Mapping of scalp potentials by surface spline interpolation

Perrin, Fabien; Pernier, J.; Bertnard, O; Giard, Marie‐Hélène; Echallier, J.F.

doi:10.1016/0013-4694(87)90141-6

Cited by 589 publications

(343 citation statements)

References 14 publications

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“…The surface Laplacian is independent of the reference electrode and ameliorates the effects of spatial smearing of ECoG voltage due to volume conduction in the tissue and fluid of the brain. The surface Laplacian required an accurate representation of the spatial distribution of potential, which was derived using spline interpolation (Perrin et al 1987;Law et al 1993). This results in a close correspondence between pre-and post-transformation waveforms, particularly at recording sites that are the closest to the foci of cortical activity (Reale et al 2007).…”

Section: Discussionmentioning

confidence: 99%

Direct Recordings from the Auditory Cortex in a Cochlear Implant User

Nourski

Etler

Brugge

et al. 2013

JARO

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Electrical stimulation of the auditory nerve with a cochlear implant (CI) is the method of choice for treatment of severe-to-profound hearing loss. Understanding how the human auditory cortex responds to CI stimulation is important for advances in stimulation paradigms and rehabilitation strategies. In this study, auditory cortical responses to CI stimulation were recorded intracranially in a neurosurgical patient to examine directly the functional organization of the auditory cortex and compare the findings with those obtained in normal-hearing subjects. The subject was a bilateral CI user with a 20-year history of deafness and refractory epilepsy. As part of the epilepsy treatment, a subdural grid electrode was implanted over the left temporal lobe. Pure tones, click trains, sinusoidal amplitude-modulated noise, and speech were presented via the auxiliary input of the right CI speech processor. Additional experiments were conducted with bilateral CI stimulation. Auditory event-related changes in cortical activity, characterized by the averaged evoked potential and eventrelated band power, were localized to posterolateral superior temporal gyrus. Responses were stable across recording sessions and were abolished under general anesthesia. Response latency decreased and magnitude increased with increasing stimulus level. More apical intracochlear stimulation yielded the largest responses. Cortical evoked potentials were phaselocked to the temporal modulations of periodic stimuli and speech utterances. Bilateral electrical stimulation resulted in minimal artifact contamination. This study demonstrates the feasibility of intracranial electrophysiological recordings of responses to CI stimulation in a human subject, shows that cortical response properties may be similar to those obtained in normal-hearing individuals, and provides a basis for future comparisons with extracranial recordings.

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Section: Discussionmentioning

confidence: 99%

Direct Recordings from the Auditory Cortex in a Cochlear Implant User

Nourski

Etler

Brugge

et al. 2013

JARO

View full text Add to dashboard Cite

show abstract

“…Data were band-pass filtered (0.1-100 Hz) and recalculated against the average reference. Electrodes with artefacts were interpolated using 3D splines (Perrin et al, 1987) and artefact-free EEG epochs (100 ms preto 400 ms post-distracter onset) were averaged for each participant.…”

Section: Eeg Acquisition and Preprocessingmentioning

confidence: 99%

Task relevance effects in electrophysiological brain activity: Early, but not first

2014

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A current controversy surrounds the question whether high-level features of a stimulus such as its relevance to the current task may affect early attentional processes. According to one view abruptly appearing stimuli gain priority during an initial feedforward processing stage and therefore capture attention even if they are irrelevant to the task. Alternatively, only stimuli that share a relevant property with the target may capture attention of the observer. Here, we used high-density EEG to test whether task relevance may modulate early feedforward brain activity, or whether it only becomes effective once the physical characteristics of the stimulus have been processed. We manipulated task relevance and visual saliency of distracters presented left or right of an upcoming central target. We found that only the relevance of distracters had an effect on manual reaction times to the target. However, the analysis of electrocortical activity revealed three discrete processing stages during which pure effects of distracter saliency (~80-160 ms), followed by an interaction between saliency and relevance (~130-240 ms) and finally pure effects of relevance (~230-370 ms) were observed. Electrical sources of early saliency effects and later relevance effects were localized in the posterior parietal cortex, predominantly over the right hemisphere. These findings support the view that during the initial feedforward stage only physical (bottom-up) factors determine cortical responses to visual stimuli, while top-down effects interfere at later processing stages.

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“…An automated artifact rejection criterion of ±100 μV was applied at all electrodes, and EEG epochs were also visually evaluated. Data from artifact electrodes from each subject and condition were interpolated using three-dimensional splines (Perrin et al, 1987). On the basis of the behavioral outcome for each subject, we separately considered three possible subgroups of trials: those in response to sounds that subjects correctly categorized as living or man-made, trials for which subjects could not guess (i.e.…”

Section: Eeg Acquisition and Preprocessingmentioning

confidence: 99%

Auditory perceptual decision-making based on semantic categorization of environmental sounds

et al. 2012

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Discriminating complex sounds relies on multiple stages of differential brain activity. The specific roles of these stages and their links to perception were the focus of the present study. We presented 250 ms duration sounds of living and man-made objects while recording 160-channel electroencephalography (EEG). Subjects categorized each sound as that of a living, man-made or unknown item. We tested whether/when the brain discriminates between sound categories even when not transpiring behaviorally. We applied a single-trial classifier that identified voltage topographies and latencies at which brain responses are most discriminative. For sounds that the subjects could not categorize, we could successfully decode the semantic category based on differences in voltage topographies during the 116-174 ms post-stimulus period. Sounds that were correctly categorized as that of a living or man-made item by the same subjects exhibited two periods of differences in voltage topographies at the single-trial level. Subjects exhibited differential activity before the sound ended (starting at 112 ms) and on a separate period at~270 ms post-stimulus onset. Because each of these periods could be used to reliably decode semantic categories, we interpreted the first as being related to an implicit tuning for sound representations and the second as being linked to perceptual decision-making processes. Collectively, our results show that the brain discriminates environmental sounds during early stages and independently of behavioral proficiency and that explicit sound categorization requires a subsequent processing stage.

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Mapping of scalp potentials by surface spline interpolation

Cited by 589 publications

References 14 publications

Direct Recordings from the Auditory Cortex in a Cochlear Implant User

Direct Recordings from the Auditory Cortex in a Cochlear Implant User

Task relevance effects in electrophysiological brain activity: Early, but not first

Auditory perceptual decision-making based on semantic categorization of environmental sounds

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