Electroencephalogram (EEG)

Definition

An electroencephalogram (EEG) is a non-invasive technique used to measure and record electrical activity in the brain through electrodes placed on the scalp. This method captures brain waves, which reflect neuronal activity, and provides insight into brain function and various neurological conditions.

5 Must Know Facts For Your Next Test

1. EEG is primarily used to diagnose conditions such as epilepsy, sleep disorders, and brain death by analyzing the patterns of brain wave activity.
2. The recording obtained from an EEG is a representation of summed electrical activity from many neurons firing in synchrony, giving insights into both normal and abnormal brain function.
3. EEGs are typically conducted in a controlled environment where patients may be asked to perform specific tasks or may be monitored during sleep to capture different brain states.
4. Real-time EEG data can be used for brain-computer interfaces, allowing for innovative applications in rehabilitation and assistive technologies for individuals with disabilities.
5. Artifacts can interfere with EEG recordings, originating from muscle activity, eye movements, or external electrical noise, which must be filtered out for accurate interpretation.

Review Questions

• How does an electroencephalogram work in measuring brain activity, and what types of information can it provide about neurological conditions?
  • An electroencephalogram measures brain activity by placing electrodes on the scalp that detect electrical signals produced by neuronal activity. These signals are recorded as waveforms that reflect different brain states. By analyzing these waveforms, clinicians can gain insights into various neurological conditions such as epilepsy, where abnormal wave patterns may indicate seizure activity.
• Discuss the significance of brain wave patterns captured in an EEG and how they relate to different states of consciousness.
  • The significance of brain wave patterns captured in an EEG lies in their ability to reflect different states of consciousness. For instance, alpha waves are present when a person is relaxed but awake, while delta waves are associated with deep sleep. Understanding these patterns helps clinicians assess brain function during various mental states and identify abnormalities that could indicate neurological disorders.
• Evaluate the impact of artifacts on EEG recordings and describe methods used to mitigate their effects during data collection.
  • Artifacts can significantly impact the quality of EEG recordings by introducing noise that masks true neural signals. Common sources of artifacts include muscle contractions, eye movements, and electrical interference from devices. To mitigate these effects, technicians often instruct patients to remain still and relax during recording sessions. Additionally, advanced signal processing techniques are applied post-collection to filter out artifacts while preserving relevant brain wave data.

Related terms

Brain Waves: Patterns of electrical activity in the brain, categorized into different types such as alpha, beta, theta, and delta waves, each associated with various states of consciousness.

Neurophysiology: The branch of physiology that focuses on the functions and activities of the nervous system, including how neurons communicate and the significance of electrical signals in brain function.

Electrodes: Conductive pads or sensors that are placed on the scalp to detect and measure electrical signals produced by neuronal activity during an EEG.