What does a higher setting for CMRR help to achieve?

A higher setting for Common Mode Rejection Ratio (CMRR) effectively filters unwanted signals, which is crucial in the context of sleep studies and neurological assessments. CMRR is a measure of how well a device, such as an electroencephalogram (EEG) or other similar equipment, can reject interference from common signals or noise that are present in both the positive and negative inputs.

By adjusting the CMRR to a higher setting, the device becomes more capable of distinguishing between the actual brain activity that it needs to measure and the extraneous signals or noise that could distort the readings. This leads to clearer, more accurate data, especially in environments where electrical interference from other devices or grounding issues might be present.

The other choices do not align with the primary purpose of increasing CMRR. Higher CMRR does not increase artifacts; instead, it helps to minimize them. It does not directly reduce overall impedance, as impedance is related to the electrical resistance within the system rather than the ability to filter signals. Lastly, increasing CMRR does not necessarily increase the sensitivity of the device, which pertains more to the ability to detect low-level signals rather than filtering out noise.