Speaker 1: be considered the sixth sense, or respectively as the sixth 36 00:02:04,760 --> 00:02:08,840 Speaker 1: and seventh senses. Appropriate reception plays a vital role in 37 00:02:08,919 --> 00:02:12,440 Speaker 1: balance and orientation, enabling us to stand upright or walk, 38 00:02:12,840 --> 00:02:16,880 Speaker 1: especially on uneven surfaces. It allows golfers to perfect their 39 00:02:16,919 --> 00:02:19,960 Speaker 1: swings and dancers to move with the grace of a butterfly. 40 00:02:20,919 --> 00:02:23,920 Speaker 1: We spoke with Dr Jack Shelley trim Blay, Professor and 41 00:02:24,040 --> 00:02:26,320 Speaker 1: Chair of the Department of Psychology at the University of 42 00:02:26,320 --> 00:02:30,320 Speaker 1: South Alabama. He said, when it functions normally, we take 43 00:02:30,360 --> 00:02:33,600 Speaker 1: it for granted. One of the most fascinating things aboutppropriate 44 00:02:33,639 --> 00:02:38,560 Speaker 1: reception is when it fails. Sometimes people experience a temporary 45 00:02:38,639 --> 00:02:41,760 Speaker 1: impairment of the sixth sense. To think of someone who 46 00:02:41,800 --> 00:02:45,839 Speaker 1: is intoxicated with alcohol with their vestibular system impaired, They 47 00:02:45,880 --> 00:02:48,960 Speaker 1: have a sense appropriate exception loss and thus may weave 48 00:02:49,000 --> 00:02:51,840 Speaker 1: a bit when they walk or bump into stationary objects, 49 00:02:51,960 --> 00:02:54,919 Speaker 1: or lose their balance and fall. But a more precise 50 00:02:54,960 --> 00:02:58,080 Speaker 1: example is when your arm falls asleep and as a result, 51 00:02:58,160 --> 00:03:01,120 Speaker 1: it feels numb and it is difficult to move. People 52 00:03:01,160 --> 00:03:05,160 Speaker 1: appropriate reception disorder or impairment may experience at times the 53 00:03:05,240 --> 00:03:09,119 Speaker 1: sensation of being off balance in coordination or clumsiness, being 54 00:03:09,120 --> 00:03:12,320 Speaker 1: more prone to falls, and or being unable to recognize 55 00:03:12,320 --> 00:03:15,000 Speaker 1: their own strength, such as pressing down too hard with 56 00:03:15,040 --> 00:03:18,919 Speaker 1: a pencil when writing. Sometimes injuries or disorders can cause 57 00:03:18,960 --> 00:03:22,959 Speaker 1: a permanent loss approprise reception, such as brain injuries, arthritis, stroke, 58 00:03:23,120 --> 00:03:27,520 Speaker 1: peripheral neuropathy, alis, or leu Garreg's disease and Parkinson's disease. 59 00:03:28,360 --> 00:03:31,760 Speaker 1: But there are two unusual conditions that are related to 60 00:03:31,720 --> 00:03:37,240 Speaker 1: approprise reception. First, alien limb syndrome, also called alien hand syndrome. 61 00:03:37,880 --> 00:03:40,680 Speaker 1: This neurological disorder can affect the hand or the leg 62 00:03:40,800 --> 00:03:44,760 Speaker 1: and causes the limb to act independently or involuntarily of 63 00:03:44,800 --> 00:03:49,080 Speaker 1: the person's desires. British neurologist Oliver Sacks describes in a 64 00:03:49,160 --> 00:03:51,880 Speaker 1: chapter of his book The Man who mistook his wife 65 00:03:51,960 --> 00:03:54,320 Speaker 1: for a hat a patient who awoke to find what 66 00:03:54,360 --> 00:03:58,240 Speaker 1: he believed to be a cadaver's leg in bed with him. Disgusted, 67 00:03:58,320 --> 00:04:00,760 Speaker 1: the man pushed the leg off the bed, only to 68 00:04:00,840 --> 00:04:04,200 Speaker 1: drop onto the floor after it. He then became distraught 69 00:04:04,280 --> 00:04:07,960 Speaker 1: when he realized that the strange leg was attached to him. 70 00:04:08,160 --> 00:04:11,040 Speaker 1: Then there's phantom limb syndrome, which is a condition that 71 00:04:11,080 --> 00:04:15,440 Speaker 1: can affect amputees. Phantom limb syndrome occurs when someone feels 72 00:04:15,440 --> 00:04:18,800 Speaker 1: sensations in the limb that has been removed. For some 73 00:04:19,000 --> 00:04:22,240 Speaker 1: it can be a painful experience. One man described the 74 00:04:22,279 --> 00:04:25,400 Speaker 1: sensation in his phantom hand as being a constant state 75 00:04:25,400 --> 00:04:28,840 Speaker 1: of tight clenching that neither pain killers nor hypnosis could 76 00:04:28,839 --> 00:04:32,760 Speaker 1: ease Researchers suggested that the signals going from his muscles 77 00:04:32,760 --> 00:04:35,279 Speaker 1: to his brain were not getting the feedback to stop 78 00:04:35,320 --> 00:04:39,720 Speaker 1: clenching because the eyes weren't seeing the hand. They successfully 79 00:04:39,760 --> 00:04:42,560 Speaker 1: showed that by placing the man's intact arm into a 80 00:04:42,600 --> 00:04:46,479 Speaker 1: mirror box, the man could visually resurrect the phantom limb 81 00:04:46,800 --> 00:04:50,440 Speaker 1: and convince his brain to stop sending clenching signals. As 82 00:04:50,440 --> 00:04:54,200 Speaker 1: a result, he found relief from the unsettling phantom hand sensation. 