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Sperber C, Wiesen D, Karnath H, de Haan B. The neuroanatomy of visual extinction following right hemisphere brain damage: Insights from multivariate and Bayesian lesion analyses in acute stroke. Hum Brain Mapp 2024; 45:e26639. [PMID: 38433712 PMCID: PMC10910281 DOI: 10.1002/hbm.26639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 01/08/2024] [Accepted: 02/06/2024] [Indexed: 03/05/2024] Open
Abstract
Multi-target attention, that is, the ability to attend and respond to multiple visual targets presented simultaneously on the horizontal meridian across both visual fields, is essential for everyday real-world behaviour. Given the close link between the neuropsychological deficit of extinction and attentional limits in healthy subjects, investigating the anatomy that underlies extinction is uniquely capable of providing important insights concerning the anatomy critical for normal multi-target attention. Previous studies into the brain areas critical for multi-target attention and its failure in extinction patients have, however, produced heterogeneous results. In the current study, we used multivariate and Bayesian lesion analysis approaches to investigate the anatomical substrate of visual extinction in a large sample of 108 acute right hemisphere stroke patients. The use of acute stroke patient data and multivariate/Bayesian lesion analysis approaches allowed us to address limitations associated with previous studies and so obtain a more complete picture of the functional network associated with visual extinction. Our results demonstrate that the right temporo-parietal junction (TPJ) is critically associated with visual extinction. The Bayesian lesion analysis additionally implicated the right intraparietal sulcus (IPS), in line with the results of studies in neurologically healthy participants that highlighted the IPS as the area critical for multi-target attention. Our findings resolve the seemingly conflicting previous findings, and emphasise the urgent need for further research to clarify the precise cognitive role of the right TPJ in multi-target attention and its failure in extinction patients.
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Affiliation(s)
- Christoph Sperber
- Center of Neurology, Division of NeuropsychologyHertie‐Institute for Clinical Brain Research, University of TübingenTübingenGermany
- Department of NeurologyInselspital, University Hospital BernBernSwitzerland
| | - Daniel Wiesen
- Center of Neurology, Division of NeuropsychologyHertie‐Institute for Clinical Brain Research, University of TübingenTübingenGermany
| | - Hans‐Otto Karnath
- Center of Neurology, Division of NeuropsychologyHertie‐Institute for Clinical Brain Research, University of TübingenTübingenGermany
- Department of PsychologyUniversity of South CarolinaColumbiaSouth CarolinaUSA
| | - Bianca de Haan
- Centre for Cognitive Neuroscience, College of Health and Life Sciences, Brunel University LondonUxbridgeUK
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Wang T, de Graaf T, Tanner L, Schuhmann T, Duecker F, Sack AT. Hemispheric Asymmetry in TMS-Induced Effects on Spatial Attention: A Meta-Analysis. Neuropsychol Rev 2023:10.1007/s11065-023-09614-2. [PMID: 37736863 DOI: 10.1007/s11065-023-09614-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 08/14/2023] [Indexed: 09/23/2023]
Abstract
Hemispheric asymmetry is a fundamental principle in the functional architecture of the brain. It plays an important role in attention research where right hemisphere dominance is core to many attention theories. Lesion studies seem to confirm such hemispheric dominance with patients being more likely to develop left hemineglect after right hemispheric stroke than vice versa. However, the underlying concept of hemispheric dominance is still not entirely clear. Brain stimulation studies using transcranial magnetic stimulation (TMS) might be able to illuminate this concept. To examine the putative hemispheric asymmetry in spatial attention, we conducted a meta-analysis of studies applying inhibitory TMS protocols to the left or right posterior parietal cortices (PPC), assessing effects on attention biases with the landmark and line bisection task. A total of 18 studies including 222 participants from 1994 to February 2022 were identified. The analysis revealed a significant shift of the perceived midpoint towards the ipsilateral hemifield after right PPC suppression (Cohen's d = 0.52), but no significant effect after left PPC suppression (Cohen's d = 0.26), suggesting a hemispheric asymmetry even though the subgroup difference does not reach significance (p = .06). A complementary Bayesian meta-analysis revealed a high probability of at least a medium effect size after right PPC disruption versus a low probability after left PPC disruption. This is the first quantitative meta-analysis supporting right hemisphere-specific TMS-induced spatial attention deficits, mimicking hemineglect in healthy participants. We discuss the result in the light of prominent attention theories, ultimately concluding how difficult it remains to differentiate between these theories based on attentional bias scores alone.
