Electroencephalogram Lab Report

In this practical an electroencephalogram was carried out. An electroencephalogram (EEG) is a test that measures the brain waves and electrical activity of the brain by way of field potentials. It is used in both awake and asleep states. The human brain allows functions of various mechanisms to occur by communication within the brain. The communication within the brain is done through neurons of various sorts, sending action potentials through various regions. Each region in the brain will have specific activity when specific exercises are done. For example, when the eye registers an image in the retina, a series of action potentials are sent through the optic nerve, through various brain structures, including the lateral geniculate nuclei,
The electrodes, as they are non-invasive, are subject to noise from the subject. Examples of noise include eye movements, electrode pops, and blinking. The noise is important as it can add to the waves of the EEG creating false brain waves and incorrect results. The electrodes are then attached to a computer or generator, which will project the waves onto a screen. The number of electrodes can vary up to two hundred and fifty-six electrodes. The more electrodes are present, the more accurate the result. For this experiment, three electrodes were used including the ground and system electrode. The EEG that was carried out in the lab therefore, was not as accurate as other EEGs carried out and so errors in results could be due to this.
For this reason, the EEG is the main diagnostic item for epilepsy. Epileptic seizures will create different waves on an EEG than those of a normal human brain activities. People with frequent seizures will often have an EEG to test whether those seizures are epileptic or not. The subjects will be instructed not to sleep the night before or other causative factors that will initiate a seizure so it can be measured. The seizure will then be recorded while the patient wears EEG electrodes so it can be concluded whether epilepsy is present or not. If sharp spikes occur in the reading, epilepsy is likely. Different seizure types can be identified with this technique as well, for example, sharp spikes constantly, in all waveforms, indicate a generalised absence seizure. [5] The patient does not need to, however, undergo having a seizure for the test to detect epilepsy. People with epilepsy have an abnormal EEG reading to those without epilepsy even when no seizure is occurring with sporadic spikes in waveforms occurring, more so than people without