83 00:04:55,000 --> 00:04:58,560 Speaker 1: In rare cases, people can lose all sense appropriate reception. 84 00:04:59,279 --> 00:05:02,160 Speaker 1: In his book of Case Studies, Sachs described the case 85 00:05:02,200 --> 00:05:05,440 Speaker 1: of Christina. The twenty seven year old woman appeared to 86 00:05:05,480 --> 00:05:08,359 Speaker 1: have a reaction to medication in which the sensory roots 87 00:05:08,360 --> 00:05:12,719 Speaker 1: of her spinal and cranial nerves became inflamed. Afterward, she 88 00:05:12,839 --> 00:05:15,920 Speaker 1: suddenly lost the ability to study herself while standing or 89 00:05:16,000 --> 00:05:20,400 Speaker 1: holding objects in her hands. Within days, if not hours, 90 00:05:20,440 --> 00:05:23,880 Speaker 1: she became quote floppy as a rag doll, unable to 91 00:05:23,960 --> 00:05:27,040 Speaker 1: even sit up. Christina never regained her sense of self, 92 00:05:27,200 --> 00:05:31,400 Speaker 1: but gradually, through rehabilitation and fierce concentration on her movements, 93 00:05:31,440 --> 00:05:34,719 Speaker 1: she was able to sit up and walk again. Another 94 00:05:34,760 --> 00:05:38,440 Speaker 1: case of total loss appropriate reception was detailed in neurologist J. 95 00:05:38,640 --> 00:05:43,040 Speaker 1: Cole's book Pride and a Daily Marathon. The book focuses 96 00:05:43,120 --> 00:05:46,520 Speaker 1: on Ian Waterman, who, at the age of nineteen, lost 97 00:05:46,560 --> 00:05:48,760 Speaker 1: all sense of his body from his neck down after 98 00:05:48,800 --> 00:05:52,400 Speaker 1: a brief illness. A waterman described feeling as if he 99 00:05:52,440 --> 00:05:56,240 Speaker 1: were just ahead floating on a pillow. Like Christina, he 100 00:05:56,320 --> 00:05:58,880 Speaker 1: had not recovered at the time of publication, but with 101 00:05:59,000 --> 00:06:01,719 Speaker 1: much therapy and her nation, he was able to sit 102 00:06:01,800 --> 00:06:06,680 Speaker 1: up and walk again. While frightening to imagine. Shelley Tremblay 103 00:06:06,720 --> 00:06:09,359 Speaker 1: assures us that the total loss of appropriate reception is 104 00:06:09,480 --> 00:06:12,760 Speaker 1: quite rare, and that the impairment of the sense is treatable. 105 00:06:13,160 --> 00:06:15,800 Speaker 1: The first line of defense when treating propose reception issues 106 00:06:15,960 --> 00:06:19,640 Speaker 1: is to determine the underlying cause and treat that Activities 107 00:06:19,680 --> 00:06:22,599 Speaker 1: that focus on mobility, muscle strength, and sense of balance 108 00:06:22,680 --> 00:06:26,919 Speaker 1: may also help sharpen propose reception, according to study published 109 00:06:26,920 --> 00:06:29,800 Speaker 1: in the Journal of Athletic Training. Some of these therapies 110 00:06:29,800 --> 00:06:35,040 Speaker 1: include physical therapies, matasensory stimulation, balance exercises, tai chi, and yoga. 111 00:06:35,839 --> 00:06:38,800 Speaker 1: The bottom line is that although our sixth sense may 112 00:06:38,839 --> 00:06:42,320 Speaker 1: be hidden from us, approprise. Reception plays a critical role 113 00:06:42,440 --> 00:06:44,640 Speaker 1: in giving us a sense of ownership of our bodies. 114 00:06:45,240 --> 00:06:47,919 Speaker 1: We may take it for granted, but without it would 115 00:06:47,960 --> 00:06:58,400 Speaker 1: be essentially disembodied. Today's episode was written by Jennifer Walker 116 00:06:58,480 --> 00:07:00,960 Speaker 1: Journey and produced by Tyler Client Firm. More on this 117 00:07:01,040 --> 00:07:03,400 Speaker 1: and lots of other curious topics, visit how stuff works 118 00:07:03,400 --> 00:07:06,039 Speaker 1: dot com. Brain Stuff is a production of I Heart Radio. 119 00:07:06,360 --> 00:07:08,480 Speaker 1: Or more podcasts from my heart Radio visit the iHeart 120 00:07:08,520 --> 00:07:11,080 Speaker 1: Radio app, Apple Podcasts, or wherever you listen to your 121 00:07:11,120 --> 00:07:11,800 Speaker 1: favorite shows.