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Affiliation(s)
- Ting Wang
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, 6200 MD, Maastricht, the Netherlands.
- Maastricht Brain Imaging Centre, Maastricht, the Netherlands.
| | - Tom de Graaf
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, 6200 MD, Maastricht, the Netherlands
- Maastricht Brain Imaging Centre, Maastricht, the Netherlands
| | - Lisabel Tanner
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, 6200 MD, Maastricht, the Netherlands
| | - Teresa Schuhmann
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, 6200 MD, Maastricht, the Netherlands
- Maastricht Brain Imaging Centre, Maastricht, the Netherlands
| | - Felix Duecker
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, 6200 MD, Maastricht, the Netherlands
- Maastricht Brain Imaging Centre, Maastricht, the Netherlands
| | - Alexander T Sack
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, 6200 MD, Maastricht, the Netherlands
- Maastricht Brain Imaging Centre, Maastricht, the Netherlands
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University Medical Centre+, Brain+Nerve Centre, Maastricht, the Netherlands
- Centre for Integrative Neuroscience, Faculty of Psychology and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, the Netherlands
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Middag‐van Spanje M, Duecker F, Gallotto S, de Graaf TA, van Heugten C, Sack AT, Schuhmann T. Transcranial magnetic stimulation over posterior parietal cortex modulates alerting and executive control processes in attention. Eur J Neurosci 2022; 56:5853-5868. [PMID: 36161393 PMCID: PMC9828423 DOI: 10.1111/ejn.15830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 09/14/2022] [Indexed: 01/12/2023]
Abstract
Attention includes three different functional components: generating and maintaining an alert state (alerting), orienting to sensory events (orienting), and resolving conflicts between alternative actions (executive control). Neuroimaging and patient studies suggest that the posterior parietal cortex (PPC) is involved in all three attention components. Transcranial magnetic stimulation (TMS) has repeatedly been applied over the PPC to study its functional role for shifts and maintenance of visuospatial attention. Most TMS-PPC studies used only detection tasks or orienting paradigms to investigate TMS-PPC effects on attention processes, neglecting the alerting and executive control components of attention. The objective of the present study was to investigate the role of PPC in all three functional components of attention: alerting, orienting, and executive control. To this end, we disrupted PPC with TMS (continuous theta-burst stimulation), to modulate subsequent performance on the Lateralized-Attention Network Test, used to assess the three attention components separately. Our results revealed hemifield-specific effects on alerting and executive control functions, but we did not find stimulation effects on orienting performance. While this field of research and associated clinical development have been predominantly focused on orienting performance, our results suggest that parietal cortex and its modulation may affect other aspects of attention as well.
