Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press Chapter11 Language Mr. Broca, on the occasion of this report, presented the brain of a fifty-one year old man who died in his care at Bicetre hospital, and who had lost the use of speech … When the patient was admitted to Bicetre at the age of 21, he had lost, for some time, the use of speech; he could no longer pronounce more than a single syllable, which he ordinarily repeated twice at a time; whenever a question was asked of him, he would always repeat tan tan, in conjunction with quite varied expressive gestures. For this reason, throughout the hospital, he was only by the name of Tan.” Pierre-Paul Broca, 1861

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press Chapter Outline 1.0 Introduction 2.0 The nature of language 3.0 The sounds of spoken language 4.0 Planning and producing speech 5.0 Evolutionary aspects of speaking and listening 6.0 Words and meanings 7.0 Syntax, nesting, and sequencing 8.0 Prosody and melody 9.0 Meaningful statements 10.0 Unified representation of language 11.0 Summary

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 1.0 Introduction Language is the foremost tool of human thought and culture It is also one of the major landmarks of child development, with no close parallel in other species. Language is not unitary -- there are many levels of analysis and production. Each level is highly complex, but is processed by skilled speakers largely unconsciously and rapidly -- within seconds.

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 2.0 The Nature of Language Language is uniquely human. Virtually all humans, regardless of their intellectual abilities, learn to speak in the first several years of life. Spoken language is a complex biological overlay over pre-existing vocal and auditory physiology. These regions for vocalizing and perceiving speech have been associated with regions in the frontal and temporal lobes, based largely upon the groundbreaking work of Broca and Wernicke in the 19th century.

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 2.0 The Nature of Language In the mid-20th century, Geschwind proposed a neurological model for language regions in the left hemisphere based on the finds of the 19th century and contemporary findings from neurology.

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 2.0 The Nature of Language Findings from the 19th and 20th centuries have been supported by neuroimaging studies in the 21st century

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 2.0 The Nature of Language Recent models, like the one proposed by Hickok-Poeppel, expand brain regions that subserve language beyond the classical Broca’s and Wernicke’s areas.

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 3.0 The Sounds of Spoken Language It is amazing how many intricate sounds the human vocal tract can produce using air from the lungs and the articulators in the nose and mouth. The vocal tract is basically a tube, with two flexible flaps just above the lungs and its diaphragm muscles, which together create air pressure when we breathe out.

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 3.0 The Sounds of Spoken Language The sounds of a language are called phonemes, consisting basically of consonants and vowels. We produce consonants by closing the entire vocal tube at one of several places. In English, we use the lips at the front of the mouth to produce consonants such as /b/, /p/, and /m/, the tongue against the palate in the back or middle of the mouth to produce consonants like /g/ and /k/, and the teeth in the front to produce consonants such as /th/ and /v/.

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 3.0 The Sounds of Spoken Language We also add intonation to syllables and sentences to add emphasis or to indicate a question or a command. Thus the sounds of language include the individual phonemes as well as syllables, words, phrases, sentences and paragraphs. Despite the complexity of these many levels and stages of speech, we learn both to produce and to perceive speech at a very young age with little conscious effort. How do we accomplish this complex task with little effort? Scientists are still working to elucidate this complex issue.

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 4.0 Planning and Producing Speech From abstract thought to spoken words Several stages and levels of processing are thought to underlie the planning and production of speech, including access to conceptual representations, encoding of grammatical aspects, and phonological encoding.

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 4.0 Planning and Producing Speech A neural network for speech production The supplementary motor area (1) and the cingulated motor area (2) are connected with the primary motor cortex (3) to form part of the neural network for speech production. Subcortical activation is in the thalamus (4), the basal ganglia (not shown), the red nucleus (6), and the cerebellum (5) is seen during production. The posterior temporal gyrus in both hemispheres is activated in speech production (7). In the brainstem, areas such as the nucleus hypoglossus (8) are innervated during speech production.

