Speech and Language Human Neuropsychology Lecture PDF

Human Neuropsychology Lecture 10 BIO N173 / PSY 163/ PSYCH 162 Speech and Language 1  What is Language? Comes from the word for “tongue” Combination of sounds for communication A symbolic s...

Human Neuropsychology Lecture 10 BIO N173 / PSY 163/ PSYCH 162 Speech and Language 1  What is Language? Comes from the word for “tongue” Combination of sounds for communication A symbolic system that is guided by rules Uniquely human? Nature vs. nurture? Innate vs. learned? 2  Components of Language Phonemes: Fundamental language sounds Morphemes: Smallest meaningful units of words Lexicon: Collection of all the words in a language Syntax: Rules of grammar Semantics: Meaning of words and sentences Prosody: Vocal intonations Discourse: Stringing sentences together to form a meaningful narrative 3  Bi-modal Integration in Language Speech is more than vocalization 90% of speech is accompanied by gestures (visual) Cocktail Party Effect We can hear speech better in a noisy environment if we see the lips You can focus on one speaker only by observing the lips (bimodal integration) McGurk Effect When we see and hear conflicting syllables, we hear the syllable that we saw 4 5 6 7 8  Language Learning R/L distinction in Japanese speakers French R [Kh] sound in Arabic, Hebrew [Ch] sound in German Infants Prefer to listen to speech Can make sounds used in all languages 9  Functional Neuroanatomy of Language Wernicke-Geschwind Model primary motor cortex supramarginal gyrus speech mouth movements reading comprehension Word sounds are sent to the Primary Auditory Cortex angular gyrus reading comprehension Word meaning is represented in Wernicke’s Area Word meaning is sent to Broca’s Area via the arcuate fasciculus Broca’s Area sends instructions for speech articulation to the motor cortex Wernicke’s area understanding words To read, visual areas send Broca’s area information to the angular producing words gyrus and to Wernicke’s or Primary auditory cortex Broca’s Area hearing words 10  Language Mapping During Neurosurgery Effects of Cortical Stimulation Total arrest of speech Hesitation and slurring of speech Speech distortion and repetition of speech Confusion of numbers Naming difficulties Misnaming and perseveration Wilder Penfield 11  Language Mapping with Neuroimaging More widespread cortical activation for language 12  Disorders of Language: Aphasias Aphasia Disorder of language, writing (agraphia), or reading (alexia) Does not include disorders that result from: Loss of sensory input Motor paralysis or incoordination Fluent, Nonfluent, and Pure Aphasia 13  Fluent Aphasias Impairment in the reception of language Wernicke’s Aphasia or Sensory Aphasia Deficits in classifying sounds Word salad Confusion of phonetic characteristics Cannot write Can read in some cases (if damage does not include angular gyrus) 14 15  Fluent Aphasias Transcortical Aphasia or isolation syndrome Can repeat, understand, and name objects Cannot speak spontaneously Cannot comprehend words Anomic Aphasia or Amnesic Aphasia Can comprehend, produce speech, and can repeat Difficulty naming objects 16  Fluent Aphasias Conduction Aphasia Can speak, name objects, and understand speech Cannot repeat Cannot perform guided speech commands 17 18  Nonfluent Aphasias Broca’s Aphasia or expressive aphasia Can understand speech Cannot produce or has difficulty producing speech Transcortical Motor Aphasia Good repetition, poor spontaneous production Global Aphasias Labored speech, poor comprehension 19 20  Pure Aphasias Alexia Inability to read Agraphia Inability to write Word deafness Cannot hear or repeat words Can be selective disorders 21 Summary of Aphasias 22