Neurophysiology of Communication

Presented by: Neha Sharma MD Date: October 11, 2019 What is Communication?

Ø The imparting or exchange of information

Ø Auditory, , , and Comprehension

Ø Focus of presentation – how language and speech are perceived and comprehended by the Neurophysiology of Hearing Neurophysiology of Hearing

Ø Frequency of sound as speech (sound waves)

Ø Frequency of speech is 60-500 Hz Ø Males – 85-180 Hz; Female – 165-255 Hz Ø Ear picks up 20-20,000 Hz Animal Frequencies Animal Vocal Frequency (Hearing Frequency) Elephants 14-24 Hz (14-12,000 Hz) Dogs 1,000-2,000 Hz (67-45,000 Hz) Birds 1,000-8,000 Hz (200-8,500 Hz) Ants 1,000 Hz (500-1500 Hz) Mice/Rats 20,000-100,000 Hz (1,000-100,000 Hz) Cow 70-7,000 Hz (16-40,000 Hz) Bats 50,000-160,000 Hz (2,000-110,000 Hz) Torrent Frog 128,000 Hz (38,000 Hz) Katydid 138,000 Hz-150,000 Hz (15,000-50,000 Hz) Dolphins 175,000 Hz (75-150,000 Hz) Wax Moth 300,000 Hz (300,000 Hz) Auditory Anatomy

https://endoplasmiccurriculum.wordpress.com/2012/03/09/internal-ear-anatomy/ Neurophysiology of Hearing

Ø Sound waves transmit through the air to the ear

Ø Travels through external acoustic meatus to auditory canal to tympanic membrane Ø Oscillate against the ossicles which causes vibration of the oval window

Ø Stimulating the cochlea which converts the vibration into electrical signals Ø Hair cells move upwards and forwards causing depolarization of the basilar membrane Ø Due to perturbation of basilar membrane against tectorial membrane Ø Inner hair cells – discriminate frequency Ø Outer hair cells – sound amplification Neurophysiology of Hearing

Ø Base of hair cell releases Glutamate after depolarization Ø Stimulates the Vestibulocochlear nerve (Cranial Nerve VIII (CN VIII)) via spiral ganglion of modiolus

https://www.studocu.com/en/document/indiana-university/cell-biology-histology/summaries/histology-of-the-ear-notes/1366464/view Auditory Pathway

Ø Cochlear nucleus Ø Dorsal cochlear nucleus and Posteroventral cochlear nucleus Ø Sound identification Ø Anteroventral cochlear nucleus Ø Sound localization Ø Efferent to medial superior olive Ø Signal ascends up to inferior colliculus then to medial geniculate body Ø Finally to primary auditory cortex

http://www.humanneurophysiology.com/soundhearing.htm Localization of Sound

Ø Localization of sound ØLateral sound source stimulates contralateral lemniscus fibers of medial superior olivary nucleus to inferior colliculus

Ø Weber test Ø Tuning fork on head – should hear it equally bilaterally Ø Affected ear louder – conductive Ø Unaffected ear louder – sensorineural Ø Rinne test http://www.humanneurophysiology.com/soundhearing.htm Ø Tuning fork on mastoid process – then anterior to acoustic meatus Ø AC>BC – normal Ø BC>AC – conductive hearing loss Neurophysiology of Language and Speech Language

Ø Form Ø Syntax – guidelines for combining words into sentences Ø Phonology – guidelines for combining sounds into a pattern of language (laryngeal muscles)

Ø Content and use Ø Grammar – guidelines for usage of vocabulary to be combined into sentences

Ø Language and speech develop mostly by age 5 Neurophysiology of Language and Speech

https://www.researchgate.net/figure/Language-specific-areas-in-the-brain_fig1_317356553 Components of Comprehension Components of Comprehension

Ø Ø Inferior frontal gyrus – Broca's area – planning and production of speech articulation

Ø BA 44,45,47

Ø Ø Angular gyrus – written comprehension (BA 39) Ø – phonological processing (BA 6)

Ø Ø Wernicke's area – language comprehension Ø Superior temporal sulcus – language comprehension Ø Heschl's gyrus – auditory reception https://www.cell.com/trends/cognitive-sciences/fulltext/S1364-6613(14)00170-3 Ø Belt – auditory signal differentiation Ø Parabelt – auditory information processing

Ø Corpus callosum – connect both cerebral hemispheres Ø Plays role in language lateralization Components of Comprehension

Ø Ø Medial geniculate nucleus – auditory relay (part of ) Ø Inferior colliculus – auditory relay (localizes sound)

