Electroencephalography, or EEG, is a non-invasive procedure used to record electrical activity in the brain. This diagnostic test helps doctors detect abnormalities in brain function and identify conditions such as epilepsy, sleep disorders, and brain tumors. To perform an EEG, specialized equipment is required.
EEG Cap
The most essential piece of equipment used in an EEG is the EEG cap. This cap contains multiple electrodes that are placed on different areas of the scalp to measure electrical activity. The number of electrodes can vary depending on the specific type of EEG being performed.
If possible, it may be advantageous for the participant and researchers to be separated into two different rooms. In such a set-up, the participants are seated immediately on the other side of a wall that separates them from the researchers. First, the researchers are able to discuss the incoming EEG during acquisition without distracting the participant, which provides an advantageous training environment. Extraneous auditory stimuli, such as that from conversations, will likely decrease the SNR, lead to messier data, and potentially mask otherwise present effects. Second, it allows for data collection to occur in a dark or dimly lit room which is particularly advantageous for studies examining visual processing.
Amplifier
It is unclear if there are differences regarding EEG features and prognostication with or without post-hypoxic myoclonus (26). The demonstration of EEG features on the ictal-interictal continuum are important both as a possible marker of poor outcome or a predictor of high risk for subsequent seizures that require treatment (15; 106; 39; 82; 92). Patients in the intensive care unit (ICU) are critically ill and require multimodal continuous physiological monitoring. Like telemetry and pulse oximetry for the cardiorespiratory systems, EEG allows for real-time neurophysiological monitoring. EEG measures electrical activity in the brain and can sensitively detect changes in brain functioning and structure (71).
Input-referred noise refers to the voltage or current noise produced by the amplifier’s internal circuitry (even when there’s no signal present at the input). Given that EEG signals can have amplitudes as low as a few microvolts, it’s crucial for this noise to be less than 1μVrms. For recording low EEG frequencies, the amplifier should either be DC coupled or have a high-pass cutoff frequency close to 0Hz. It’s worth mentioning that DC coupled amplifiers can capture various slow cortical potentials, which is an important factor to consider.
EEG brain recording methods are relatively cheap and feasible compared to other neuroimaging methods. However, the design and setup of an EEG lab poses non-trivial consequences on EEG data quality. As a result, care and planning is recommended for principal investigators and stakeholders who are interested in developing a new EEG lab. Successful development of such a lab will lead to increased interdisciplinary curricula in the neurosciences and diversify undergraduate student research experiences.
Another crucial component of an EEG setup is the amplifier. This device takes the electrical signals picked up by the electrodes and amplifies them for better analysis. The amplifier also filters out any unwanted noise to ensure accurate readings.
Doctors can also use it to understand the brain’s activity after a brain trauma such as a head injury or brain tumor. An EEG looks at what is happening in the brain for the duration of the test rather than the brain’s physical structure. In general, the cost of a routine in-office EEG ranges from around $200 to $800 or more. If video monitoring is included or if the test is longer or takes place overnight in a hospital, the total could be $3,000 or more. Often EEGs are named based on the length of recording time required (e.g., two-hour EEG, 24-hour EEG). If your healthcare provider does not tell you, ask how long your test will last from start to finish so you can plan accordingly.
Consequently, EEG/ERP provide a feasible human cognitive neuroscience technique that students at PUIs may use in the classroom or research space. The use of EEG methods in neuroscience courses may vary from the analysis of archival data (Miller et al., 2008), to data collection and analysis (Marshall et al., 2011; Shields et al., 2016). Adding an EEG/ERP lab to a neuroscience program at a PUI would advance neuroscience curricula and research experiences, reflecting the evolving interdisciplinary field of neuroscience. You’ll probably want to wash your hair to get rid of any remaining glue. You may find that your scalp is red and irritated in the spots where the electrodes were placed, but it shouldn’t last long. The wires from the electrodes will be attached to a recording device that’s a little bigger than a portable tape player.
Computer
A computer is used to process and display the data collected during an EEG. Specialized software allows healthcare providers to analyze the electrical patterns in the brain and make a diagnosis based on the results.
Additional Accessories
Other equipment that may be used in an EEG setup includes conductive gel (to improve electrode-skin contact), a head measuring tool (to ensure proper electrode placement), and a video camera (to record the patient’s behavior during the test).
In conclusion, the equipment used in an EEG plays a crucial role in capturing and analyzing electrical brain activity. By understanding how these components work together, healthcare providers can accurately diagnose and treat various neurological conditions.