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 5.0 Evolutionary Aspects of Speaking and Listening Our highly specialized vocal apparatus is attuned to producing spoken language. It evolved from the non-linguistic vocal organs of ancestral species. These, in time, built upon a breathing apparatus that we share with other land-dwelling creatures, as well as neuromuscular control of chewing and swallowing.

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 6.0 Words and Meanings A cultural treasury of words and ideas Words are the basic building blocks of meaning. However, sentences and particularly propositions built out of sentences can be taken as basic ‘meaning formulae’. We think and communicate in sentences. The words and meanings that we know as skilled speakers of human language are enormous! The brain basis of semantic knowledge has not been elucidated to date: there are likely large neural networks, highly interconnected, that form the neural basis for semantic knowledge. Some recent neuroimaging studies have investigated brain activation for tasks that tap different aspects of semantic knowledge in order to understand how words and meanings are stored and accessed in the cortex.

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 6.0 Words and Meanings Recognizing synonyms What brain areas activate for heard words? For seen words? An fMRI experiment recorded activation for words that were homonyms (words with different spellings but the same pronunciation such as ‘rain’ and ‘reign’) and synonyms (words with different pronunciations and related meanings such as ‘ship’ and ‘boat’). Homonyms activated left hemisphere posterior central sulcus and inferior frontal gyrus. Meaning-related activation for synonyms activated broader regions in the inferior temporal and frontal lobes

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 7.0 Syntax, Nesting, and Sequencing Syntax -- or grammar -- is often said to be the most distinctive aspect of language. Syntax is typically represented in ‘tree’ diagrams which show the relationship between individual words in a sentence and their grammatical case and structure.

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 7.0 Syntax, Nesting, and Sequencing A sentence has a ‘surface‘ structure which is the word order and structure that you see when you hear or read it. The ‘tree’ diagram reveals the ‘deep’ structure of the sentence, showing its grammatical parts and relationships. S sentence VP Verb phrase NP Noun phrase How would the tree diagram for this sentence be changed if the sentence read “The dog that scratched the cat that killed the mouse … “

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 7.0 Syntax, Nesting, and Sequencing What brain areas are involved in decoding syntax? This is a complex question that is still being resolved: it is difficult to tease apart brain activity that is specific to syntax decoding and not related to phonological and semantic processe or working memory functions. Results of a recent neuroimaging study show different brain areas in the frontal and temporal lobes that are involved in differing aspects of syntactic processing

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 8.0 Prosody and Melody Prosody is the ‘melody’ of language -- the pitch changes that convey emotion as well as linguistic information, such as the rising pitch indicating a question. Each language not only has emotional and linguistic intonations, it also has its own rhythm that can be quite distinctive. For example, when you listen to a native speaker of Italian and compare it to a native speaker of French, you realize that although the two languages share many aspects of syntax and semantics their cadence is quite different. Music and language are unique to humans -- the prosody or melody of language seems closely intertwined with the melody of music, and may share some biological roots.

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 9.0 Meaningful Statements Propositions We do not speak in single words, but in propositions: semantically meaningful statements about the world. Language scientists have put forth models about how neural networks may decode meaningful propositions. Here is an example of how different neurons might express different parts of a proposition (Shastri, 2000).

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 10.0 Unified Representations of Language Language is not unitary -- while we are still elucidating brain areas that support language processing, here is a current view of where stages of language processing are occurring

Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience Edited by Bernard J. Baars and Nicole M. Gage 2007 Academic Press 11.0 Summary The brain bases of language are still being clarified. Early work from 19th century scientists, such as Broca and Wernicke, have formed models for brain bases for speech production and perception that are still relevant today. While the detailed aspects of the roles of Broca’s and Wernicke’s areas in language processing are still being elucidated with modern neuroimaging studies, their basic functions remain quite similar to the views put forward by Broca, Wernicke, and their peers. Language systems involve large interconnected networks that are in constant contact with long-term memory stores and abstract conceptual representations. Current imaging techniques are investigating the relationship between these large scale neural networks in the brain.