Ø Thalamus Ø Pulvinar – language relay Ø Medial geniculate nucleus – auditory relay Ø Ventral (BA 41), dorsal (BA 42 and belt) Ø Belt and parabelt project to temporal, parietal and frontal lobes for processing Components of Comprehension

Ø Ø Executive functions, speech motor control, learning

Ø Superior olivary nucleus Ø Lateral superior olive Ø Sound intensity and determines location in horizontal space Ø Medial superior olive Ø Frequency for timing of sound and determines location in horizontal space Ø Olivocochlear bundle Ø Efferent auditory pathway, from superior olivary complex to cochlea, allows for discrimination of noise (focus on signal) Components of Comprehension

Ø Insular cortex (dominant hemisphere) Ø Speech praxis

Ø Ø Cochlear nuclei – first relay to for auditory Ø Superior olivary complex – auditory localization Ø Periolivary nuclei – efferent auditory system Ø Lateral lemniscus – cochlear nucleus to inferior colliculus auditory tract Ø Striae of Held and Monaco – dorsal nucleus bilateral input; ventral nucleus contralateral input Components of Comprehension

Ø Cerebellum Ø Cerebro-cerebellar pathways Ø Corticopontine-cerebellar and cerebellar-thalamic-cortical loops Ø Connect cerebellum with motor, paralimbic and association cortices sub serving cognitive and affective processes

Ø Speech timing, pitch discrimination and verbal fluency

Ø Cerebellum is part of a sub-cortical pathway Ø Input from Broca's area (BA 44) via the left anterior insula and projects to left primary motor cortex (M 1) via the (left) ventral premotor cortex (PMC) Left side: thought and motor aspect of speech; Right side: auditory comprehension Seikel, J., Konstantopoulos, K., & Drumright, D. (2019). Neuroanatomy and neurophysiology for speech and hearing sciences. Thoughts, Speech, Interpretation Neural Control of Speech

Ø Linguistic system in lateral frontal lobe of the dominant hemisphere Ø Grammar in Broca's area, phonetic encoding in left insular cortex and left supramarginal gyrus

Ø Motor loops for speech Ø Preparative loop – left dorsolateral prefrontal cortex, anterior insular cortex, supplementary motor area and superior cerebellum

Ø Executive loop – motor cortex, thalamus, putamen, caudate, inferior cerebellum Ø Basal ganglia support initiation of speech production and phonological processing Thoughts, Speech, Interpretation

Ø Producer of speech Ø Starts as a concept (thought) – formulated into a sound (temporoparietal junction and cerebellum) – articulation (motor movement at Broca's) Ø Supramarginal gyrus and primary sensory cortex (BA 1) interpret articulation and if correction is needed information is sent to cerebellum and premotor cortex

Ø Listener of speech Ø Internalization of words then are interpreted to match already learned language

Ø Lemma – mental representation reflecting the stage between activating an idea and activating speech to express the idea Ø Use of definitions and syntax for interpretation Bilingualism What is Bilingualism?

Ø Bilingual – fluency in two Ø One language is dominant, other language is secondary Ø Ability to move from one language to the other Ø Word association model – words can be interchanged from L1 to L2 and vice versa https://www.cambridge.org/core/books/teaching-chinese-as-an-international-language/use-of-english-in-the-teaching-of-chinese-making-the-most-of-the-learners-linguistic-resources/AEAE802107F0737E36E52DBEE8057EF4 Ø Concept mediation hypothesis – L1 needs to refer to concept and with L2 Green's Inhibitory Control Model – how to switch from L1 to L2 to complete a task after goal has been established

https://www.researchgate.net/figure/Greens-Inhibitory-Control-Model_fig4_259800186 Bilingual "Code-Switching"

Ø Bilingual people can "Code-switch" Ø Switching between language one and language two

Ø Common in immigrant families

Ø People switch between languages in one conversation or even sentence

Ø Hypothesis Ø Left caudate has been shown to be primary site of language switching Ø Damage to left caudate causes person to involuntary switch Bilingual "Code-Switching"

Ø Equivalence Constraint Ø Codes are switched when surface structure of language maps overlap

Ø Free Morpheme Constraint Ø Codes are switched whenever possible/desired

Ø L1-L2 share similar language areas but are not identical Ø Proficiency determines neural composition Bilingual "Code-Switching"

Ø Conflicts in grammar and syntax between languages occur and processes need to be inhibited appropriately Ø Basal ganglia, thalamus, anterior cingulate cortex, and frontal lobe control inhibition of language Ø Inhibition is not all or none – hence allowing for sentential switching

Ø Abutalebi and Green model features five brain regions at work: left DLPFC, ACC, caudate nucleus, and bilateral SMG

