FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W1567506491> ?p ?o ?g. }

• W1567506491 abstract "This thesis describes studies on the electric potential of a neuronal population of about half a million neurons. It is essential to understand neurophysiology at the millimeter scale since ECoG and fMRI studies have shown that some functional units are specifically defined at this scale. While ECoG measures neuronal activity, fMRI only reflects its vascular and metabolic correlate and it is not well understood how this relates to the underlying neurophysiology. In the setting of motor and language function we used ECoG to define the dominant neurophysiological processes at the scale of millimeters: high frequency changes that are related to local neuronal activity and low frequency changes that reflect more global processes. We studied their interaction and investigated how these are related to the fMRI BOLD change to gain a better understanding of the role of these processes. The studies described in this thesis were done in a clinical setting with a brain computer interface (BCI) application in mind. These studies are relevant for at least two questions from the BCI field. First, which part of the ECoG signal is optimal for BCI and whether the optimal location for a BCI device can be predicted with fMRI. This thesis has shown several characteristics of the fMRI and ECoG signal that can help to answer these questions. First, chapter 4 showed that in the subjects who were scanned on a 1.5 T scanner instead of on a 3 T scanner, the signal in primary sensorimotor cortex did not correlate as well with high frequencies. It is thus necessary to have a good signal to noise ratio to be able to use fMRI as a localizer for high frequencies. Second, chapter 4 shows that large fMRI signal changes in primary sensorimotor areas corresponded best with high frequency increases, similar as what we have shown in chapter 3 for premotor cortex during motor imagery and for dorsolateral prefrontal cortex during working memory 58. However, in nonprimary areas, there may be BOLD changes that do not correspond to high frequency power change, but only to low frequency power changes. It is thus essential to choose areas with a primary involvement in a task, with a large BOLD signal change, before implantation of an electrode is considered. Furthermore, it is often assumed for brain computer interfaces that every action is linked to the same neuronal activity. Chapter 5 shows a drastic decrease in high frequency activity during fast repeated movement. It may be much more difficult to classify these faster movements compared to slower movement. In short, using fMRI to localize target areas for BCI seems possible when people are scanned on a 3T machine or at even higher field strength, provided that a) an electrode is placed on an area primarily involved in the task at hand, b) high frequency power changes are used to control a BCI and c) repetition effects are well understood before an electrode is placed." @default.
• W1567506491 created "2016-06-24" @default.
• W1567506491 creator A5049122374 @default.
• W1567506491 date "2012-04-03" @default.
• W1567506491 modified "2023-09-27" @default.
• W1567506491 title "The potential of half a million neurons. Studies with electrocorticography and functional MRI in motor and language areas" @default.
• W1567506491 hasPublicationYear "2012" @default.
• W1567506491 type Work @default.
• W1567506491 sameAs 1567506491 @default.
• W1567506491 citedByCount "0" @default.
• W1567506491 crossrefType "dissertation" @default.
• W1567506491 hasAuthorship W1567506491A5049122374 @default.
• W1567506491 hasConcept C152478114 @default.
• W1567506491 hasConcept C15744967 @default.
• W1567506491 hasConcept C169760540 @default.
• W1567506491 hasConcept C173201364 @default.
• W1567506491 hasConcept C24998067 @default.
• W1567506491 hasConcept C2778373776 @default.
• W1567506491 hasConcept C2780117969 @default.
• W1567506491 hasConcept C2780307956 @default.
• W1567506491 hasConcept C2908647359 @default.
• W1567506491 hasConcept C41008148 @default.
• W1567506491 hasConcept C522805319 @default.
• W1567506491 hasConcept C71924100 @default.
• W1567506491 hasConcept C99454951 @default.
• W1567506491 hasConceptScore W1567506491C152478114 @default.
• W1567506491 hasConceptScore W1567506491C15744967 @default.
• W1567506491 hasConceptScore W1567506491C169760540 @default.
• W1567506491 hasConceptScore W1567506491C173201364 @default.
• W1567506491 hasConceptScore W1567506491C24998067 @default.
• W1567506491 hasConceptScore W1567506491C2778373776 @default.
• W1567506491 hasConceptScore W1567506491C2780117969 @default.
• W1567506491 hasConceptScore W1567506491C2780307956 @default.
• W1567506491 hasConceptScore W1567506491C2908647359 @default.
• W1567506491 hasConceptScore W1567506491C41008148 @default.
• W1567506491 hasConceptScore W1567506491C522805319 @default.
• W1567506491 hasConceptScore W1567506491C71924100 @default.
• W1567506491 hasConceptScore W1567506491C99454951 @default.
• W1567506491 hasLocation W15675064911 @default.
• W1567506491 hasOpenAccess W1567506491 @default.
• W1567506491 hasPrimaryLocation W15675064911 @default.
• W1567506491 hasRelatedWork W1970598418 @default.
• W1567506491 hasRelatedWork W1988181650 @default.
• W1567506491 hasRelatedWork W2002737583 @default.
• W1567506491 hasRelatedWork W2079509976 @default.
• W1567506491 hasRelatedWork W2088766828 @default.
• W1567506491 hasRelatedWork W2101256131 @default.
• W1567506491 hasRelatedWork W2137086935 @default.
• W1567506491 hasRelatedWork W2145256906 @default.
• W1567506491 hasRelatedWork W2304850915 @default.
• W1567506491 hasRelatedWork W2346108182 @default.
• W1567506491 hasRelatedWork W2533920354 @default.
• W1567506491 hasRelatedWork W2806822078 @default.
• W1567506491 hasRelatedWork W2890696551 @default.
• W1567506491 hasRelatedWork W2913280815 @default.
• W1567506491 hasRelatedWork W2956035081 @default.
• W1567506491 hasRelatedWork W3023214091 @default.
• W1567506491 hasRelatedWork W3047438592 @default.
• W1567506491 hasRelatedWork W1665183887 @default.
• W1567506491 hasRelatedWork W2152436945 @default.
• W1567506491 hasRelatedWork W2943937597 @default.
• W1567506491 isParatext "false" @default.
• W1567506491 isRetracted "false" @default.
• W1567506491 magId "1567506491" @default.
• W1567506491 workType "dissertation" @default.