1. The sensorimotor interface Oct 9, 2017 – DAY 18
Brain & Language
LING
NSCI
Harry Howard
Tulane University

2. Brain & Language - Harry Howard - Tulane University
09-Oct-17
Brain & Language - Harry Howard - Tulane University
Course organization
Fun with

3. Brain & Language - Harry Howard - Tulane University
09-Oct-17
Brain & Language - Harry Howard - Tulane University
Quiz stats P1 P2 P3 P4 P5 P6 P7 P8 P9
P10
P11
tot
MIN 4 5 6
AVG
7.7
8.2
8.4
9.1
MAX 10

4. Brain & Language - Harry Howard - Tulane University
09-Oct-17
Brain & Language - Harry Howard - Tulane University
Wernicke's aphasia
The quiz was the review

5. The sensorimotor interface
09-Oct-17
Brain & Language - Harry Howard - Tulane University
The sensorimotor interface
Parietal-temporal Spt

6. The Sylvian parieto-temporal junction
09-Oct-17
Brain & Language - Harry Howard - Tulane University
The Sylvian parieto-temporal junction

7. Brain & Language - Harry Howard - Tulane University
09-Oct-17
Brain & Language - Harry Howard - Tulane University
My version
Dorsal stream: REPEAT
t11-HickokPoeppelHoward2

8. Motivation for the dorsal stream in general
09-Oct-17
Brain & Language - Harry Howard - Tulane University
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.

9. Specific questions about the SMI
09-Oct-17
Brain & Language - Harry Howard - Tulane University
Specific questions about the SMI
Where is it located?
Why is a sensorimotor interface necessary?
How does it work?

10. Temporoparietal junction (TPJ)
09-Oct-17
Brain & Language - Harry Howard - Tulane University
Temporoparietal junction (TPJ)

11. Wikipedia's description
09-Oct-17
Brain & Language - Harry Howard - Tulane University
Wikipedia's description
The temporoparietal junction (TPJ) is an area of the brain where the temporal and parietal lobes meet, at the posterior end of the Sylvian fissure.
The TPJ incorporates information from the thalamus and the limbic system, as well as from the visual, auditory, and somatosensory systems.
The TPJ is responsible for collecting all of this information and then processing it. This area is also known to play a crucial role in self-other distinctions processes and theory of mind (ToM). Furthermore, damage to the TPJ has been implicated in having adverse effects on an individual’s ability to make moral decisions and has been known to produce out-of-body experiences (OBEs). Electromagnetic stimulation of the TPJ can also cause these effects.
Apart from these diverse roles that the TPJ plays, it is also known for its involvement in a variety of widespread disorders including amnesia, Alzheimer's disease, and schizophrenia.

12. Back to H&P: The initial bit of evidence
09-Oct-17
Brain & Language - Harry Howard - Tulane University
Back to H&P: 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:

13. Data that has been collected so far
09-Oct-17
Brain & Language - Harry Howard - Tulane University
Data that has been collected so far
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?
the ability to acquire new vocabulary.
altered auditory feedback disrupts speech production.
articulatory decline in late-onset deafness.
the basic neural mechanisms for phonological short-term memory
disruption by lesions: conduction aphasia
the non-phonological residue of Wernicke's aphasia: deficient self-monitoring

14. The ability to acquire new vocabulary
09-Oct-17
Brain & Language - Harry Howard - Tulane University
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.

15. The effect of auditory feedback on speech production
09-Oct-17
Brain & Language - Harry Howard - Tulane University
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!

16. Brain & Language - Harry Howard - Tulane University
09-Oct-17
Brain & Language - Harry Howard - Tulane University
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)
Originally thought due to damage to arcuate fasciculus > can't conduct information from Wernicke's to Broca’s area

17. Brain & Language - Harry Howard - Tulane University
09-Oct-17
Brain & Language - Harry Howard - Tulane University
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)

18. Conduction aphasia checklist
09-Oct-17
Brain & Language - Harry Howard - Tulane University
Conduction aphasia checklist
comprehension of spoken material
comprehension of written material
segmental phonology
word selection
word semantics
fluency (production of speech)
production of writing
use function words
grammaticality
repetition of what others say
conversational proficiency, e.g. turn taking
concern about impairment
concern about errors
short-term retention & recall of verbal materials
other
normal
impaired: phonemic & semantic paraphasias
yes ?
can’t write to dictation

19. Brain & Language - Harry Howard - Tulane University
09-Oct-17
Brain & Language - Harry Howard - Tulane University
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.

20. Brain & Language - Harry Howard - Tulane University
09-Oct-17
Brain & Language - Harry Howard - Tulane University
NEXT TIME
Continue with the sensorimotor interface