Lecture 19: Measuring Activity of the CNS

0.0(0)
studied byStudied by 0 people
learnLearn
examPractice Test
spaced repetitionSpaced Repetition
heart puzzleMatch
flashcardsFlashcards
Card Sorting

1/9

encourage image

There's no tags or description

Looks like no tags are added yet.

Study Analytics
Name
Mastery
Learn
Test
Matching
Spaced

No study sessions yet.

10 Terms

1
New cards

Electroencephalography (EEG)

  • Measures electrical activity of the brain

  • Post-synaptic activity of 1000s or more neurons

  • Event-related brain potentials (ERP)

  • Excellent temporal resolution BUT “inverse problem”

  • Fast measurement technique → measures electro-activity in milliseconds

  • Doesn’t allow you to localize brain area → very poor spatial resolution

  • Measure technique time locked to sensory, cognitive, or motor event.

  • Hundreds of trials

  • Going above 0 voltage → increase; going below 0 voltage → decrease

<ul><li><p>Measures <strong>electrical activity of the brain</strong></p></li><li><p>Post-synaptic activity of 1000s or more neurons</p></li><li><p>Event-related brain potentials (ERP)</p></li><li><p>Excellent temporal resolution BUT “inverse problem”</p></li><li><p><strong>Fast measurement technique </strong>→ measures electro-activity in milliseconds</p></li><li><p>Doesn’t allow you to localize brain area → <strong>very poor spatial resolution</strong></p></li><li><p>Measure technique time locked to <strong>sensory</strong>, cognitive, or motor event.</p></li><li><p>Hundreds of trials</p></li><li><p>Going above 0 voltage → increase; going below 0 voltage → decrease</p></li></ul>
2
New cards

Positron Emission Tomography (PET)

  • Nuclear imaging technique

    • Injected with radioactive (isotope) trackers

  • Measures physiological changes → metabolism, blood flow, glucose uptake

  • Primarily used as diagnostic tool → identify specific neurodegenerate diseases

  • Very poor spatial resolution

<ul><li><p><strong>Nuclear imaging technique</strong></p><ul><li><p>Injected with radioactive (<strong>isotope</strong>) trackers</p></li></ul></li><li><p>Measures<strong> physiological changes</strong> → metabolism, blood flow, glucose uptake</p></li><li><p>Primarily used as diagnostic tool → identify specific <strong>neurodegenerate diseases</strong></p></li><li><p>Very poor spatial resolution</p></li></ul>
3
New cards
<p>Which is the healthy brain and which is the Alzheimer’s brain?</p>

Which is the healthy brain and which is the Alzheimer’s brain?

  • Scan 1 → healthy participant

  • Scan 2 → Alzheimer’s Disease; slight reduction in overall cortical and subcortical regions of the brain

4
New cards
<p>Which is the healthy brain and which is the Parkinson’s brain?</p>

Which is the healthy brain and which is the Parkinson’s brain?

  • Scan 1 → healthy participant

  • Scan 2 → Parkinson’s Disease

5
New cards

What was neuroimaging originally used for and what does it do now?

  • Originally to localize function in the brain

  • Now clinical to look at onset and progression of neuro-degenerate diseases like Alzheimer’s and Parkinson’s

6
New cards

Functional Magnetic Resonance Imaging (fMRI)

  • Measures brain activity by identifying changes in blood flow

    • Brain activity and blood flow linked

  • Bold signal

  • System level of the brain

  • All about structure and function

  • Measuring neural activity in brain by proving good spatial resolution but terrible temporal resolution

  • A little slow → ~1 second

  • Participant tapping finger → fMRI sees primary motor cortex active, able to evaluate bold signal through blood oxygen level → magnet spins biomolecules and blood cells in brain (carrying O2) able to measure spin frequency and determine where there is significant uptake of blood

<ul><li><p>Measures brain activity by <strong>identifying changes in blood flow</strong></p><ul><li><p>Brain activity and blood flow linked</p></li></ul></li><li><p><strong>Bold signal</strong></p></li><li><p>System level of the brain</p></li><li><p>All about <strong>structure and function</strong></p></li><li><p>Measuring neural activity in brain by proving <strong>good spatial resolution</strong> but <strong>terrible temporal resolution</strong></p></li><li><p>A little slow → ~1 second</p></li><li><p>Participant tapping finger → fMRI sees primary motor cortex active, able to evaluate bold signal through blood oxygen level → magnet spins biomolecules and blood cells in brain (carrying O2) able to measure spin frequency and determine where there is significant uptake of blood</p></li></ul>
7
New cards

Near-Infrared Spectroscopy

  • Technique using light to detect changes in oxygenated (and deoxygenated) hemoglobin in blood.

  • Decrease in oxygenation of the blood cells as a function of exercise → cells using more oxygen

<ul><li><p>Technique using light to <strong>detect changes in oxygenated (and deoxygenated) hemoglobin in blood.</strong></p></li><li><p>Decrease in oxygenation of the blood cells as a function of exercise → cells using more oxygen</p></li></ul>
8
New cards

Transcranial Magnetic Stimulation (TMS, rTMS)

  • Non-invasive brain stimulating technique in which a changing magnetic current induces electrical activity at a specific region of the brain

  • “Virtual” lesion technique → disrupts or facilitates neural activity in the brain

    • If disrupt is virtual lesion → area doesn’t work for a couple milliseconds

  • Increases or decreases localized brain activity

  • Single pulse creates scotoma (small area where you can’t see) in visual cortex → no processing of visual information

9
New cards

Purdue Pegboard Test Findings

  • 1 and 3 Hz groups showed better functional recovery at every assessment

  • 1 Hz to unimpaired Hz has the greatest recovery

<ul><li><p>1 and 3 Hz groups showed better functional recovery at every assessment</p></li><li><p>1 Hz to unimpaired Hz has the greatest recovery</p></li></ul>
10
New cards

TMS and Visual Spatial Neglect

  • One treatment of 5 Hz, 15 days later

  • Difference of severity of visual spatial neglect → gradually faded back to baseline