Ø Luk et al. model supports the role of left PFC and caudate, doesn't include the ACC and bilateral SMG. Additionally, activations are seen in the pre-SMA, the right precentral gyrus, and the left middle temporal gyrus Bilingual "Code- Figure 1 Switching"

L1 and L2 Mixed against control condition showed increased activity in a network of areas including the left IFG, the precentral gyrus, SMA, the left IPG, the bilateral fusiform gyrus extending to the , as well as the subcortical regions including the left caudate, and the right hippocampus Bilingual "Code- Figure 2 Switching"

L1 Chinese naming condition showed broadly distributed areas falling into two big clusters. One peaked at the posterior part of the left IFG and extended all over the prefrontal cortex and to the bilateral SMA, left insula, left putamen and right caudate. The other peaked at the left inferior parietal gyrus and extended to the SMG and the Angular and precuneus Bilingual "Code- Figure 3 Switching"

L2 English naming condition showed activations in the left IFG, the bilateral Precentral gyrus and SMA, the bilateral IPG, the bilateral fusiform, the left lingual gyrus, the left inferior temporal gyrus, and the bilateral hippocampus Bilingual "Code-Switching"

Ø L1 to L2 language switching stimulated broad activations in bilateral inferior frontal, and DLPFC areas

Ø Only the posterior part of the left DLPFC was activated for the language switching against L2

Ø Left DLPFC activity shows that this area might be a key mediator in cognitive control of bilingual switching Language & Speech Pathologies Types of

Ø Broca's aphasia – Ø Inability to form words, motor complex of speech is damaged

Ø Wernicke's aphasia – Ø Inability to comprehend language and speech, sensory complex of speech is damaged

Ø Global aphasia Ø Both receptive and expressive aphasia Types of Aphasia

Ø – inability to repeat what is heard

Ø Transcortical sensory aphasia – poor auditory comprehension, repetition is intact

Ø Transcortical motor aphasia – similar to Broca's aphasia, repetition is intact

Ø – difficulty with word recall

Ø Apraxia of speech – planning and programming difficulties leading to articulation problems (Broca's)

Ø Dysarthria – difficulty with speaking due to muscle weakness Bilingual Aphasia What is Bilingual aphasia?

Ø Bilingual aphasia is a type of aphasia specific to bilingual patient

Ø Most commonly occurs secondary to or Traumatic Brain Injury (TBI) Ø Damage to language planning and production centers of speech in the brain Ø Can occur secondary to Multiple Sclerosis, vasculitis, tumors

Ø Can affect both language processes Bilingual aphasia

Ø Acute phase – 4 weeks after onset Ø There are 6 recovery patterns Ø Lesion phase – weeks to months after Ø Parallel recovery – both languages onset are impaired and restored at the same rate. Ø Late phase – few months after onset Ø Differential recovery – to life languages recovered differentially relative to their premorbid levels.

Ø Patient can recover one or both Ø Selective recovery – one language is not recovered. languages, depends on the severity of insult Ø Blended recovery – patients inappropriately mix Ø Most commonly, mother tongue their languages returns first Ø Antagonistic recovery – one ØHypothesized due to recovers partially first then regresses stronger neural connections as other language recovers. made in childhood language Ø Successive recovery – second and speech development of language recovered only after the mother tongue first is recovered Ø Mixed recovery Foreign Accent Syndrome What is Foreign Accent Syndrome?

Ø Rare motor speech disorder where others perceive the person speaking with a foreign accent

Ø Four operational criteria Ø Considered foreign by patient and investigator Ø Unlike patient's native dialect before insult Ø Related to CNS damage Ø No history of being a speaker of the foreign language Foreign Accent Syndrome

Ø Three types of FAS Ø Neurogenic Ø Acquired or developmental variants Ø Programming disorder of speech with variance in speech sounds Ø Psychogenic ØMost common with conversion disorder Ø Mixed

Ø Most commonly occurs secondary to Stroke or TBI Ø Damage to language planning and production centers of speech in the brain Ø Can occur secondary to Multiple Sclerosis, vasculitis, tumors Foreign Accent Syndrome

Ø Foreign Accent Syndrome disrupts speech planning and execution of speech Ø Changes to motor output from the brain to muscles of speech Ø Commonly causes changes (slowing) in phonation, pronunciation, and articulation Ø Damage to dominant cerebral hemisphere Ø Precentral/middle frontal gyrus, anterior insular, inferior parietal, thalamus, cerebellar regions

Ø Improvement can be seen with intensive speech therapy Ø Some patients can undergo remission in one day to five year time frame (20- 25%) Thank You!

