What does a decrease in the power of Spectral Edge indicate?

A decrease in the power of Spectral Edge indicates a greater proportion of EEG power at lower frequencies. The Spectral Edge frequency is defined as the frequency below which a certain percentage of the total power of the EEG signal is located, often set at 95% in clinical settings. When the Spectral Edge decreases, it signifies that the highest frequencies contributing to the EEG signal are diminishing, resulting in an overall shift toward lower frequencies.

In neurophysiological contexts, a predominance of low-frequency activity can be associated with various states, including sedation or certain pathological conditions. This shift can be clinically relevant, as it may indicate changes in brain function or the effects of anesthetics. Understanding this relationship is crucial for intraoperative monitoring, as it helps inform the anesthetic depth or potential neurological changes during surgery.