WEBVTT - How Do You Sense Your Own Body -- And How Can That Go Wrong? 0:00:02.080 --> 0:00:04.560 Welcome to brain Stuff, a production of I Heart Radio, 0:00:07.120 --> 0:00:11.200 Hey brain Stuff Lauren Voglebon here. What if you lost 0:00:11.360 --> 0:00:14.640 all sense of self? You know you have a body, 0:00:14.720 --> 0:00:17.040 You can see it there beneath you, but you can't 0:00:17.360 --> 0:00:21.479 feel it. You aren't paralyzed per se, just unaware that 0:00:21.560 --> 0:00:24.360 your body is moving unless you're looking at it, and 0:00:24.480 --> 0:00:28.320 then only under intense concentration and your own watchful eye 0:00:28.560 --> 0:00:31.880 can you reach out towards something and grasp it. But 0:00:31.920 --> 0:00:34.760 if you don't look or pay close attention, the object 0:00:34.840 --> 0:00:37.160 will either slip out of your hand because you're holding 0:00:37.159 --> 0:00:40.080 it too loosely, or you'll squeeze up with such intensity 0:00:40.120 --> 0:00:43.680 that your knuckles go pale. The ability to feel our 0:00:43.720 --> 0:00:47.839 bodies to unconsciously sense them, is known as propri exception. 0:00:48.520 --> 0:00:50.839 It's sometimes referred to as the secret sense or the 0:00:50.920 --> 0:00:55.200 sixth sense. Unlike our five senses sight, sound, smell, touch, 0:00:55.240 --> 0:00:58.120 and taste, which are obvious to us, the sense of 0:00:58.160 --> 0:01:02.520 controlling and owning our own bodies is hidden. We're usually 0:01:02.600 --> 0:01:07.480 unaware of the sensation unless something goes wrong. Appropriate reception 0:01:07.600 --> 0:01:10.000 is the awareness of where your body is in space. 0:01:10.720 --> 0:01:14.279 For example, while walking, sensor receptors on your skin joints 0:01:14.280 --> 0:01:16.760 and muscles send signals to the brain that make you 0:01:16.840 --> 0:01:19.240 aware of your right foot being in front of you, 0:01:19.440 --> 0:01:21.400 even if your eyes are closed or if you're not 0:01:21.440 --> 0:01:25.200 looking down at your feet. Appropriate reception is sometimes used 0:01:25.200 --> 0:01:28.840 interchangeably with the teram at caynesthesia, but they're actually very 0:01:28.880 --> 0:01:33.560 different perceptions. Canesthesia is the sense of movement of our muscles, tendons, 0:01:33.560 --> 0:01:37.480 and joints. For example, while walking, the brain picks up 0:01:37.480 --> 0:01:40.440 on the sensations of force, velocity, and the propelling of 0:01:40.480 --> 0:01:43.959 your body forward from the inner ear, which oversees balance 0:01:44.000 --> 0:01:47.880 orientation to sense movement. You're aware of the sensation of 0:01:47.880 --> 0:01:50.480 your body being in motion even if you're focused on 0:01:50.520 --> 0:01:53.840 the scenery around you and not on your body. Appropriate 0:01:53.880 --> 0:01:57.560 reception in kinnesthesia, while different work together to make us 0:01:57.600 --> 0:02:01.280 cognizant of our own bodies in space. Combined, they can 0:02:01.320 --> 0:02:04.720 be considered the sixth sense, or respectively as the sixth 0:02:04.760 --> 0:02:08.840 and seventh senses. Appropriate reception plays a vital role in 0:02:08.919 --> 0:02:12.440 balance and orientation, enabling us to stand upright or walk, 0:02:12.840 --> 0:02:16.880 especially on uneven surfaces. It allows golfers to perfect their 0:02:16.919 --> 0:02:19.960 swings and dancers to move with the grace of a butterfly. 