1. neurons sepT. 18, 2017 – DAY 9 Brain & Language
LING
NSCI
Harry Howard
Tulane University

2. Brain & Language - Harry Howard - Tulane University
18-sep-17
Brain & Language - Harry Howard - Tulane University
Course organization
Fun with

3. Brain & Language - Harry Howard - Tulane University
18-sep-17
Brain & Language - Harry Howard - Tulane University
Review
The quiz was the review.

4. Change in organization
18-sep-17
Brain & Language - Harry Howard - Tulane University
Change in organization
Old
New
Background
Introduction to the course
The fields of linguistics
The macrostructure of the brain
Speech
Sound
Speech sounds and their articulation
Auditory transduction
Subcortical audition
The auditory cortex
The superior temporal sulcus
Wernicke’s aphasia
Leftovers
The microstructure of the brain
Methodologies
Background
Introduction to the course
My philosophy of teaching
The fields of linguistics
Sound
Speech sounds and their articulation
The extended ascending auditory pathway
Perception
Auditory transduction
The microstructure of the brain (neurons)
Subcortical audition
The macrostructure of the brain (cortex)
The auditory cortex
The superior temporal sulcus
Wernicke’s aphasia

5. Auditory transduction
18-sep-17
Brain & Language - Harry Howard - Tulane University
Auditory transduction
Review

6. Anatomy of the human ear
18-sep-17
Brain & Language - Harry Howard - Tulane University
Anatomy of the human ear

7. Sample frequency cross-sections of the coiled cochlea, in Hertz
18-sep-17
Brain & Language - Harry Howard - Tulane University
Sample frequency cross-sections of the coiled cochlea, in Hertz
tonotopy: a mapping from sound frequency to place on the basilar membrane

8. Brain & Language - Harry Howard - Tulane University
18-sep-17
Brain & Language - Harry Howard - Tulane University
Sample frequency cross-sections of an uncoiled cochlea, in Hertz [tonotopy]

9. Brain & Language - Harry Howard - Tulane University
18-sep-17
Brain & Language - Harry Howard - Tulane University
Hair cells along the basilar membrane [this is what I want to explain today]

10. Ascending auditory pathway 1 (not review)
18-sep-17
Brain & Language - Harry Howard - Tulane University
Ascending auditory pathway 1 (not review)
300px-Hearing_mechanics_cropped_A1.jpg

11. Ascending auditory pathway 2 (not review)
18-sep-17
Brain & Language - Harry Howard - Tulane University
Ascending auditory pathway 2 (not review)
666669_m.png

12. Brain & Language - Harry Howard - Tulane University
18-sep-17
Brain & Language - Harry Howard - Tulane University
Neurons

13. Brain & Language - Harry Howard - Tulane University
18-sep-17
Brain & Language - Harry Howard - Tulane University
A pyramidal neuron

14. Electrical activity of neurons
18-sep-17
Brain & Language - Harry Howard - Tulane University
Electrical activity of neurons
Each neuron consists of a cell body, short threadlike projections called dendrites, and one longer thread called an axon.
Impulses travel within a neuron in the form of electrical signals, but between them as chemical signals.
The electrical signal is changed to a chemical one at the synapse, and then changed back to an electrical one on the other side of the synapse.
post-synaptic,
dendrites
pre-synaptic,
axon

15. Another way of saying it
18-sep-17
Brain & Language - Harry Howard - Tulane University
Another way of saying it

16. Electrical-chemical-electrical communication at the synapse
18-sep-17
Brain & Language - Harry Howard - Tulane University

17. Brain & Language - Harry Howard - Tulane University
18-sep-17
Brain & Language - Harry Howard - Tulane University
A bit of cell membrane

18. Electrical and hydraulic models
18-sep-17
Brain & Language - Harry Howard - Tulane University
Electrical and hydraulic models

19. The Hodgkin-Huxley model
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Brain & Language - Harry Howard - Tulane University
The Hodgkin-Huxley model

20. Close-up of an action potential
18-sep-17
Brain & Language - Harry Howard - Tulane University
Close-up of an action potential

21. Brain & Language - Harry Howard - Tulane University
18-sep-17
Brain & Language - Harry Howard - Tulane University
A spike train

22. Layout of dendrites of pyramidal cells
18-sep-17
Brain & Language - Harry Howard - Tulane University
Layout of dendrites of pyramidal cells
apical
dendrites
basal
dendrites

23. Axons vs. apical dendrites (in cortex)
18-sep-17
Brain & Language - Harry Howard - Tulane University
Axons vs. apical dendrites (in cortex)
Axons are oriented randomly along the cortical sheet, which results in their potentials cancelling one other out.
Apical dendrites are oriented in parallel along the cortical sheet, which results in their potentials to reinforce one another and sum together, creating a large “dipole”, which is measurable with EEG/MEG.

24. Hair cells along the basilar membrane
18-sep-17
Brain & Language - Harry Howard - Tulane University
Hair cells along the basilar membrane

25. The physical basis of the cognitive attributes of sound
18-sep-17
Brain & Language - Harry Howard - Tulane University
The physical basis of the cognitive attributes of sound
Physical
Neural coding
Cognitive
quantity
duration of spike trains
duration
frequency
tonotopy: frequency-to-place mapping
tone
intensity
rate (of action potential firing)
loudness

26. Brain & Language - Harry Howard - Tulane University
18-sep-17
Brain & Language - Harry Howard - Tulane University
NEXT TIME
Ascending auditory pathway (sub-cortical audition)