Craniocerebral topography within the international 10–20 system

Steinmetz, Helmuth; Fürst, G.; Meyer, Bernd‐Ulrich

doi:10.1016/0013-4694(89)90227-7

Cited by 236 publications

(112 citation statements)

References 10 publications

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“…Since the optodes were all attached to the piece of plastic, their relative positions did not change from subject to subject, though differences in the size of each person's head influenced the precise location of the optodes. It can be reasonably assumed that with this positioning of the optodes that the motor cortex is part of the sampling volume (Homan et al 1987, Steinmetz et al 1989.…”

Section: Optode Localizationmentioning

confidence: 99%

Can the cerebral metabolic rate of oxygen be estimated with near-infrared spectroscopy?

et al. 2003

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We have measured the changes in oxy-haemoglobin and deoxy-haemoglobin in the adult human brain during a brief finger tapping exercise using near-infrared spectroscopy (NIRS). The cerebral metabolic rate of oxygen (CMRO 2 ) can be estimated from these NIRS data provided certain model assumptions. The change in CMRO 2 is related to changes in the total haemoglobin concentration, deoxy-haemoglobin concentration and blood flow. As NIRS does not provide a measure of dynamic changes in blood flow during brain activation, we relied on a Windkessel model that relates dynamic blood volume and flow changes, which has been used previously for estimating CMRO 2 from functional magnetic resonance imaging (fMRI) data. Because of the partial volume effect we are unable to quantify the absolute changes in the local brain haemoglobin concentrations with NIRS and thus are unable to obtain an estimate of the absolute CMRO 2 change. An absolute estimate is also confounded by uncertainty in the flow-volume relationship. However, the ratio of the flow change to the CMRO 2 change is relatively insensitive to these uncertainties. For the finger tapping task, we estimate a most probable flow-consumption ratio ranging from 1.5 to 3 in agreement with previous findings presented in the literature, although we cannot exclude the possibility that there is no CMRO 2 change. The large range in the ratio arises from the large number of model parameters that must be estimated from the data. A more precise estimate of the flow-consumption ratio will require better estimates of the model parameters or flow information, as can be provided by combining NIRS with fMRI.

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Section: Optode Localizationmentioning

confidence: 99%

Can the cerebral metabolic rate of oxygen be estimated with near-infrared spectroscopy?

et al. 2003

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“…Using the International 10-20 system [21], the PPC was located and marked over the EEG cap on the left (P3) and right side (P4) of the head. TMS was therefore applied over a region thought to correspond to BA7 in the right and left hemisphere.…”

Section: Tms: the Equipment Consisted Of A Magstim Model 200mentioning

confidence: 99%

Event-related TMS over the right posterior parietal cortex induces ipsilateral visuo-spatial interference

Vandermeeren¹,

Olivier²,

Gelder³

2001

Neuroreport

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The right posterior parietal cortex (PPC) is implicated in visuo-spatial processing, as illustrated by patients with visuo-spatial neglect, but the precise time-course of its contribution is still an open question. In the present study we assessed whether single-pulse transcranial magnetic stimulation (TMS) can interfere with the performance of normal subjects in a standard visuo-spatial task. Participants had to perform a landmark task while TMS was applied over the right PPC, the homologue region in the left hemisphere or the right primary motor cortex. Stimulation was time-locked to the stimulus presentation with a stimulus onset asynchrony (SOA) varying between 50 and 200 ms. Our results indicate that TMS interfered mainly with the visuo-spatial task when applied over the right PPC at an early stage (50 ms post-stimulus). The interference effect of single-pulse TMS in the present visuo-spatial processing is revealed by a processing cost for ipsilateral targets. These results are ... The right posterior parietal cortex (PPC) is implicated in visuospatial processing, as illustrated by patients with visuo-spatial neglect, but the precise time-course of its contribution is still an open question. In the present study we assessed whether single-pulse transcranial magnetic stimulation (TMS) can interfere with the performance of normal subjects in a standard visuo-spatial task. Participants had to perform a landmark task while TMS was applied over the right PPC, the homologue region in the left hemisphere or the right primary motor cortex. Stimulation was time-locked to the stimulus presentation with a stimulus onset asynchrony (SOA) varying between 50 and 200 ms. Our results indicate that TMS interfered mainly with the visuo-spatial task when applied over the right PPC at an early stage (50 ms post-stimulus). The interference effect of single-pulse TMS in the present visuo-spatial processing is revealed by a processing cost for ipsilateral targets. These results are in agreement with neuropsychological and brain imaging studies showing a right hemispheric dominance in visuo-spatial processing but add crucial information about the time-course of visuo-spatial processing within the right PPC.

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“…In addition, the location of the medial ('PI') ECDs is probably dorsal to the primary visual area. In our coordinate system, the location of the medial dipoles would lie beneath a position approximately halfway between Pz and Oz, whereas the calcarine sulcus is reported to lie approximately beneath Oz (Steinmetz et al 1989). One could speculate, therefore, that the P1 and not the N1 reflects activity along the dorsal projection route.…”

Section: Discussionmentioning

confidence: 78%

Topography and source analysis of brain activity associated with selective spatial attention and memory search

et al. 1993

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Sum~nary~ We investigated the topographical aspects of the ERP reflections of visual spatial attention and memory search. Spatial attention was found to enhance the amplitudes of the P1 and N1 deflections. The brain activity in the P1-N1 latency range could be modeled with a single moving equivalent dipole, or alternatively with two stationary dipoles in a spatio-temporal dipole model. The dipoles were located in mesial and lateral posterior brain regions. Similar dipole solutions were obtained for ERPs to attended and unattended stimuli. Increasing the memory search requirements of the task resulted in an increase of late negativity, which was topographically distinguishable from the P3 component.

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Craniocerebral topography within the international 10–20 system

Cited by 236 publications

References 10 publications

Can the cerebral metabolic rate of oxygen be estimated with near-infrared spectroscopy?

Can the cerebral metabolic rate of oxygen be estimated with near-infrared spectroscopy?

Event-related TMS over the right posterior parietal cortex induces ipsilateral visuo-spatial interference

Topography and source analysis of brain activity associated with selective spatial attention and memory search

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