The electrophysiological setup Signal to noise ratio Physiological
- Slides: 19
The electrophysiological setup
Signal to noise ratio Physiological signal Artifacts from physiological source Artifacts from non-physiological source
The signal: EEG Beta: > 13 Hz Alpha: 8 -13 Hz Theta: 4 -8 Hz Delta: < 4 Hz
The signal: EKG
The signal: EOG (nystagmus)
The signal: EMG Human EMG recorded during squeezing a ball with increasing force
The signal: tonic & reactive SCR
The signal: spike
Amplifier
Amplitude resolution
Hardware filters
Electrodes
Sampling: time resolution In order to get signals into a form computers can manipulate they must be changed from their analog form (continuous gradients) into a digital form (step gradients) using the technique of sampling. Sampling: A technique used to capture continuous phenomena, whereby periodic snapshots are taken. If the sampling rate is fast enough, the human sensory organs cannot discern the gaps between each snapshot when they are played back. This is the principle behind motion pictures.
Sampling and the Nyquist Theorem The Nyquist Theorem states that in order to adequately regenerate a signal it should be sampled at a rate that is 2 X the highest frequency. That is, the sample, or pixel, size should be 1/2 the size of the smallest desired object.
Aliasing If the sampling rate is too low the resultant signal will show a curve that is not representative of the original. This is called aliasing. Aliasing does not occur if the sampling rate is greater than twice the frequency of a sinusoid.
Oscilloscope
Audio record of neurons
Analysis: FFT
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- S/n ratio
- Snr signal to noise ratio
- Baseband and broadband transmission
- Kamran nishat
- Snr signal to noise ratio
- Semantic noise
- Companding quantization
- Frankel signal to noise
- Noise is added to a signal in a communication system *
- Signal vs noise
- Carrier to noise ratio
- Carrier power formula
- Classification of signal
- Digital signal as a composite analog signal
- Baseband signal and bandpass signal
- Baseband signal and bandpass signal
- Fixed interval vs fixed ratio
- Rr statistics
- Incomplete vs codominance
- Simple machines that use gears