Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Speech and Language Dr Derakhshandeh, PhD 1 Thinking and Language Language is the ability to encode ideas into signals for communication Nothing is more human than speech 3 Language is the most complex everyday human behavior • 100 muscles work at any given time for speech • For each of these there are about 100 nerve endings • We produce 14 sounds per second • (100 x 100 x 14=140,000 nerve-to-muscle events each second of conversational speech 4 How complex? …linguistic knowledge 5 • more than 6,000 languages exist • it is incomprehensible to suggest: language could be viewed as some sort of simple, clear-cut addition to human physiology made possible by an enlarged brain unique to Homo sapiens 6 The central ideas of evolution • The life has a history • Changed over time • Different species share common ancestors 7 DNA (deoxyribonucleic acid) • DNA is the double-stranded molecule that contains the genetic code • Jared Diamond suggests: –the amount of DNA similarity is a key indicator of the closeness to other primates, esp., the Bonobos 8 Almost us! 9 • Common and pygmy chimps differ in 0.7% DNA »Gorillas differ in 2.3% 10 • Humans and chimps differ in 1.6% (98.4% the same) • Gorillas separated from chimps before humans did 11 DNA • One of the ways we determine closeness with other primates • Closest primates are: – Bonobo (pygmy) – chimpanzees – Gorilla – Orangutan 12 13 the genetic distances between Hominoids Chimpanzees are actually closer to humans genetically than to Orangutans and the same genetic distance from Gorillas Orangutans are the most different from humans genetically yet relatively closer to Chimpanzees 14 Hominoids 15 A polygenetic or monogenetic linguistic origin? • Monogenesis? –A single location from which all humans emerged • Polygenesis? –More than one location –but similar development in each site 16 17 Speech begins… When? • By at least 30,000 years ago: – humans speech was fully modern • Begins between Australopithecines and Homo habilus (between 4M B.P. and 700,000B.P.) 18 Were there other human species? • Homo habilis • About 5 foot tall • average brain size 650cc, much larger than Australopithecines • Brain organization may have included an area for speech (Broca's area) 19 H. habilis 20 Australopithecus afarensis • 3.5 to 4 foot tall, known as "Lucy“ • Pelvis and legs more like humans but skull chimp like • Protruding mouth, small brained, canines project slightly 21 22 23 One possible relationship to other hominids 24 • • • • • • • • Basic biological aspects of human language: Brain Cerebral Left hemisphere Corpus callosum Neo-Cortex Broca’s Area Wernicke’s Area Angular Gyrus 25 Comprehension of speech Controls the muscles of the lips, jaw, tongue, vocal cord,… 26 Basic biological aspects of human language: Voice Box • • • • • Hyoid Bone Larynx Trachea Tongue Oral/Nasal Cavity 27 Voice Box 28 29 30 31 Sound • Sound is produced when air flowing from the lungs passes into the voice box • through the gap made by the vocal cords, which open and close like a valve • During speech, the vocal cords vibrate as air passes through them • releasing a rapid series of puffs into the vocal tract • determines the pitch of a person's voice • the faster the rate, the higher the pitch 32 Sound systems • The human upper respiratory tract made speech possible • as the high larynx seen in species like the chimp dropped • creating an expanded pharynx in human 33 Sound systems 34 Unfortunately: "speech does not fossilize" • notes anthropologist John Shea of the State University of New York: • Writing appears 6000 years ago • there is scant evidence for the existence of notation before 13,000 years ago • How long might LANGUAGE have been around before that? 35 Fossils: the brain capacity • Is raw for complex LANGUAGE • with the necessary mouth and throat anatomy • were probably in place before 150,000 years ago • But most of the behaviors thought to depend on LANGUAGE did not appear until 40,000 years ago • tools, burials, living sites, and occasional hints of art and social organization • "Everybody would accept that by 40,000 years ago, LANGUAGE is everywhere" (Stanford University archaeologist Richard Klein) 36 Delayed takeoff. The anatomy needed for speech was in place before 150,000 years ago, but the signs of complex language don't proliferate until around 40,000 years ago 37 • Where/When was the first Language? • What does comparative linguistics tell us? • What does an analysis of human mitochondrial DNA tell us? 38 The term Proto-World language • the hypothetical latest common ancestor of all the world's languages • an ancient language • all modern languages • and language families • Including all known dead languages • would have been spoken roughly 200,000 years ago 39 The Origin of Language • Merritt Ruhlen: • Suggests that if you go systematically back and compare cognates • you can eventually find a common relationship among all languages • Says that mitochondrial DNA analysis suggests that it is true • Critics suggest: • that it is too easy to mistake words that are not cognatic as cognates 40 Proto-World language • • • • • • Chinese Quechua French Greek Dutch Turkish shui sut'u suée hudor schuit su 'water' 'wet' 'sweat' 'water' 'boat' 'water' 41 Proto-World language • Chinese Quechua Dutch Greek Latin French German nü ñusta nuf (gy)ne (femi)na nana -in 'woman' 'princess' 'aloof girl' 'woman' 'woman' 'woman' fem. suffix 42 43 Blood factor Rhesus negative 44 45 Are there any answers in language acquisition theory? Critical Age hypothesis: • Order of language development • Babbling • One-word stage • Two-word stage • Telegraphic speech • Orderly addition of grammar • Orderly addition of cognitive concepts 46 A new stage in human evolution • The origin of language • the beginning of culture, including art, desire, and the sacred • new forms of social organization which are radically different from animal • language is so radically different from animal communication systems • its origin must have been a singular event • Since this event leaves no fossil record • only hypothesize about the conditions of its origin 47 • For archaeologists eager to learn how we became human • when and how LANGUAGE emerged is a crucial question 48 “Speech” is a wonderful gift from God 49