0:02:20.919 --> 0:02:23.920 We spoke with Dr Jack Shelley trim Blay, Professor and 0:02:24.040 --> 0:02:26.320 Chair of the Department of Psychology at the University of 0:02:26.320 --> 0:02:30.320 South Alabama. He said, when it functions normally, we take 0:02:30.360 --> 0:02:33.600 it for granted. One of the most fascinating things aboutppropriate 0:02:33.639 --> 0:02:38.560 reception is when it fails. Sometimes people experience a temporary 0:02:38.639 --> 0:02:41.760 impairment of the sixth sense. To think of someone who 0:02:41.800 --> 0:02:45.839 is intoxicated with alcohol with their vestibular system impaired, They 0:02:45.880 --> 0:02:48.960 have a sense appropriate exception loss and thus may weave 0:02:49.000 --> 0:02:51.840 a bit when they walk or bump into stationary objects, 0:02:51.960 --> 0:02:54.919 or lose their balance and fall. But a more precise 0:02:54.960 --> 0:02:58.080 example is when your arm falls asleep and as a result, 0:02:58.160 --> 0:03:01.120 it feels numb and it is difficult to move. People 0:03:01.160 --> 0:03:05.160 appropriate reception disorder or impairment may experience at times the 0:03:05.240 --> 0:03:09.119 sensation of being off balance in coordination or clumsiness, being 0:03:09.120 --> 0:03:12.320 more prone to falls, and or being unable to recognize 0:03:12.320 --> 0:03:15.000 their own strength, such as pressing down too hard with 0:03:15.040 --> 0:03:18.919 a pencil when writing. Sometimes injuries or disorders can cause 0:03:18.960 --> 0:03:22.959 a permanent loss approprise reception, such as brain injuries, arthritis, stroke, 0:03:23.120 --> 0:03:27.520 peripheral neuropathy, alis, or leu Garreg's disease and Parkinson's disease. 0:03:28.360 --> 0:03:31.760 But there are two unusual conditions that are related to 0:03:31.720 --> 0:03:37.240 approprise reception. First, alien limb syndrome, also called alien hand syndrome. 0:03:37.880 --> 0:03:40.680 This neurological disorder can affect the hand or the leg 0:03:40.800 --> 0:03:44.760 and causes the limb to act independently or involuntarily of 0:03:44.800 --> 0:03:49.080 the person's desires. British neurologist Oliver Sacks describes in a 0:03:49.160 --> 0:03:51.880 chapter of his book The Man who mistook his wife 0:03:51.960 --> 0:03:54.320 for a hat a patient who awoke to find what 0:03:54.360 --> 0:03:58.240 he believed to be a cadaver's leg in bed with him. Disgusted, 0:03:58.320 --> 0:04:00.760 the man pushed the leg off the bed, only to 0:04:00.840 --> 0:04:04.200 drop onto the floor after it. He then became distraught 0:04:04.280 --> 0:04:07.960 when he realized that the strange leg was attached to him. 0:04:08.160 --> 0:04:11.040 Then there's phantom limb syndrome, which is a condition that 0:04:11.080 --> 0:04:15.440 can affect amputees. Phantom limb syndrome occurs when someone feels 0:04:15.440 --> 0:04:18.800 sensations in the limb that has been removed. For some 0:04:19.000 --> 0:04:22.240 it can be a painful experience. One man described the 0:04:22.279 --> 0:04:25.400 sensation in his phantom hand as being a constant state 0:04:25.400 --> 0:04:28.840 of tight clenching that neither pain killers nor hypnosis could 0:04:28.839 --> 0:04:32.760 ease Researchers suggested that the signals going from his muscles 0:04:32.760 --> 0:04:35.279 to his brain were not getting the feedback to stop 0:04:35.320 --> 0:04:39.720 clenching because the eyes weren't seeing the hand. They successfully 0:04:39.760 --> 0:04:42.560 showed that by placing the man's intact arm into a 0:04:42.600 --> 0:04:46.479 mirror box, the man could visually resurrect the phantom limb 0:04:46.800 --> 0:04:50.440 and convince his brain to stop sending clenching signals. As 0:04:50.440 --> 0:04:54.200 a result, he found relief from the unsettling phantom hand sensation. 