Ch13. Biological Foundations of Language David W. Carroll Psychology of Language, 5th edition

Index Introduction Brain Mechanisms and Language Lateralization of Language Processes Evolution of Language

Introduction Language processes from a biological viewpoint Two reasons to know about biology of language Previous discussion comprehension & production Further discussion Acquisition Three sections Brain Damage related to language Nature of hemisphere difference Evolutionary human language

What is Language? Language is thought to be a mechanism for transmitting the information within thoughts. One experiment used to demonstrate this idea requires subjects to listen to a short passage of several sentences. The subjects are then asked to repeat the passage. Most subjects accurately convey the gist of the passage in the sentences they produce, but they do not come close to repeating the sentences verbatim. It appears as if two transformations have occurred. Upon hearing the passage, the subjects convert the language of the passage into a more abstract representation of its meaning, which is more easily stored within memory. In order to recreate the passage, the subject recalls this representation and converts its meaning back into language. http://www.brainconnection.com/topics/?main=fa/evolution-language6

Brain Mechanisms and Language

Wernicke’s Area Broca’s Area

Superolateral Surface of brain

Insula

Medial surface of Brain

Bottom surface of Brain

Geschwind’s Model (1/2)

Geschwind’s Model (2/2)

Major Aphasic Syndromes Behavioral Deficit Lesion Site(s) Broca’s aphasia Disturbance of speech production; agrammatic speech; relatively good comprehension and naming Frontal lobe adjacent to primary motor cortex Wernicke’s aphasia Disturbance in auditory comprehension; fluent speech Posterior portion of first temporal gyrus Conduction aphasia Disturbance of repetition and spontaneous speech Lesion in arcuate fasciculus and/or other connections between frontal and temporal lob Transcortical sensory aphasia Disturbance of single word comprehension with relatively intact repetition Connections between parietal and temporal lobe Transcortical motor aphasia Disturbance of spontaneous speech, with sparing of naming Subcortical lesions in areas underlying motor cortex Anomic aphasia Disturbance of production of single words Various parts of parietal and temporal lobes Global aphasia Major disturbance of all language function Large portions of association cortex

Some example syntactic deficit Ambiguous sentence It was the girl who chased the boy. (o) It was the boy whom the girl chased. (x) Ambiguous sentence The experienced soldiers warned about the dangers before the midnight raid. (easy) The experienced soldiers warned about the dangers conducted the midnight raid. (hard)

Dapretto & Bookheimer (1999).

IFG activation Syntactic Semantic Phonologic tasks coordination

IFG activation plot

Lateralization of Language Process

Optic pathway

Auditory pathway Ipsalateral pathway Contralateral pathway Corpus callosum Ipsalateral < Contralateral

Lateralization of brain Bever (1980) left hemi – relational processing right hemi – holistic processing ?

Picture – sentences matching test in split-brain condition Subject-Object The boy kisses the girl. The girl kisses the girl. Tense The girl is drinking. The girl will drink. Plural noun The dog jumps over the fence. The dogs jump over the fence.

Experienced Musician Bever and Chiarello (1974) On musical task (non-speech task) Right-ear advantages for the experienced No left-ear advantages

Right-hemisphere damage Kaplan and colleagues Difficulty integrating information about performance with information about character’s relationship.

Lexical task Word in left visual field Dominant meaning is immediately facilitated, but not for subordinated meaning. Particular meaning Dominant meaning is facilitated immediately, but inappropriate meaning is not suppressed. Alternative meaning Burgess and Simpson (1988) Chiarello (1991)

Cortical Activation during Semantic processing

Evolution of Language

Language evolution and the arcuate fasciculus Figure from the News and Views summary by Ghazanfar - Chimpanzees are phylogenetically between macaques and humans in the primate lineage, and the similarly 'in between' pattern of their arcuate pathway terminations strongly suggest a gradual evolution of this pathway.(a) Changing patterns of connections between frontal cortical areas and the temporal lobe in humans, chimpanzees and macaque monkeys. AS, arcuate sulcus; CS, central sulcus; IFS, inferior frontal sulcus; IPS, intraparietal sulcus; PS, principal sulcus; PrCS, precentral sulcus; STS, superior temporal sulcus. (b) The voice area in the rhesus macaque relative to other auditory cortical areas and where the voice area would be if it were in a similar location as the human voice area. LS, lateral sulcus; IOS, inferior occipital sulcus; STS, superior temporal sulcus; other labels refer to cytoarchitectonic areal designations. The lateral sulcus is cut open to reveal the superior temporal plane. In this plane, the core region is thought to contain 'primary-like' areas, responding best to pure tones, whereas the surrounding belt areas are more responsive to complex sounds. The voice area in macaques is anterior to the core and belt regions. INS, insula; IT, inferotemporal cortex; Tpt, temporoparietal area. http://mindblog.dericbownds.net/2008/04/language-evolution-and-arcuate.html

Comparison of the supralaryngeal vocal tracts in a new born infant, Neanderthal, and an adult human