Reproducibility of measures of neurophysiological activity in Wernicke's area: A magnetic source imaging study

Simos, Panagiotis G.; Sarkari, Shirin; Castillo, Eduardo M.; Billingsley-Marshall, Rebecca; Pataraia, Ekaterina; Clear, T.; Papanicolaou, Andrew C.

doi:10.1016/j.clinph.2005.06.019

Cited by 12 publications

(6 citation statements)

References 42 publications

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“…Posterior regions of the superior temporal gyrus are often included into a well known concept of the cortical organization of language processing known as Wernicke’s region (Boatman and Krauss, 2000, Bogen and Bogen, 1976, Harpaz et al, 2009, Luria, 1980, Simos et al, 2005). This is the brain region thought to engage in language-specific processing as it is well known historically that lesions in this region are capable of severely disrupting language comprehension; “Investigation of patients with a lesion of the posterior third of the first temporal gyrus of the left hemisphere and with sensory aphasia shows that, as a rule, they have no permanent hearing disturbance in the sphere of sounds not concerned with speech” (Luria, 1980).…”

Section: Discussionmentioning

confidence: 99%

Evaluating signal-correlated noise as a control task with language-related gamma activity on electrocorticography

Brown¹,

Muzik²,

Robert³

et al. 2014

Clinical Neurophysiology

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Objective Our recent electrocorticography (ECoG) study suggested reverse speech, a widely used control task, to be a poor control for non-language-related auditory activity. We hypothesized that this may be due to retained perception as a human voice. We report a follow-up ECoG study in which we contrast forward and reverse speech with a signal-correlated noise (SCN) control task that cannot be perceived as a human voice. Methods Ten patients were presented 90 audible stimuli, including 30 each of corresponding forward speech, reverse speech, and SCN trials, during ECoG recording with evaluation of gamma activity between 50–150 Hz. Results Sites of the lateral temporal gyri activated throughout speech stimuli were generally less activated by SCN, while some temporal sites seemed to process both human and non-human sounds. Reverse speech trials were associated with activities across the temporal lobe similar to those associated with forward speech. Conclusions Findings herein externally validate functional neuroimaging studies utilizing SCN as a control for non-language-specific auditory function. Our findings are consistent with the notion that stimuli perceived as originating from a human voice are poor controls for non-language auditory function. Significance Our findings have implications in functional neuroimaging research as well as improved clinical mapping of auditory functions.

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Section: Discussionmentioning

confidence: 99%

Evaluating signal-correlated noise as a control task with language-related gamma activity on electrocorticography

Brown¹,

Muzik²,

Robert³

et al. 2014

Clinical Neurophysiology

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“…Following filtering, single-trial MEG event-related field segments (ERFs) in response to 110–125 stimulus presentations were averaged and brain activity sources were modeled as single equivalent current dipoles (ECDs) and fitted independently at successive 2 ms intervals (Sarvas, 1987; Papanicolaou et al, 2004; Simos et al, 2005) using the 4D-Neuroimaging proprietary software. The algorithm searched for the source most likely to have produced the observed magnetic field distribution at a given point in time.…”

Section: Methodsmentioning

confidence: 99%

Assessment of hemispheric dominance for receptive language in pediatric patients under sedation using magnetoencephalography

Rezaie

Narayana

Schiller

et al. 2014

Front. Hum. Neurosci.

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Non-invasive assessment of hemispheric dominance for receptive language using magnetoencephalography (MEG) is now a well-established procedure used across several epilepsy centers in the context of pre-surgical evaluation of children and adults while awake, alert and attentive. However, the utility of MEG for the same purpose, in cases of sedated patients, is contested. Establishment of the efficiency of MEG is especially important in the case of children who, for a number of reasons, must be assessed under sedation. Here we explored the efficacy of MEG language mapping under sedation through retrospective review of 95 consecutive pediatric patients, who underwent our receptive language test as part of routine clinical evaluation. Localization of receptive language cortex and subsequent determination of laterality was successfully completed in 78% (n = 36) and 55% (n = 27) of non-sedated and sedated patients, respectively. Moreover, the proportion of patients deemed left hemisphere dominant for receptive language did not differ between non-sedated and sedated patients, exceeding 90% in both groups. Considering the challenges associated with assessing brain function in pediatric patients, the success of passive MEG in the context of the cases reviewed in this study support the utility of this method in pre-surgical receptive language mapping.

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“…The MEG recordings were conducted using a 148‐channel magnetometer whole head system (Magnes 2500 WH; 4‐D Neuroimaging Inc., San Diego, CA, U.S.A.). Single equivalent current dipole (ECD) model was used in the analysis of language data and has been validated by other institutions (Papanicolaou et al., 1999; Simos et al., 2005). The methodology closely followed that described by Papanicolaou et al.…”

Section: Methodsmentioning

confidence: 99%

Lateralizing language with magnetic source imaging: Validation based on the Wada test

et al. 2009

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SUMMARYPurpose: Magnetoencephalography (MEG)/magnetic source imaging (MSI) is a noninvasive functional neuroimaging procedure used to localize language-specific regions in the brain. The Wada test, or intracarotid amobarbital procedure (IAP), is the gold standard in determining speech/language lateralization for presurgical planning, although it is invasive and associated with morbidity. The purpose of this study is to provide further validation on the use of MSI for presurgical language lateralization by comparing results against the IAP. Methods: The sample consisted of 35 patients with epilepsy and/or brain tumor undergoing presurgical evaluation at the Minnesota Epilepsy Group. All patients received both an IAP and MSI to determine hemispheric language dominance. For MSI, a 148-channel MEG system was used to record activation of language-specific cortex by an auditory word-recognition task.Results: The MSI and IAP were concordant in determining language in the hemisphere to be treated in 86% of the cases with sensitivity and specificity values of 80% and 100%, respectively. Conclusions: The results from this study are consistent with prior research findings comparing functional neuroimaging procedures to the IAP in determining language lateralization in presurgical patients. The current study provides an important replication and support for Papanicolaou et al.'s findings in 2004 using a consecutive clinical sample from a different institution. An unusually high rate of atypical IAP language cases in this sample and differences between the two procedures are believed to explain the noted discrepancies. MSI is a viable noninvasive alternative to the IAP in the presurgical determination of language lateralization.

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Reproducibility of measures of neurophysiological activity in Wernicke's area: A magnetic source imaging study

Cited by 12 publications

References 42 publications

Evaluating signal-correlated noise as a control task with language-related gamma activity on electrocorticography

Evaluating signal-correlated noise as a control task with language-related gamma activity on electrocorticography

Assessment of hemispheric dominance for receptive language in pediatric patients under sedation using magnetoencephalography

Lateralizing language with magnetic source imaging: Validation based on the Wada test

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