Instrumentation amplifiers are optimized for precision while consuming minimal power. This means they are not designed to handle fast signals. The slow transistors in the instrumentation amplifier are unable to track incoming high frequency waves, and may rectify them instead. In other words, they may convert the high frequency waves, which are far beyond the signal of interest, into low frequency waves than can interfere with the signal of interest. Instrumentation amplifiers often are the first IC in the signal chain and can be connected to long leads that go to the external sensor. These long leads can function as excellent antennas, picking up high frequency content in the environment.