electrophysiological methods

Question 1

what is single cell recording

Answer 1

• Uncommon method for studying humans
  
  • Relevant for research with animals
    Patch clamp technique - enters nerve cells and records action potentials

Question 2

what does an EEG do

Answer 2

• Measures electrical activity from the scalp
  
  • Conductivity of skull between 1/40 and 1/80 of the conductivity of the brain
    We are only picking up a tiny fraction of actual brain activity

Question 3

what is required for an EEG of cognition

Answer 3

active and relaxed activity

Question 4

describe electromyography (EMG)

Answer 4

• Measures muscle response
  Detects invisible neuromuscular activity - used to detect emotions in psychological experiments

Question 5

what is electrodermal activity

Answer 5

EDA refers to the variation of the electrical conductance of the skin in response to sweat secretion.

Question 6

describe event related potentials (ERPs)

Answer 6

Stimulus onset = event to which we relate the potentials we are measuring
- Polarity - positive or negative
- Latency - how long after onset
- Amplitude
- Topographic distribution

Question 7

what is an open brain EEG

Answer 7

• recording electro-encephalographic signals directly from the surgically exposed cerebral cortex.
  
  • It detects intraoperatively the cortical regions with substantial epileptiform interictal discharges. Often used simultaneously with cognitive testing.
  • Promising technique as implants for use of brain-computer interfaces (direct neural interfaces that provide control of prosthetic, electronic, or communication devices via direct use of the individual’s brain signals).

Question 8

describe Magneto-encephalo-graphy (MEG)

Answer 8

• a functional neuroimaging technique for mapping brain activity by recording magnetic fields
  MEG outperforms EEG with respect to spatial resolution

Question 9

strengths of ERPs and ERFs

Answer 9

• high temporal resolution
  Direct measure of neural activity

Question 10

weaknesses of ERPs and ERFs

Answer 10

• Measures only a part of neural activity
  
  • Poor spatial resolution