Your SlideShare is downloading. ×
3680Lecture8.pptx - Slide 1
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×

Saving this for later?

Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime - even offline.

Text the download link to your phone

Standard text messaging rates apply

3680Lecture8.pptx - Slide 1

150
views

Published on


0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
150
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
0
Comments
0
Likes
0
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. The Event-Related Potential (ERP) • We have an ERP waveform for every electrode
  • 2. The Event-Related Potential (ERP) • We have an ERP waveform for every electrode • Sometimes that isn’t very useful
  • 3. The Event-Related Potential (ERP) • We have an ERP waveform for every electrode • Sometimes that isn’t very useful • Sometimes we want to know the overall pattern of potentials across the head surface – isopotential map
  • 4. The Event-Related Potential (ERP) • We have an ERP waveform for every electrode • Sometimes that isn’t very useful • Sometimes we want to know the overall pattern of potentials across the head surface – isopotential map Sometimes that isn’t very useful - we want to know the generator source in 3D
  • 5. Brain Electrical Source Analysis • Given this pattern on the scalp, can you guess where the current generator was?
  • 6. Brain Electrical Source Analysis • Given this pattern on the scalp, can you guess where the current generator was?
  • 7. Brain Electrical Source Analysis • Source Analysis models neural activity as one or more equivalent current dipoles inside a head-shaped volume with some set of electrical characteristics
  • 8. Brain Electrical Source Analysis This is most likely location of dipole Project “Forward Solution” Compare to actual data
  • 9. Brain Electrical Source Analysis • EEG data can now be coregistered with high- resolution MRI image
  • 10. Intracranial and “single” Unit • Single or multiple electrodes are inserted into the brain • “chronic” implant may be left in place for long periods
  • 11. Intracranial and “single” Unit • Single electrodes may pick up action potentials from a single cell • An electrode may pick up the combined activity from several nearby cells – spike-sorting attempts to isolate individual cells
  • 12. Intracranial and “single” Unit • Simultaneous recording from many electrodes allows recording of multiple cells
  • 13. Intracranial and “single” Unit • Output of unit recordings is often depicted as a “spike train” and measured in spikes/second Stimulus on Spikes
  • 14. Intracranial and “single” Unit • Output of unit recordings is often depicted as a “spike train” and measured in spikes/second • Spike rate is almost never zero, even without sensory input – in visual cortex this gives rise to “cortical grey” Stimulus on Spikes
  • 15. Intracranial and “single” Unit • By carefully associating changes in spike rate with sensory stimuli or cognitive task, one can map the functional circuitry of one or more brain regions • What are the advantages and limitations of this approach?
  • 16. Your Research Proposal Project • A research proposal attempts to persuade the reader that: – The underlying question is highly important – The proposed methodology and experimental design is the best available approach – That you have the knowledge and talent to do the proposed research – That you have a research program worth funding L
  • 17. Your Research Proposal Project • A research proposal is therefore similar to many other situations in which you will try to persuade someone of something – The skill is portable L
  • 18. Your Research Proposal Project • As in other situations, your reader should be assumed to be unconvinced and thus unwilling to spend much time and energy entertaining your argument! • You must make your argument easy and fast • The key to that is organization L
  • 19. Research Proposals Should be “Theory Driven” • Most proposals are organized around a specific theory • What is the difference between a theory and a question? L
  • 20. The Parts of a Research Proposal • Background • Statement of the theory • Prediction(s) that follow from the theory • Experimental Method and Design • Timeline • Budget • References L
  • 21. The Parts of a Research Proposal • Background • Statement of the theory • Prediction(s) that follow from the theory • Experimental Method and Design • Timeline • Budget • References L These aren’t necessary for your project
  • 22. Assignment • Rules: – Must be human Cognitive Neuroscience – Experimental approach may involve animal research only if this is the best way to test your theory • Studying humans is preferable to studying animals when you have a specific theory about human cognition • One moves to animal research because it tells you something that human research cannot • If this applies to your theory, you will make this constraint explicit in your proposal L