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Affiliation(s)
- Marij Middag‐van Spanje
- Department of Cognitive Neuroscience, Faculty of Psychology and NeuroscienceMaastricht UniversityMaastrichtThe Netherlands,InteraktContourNunspeetThe Netherlands
| | - Felix Duecker
- Department of Cognitive Neuroscience, Faculty of Psychology and NeuroscienceMaastricht UniversityMaastrichtThe Netherlands,Maastricht Brain Imaging CenterMaastrichtThe Netherlands
| | - Stefano Gallotto
- Department of Cognitive Neuroscience, Faculty of Psychology and NeuroscienceMaastricht UniversityMaastrichtThe Netherlands
| | - Tom A. de Graaf
- Department of Cognitive Neuroscience, Faculty of Psychology and NeuroscienceMaastricht UniversityMaastrichtThe Netherlands,Maastricht Brain Imaging CenterMaastrichtThe Netherlands
| | - Caroline van Heugten
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and NeuroscienceMaastricht UniversityMaastrichtThe Netherlands,Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Brain + Nerve CentreMaastricht University Medical Centre+MaastrichtThe Netherlands,Limburg Brain Injury CenterMaastrichtThe Netherlands
| | - Alexander T. Sack
- Department of Cognitive Neuroscience, Faculty of Psychology and NeuroscienceMaastricht UniversityMaastrichtThe Netherlands,Maastricht Brain Imaging CenterMaastrichtThe Netherlands,Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Brain + Nerve CentreMaastricht University Medical Centre+MaastrichtThe Netherlands
| | - Teresa Schuhmann
- Department of Cognitive Neuroscience, Faculty of Psychology and NeuroscienceMaastricht UniversityMaastrichtThe Netherlands,Maastricht Brain Imaging CenterMaastrichtThe Netherlands
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Effects of Intermittent Theta Burst Stimulation on the Clock Drawing Test Performances in Patients with Alzheimer's Disease. Brain Topogr 2021; 34:461-466. [PMID: 33830403 DOI: 10.1007/s10548-021-00836-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 03/30/2021] [Indexed: 10/21/2022]
Abstract
The clock drawing test (CDT) is widely used in clinical neuropsychological practice. However, its neuroanatomical correlates have not been well established. This study investigated the effects of theta burst stimulation (TBS) applied over different brain regions on CDT scores in patients with Alzheimer's disease (AD). The 10-20 positions F3, F4, T3, T4, TP3, TP4, P3, P4, as determined by a 10-20 positioning cap, were targeted. Excitatory intermittent TBS (iTBS) was given over the above-mentioned eight regions to ten AD patients and ten control subjects on separate days. CDT was administered at baseline (T0), during the 5 min following the TBS (T1) and 60 min after TBS (T2), with an inter-session interval of at least 4 days. iTBS over TP4 and P4 transiently increased Rouleau CDT score in AD patients. When targeting TP4 and P4, mainly the area of the supramarginal/angular gyrus and the inferior parietal lobe, corresponding respectively to the Brodmann areas 40/39 and 7/40, are reached. iTBS thus seems able to modulate activity of the right posterior parietal cortex in AD patients performing the CDT. Our results provide physiological evidence that those parietal regions are functionally important for the execution of the Rouleau CDT. This finding suggests that CDT has reliable neuroanatomical correlates, and support the notion that this test can be used as a good marker of right parietal brain dysfunction. The present study also highlights the therapeutic potential of the induction of neuromodulatory effects using non-invasive brain stimulation techniques.
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Valero-Cabré A, Amengual JL, Stengel C, Pascual-Leone A, Coubard OA. Transcranial magnetic stimulation in basic and clinical neuroscience: A comprehensive review of fundamental principles and novel insights. Neurosci Biobehav Rev 2017; 83:381-404. [DOI: 10.1016/j.neubiorev.2017.10.006] [Citation(s) in RCA: 190] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 09/29/2017] [Accepted: 10/06/2017] [Indexed: 01/13/2023]
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6
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Duecker F, Schuhmann T, Bien N, Jacobs C, Sack AT. Moving Beyond Attentional Biases: Shifting the Interhemispheric Balance between Left and Right Posterior Parietal Cortex Modulates Attentional Control Processes. J Cogn Neurosci 2017; 29:1267-1278. [DOI: 10.1162/jocn_a_01119] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Abstract
The concept of interhemispheric competition has been very influential in attention research, and the occurrence of biased attention due to an imbalance in posterior parietal cortex (PPC) is well documented. In this context, the vast majority of studies have assessed attentional performance with tasks that did not include an explicit experimental manipulation of attention, and, as a consequence, it remains largely unknown how these findings relate to core attentional constructs such as endogenous and exogenous control and spatial orienting and reorienting. We here addressed this open question by creating an imbalance between left and right PPC with transcranial direct current stimulation, resulting in right-hemispheric dominance, and assessed performance on three experimental paradigms that isolate distinct attentional processes. The comparison between active and sham transcranial direct current stimulations revealed a highly informative pattern of results with differential effects across tasks. Our results demonstrate the functional necessity of PPC for endogenous and exogenous attentional control and, importantly, link the concept of interhemispheric competition to core attentional processes, thus moving beyond the notion of biased attention after noninvasive brain stimulation over PPC.
