1 00:00:07,155 --> 00:00:11,650 Long before Descartes famously declared, "I think, therefore I am," 2 00:00:11,650 --> 00:00:13,251 and long after that, 3 00:00:13,251 --> 00:00:15,282 scientists and philosophers alike 4 00:00:15,282 --> 00:00:19,095 have puzzled over what they call the mind-body problem. 5 00:00:19,095 --> 00:00:23,562 Is the mind some separate, non-material entity piloting a machine of flesh? 6 00:00:23,562 --> 00:00:27,321 Or if it's just a particularly elusive part of our physical body, 7 00:00:27,321 --> 00:00:30,323 how can it translate the input of our animal senses 8 00:00:30,323 --> 00:00:34,771 into the seemingly non-physical experiences that we call thoughts? 9 00:00:34,771 --> 00:00:37,215 But though the answers have been debated endlessly, 10 00:00:37,215 --> 00:00:39,884 new research suggests that part of the problem lies 11 00:00:39,884 --> 00:00:42,549 in how we pose the question in the first place, 12 00:00:42,549 --> 00:00:46,614 assuming a distinction between our sensory perception and our ideas 13 00:00:46,614 --> 00:00:48,872 that may not really be there. 14 00:00:48,872 --> 00:00:51,074 The traditional model of our mental function 15 00:00:51,074 --> 00:00:54,778 has been that the senses provide separate data to our brain 16 00:00:54,778 --> 00:00:58,725 which are then translated into the appropriate mental phenomena: 17 00:00:58,725 --> 00:01:04,509 visual images into trees, auditory experiences into bird songs, and so on. 18 00:01:04,509 --> 00:01:06,793 But occasionally, we have come across people 19 00:01:06,793 --> 00:01:10,914 whose senses seem to mingle together, allowing them to hear colors, 20 00:01:10,914 --> 00:01:12,771 or taste sounds. 21 00:01:12,771 --> 00:01:15,901 Until recently, the common understanding was that this phenomenon, 22 00:01:15,901 --> 00:01:17,061 called synesthesia, 23 00:01:17,061 --> 00:01:19,905 was a direct connection between the parts of the brain 24 00:01:19,905 --> 00:01:22,039 responsible for sensory stimuli such as 25 00:01:22,039 --> 00:01:26,825 seeing the color yellow immediately upon hearing the tone of b flat. 26 00:01:26,825 --> 00:01:29,095 But newer studies have shown that synesthesia 27 00:01:29,095 --> 00:01:31,742 is actually mediated through our understanding 28 00:01:31,742 --> 00:01:36,193 of the shapes, colors and sounds that our senses apprehend. 29 00:01:36,193 --> 00:01:39,060 In order for the cross-sensory experiences to occur, 30 00:01:39,060 --> 00:01:43,032 the higher level ideas and concepts that our minds associate 31 00:01:43,032 --> 00:01:46,060 with the sensory input must be activated. 32 00:01:46,060 --> 00:01:50,831 For example, this shape can be seen as either the letter "s" or the number "5," 33 00:01:50,831 --> 00:01:54,525 and synesthetes associate each with different colors or sounds 34 00:01:54,525 --> 00:01:56,437 based on how they interpret it 35 00:01:56,437 --> 00:02:00,615 despite the purely visual stimulus remaining identical. 36 00:02:00,615 --> 00:02:04,484 In another study, synesthetes created novel color associations 37 00:02:04,484 --> 00:02:08,488 for unfamiliar letters after learning what the letters were. 38 00:02:08,488 --> 00:02:12,433 So because it relies on a connection between ideas and senses, 39 00:02:12,433 --> 00:02:15,321 this mental phenomenon underlying synesthesia 40 00:02:15,321 --> 00:02:18,187 is known as ideasthesia. 41 00:02:18,187 --> 00:02:20,467 Synesthesia only occurs in some people, 42 00:02:20,467 --> 00:02:23,179 although it may be more common than previously thought. 43 00:02:23,179 --> 00:02:26,890 But ideasthesia itself is a fundamental part of our lives. 44 00:02:26,890 --> 00:02:32,336 Virtually all of us recognize the color red as warm and blue as cold. 45 00:02:32,336 --> 00:02:35,920 Many would agree that bright colors, italic letters and thin lines 46 00:02:35,920 --> 00:02:37,066 are high-pitched, 47 00:02:37,066 --> 00:02:39,439 while earth tones are low-pitched. 48 00:02:39,439 --> 00:02:43,348 And while many of these associations are acquired through cultural exposure, 49 00:02:43,348 --> 00:02:47,241 others have been demonstrated even in infants and apes, 50 00:02:47,241 --> 00:02:51,021 suggesting that at least some associations are inborn. 