Improving Neglect by TMS

Fierro, Brigida; Brighina, Filippo; Bisiach, Edoardo

doi:10.1155/2006/465323

Cited by 58 publications

(36 citation statements)

References 63 publications

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“…Evidence for this proposal is derived from TMS studies in neglect patients showing that spatial extinction can be transiently alleviated by deactivating the hemisphere opposite to the lesion (19,61,62) and by demonstrating hyperexcitability of parietal-motor pathways in the intact hemisphere (18). Similarly, studies in cats have shown a restoration of spatial functions as a consequence of deactivation of homolog areas in the hemisphere opposite to the lesion (14,29,63).…”

Section: Discussionmentioning

confidence: 99%

Functional imaging reveals rapid reorganization of cortical activity after parietal inactivation in monkeys

Wilke

Kagan

Andersen

2012

Proc. Natl. Acad. Sci. U.S.A.

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Impairments of spatial awareness and decision making occur frequently as a consequence of parietal lesions. Here we used event-related functional MRI (fMRI) in monkeys to investigate rapid reorganization of spatial networks during reversible pharmacological inactivation of the lateral intraparietal area (LIP), which plays a role in the selection of eye movement targets. We measured fMRI activity in control and inactivation sessions while monkeys performed memory saccades to either instructed or autonomously chosen spatial locations. Inactivation caused a reduction of contralesional choices. Inactivation effects on fMRI activity were anatomically and functionally specific and mainly consisted of: (i) activity reduction in the upper bank of the superior temporal sulcus (temporal parietal occipital area) for single contralesional targets, especially in the inactivated hemisphere; and (ii) activity increase accompanying contralesional choices between bilateral targets in several frontal and parieto-temporal areas in both hemispheres. There was no overactivation for ipsilesional targets or choices in the intact hemisphere. Task-specific effects of LIP inactivation on blood oxygen level-dependent activity in the temporal parietal occipital area underline the importance of the superior temporal sulcus for spatial processing. Furthermore, our results agree only partially with the influential interhemispheric competition model of spatial neglect and suggest an additional component of interhemispheric cooperation in the compensation of neglect deficits.extinction | hemispheric imbalance | saccadic decision | recovery

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Section: Discussionmentioning

confidence: 99%

Functional imaging reveals rapid reorganization of cortical activity after parietal inactivation in monkeys

Wilke

Kagan

Andersen

2012

Proc. Natl. Acad. Sci. U.S.A.

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“…Importantly, our model strongly suggests that TMS protocols that are effective over parietal cortex should not simply be translated to frontal cortex. For example, a common rationale in stroke rehabilitation is based on the concept of interhemispheric competition, namely applying inhibitory TMS protocols over the healthy hemisphere in order to reduce the attention bias towards the ipsilesional visual field (Cazzoli et al, 2010;Fierro et al, 2006;Hesse et al, 2011;Sparing et al, 2009). Based on our hybrid model, this approach would be ineffective or potentially even counterproductive over frontal cortex due to its different functional organization.…”

Section: Future Perspectivesmentioning

confidence: 99%

The hybrid model of attentional control: New insights into hemispheric asymmetries inferred from TMS research

Duecker

Sack

2015

Neuropsychologia

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Several competing theories on the mechanisms underlying attentional control have emerged over the years that, despite their substantial differences, all emphasize the importance of hemispheric asymmetries. Transcranial magnetic stimulation (TMS) has proven particularly successful in teasing them apart by selective perturbation of the dorsal and ventral fronto-parietal network. We here critically review the TMS literature and show that hemispheric asymmetries within the dorsal attention network differ between parietal and frontal cortex. Specifically, posterior parietal cortex seems to be characterized by a contralateral bias of each hemisphere and competition between them. In contrast, the right frontal eye field seems to be involved in shifting attention toward both hemifields, whereas left frontal eye field is only involved on shifting attention toward the contralateral hemifield. In the light of presented evidence, we propose to revise the functional-anatomical model originally proposed by Corbetta and Shulman (2011, 2002) and introduce a hybrid model of hemispheric asymmetries in attentional control.

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“…After right, but not left, parietal TMS, an overestimation of the length of the right section of a bisected line was observed, indicating a rightward shift in attentional bias. By now, several studies have demonstrated that parietal TMS is capable of causing contralateral hemineglect-like symptoms in healthy volunteers (Koch et al, 2008;Dambeck et al, 2006;Fierro, Brighina, & Bisiach, 2006;Meister et al, 2006;Muggleton et al, 2006;Koch, Oliveri, Torriero, & Caltagirone, 2005;Bjoertomt, Cowey, & Walsh, 2002;Fierro, Brighina, Piazza, Oliveri, & Bisiach, 2001;Hilgetag et al, 2001;Fierro et al, 2000;Pascual-Leone et al, 1994). Taken together, these studies showed that TMS can be employed to mimic lesions under controlled experimental conditions in healthy adults (Sack, 2010).…”

Section: Introductionmentioning

confidence: 97%

Extinguishing Extinction: Hemispheric Differences in the Modulation of TMS-induced Visual Extinction by Directing Covert Spatial Attention

Bien¹,

Goebel²,

Sack³

2012

Journal of Cognitive Neuroscience

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The topic of spatial attention is of great relevance for researchers in various fields, including neuropsychology, cognitive neuroscience, and cognitive psychology, as well as for clinical practice. Deficits of spatial attentional arising from parietal brain damage remain largely confined to the left visual field. The mechanisms underlying this hemispheric asymmetry are still elusive. We mimicked the neuropsychological syndrome of contralesional extinction by temporarily inducing a spatial attentional bias in healthy volunteers with TMS. We investigated whether directing covert spatial attention could enhance or, more importantly, counteract the resulting behavioral deficits. Although both the left and right parietal TMS induced contralateral extinction, only left hemifield extinction following right parietal TMS was severely aggravated by a competing stimulus in the ipsilesional (right) hemifield. We put forward the hypothesis that an asymmetry with respect to the ability of detaching attention from a distractor is contributing to the right hemispheric lateralization with regard to extinction. On a broader level, we suggest that "virtual patients" might be used for evaluating neuropsychological treatment in an early stage of development, reducing the burden on actual patients.

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Improving Neglect by TMS

Cited by 58 publications

References 63 publications

Functional imaging reveals rapid reorganization of cortical activity after parietal inactivation in monkeys

Functional imaging reveals rapid reorganization of cortical activity after parietal inactivation in monkeys

The hybrid model of attentional control: New insights into hemispheric asymmetries inferred from TMS research

Extinguishing Extinction: Hemispheric Differences in the Modulation of TMS-induced Visual Extinction by Directing Covert Spatial Attention

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