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7
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Vesia M, Niemeier M, Black SE, Staines WR. The time course for visual extinction after a 'virtual' lesion of right posterior parietal cortex. Brain Cogn 2015; 98:27-34. [PMID: 26051527 DOI: 10.1016/j.bandc.2015.05.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 03/30/2015] [Accepted: 05/19/2015] [Indexed: 11/30/2022]
Abstract
Our understanding of the attentional networks in the human brain largely relies on neuropsychological studies in patients with lesions to the posterior parietal cortex (PPC), particularly in the right hemisphere, that may cause severe disruptions of attentional functions. However, lesion studies only capture a point in time when the dysfunctions caused by the damage have triggered a chain of adaptive responses in the brain. To disentangle deficits and ensuing cortical plasticity, here we examined the time course for one's ability to detect objects in the visual periphery after an inhibitory continuous theta-burst stimulation (cTBS) protocol to the left or right PPC. Our results showed that cTBS of right PPC caused participants to be less sensitive to objects appearing on the left side as well as to objects appearing on both sides at the same time, consistent with an overall shift of attention to the right side of space. In addition, we found that participants missed more objects during bilateral presentations similar to patients with visual extinction. Critically, extinction evolved over time; that is, visual extinction for ipsilateral objects improved after 10 min whereas contralateral extinction peaked around 15-25 min after cTBS. Our findings suggest that lesions to the PPC impair competition between the two visual hemifields, resulting in contralateral extinction as a secondary response, arguably due to ensuing disruptions in interhemispheric balance.
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Affiliation(s)
- Michael Vesia
- Heart and Stroke Foundation Centre for Stroke Recovery, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; Department of Kinesiology and Faculty of Applied Health Sciences, University of Waterloo, Waterloo, ON, Canada
| | - Matthias Niemeier
- Department of Psychology, University of Toronto Scarborough, Toronto, ON, Canada.
| | - Sandra E Black
- Heart and Stroke Foundation Centre for Stroke Recovery, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | - W Richard Staines
- Heart and Stroke Foundation Centre for Stroke Recovery, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; Department of Kinesiology and Faculty of Applied Health Sciences, University of Waterloo, Waterloo, ON, Canada
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Duecker F, Sack AT. The hybrid model of attentional control: New insights into hemispheric asymmetries inferred from TMS research. Neuropsychologia 2014; 74:21-9. [PMID: 25451041 DOI: 10.1016/j.neuropsychologia.2014.11.023] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 11/17/2014] [Accepted: 11/19/2014] [Indexed: 11/19/2022]
Abstract
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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Affiliation(s)
- Felix Duecker
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands; Maastricht Brain Imaging Center, Maastricht University, Maastricht, The Netherlands.
| | - Alexander T Sack
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands; Maastricht Brain Imaging Center, Maastricht University, Maastricht, The Netherlands
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de Haan B, Bither M, Brauer A, Karnath HO. Neural Correlates of Spatial Attention and Target Detection in a Multi-Target Environment. Cereb Cortex 2014; 25:2321-31. [PMID: 24642422 DOI: 10.1093/cercor/bhu046] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Our ability to attend and respond in a multi-target environment is an essential and distinct human skill, as is dramatically demonstrated in stroke patients suffering from extinction. We performed a functional magnetic resonance imaging study to determine the neural anatomy associated with attending and responding to simultaneously presented targets. In healthy subjects, we tested the hypothesis that the right intraparietal sulcus (IPS) is associated both with the top-down direction of attention to multiple target locations and the bottom-up detection of multiple targets, whereas the temporo-parietal junction (TPJ) is predominantly associated with the bottom-up detection of multiple targets. We used a cued target detection task with a high proportion of catch trials to separately estimate top-down cue-related and bottom-up target-related neural activity. Both cues and targets could be presented unilaterally or bilaterally. We found no evidence of target-related neural activation specific to bilateral situations in the TPJ, but observed both cue-related and target-related neural activation specific to bilateral situations in the right IPS and target-related neural activity specific to bilateral situations in the right inferior frontal gyrus (IFG). We conclude that the IPS and the IFG of the right hemisphere underlie our ability to attend and respond in a multi-target environment.
