1. THE SENSORIMOTOR INTERFACE OCT 5, 2015 – DAY 17 Brain & Language LING 4110-4890-5110-7960 NSCI 4110-4891-6110 Fall 2015

2. Course organization http://www.tulane.edu/~howard/BrLg/ Fun with https://www.facebook.com/BrLg15/https://www.facebook.com/BrLg15/ I am still working on grading. http://www.tulane.edu/~howard/BrLg/t11- SensorimotorInterface.html http://www.tulane.edu/~howard/BrLg/t11- SensorimotorInterface.html 10/05/15Brain & Language - Harry Howard - Tulane University 2

3. WERNICKE'S APHASIA The quiz was the review http://www.tulane.edu/~howard/BrLg/t10-Wernicke.html 10/05/15Brain & Language - Harry Howard - Tulane University 3

4. THE SENSORIMOTOR INTERFACE Parietal-temporal Spt http://www.tulane.edu/~howard/BrLg/t11- SensorimotorInterface.html 10/05/15Brain & Language - Harry Howard - Tulane University 4

5. The Sylvian parieto-temporal junction 10/05/15Brain & Language - Harry Howard - Tulane University 5

6. Motivation for the dorsal stream in general Learning to speak is essentially a motor learning task. The primary input to this is sensory, speech in particular. So, there must be a neural mechanism that both codes and maintains instances of speech sounds, and can use these sensory traces to guide the tuning of speech gestures so that the sounds are accurately reproduced. 10/05/15Brain & Language - Harry Howard - Tulane University 6

7. The initial bit of evidence In these experiments, subjects were asked to listen to pseudo-words and then repeat them subvocally, that is, in their imagination as opposed to out loud. The analysis combined the regions that were active for both the sensory task of listening to the stimuli and the motor task of repeating them subvocally into the image below: 10/05/15Brain & Language - Harry Howard - Tulane University 7

8. Specific questions about the SMI 1. Why is a sensorimotor interface necessary? 2. Where is it located? 3. How does it work? 10/05/15Brain & Language - Harry Howard - Tulane University 8

9. Data that has been collected so far 1. Spt becomes active in the perception and reproduction by humming of tonal sequences and even by reading written words > interface specifically to vocal motor control? 2. the ability to acquire new vocabulary. 3. altered auditory feedback disrupts speech production. 4. articulatory decline in late-onset deafness. 5. the basic neural mechanisms for phonological short- term memory 6. disruption by lesions: conduction aphasia 7. the non-phonological residue of Wernicke's aphasia: deficient self-monitoring 10/05/15Brain & Language - Harry Howard - Tulane University 9

10. The ability to acquire new vocabulary We propose that auditory–motor interactions in the acquisition of new vocabulary involve generating a sensory representation of the new word that codes the sequence of segments or syllables. This sensory representation can then be used to guide motor articulatory sequences. This might involve true feedforward mechanisms (whereby sensory codes for a speech sequence are translated into a motor speech sequence), feedback monitoring mechanisms, or both. As the word becomes familiar, the nature of the sensory–motor interaction might change. New, low-frequency or more complex words might require incremental motor coding and thus more sensory guidance known, high-frequency or simpler words might become 'automated' as motor chunks that require little sensory guidance. 10/05/15Brain & Language - Harry Howard - Tulane University 10

11. The effect of auditory feedback on speech production Delayed Auditory Feedback (DAF) records a person's speech and then plays it back through his or her headphones a fraction of a second later. It is used to treat stuttering, but it can induce stuttering in non-stutters (like me). There is no picture of this, but there are videos! https://www.youtube.com/watch?t=173&v=cwoTXE0PQiw https://www.youtube.com/watch?t=43&v=ujmQlgNWZn4 10/05/15Brain & Language - Harry Howard - Tulane University 11

12. 10/05/15Brain & Language - Harry Howard - Tulane University 12 Conduction aphasia, #1 Clinician: Now, I want you to say some words after me. Say ‘boy’. Patient: Boy. Clinician: Home. Patient: Home. Clinician: Seventy-nine. Patient: Ninety-seven. No … sevinty-sine … siventy- nice…. Clinician: Let’s try another one. Say ‘refrigerator’. Patient: Frigilator … no? how about … frerigilator … no frigaliterlater … aahh! It’s all mixed up! (Brookshire 2003:158)

13. 10/05/15Brain & Language - Harry Howard - Tulane University 13 Conduction aphasia, #2 Clinician: Circus. Patient: It’s a kriskus. … No, that’s not right, but it’s near. … Sirsis. … No. … This is very strange that I can’t say this word.… How about kirsis? … No. … I'll have to by that. Kriskus? For some reason I can’t say it right now. But I'm close. Kirsis? No … (Brookshire 2003:158)

14. 10/05/15Brain & Language - Harry Howard - Tulane University 14 Conduction aphasia checklist a) comprehension of spoken material b) comprehension of written material c) segmental phonology d) word selection e) word semantics f) fluency (production of speech) g) production of writing h) use function words i) grammaticality j) repetition of what others say k) conversational proficiency, e.g. turn taking l) concern about impairment m) concern about errors n) short-term retention & recall of verbal materials o) other a) normal b) normal c) normal d) normal e) normal f) normal g) normal h) normal i) normal j) impaired: phonemic & semantic paraphasias k) normal l) yes m) yes n) ? o) can’t write to dictation

15. 10/05/15Brain & Language - Harry Howard - Tulane University 15 Hickok & Poeppel The production deficit is load-sensitive: errors are more likely on longer, lower-frequency words and verbatim repetition of strings of speech with little semantic constraint. Comprehension of speech is preserved because the lesion does not disrupt ventral stream pathways …. Phonological errors occur because sensory representations of speech are prevented from providing online guidance of speech sound sequencing; this effect is most pronounced for longer, lower-frequency or novel words, because these words rely on sensory involvement to a greater extent than shorter, higher-frequency words.

16. NEXT TIME Continue with the sensorimotor interface 10/05/15Brain & Language - Harry Howard - Tulane University 16