Sequential colour mapping system of brain potentials

Giard, Marie‐Hélène; Péronnet, F; Pernier, J.; Mauguı̀ere, François; Bertrand, Olivier

doi:10.1016/0169-2607(85)90040-9

Cited by 13 publications

(1 citation statement)

References 6 publications

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“…The choice of the best référence électrode for avoid ing distortions when recording somatosensory evoked potentials (SEPs) still raises problems. The frontal référence is now viewed as incompatible with any gen uine topographie study of SEP components because it picks up the frontal responses (Desmedt and Cheron 1981;Mauguière et al 1983a;Giard et al 1985;Desmedt and Bourguet 1985;Deiber et al 1986;Desmedt et al 1987Desmedt et al , 1990Tsuji et al 1988;Desmedt and Tomberg 1990). The noncephalic référence allows ail recordable components, including subcortically gen erated farfields, to be displayed (Cracco and Cracco 1976;Kimura et al 1978), but may complicate the topographie mapping of cortical SEPs which are then superimposed on the prolonged N18 farfield (Tom berg et al 1991).…”

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confidence: 99%

Right or left ear reference changes the voltage of frontal and parietal somatosensory evoked potentials

Tomberg

Desmedt

Ozaki

1991

Electroencephalography and Clinical Neurophysiology/Evoked Pote

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Short-latency cortical somatosensory evoked potentials (SEPs) to left median nerve stimulation were recorded with either the left or right earlobe as reference. With a right earlobe reference the voltage of the parietal N20 and P27 was reduced while the voltage of the frontal P20 and N30 was enhanced. The effects were consistent, but their size varied with the SEP component considered and also among the subjects. Analysis of SEPs at different scalp sites and at either earlobe suggested that the ear contralateral to the side stimulated picked up transient potential differences, depending a.o. on side asymmetry and geometry of the neural generators as disclosed in topographic mapping. For example, the right ear potential can be shifted negatively by the right N20 field evoked by left median nerve stimulation. The changes involve the absolute potential values, but not the time features or the gradients of potential fields. Scalp current density (SCD) maps are not affected. The results are pertinent for current discussions about which reference to use and document the practical recommendation of recording short-latency cortical SEPs with a reference at the ear ipsilateral (not contralateral) to the side of stimulation.

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mentioning

confidence: 99%

Right or left ear reference changes the voltage of frontal and parietal somatosensory evoked potentials

Tomberg

Desmedt

Ozaki

1991

Electroencephalography and Clinical Neurophysiology/Evoked Pote

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Evidence for Shared Structures Between Imagery and Perception

Péronnet

Farah

Gonon

1988

Cognitive and Neuropsychological Approaches to Mental Imagery

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Topographic analysis in brain mapping can be compromised by the average reference

Desmedt¹,

Tomberg²

1990

Brain Topogr

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The average reference introduces ghost potential fields at the latencies for which the integral of scalp-recorded potentials differs from zero. These spurious effects occur because the average reference is computed from a limited number of (scalp) electrodes which do not survey the bottom half of the head. By arbitrarily re-setting the zero at each latency in the maps to be compared, it can also obliterate or even reverse topographical differences in the case of focal brain potentials enhancements thereby defeating the purpose of brain mapping.

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Sequential colour mapping system of brain potentials

Cited by 13 publications

References 6 publications

Right or left ear reference changes the voltage of frontal and parietal somatosensory evoked potentials

Right or left ear reference changes the voltage of frontal and parietal somatosensory evoked potentials

Evidence for Shared Structures Between Imagery and Perception

Topographic analysis in brain mapping can be compromised by the average reference

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