51 00:02:51,021 --> 00:02:54,263 When asked to choose between two possible names for these shapes, 52 00:02:54,263 --> 00:02:57,480 people from entirely different cultural and language backgrounds 53 00:02:57,480 --> 00:03:00,976 overwhelmingly agree that "kiki" is the spiky star, 54 00:03:00,976 --> 00:03:03,654 while "bouba" is the rounded blob, 55 00:03:03,654 --> 00:03:06,875 both because of the sounds themselves and the shapes our mouths make 56 00:03:06,875 --> 00:03:08,050 to produce them. 57 00:03:08,050 --> 00:03:09,923 And this leads to even more associations 58 00:03:09,923 --> 00:03:12,069 within a rich semantic network. 59 00:03:12,069 --> 00:03:14,390 Kiki is described as nervous and clever, 60 00:03:14,390 --> 00:03:17,896 while bouba is perceived as lazy and slow. 61 00:03:17,896 --> 00:03:20,873 What all of this suggests is that our everyday experiences 62 00:03:20,873 --> 00:03:25,889 of colors, sounds and other stimuli do not live on separate sensory islands 63 00:03:25,889 --> 00:03:28,627 but are organized in a network of associations 64 00:03:28,627 --> 00:03:30,837 similar to our language network. 65 00:03:30,837 --> 00:03:33,102 This is what enables us to understand metaphors 66 00:03:33,102 --> 00:03:35,033 even though they make no logical sense, 67 00:03:35,033 --> 00:03:38,244 such as the comparison of snow to a white blanket, 68 00:03:38,244 --> 00:03:41,555 based on the shared sensations of softness and lightness. 69 00:03:41,555 --> 00:03:44,385 Ideasthesia may even be crucial to art, 70 00:03:44,385 --> 00:03:48,196 which relies on a synthesis of the conceptual and the emotional. 71 00:03:48,196 --> 00:03:52,023 In great art, idea and aesthesia enhance each other, 72 00:03:52,023 --> 00:03:54,894 whether it's song lyrics combining perfectly with a melody, 73 00:03:54,894 --> 00:03:56,690 the thematic content of a painting 74 00:03:56,690 --> 00:03:59,058 heightened by its use of colors and brushstrokes, 75 00:03:59,058 --> 00:04:01,135 or the well constructed plot of a novel 76 00:04:01,135 --> 00:04:03,555 conveyed through perfectly crafted sentences. 77 00:04:03,555 --> 00:04:07,968 Most importantly, the network of associations formed by ideasethesia 78 00:04:07,968 --> 00:04:10,731 may not only be similar to our linguistic network 79 00:04:10,731 --> 00:04:13,457 but may, in fact, be an integral part of it. 80 00:04:13,457 --> 00:04:15,075 Rather than the traditional view, 81 00:04:15,075 --> 00:04:18,226 where our senses first capture a collection of colors and shapes, 82 00:04:18,226 --> 00:04:19,769 or some vibrations in the air, 83 00:04:19,769 --> 00:04:22,884 and our mind then classifies them as a tree or a siren, 84 00:04:22,884 --> 00:04:27,523 ideasthesia suggests that the two processes occur simultaneously. 85 00:04:27,523 --> 00:04:32,526 Our sensory perceptions are shaped by our conceptual understanding of the world. 86 00:04:32,526 --> 00:04:36,284 and the two are so connected that one cannot exist without the other. 87 00:04:36,284 --> 00:04:39,777 If this model suggested by ideasthesia is accurate, 88 00:04:39,777 --> 00:04:42,311 it may have major implications for some of the biggest 89 00:04:42,311 --> 00:04:46,578 scientific and philosophical issues surrounding the study of mind. 90 00:04:46,578 --> 00:04:48,739 Without a preexisting concept of self, 91 00:04:48,739 --> 00:04:52,761 Descartes would not have had an "I" to attribute the thinking to. 92 00:04:52,761 --> 00:04:56,856 And without a preexisting network of interrelated and distinct concepts, 93 00:04:56,856 --> 00:05:00,969 our sensory experience of the world would be an undifferentiated mass 94 00:05:00,969 --> 00:05:04,751 rather than the discrete objects we actually apprehend. 95 00:05:04,751 --> 00:05:08,232 For science, the task is to find where this network lies, 96 00:05:08,232 --> 00:05:11,950 how it is formed, and how it interacts with external stimuli. 97 00:05:11,950 --> 00:05:14,572 For philosophy, the challenge is to rethink 98 00:05:14,572 --> 00:05:18,601 what this new model of consciousness means for our understanding of our selves 99 00:05:18,601 --> 00:05:21,107 and our relation to the world around us.