w2 Transtech: class notes

parasympathetic vs sympathetic systems

exercise: inhale for 4 counts, exhale for 8 counts
> slows down heart rate, puts body into parasympathetic system, lowers cortisol levels

Allostatic load: good, tolerable and toxic stress
Allostasis system tries to regulate

norepinephrine is low: can’t identify what is important
dopamine is low: can’t sustain attention but can see what is important; low sense of reward, no interest in life

mental quiescence/absorption meditations:
> yoga, TM (repeat mantra with least amount of effort possible, enjoy pleasure of meditation; switches into parasympathetic system), shamata (focus on breathing, attention stabilizes)
> you don’t experience outside perceptions, body, etc, just what you are focusing on
> can come into contact with the “deepest part of yourself”
> decreased sympathetic and increased parasympathetic ANS
>> decrease in heart rate and blood pressure, but increase in cerebral activity (in alpha and theta bands)
>> with repeated practice, this type of meditation leads to the establishing of internal metabolic rest as the baseline state of the organism

Tonic alertness: controlled parasympathetic system
Mindfulness/zen elicit heightened parasympathetic activity and tonic alertness

deity yoga, deity meditation, chakra meditations, etc lead to heightened sympathetic activation and phasic alertness

relaxation meditations lower stress but do not affect cognitive function

 

Current Imagining Modalities

  • Hemodynamic/Metabolic
    • PET
    • fMRI
  • Nuclear
    • MRS
  • ElectroMagnetic
    • MEG
    • EEF/ iEEF-EcoG (intracranial)
  • Optical (tracks blood flow using laser, or makes cells responsive to certain lights)
    • NIRS
    • Optogenetic

Electromagnetic methods:

  • high temporal resolution ~ 1ms (can see how signal enfolds)
  • Can’t tell exactly where signal is coming from
  • high density of electrodes allows mathematical analysis to give idea of where signals are coming from
  • picks up a lot of “garbage”: signals from the environment, muscles around the skull (gamma, hard to clean out), eye movements (blinking, moving eyes left to right creates strong magnetic field, darting of eyes), heart rate
  • Frequencies: greater the frequency, the weaker it is
    • delta waves: 1-12 hertz, slower and dominate brain while it’s inactive (deep dreams, comas
      • deep sleep: memories consolidated
      • REM: cleaning out info
    • theta frequencies:
      • hippocampus: broadcasts theta, carries memories
      • prefrontal: cognitive activity (paying attention)
      • posterior channels: alpha/theta during creativity
      • daydreaming, not paying attention
    • alpha: most predominate frequency in brain
      • thalamus: uses it to organize other parts of brain
      • prefrontal: suppresses non-preferred parts of experience
      • idling signal
      • posterior: alpha increases when you close your eyes
    • beta: (13-35 hertz) most associated with every day thinking, language processing,
      • motor areas are mostly beta
      • prefrontal: “high beta stress”
    • gamma range (35-80+ low gamma, 80-250+ high gamma):
      • difficult to pick up w/ eeg because of muscle contamination

Neurofeedback

  • alpha-theta protocol: increase alpha and theta in posterior areas (increases creativity?)
  • beta protocol: increase beta and decrease theta in frontal sites

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