Stacking Jumper Electrodes & Linking References

A Stacking Electrode Jumper (sometimes called ‘stacking electrode’, ‘stacking lead’, or ‘jumper’) is a special type of electrode connecter can be used to bridge two electrode inputs together. This can be used to reduce the number of electrodes to the client’s scalp, block non-EEG signal, or combine different inputs together. Some amplifiers also require something to be inserted into each input to function, which stacking electrode jumpers help with.

Jumpers come in a variety of colors including red, green, white, and black. They are often included with four-channel amplifiers as a way of connecting references together but can also be purchased separately as needed. A small wire traveling through the cable connects both ends of the jumper together. If needed, electrodes can then be inserted into each end of the jumper once connected to an amplifier.

Some common uses include:

Single-Channel Training

When training with a two-channel amplifier, a jumper can be used to block out unwanted signal from the unused Channel B. Inserting one end of the jumper into SigB and the other end into RefB will bridge the two inputs and help to reduce incoming noise, that can have an effect on certain models of amplifiers.

‘Linked Ears’ Training

Some training protocols require that the reference inputs are linked together. In this type of training, a jumper is connected from RefA to RefB. Electrodes are then connected into one or both of the jumper ends.

Reducing Electrodes

During four-channel training, jumpers can be used to connect reference inputs together and reduce the number of electrodes connected to the client’s ears or scalp. This is especially helpful when working with younger clients, where there may not be space to connect multiple electrodes to the same ear.

While jumpers are helpful in many applications, they are not needed for all amplifiers. Some amplifiers have the ability to internally link different inputs together, like the references for each channel. This has the same benefit as using a jumper, except there is no additional equipment needed that may add complexity to the setup. Most amplifiers that allow for internal or software linking can have this setting turned off, allowing for physical jumpers to be used if needed.