John-Nadra-Neurotech-Talk

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📗 -> John Nadra Neurotech Talk

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❗ Information

How John Nadra became John Nadra PHD

Academics

AA in Psych and Soc at CC
BA in Psych from Sonoma State

• Cog neuro lab
• presented posters
  Ph.D. and Masters at Davis
• Publish papers, TA, fellowships
  Post Doc and Lecturer at Davis
• Papers, teach, fellowships

Non Academic

Grew up in Stockton and NY, did not know/like academia. No academics in life.

✒️ -> Scratch Notes

Electrophysiological Correlates of Willed Attention

What do you do? - from family over & over again

Attention

William James 1890 quote. “Everyone knows what attention is.”
Operational Def:

• Attention is the ability to focus one’s awareness on relevant events and objects while ignoring distractions

Background: Voluntary attention

Posner task:

• Primary way to test voluntary attention
• Attend right or left
• Cue -> SOA -> Target -> REsponse
• SOA - synchronous stimulus onset asynchrony?
  He doesn’t think this is a good way to study attention

Willed attention

• Cue -> SOA -> Target -> Response -> SOA -> Report
• Bengson et al. 2014
  In posner task you aren’t making a choice. Doing what told.
  Instead, generate your own decision. This is the crux of willed atention

Self-initiated attnetion, in the abscence of external cues
MInimized external influence, pushing for internally-driven attentional shift

Known neural mechanisms of willed attention (EEG)

Predictive alpha-band activity precedes the onset of a cue

• Signal in the brain is biasing decision to attend before the prompt to choose occurs

(-800 - 0) Found a significant difference in the brain predicting their choice. See what their brain is going to choose on a trial by trial basis.
(-1700 - -900) Found that this effect vanishes

Why study?

• BCI
  • Could predict choices before their presented? didn’t understand
• Free will
  • Libet’s work about intention to act originating before conscious awareness of wanting to move finger

Electrophysiological Correlates of Willed Attention

• Temporal dynamics of covert willed attention
• Overt willed attention in visual search
• Color-willed attention

Experiment 1 - Temporal dynamics of covert willed attention

• Filly willed attention
  • Participants directing and redirecting attention whenever they wanted. Not being directed by experimenter
  • Decision to shift attention when and where
• Analysis focused relative to button press
  • Signaling active attention

Alpha - To pay attention in right, you have to inhibit left

• You will see more alpha band power when you are inhibiting something
  • More in left, less in right

SVM Decoding

• Feed in classes of data.
• Provide a set ratio of data to training an test.
• SVM distinguishes between classes (hyperplane).
• Cross-validation (shuffle train and test and run again).
• Compare true labels with predicted labels.
• Compare test against chance.

Button Press Decoding

• Epoched relative to the button press
  • Over 19 occipital electrodes
• Shows a ramp-up in decodability to the onset of the button press
• Gradual ramp-down post button-press

CSD Analyses

• Alpha band CSD topographic maps
• Alpha band CSD posterior electrode decoding
  Mu rythm over motor cortex predicting button press?
• Did a control, did not find highly significant findings

Conclusion

• Developed a unique paradigm that breaks out of the cue-to-target standard
• Replicaed the classic alpha-lateralization found in cued attention without cues
  • First study to do so; important for future BCIs

Research is EXPENSIVE. Running a lab burns money. Land space, equipment, participants…

Q&A

Pressing a button small enough for no artifact. Motor signal in brain is a factor though.

Rock Paper Scissors intention study.

Decision network stuff?

Ron Mangun and Mike Gazzaniga (Michael S. Gazzaniga) best neuroscientists

🔗 -> Links

Resources

• Put useful links here

Connections

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