Statistic analysis on EEG data – how to deal with it properly?

How do you analyze EEG data?

There are two important methods for time domain EEG analysis: Linear Prediction and Component Analysis. Generally, Linear Prediction gives the estimated value equal to a linear combination of the past output value with the present and past input value.

How can EEG be improved?

There are major points that should be considered to improve the measurement performance in the design of the bio-signal measurement system or recording session. Specifically choosing the correct electrode, skin preparation, and reduction of power line noise are the important issues for EEG recordings.

What are the problems with EEG?

A small SNR and different noise sources are amongst the greatest challenges in EEG-based BCI application studies. Unwanted signals contained in the main signal can be termed noise, artifacts, or interference. There are two sources of EEG artifacts: external or environmental source and physiological source.

What data do you get from EEG?

An EEG records the electrical activity of your brain via electrodes affixed to your scalp. EEG results show changes in brain activity that may be useful in diagnosing brain conditions, especially epilepsy and other seizure disorders.

What are the 5 main frequencies measured by EEG?

Signal frequency: the main frequencies of the human EEG waves are:

  • Delta: has a frequency of 3 Hz or below. …
  • Theta: has a frequency of 3.5 to 7.5 Hz and is classified as “slow” activity. …
  • Alpha: has a frequency between 7.5 and 13 Hz. …
  • Beta: beta activity is “fast” activity.

What is EEG wave analysis?

An EEG is a test that detects abnormalities in your brain waves, or in the electrical activity of your brain. During the procedure, electrodes consisting of small metal discs with thin wires are pasted onto your scalp. The electrodes detect tiny electrical charges that result from the activity of your brain cells.

How do you use EEG electrodes?

Do not overfill the electrode cup applying. Too much paste. Will spread the conductive paste and could result in asymmetrical EEG signals we're going to place the EEG electrode on the mark spot.

How does an EEG headset work?

These headsets sense the electrical activity inside a person’s brain using a technique known as electroencephalography, or EEG. The technique works like this: Electrodes are placed on the surface of someone’s head; these electrodes can measure the electrical signals produced by the brain’s neurons through the scalp.

How do I get an EEG signal?

EEG signals are normally acquired using a differential amplifier. This is a component that measures small electrical potential difference between two points and then amplifies several times that potential for recording.

How do you measure brain frequency?

The EEG (electroencephalograph) measures brainwaves of different frequencies within the brain. Electrodes are placed on specific sites on the scalp to detect and record the electrical impulses within the brain. A frequency is the number of times a wave repeats itself within a second.

Does EEG measure action potential?

To be clear, EEG does not measure action potentials, but rather postsynaptic potentials. Action potentials are the rapid current flow from the soma along the axon, resulting from the depolarization (making more positive) of a neuron from its typical –70 mV resting potential to –55 mV.

What does background slowing on EEG mean?

As previously discussed, generalized background slowing in the theta and delta frequency ranges is a normal finding on EEG when it represents developmental slowing in children, adolescents, and some young adults or the evolution of drowsiness and sleep activity.

What does a mildly abnormal EEG mean?

An abnormal EEG means that there is a problem in an area of brain activity. This can offer a clue in diagnosing various neurological conditions.

How do I report EEG results?

The EEG report is structured to include demographics of the patient studied and reason for the EEG; specifics of the EEG techniques used; a description of the patterns, frequencies, voltages, and progression of the EEG pattern that were recorded; and finally a clinical impression of the EEG significance.

What does left temporal slowing mean on an EEG?

Re: left side temporal slowing

Focal slowing, where the frequency of the waves in one area of the brain is slower than the frequency in the rest of the brain, has more than one cause, so you’re going to have to get your doctor’s diagnosis to know exactly what it means to you.

What causes EEG slowing?

The slowing can be high or low amplitude. Several etiologies can cause diffuse slowing, including sedative medications, metabolic encephalopathy, toxic encephalopathy, cerebral infections like meningoencephalitis, or deep midline brainstem structural lesions.

What causes slowing of the brain?

Some people may have a genetic predisposition to age-related white matter decay, a poorly understood but actively studied hypothesis. In other individuals, slowed processing speed could be the first sign of a neurodegenerative illness, such as Alzheimer’s disease. Head trauma, including concussions, may play a role.

Can an abnormal EEG be wrong?

Yes, EEG can be bad for you. The consequences of being misdiagnosed with epilepsy are obvious and serious [9]. When the diagnosis is based largely on an abnormal EEG, no amount of subsequent normal EEGs will ‘cancel’ the previous abnormal one, and the wrong diagnosis is very difficult to undo.

How accurate is EEG test?

EEG review yielded 1-week accuracy in 10–52% of recordings, and 2-week accuracy in 28–75% of recordings (n = 146; Fig. 3E and F).

Can an EEG give a false positive?

EEG will be negative in a large portion of patients with epilepsy, and may be positive in patients without epilepsy. False positive EEG findings commonly lead to unnecessary use of antiepileptic drugs and may delay the syncope diagnosis and treatment.

Is an EEG always accurate?

If abnormalities on the routine EEG are found, such as focal spikes and generalized spike waves, the risk of seizure recurrence increases two times. However, the routine EEG has its limitations as its accuracy to detect abnormalities after a FSUS has a sensitivity of 17% and specificity of 95% (7).

What causes epileptiform?

The most common cause of PLEDs is an acute or subacute structural injury of the cerebral cortex, either diffuse or focal; however, PLEDs may also be seen in patients with a chronic static cerebral lesion or chronic epilepsy.

What is the meaning of epileptiform?

Epileptiform refers to spike waves, sharp waves, spike and wave activity, or other rhythmic waveforms that imply epilepsy or may be associated with epilepsy. However, epileptiform activity alone does not confirm a diagnosis of epilepsy.

Should epileptiform discharges be treated?

Although there is no solid evidence for or against treatment of EDs, a non-evidence based practical approach is suggested. EDs in otherwise asymptomatic individuals should not be treated as the risks of treatment probably outweigh its dubious benefits.

What is focal epileptiform discharges?

Focal interictal epileptiform discharges (IEDs) are sharply contoured transients that are distinct from and usually interrupt background activities. IEDs are almost always of negative polarity at the scalp surface. IEDs usually occur sporadically.