Questions? Abbreviations

Ø Hz – Hertz Ø IFG – Inferior frontal gyrus Ø AC – Air conduction Ø IPG – Inferior parietal gyrus Ø BC – Bone conduction Ø SMG – Supramarginal gyrus Ø Ø BA – Broadman area SMA – Supplementary motor area Ø DLPFC – Dorsolateral prefrontal Ø L1 – Language one cortex Ø L2 – Language two Ø ACC – Anterior cingulate cortex Ø SAS – Supervisory attention Ø PFC – Prefrontal cortex system References Ø Seikel, J., Konstantopoulos, K., & Drumright, D. (2019). Neuroanatomy and neurophysiology for speech and hearing sciences.

Ø Hartwigsen, G. (2015). The neurophysiology of language: Insights from non-invasive brain stimulation in the healthy human brain. Brain And Language, 148, 81-94. doi: 10.1016/j.bandl.2014.10.007

Ø Etchell, A., Adhikari, A., Weinberg, L., Choo, A., Garnett, E., Chow, H., & Chang, S. (2018). A systematic literature review of sex differences in childhood language and brain development. Neuropsychologia, 114, 19-31. doi: 10.1016/j.neuropsychologia.2018.04.011

Ø Moreno-Torres, I., Mariën, P., Dávila, G., & Berthier, M. (2016). Editorial: Language beyond Words: The Neuroscience of Accent. Frontiers In Human Neuroscience, 10. doi: 10.3389/fnhum.2016.00639

Ø Keulen, S., Mariën, P., Wackenier, P., Jonkers, R., Bastiaanse, R., & Verhoeven, J. (2016). Developmental Foreign Accent Syndrome: Report of a New Case. Frontiers In Human Neuroscience, 10. doi: 10.3389/fnhum.2016.00065

Ø ESPERSON, J. (1994). Do Ants Use Ultrasound for Personal Communication (Hymenoptera: Formicidae)?. Australian Journal Of Entomology, 33(3), 213-215. doi: 10.1111/j.1440-6055.1994.tb01220.x

Ø Ma, H., Hu, J., Xi, J., Shen, W., Ge, J., Geng, F., Wu, Y., Guo, J. and Yao, D. (2014). Bilingual Cognitive Control in Language Switching: An fMRI Study of English-Chinese Late Bilinguals. PLoS ONE, 9(9), p.e106468.

Ø MacSwan, J. (2000). The architecture of the bilingual language faculty: evidence from intrasentential code switching. Bilingualism: Language and Cognition, 3(1), pp.37-54.

Ø Acoustics.org. (2019). ASA/EAA/DAGA '99 - Ants Have an Acoustic World of Their Own. [online] Available at: https://acoustics.org/pressroom/httpdocs/137th/hickling.html References

Ø Verhoeven, J., & Mariën, P. (2010). Neurogenic foreign accent syndrome: Articulatory setting, segments and prosody in a Dutch speaker. Journal Of Neurolinguistics, 23(6), 599-614. doi: 10.1016/j.jneuroling.2010.05.004

Ø Mariën, P., Keulen, S., & Verhoeven, J. (2019). Neurological Aspects of Foreign Accent Syndrome in Stroke Patients. Journal Of Communication Disorders, 77, 94-113. doi: 10.1016/j.jcomdis.2018.12.002

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Ø Mariën, P., Ackermann, H., Adamaszek, M., Barwood, C., Beaton, A., Desmond, J., De Witte, E., Fawcett, A., Hertrich, I., Küper, M., Leggio, M., Marvel, C., Molinari, M., Murdoch, B., Nicolson, R., Schmahmann, J., Stoodley, C., Thürling, M., Timmann, D., Wouters, E. and Ziegler, W. (2013). Consensus Paper: Language and the Cerebellum: an Ongoing Enigma. The Cerebellum.

Ø Mehrpour, M., Motamed, M. R., Aghaei, M., Jalali, N., & Ghoreishi, Z. (2014). Unusual recovery of aphasia in a polyglot Iranian patient after ischemic stroke. Basic and clinical neuroscience, 5(2), 173–175.

Ø Frequency Hearing Ranges in Dogs and Other Species (2019). https://www.lsu.edu/deafness/HearingRange.html

Ø Kutas, Marta & Moreno, Eva & Wicha, Nicole. (2008). Code-switching and the brain.

Ø Yates, C. (2019). Ultrasonic Animals That Vocalize at Frequencies Beyond Our Hearing Range – Soundfly. [online] Soundfly. Available at: https://flypaper.soundfly.com/discover/ultrasonic-animals-that-vocalize-at-frequencies-beyond-our-hearing-range/

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Ø Fabbro, F. (2001). The Bilingual Brain: Bilingual Aphasia. Brain and Language, [online] 79, pp.201-210. Available at: https://lingue.uniurb.it/matdid/donati/LinguisticaGenerale/2006-07/bilinguismo2.pdf