What information is necessary to calculate sensitivity in EEG?

To calculate sensitivity in EEG, it is crucial to understand the relationship between the output observed on the EEG trace and the actual physiological signals being measured. Sensitivity refers to how much deflection in the EEG record corresponds to a specific amount of voltage applied to the electrodes.

Deflection, measured in millimeters on the EEG paper or screen, represents the graphical output of the brain's electrical activity. Voltage is measured in microvolts (µV), which provides a direct measure of the electrical potential differences that the EEG is capturing. The sensitivity value is determined by the ratio of these two quantities, specifically how many millimeters of deflection correspond to a certain number of microvolts.

Therefore, having both deflection (in mm) and voltage (in µV) is essential to calculate sensitivity because you need to relate the visual output to the electrical input accurately. Understanding this relationship helps in interpreting the EEG and ensuring that the recorded activity is presented effectively for clinical assessment.