The technician attached the scalp electrodes and turned on the machine.

'Sorry we've had to shave your head, but scalp electrodes don't like hair.

A scalp electrode is placed against the baby's head and an ECG of the baby's heart beat can be directly recorded.

Patients wear 21 scalp electrodes, glued to the head, along with two needle-like electrodes in the jaw muscle to pick up signals from within the brain.

A routine clinical EEG recording typically lasts 20-30 minutes (plus preparation time) and usually involves recording from scalp electrodes.

Brain signals may be recorded either invasively, with recording devices implanted directly into the cortex, or noninvasively, using EEG scalp electrodes.

More invasive monitoring can involve a foetal scalp electrode to give an additional measure of fetal heart activity, and/or intrauterine pressure catheter (IUPC).

Each patient was evaluated using structural MRI, long-term video EEG monitoring with scalp electrodes, and subsequently with subdural electrodes.

Recording the average event-related electrical potentials from scalp electrodes became a research tool in the 1960s, with the advent of analog and then digital computers to accomplish the recording and averaging.

However, to reach the scalp electrodes of an electroencephalogram (EEG), electrical signals must also be conducted through the skull, where potentials rapidly attenuate due to the low conductivity of bone.

A third EOG component is the radial EOG channel, which is the average of the EOG channels referenced to some posterior scalp electrode.

Electroencephalography - Or EEG; and the derivative technique of event-related potentials, in which scalp electrodes monitor the average activity of neurons in the cortex (again, used most frequently with human subjects).

The brain emits electrical signals of only one-millionth of a volt or so, but a powerful amplifier developed for the Air Force project enhances the signal coming from the scalp electrodes and transmits it to an analog computer.

The signals picked up by scalp electrodes are comparatively small and diffuse, and arise almost entirely from the cerebral cortex-the hippocampus is too small and too deeply buried to generate recognizable scalp EEG signals.

Dr. Donoghue and other proponents of the implants say they have the potential to be a lot better, because they are much closer to the relevant neurons than are the scalp electrodes, which get signals from millions of neurons all over the brain.

An experiment employing a subsequent memory paradigm generally consists of two phases, a study phase (encoding phase) and a test phase (retrieval phase), with ERPs from scalp electrodes being recorded during each phase, time locked to stimulus onset.

Lesions are likely to appear on trauma sites such as the attachment site of fetal scalp electrodes, forceps or vacuum extractors that are used during delivery, in the margin of the eyes, the nasopharynx, and in areas associated with trauma or surgery (including circumcision).

Mothers infected with HSV are advised to avoid procedures that would cause trauma to the infant during birth (e.g. fetal scalp electrodes, forceps, and vacuum extractors) and, should lesions be present, to elect caesarean section to reduce exposure of the child to infected secretions in the birth canal.