0:04:55.000 --> 0:04:58.560 In rare cases, people can lose all sense appropriate reception. 0:04:59.279 --> 0:05:02.160 In his book of Case Studies, Sachs described the case 0:05:02.200 --> 0:05:05.440 of Christina. The twenty seven year old woman appeared to 0:05:05.480 --> 0:05:08.359 have a reaction to medication in which the sensory roots 0:05:08.360 --> 0:05:12.719 of her spinal and cranial nerves became inflamed. Afterward, she 0:05:12.839 --> 0:05:15.920 suddenly lost the ability to study herself while standing or 0:05:16.000 --> 0:05:20.400 holding objects in her hands. Within days, if not hours, 0:05:20.440 --> 0:05:23.880 she became quote floppy as a rag doll, unable to 0:05:23.960 --> 0:05:27.040 even sit up. Christina never regained her sense of self, 0:05:27.200 --> 0:05:31.400 but gradually, through rehabilitation and fierce concentration on her movements, 0:05:31.440 --> 0:05:34.719 she was able to sit up and walk again. Another 0:05:34.760 --> 0:05:38.440 case of total loss appropriate reception was detailed in neurologist J. 0:05:38.640 --> 0:05:43.040 Cole's book Pride and a Daily Marathon. The book focuses 0:05:43.120 --> 0:05:46.520 on Ian Waterman, who, at the age of nineteen, lost 0:05:46.560 --> 0:05:48.760 all sense of his body from his neck down after 0:05:48.800 --> 0:05:52.400 a brief illness. A waterman described feeling as if he 0:05:52.440 --> 0:05:56.240 were just ahead floating on a pillow. Like Christina, he 0:05:56.320 --> 0:05:58.880 had not recovered at the time of publication, but with 0:05:59.000 --> 0:06:01.719 much therapy and her nation, he was able to sit 0:06:01.800 --> 0:06:06.680 up and walk again. While frightening to imagine. Shelley Tremblay 0:06:06.720 --> 0:06:09.359 assures us that the total loss of appropriate reception is 0:06:09.480 --> 0:06:12.760 quite rare, and that the impairment of the sense is treatable. 0:06:13.160 --> 0:06:15.800 The first line of defense when treating propose reception issues 0:06:15.960 --> 0:06:19.640 is to determine the underlying cause and treat that Activities 0:06:19.680 --> 0:06:22.599 that focus on mobility, muscle strength, and sense of balance 0:06:22.680 --> 0:06:26.919 may also help sharpen propose reception, according to study published 0:06:26.920 --> 0:06:29.800 in the Journal of Athletic Training. Some of these therapies 0:06:29.800 --> 0:06:35.040 include physical therapies, matasensory stimulation, balance exercises, tai chi, and yoga. 0:06:35.839 --> 0:06:38.800 The bottom line is that although our sixth sense may 0:06:38.839 --> 0:06:42.320 be hidden from us, approprise. Reception plays a critical role 0:06:42.440 --> 0:06:44.640 in giving us a sense of ownership of our bodies. 0:06:45.240 --> 0:06:47.919 We may take it for granted, but without it would 0:06:47.960 --> 0:06:58.400 be essentially disembodied. Today's episode was written by Jennifer Walker 0:06:58.480 --> 0:07:00.960 Journey and produced by Tyler Client Firm. More on this 0:07:01.040 --> 0:07:03.400 and lots of other curious topics, visit how stuff works 0:07:03.400 --> 0:07:06.039 dot com. Brain Stuff is a production of I Heart Radio. 0:07:06.360 --> 0:07:08.480 Or more podcasts from my heart Radio visit the iHeart 0:07:08.520 --> 0:07:11.080 Radio app, Apple Podcasts, or wherever you listen to your 0:07:11.120 --> 0:07:11.800 favorite shows.