Toolkit 2 - Electrophysiological methods Flashcards
What is single cell recording?
Relatively uncommon method for studying humans
Relevant for research with animals
What is EEG?
Measures electrical activity from the scalp
What are the EEG wave types
active
relaxed
sleepy
(those are relevent for studying cognition)
sleep
deep sleep
coma
What are the frequency bands and underlying assumptions?
Gamma: >30 Hz
- problem solving and concentration
Beta: 13-30 Hz
- busy active mind
Alpha: 8-13 Hz
- reflective, restful
Theta: 4-8 Hz
- drowsiness
Delta: 0.3-4 Hz
- sleep, dreaming
(delta is not relevant for studying cognition)
What is sensory motor rhythm?
the individual & specific frequency band in which the sensory and motor cortex communicate to facilitate efficient interaction with the world (unique frequency band to reduce interfering noise)
What are the other measures of electrophysiology? (not brain)
Electro cardiogram - heart beat
Respiratory rate
Emg - muscle response
What is electromyography (EMG)?
Measures muscle response.
EMG can sense isometric muscular activity where no movement is produced. Reveals nerve or muscle dysfunction, or problems with nerve-to-muscle signal transmission.
EMG detects invisible neuromuscular activity (e.g. hidden frowning or smiling) and can be used to detect emotions in psychological experiments because even if we do not move our face, the frowning and smiling muscles get impulses when we experience emotions
What is Electrodermal activity?
(EDA)
EDA refers to the variation of the electrical conductance of the skin in response to sweat secretion.
EDA biofeedback measures the electrical characteristics of the skin using methods such as skin conductance response (SCR), and skin conductance level (SCL).
Measures: stress, arousal, emotion, cognitive load
Method underlying lie detectors
What are event related potentials?
Stimulus Onset = Event to which we relate the electric potentials that we are measuring
ERPS are categorised by:
Polarity (neg vs pos)
Latency (how long after onset?)
Amplitude (in μV)
Topographic distribution (maps)
What is an open brain EEG?
recording electro-encephalographic signals directly from the surgically exposed cerebral cortex
What is MEG?
Magneto-Encephalo-Graphy
a functional neuroimaging technique for mapping brain activity by recording magnetic fields
What are the strengths and weaknesses of ERPs?
Strengths:
High temporal resolution
Direct measure of neural activity
Weaknesses:
Measures only a part of the neural activity (open fields)
Poor spatial resolution (inverse problem)
