Thus, researchers should use Huynh-Feldt, Geisser-Greenhouse, or other similar corrections to alter the degrees of freedom and the significance of the F-ratio. The epsilon value should be reported in manuscripts (Jennings, 1987). An appropriate alternative is to analyze data with repeated-measures MANOVA, which does not assume sphericity. Before the test starts, your scalp will be cleaned and about 20 small sensors called electrodes will be attached using a special glue or paste. The main use of an EEG is to detect and investigate epilepsy, a condition that causes repeated seizures. An EEG will help your doctor identify the type of epilepsy you have, what may be triggering your seizures and how best to treat you.
To overcome these challenges, researchers employ various signal processing techniques and advanced algorithms to minimize and remove noise from EEG signals, enabling more accurate and meaningful data interpretation. Additionally, the interpretation of complex brainwave patterns requires expertise and careful analysis to decipher the underlying neural activity. Once the electrodes are in place, the technician will have you close your eyes and relax.
An electroencephalogram (EEG) is a test that detects electrical activity in the brain using electrodes attached to the scalp. It is a valuable tool in diagnosing various neurological conditions, but like any medical procedure, it has its own set of pros and cons.
In this review, we highlight some of the challenges for using EEG in cognitive development research. We also list best practices for incorporating this methodology into the study of early cognitive processes. Consideration of these issues is critical for making an informed decision regarding implementation of EEG methodology. Functional magnetic resonance imaging (fMRI) operates on the same principles but it shows changes in brain activity over time by tracking blood flow and oxygen levels (Fig.11.3.1).
The EEG has been used for many years and is considered a safe procedure. For quicker, affordable, and accessible insights about brain function, with a tight temporal resolution, EEG is the method of choice. This can of course undermine the accuracy of recording a novel response, but does provide a full range of brain responses. Below we will go through the most common brain imaging techniques – EEG, and (f)MRI, to see how they work, and how they compare, looking at the advantages and disadvantages of each.
Pros:
For example, people who are nonverbal and have limited mobility from conditions like cerebral palsy may have subtle or no physical activity when they have seizures. An ambulatory EEG is where brain activity is recorded throughout the day and night over a period of one or more days. The electrodes will be attached to a small portable EEG recorder that can be clipped onto your clothing. Your technician will remove the electrodes and clean the part of your scalp where they placed the electrodes.
- Non-invasive: One of the biggest advantages of an EEG is that it is a non-invasive procedure, meaning it does not require any incisions or needles.
- Diagnostic tool: EEGs can help diagnose epilepsy, sleep disorders, and other neurological conditions by measuring brain wave patterns.
- Safe: EEGs are considered safe and painless, making them suitable for patients of all ages.
- Real-time monitoring: EEGs provide real-time information on brain activity, allowing healthcare providers to make immediate treatment decisions.
It is important to remember that poor quality data leads to more noise, which in turn leads to more trials that might need to be rejected. Participants can often get tired and fed-up with long, monotonous studies. It is thought that blocks lasting 5–7 min, separated by a short break, are optimal (Luck 2005). Thirdly, a large number of trials often lead to more artefacts and more trials that will have to be removed. Eye blinks, muscle movements, accidental head turns, even swallowing can create artefacts which will affect the ERPs. A large number of trials make it impractical for the ERPs to be used in certain experiments, such as those in which each participant can only receive one trial in each condition (Luck 2005).
Skin irritation or redness may be present at the locations where the electrodes were placed. To discover more evidence-based information and resources on the science of healthy sleep, visit our dedicated hub. For close to a century, EEG has been used and refined, leading to many discoveries in neurology and psychiatry, as well as helping doctors diagnose and treat their patients. Through these applications, EEG contributes to our understanding of cognitive function and can aid in the diagnosis and treatment of cognitive disorders. Your provider will tell you when you can go back to taking any medicines you stopped before the test. Instead of keeping you up the night before, your provider may have you go in for your EEG very early in the morning while you’re still drowsy.
Cons:
- Limited spatial resolution: EEGs have limited ability to pinpoint the exact location of abnormal brain activity due to the placement of electrodes on the scalp.
- Interpretation challenges: EEG results can be complex and require specialized training to interpret accurately.
- Noisy environment: External factors such as movement and electrical interference can affect the quality of EEG recordings.
- Cost: While EEGs are generally affordable, the cost can vary depending on the facility and location.
Frequently Asked Questions:
Q: Are there any risks associated with an EEG?
A: EEGs are considered safe, with minimal risks involved. Some patients may experience mild discomfort from the adhesive used to attach the electrodes.
Q: How long does an EEG procedure take?
A: An EEG typically takes about 60-90 minutes to complete, including prep time for electrode placement and recording.
Q: Can I drive myself home after an EEG?
A: In most cases, it is safe to drive yourself home after an EEG unless sedation was used during the procedure.
