Spatiotemporal patterns of oscillatory brain activity during auditory word recognition in children: A synthetic aperture magnetometry study

Mohamed, Ismail; Cheyne, Douglas; Gaetz, William; Otsubo, Hiroshi; Logan, William J.; Snead, O. Carter; Pang, Elizabeth W.

doi:10.1016/j.ijpsycho.2007.11.005

Cited by 9 publications

(8 citation statements)

References 56 publications

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“…Previous normative studies focusing on TF ranges using a beamformer (Mohamed et al, 2008; Cornelissen et al, 2009) do not report individual measures of laterality and thus do not provide a measurable level of laterality agreement among the general population. If we assume that all right-handed subjects in a small sample are left-lateralized for language based on the evidence (Moser et al, 2010) reporting an overwhelming percentage of left-lateralized individuals across large samples (94%), then individual measures of laterality may be reported.…”

Section: Discussionmentioning

confidence: 99%

Optimizing estimation of hemispheric dominance for language using magnetic source imaging

et al. 2011

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The efficacy of magnetoencephalography (MEG) as an alternative to invasive methods for investigating the cortical representation of language has been explored in several studies. Recently, studies comparing MEG to the gold standard Wada procedure have found inconsistent and often less-than accurate estimates of laterality across various MEG studies. Here we attempted to address this issue among normal right-handed adults (N=12) by supplementing a well-established MEG protocol involving word recognition and the single dipole method with a sentence comprehension task and a beamformer approach localizing neural oscillations. Beamformer analysis of word recognition and sentence comprehension tasks revealed a desynchronization in the 10–18 Hz range, localized to the temporo-parietal cortices. Inspection of individual profiles of localized desynchronization (10–18 Hz) revealed left hemispheric dominance in 91.7% and 83.3% of individuals during the word recognition and sentence comprehension tasks, respectively. In contrast, single dipole analysis yielded lower estimates, such that activity in temporal language regions was left-lateralized in 66.7% and 58.3% of individuals during word recognition and sentence comprehension, respectively. The results obtained from the word recognition task and localization of oscillatory activity using a beamformer appear to be in line with general estimates of left hemispheric dominance for language in normal right-handed individuals. Furthermore, the current findings support the growing notion that changes in neural oscillations underlie critical components of linguistic processing.

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Section: Discussionmentioning

confidence: 99%

Optimizing estimation of hemispheric dominance for language using magnetic source imaging

et al. 2011

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“…Importantly, the virtual electrodes can be inspected for the presence of epileptiform activity, and exhibit a strong agreement with the activity recorded by ICEEG [21,26]. A second variant of the SAM method, dual-state SAM, can be used to image trial-based tasks typically employed for functional mapping [87,91,93]. We have recently extended the uses of SAM to successfully map patients with vagal nerve stimulators (VNS, [11]; see below for examples), cerebrospinal fluid (CSF) shunts, metal plates, and cardiac pacemakers.…”

Section: Meg At Wake Forest Baptist Healthmentioning

confidence: 99%

“…Finally, MEG and MSI can also be used to map eloquent cortex as a part of surgical planning, another task that is often performed invasively with ICEEG. MSI has been used to map such functional regions as somatosensory [73,74,75,76,77,78,79,80,81,82,83,84,85], motor [86,87,88,89], visual [90] and language networks [91,92,93,94,95,96]. …”

Section: Introductionmentioning

confidence: 99%

Magnetoencephalography: Clinical and Research Practices

et al. 2018

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Magnetoencephalography (MEG) is a neurophysiological technique that detects the magnetic fields associated with brain activity. Synthetic aperture magnetometry (SAM), a MEG magnetic source imaging technique, can be used to construct both detailed maps of global brain activity as well as virtual electrode signals, which provide information that is similar to invasive electrode recordings. This innovative approach has demonstrated utility in both clinical and research settings. For individuals with epilepsy, MEG provides valuable, nonredundant information. MEG accurately localizes the irritative zone associated with interictal spikes, often detecting epileptiform activity other methods cannot, and may give localizing information when other methods fail. These capabilities potentially greatly increase the population eligible for epilepsy surgery and improve planning for those undergoing surgery. MEG methods can be readily adapted to research settings, allowing noninvasive assessment of whole brain neurophysiological activity, with a theoretical spatial range down to submillimeter voxels, and in both humans and nonhuman primates. The combination of clinical and research activities with MEG offers a unique opportunity to advance translational research from bench to bedside and back.

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“…Vigilance trials, which have hand movements, were discarded from further processing. Data were filtered with three bandpasses (5-15, 15-25, and 25-50 Hz), selected as per previous language studies using this approach (Kadis, et al, 2008;Mohamed, et al, 2008;Ressel, et al, 2008), and analysed with differential beamforming (see Robinson and Vrba, 1999;Sekihara, et al, 2001;Van Veen, et al, 1997;Vrba and Robinson, 2001). Time windows were set at 150 ms widths with baseline defined as −200 to −50 ms pre-stimulus.…”

Section: Data Processing and Statistical Testingmentioning

confidence: 99%

An MEG study of the spatiotemporal dynamics of bilingual verb generation

Pang

MacDonald

2012

Brain Research

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Studies of first (L1) and second (L2) language representation in the brain have not identified the timing and locations of neural regions involved in L1 and L2 processing. Magnetoencephalography offers high spatial and temporal resolution and can be employed to disentangle subtle timing and neural control differences between L1 and L2 use. We tested bilingual adults in the MEG as they completed a picture verb generation task in L1 and L2. We found the expected progression of activation from occipital to temporal to inferior frontal areas. We also observed the following differences. A sustained insula and early cingulate event-related desynchrony was observed only with L2; the fMRI literature suggests that the former reflects an activation, and the latter an inhibition, sub-process for language selection. L2 processes exhibited a lag and were bilateral compared to L1 processes. Finally, L1 and L2 activated adjacent language control in dorsolateral pre-frontal cortex.

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Spatiotemporal patterns of oscillatory brain activity during auditory word recognition in children: A synthetic aperture magnetometry study

Cited by 9 publications

References 56 publications

Optimizing estimation of hemispheric dominance for language using magnetic source imaging

Optimizing estimation of hemispheric dominance for language using magnetic source imaging

Magnetoencephalography: Clinical and Research Practices

An MEG study of the spatiotemporal dynamics of bilingual verb generation

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