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Affiliation(s)
- Bianca de Haan
- Division of Neuropsychology, Center of Neurology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Maria Bither
- Division of Neuropsychology, Center of Neurology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Anne Brauer
- Division of Neuropsychology, Center of Neurology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Hans-Otto Karnath
- Division of Neuropsychology, Center of Neurology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany Department of Psychology, University of South Carolina, Columbia, SC, USA
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Mylius V, Ayache SS, Zouari HG, Aoun-Sebaïti M, Farhat WH, Lefaucheur JP. Stroke rehabilitation using noninvasive cortical stimulation: hemispatial neglect. Expert Rev Neurother 2013; 12:983-91. [PMID: 23002941 DOI: 10.1586/ern.12.78] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The rehabilitation of neuropsychological sequels of cerebral stroke such as hemispatial neglect by noninvasive cortical stimulation (NICS) attracts increasing attention from the scientific community. The NICS techniques include primarily repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS). They are based on the concept of either reactivating a hypoactive cortical region affected by the stroke (the right hemisphere in case of neglect) or reducing cortical hyperactivity of the corresponding cortical region in the contralateral hemisphere (the left hemisphere). In the studies published to date on the topic of neglect rehabilitation, rTMS was used to inhibit the left parietal cortex and tDCS to either activate the right or inhibit the left parietal cortex. Sham-controlled NICS studies assessed short-term effects, whereas long-term effects were only assessed in noncontrolled rTMS studies. Further controlled studies of large series of patients are necessary to determine the best parameters of stimulation (including the optimal cortical target location) according to each subtype of neglect presentation and to the time course of stroke recovery. To date, even if there are serious therapeutic perspectives based on imaging data and experimental studies, the evidence is not compelling enough to recommend any particular NICS protocol to treat this disabling condition in clinical practice.
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Affiliation(s)
- Veit Mylius
- Université Paris-Est-Créteil, Faculté de Médecine, EA 4391, Créteil, France.
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de Haan B, Karnath HO, Driver J. Mechanisms and anatomy of unilateral extinction after brain injury. Neuropsychologia 2012; 50:1045-53. [DOI: 10.1016/j.neuropsychologia.2012.02.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 02/14/2012] [Accepted: 02/20/2012] [Indexed: 11/24/2022]
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Bien N, Goebel R, Sack AT. Extinguishing Extinction: Hemispheric Differences in the Modulation of TMS-induced Visual Extinction by Directing Covert Spatial Attention. J Cogn Neurosci 2012; 24:809-18. [DOI: 10.1162/jocn_a_00179] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Abstract
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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Maniglia M, Grassi M, Casco C, Campana G. The origin of the audiovisual bounce inducing effect: a TMS study. Neuropsychologia 2012; 50:1478-82. [PMID: 22414590 DOI: 10.1016/j.neuropsychologia.2012.02.033] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 02/20/2012] [Accepted: 02/27/2012] [Indexed: 11/24/2022]
Abstract
The audiovisual bounce inducing effect (ABE) is a bouncing percept induced by the presence of a sound at the moment of two moving objects intercepting in a motion display otherwise perceived as streaming. The origin of the ABE is still debated: the effect could arise from the subtraction of attentional resources caused by the sound (needed to favor the perception of streaming), and/or from the cross-modal integration (binding) of visual and auditory information: indeed bouncing-like sounds are best in inducing the ABE. The neural mechanism responsible for the ABE is still unknown. Here, by using offline TMS, we investigated the role of the posterior parietal cortex (PPC), thought to be involved in both attentional and binding processes, in the generation of the ABE. Results show that disrupting the functional integrity of the right (but not the left) PPC has the effect of weakening the binding of cross-modal information, which reduces the magnitude of the ABE. Indeed, if the effect of parietal stimulation was merely to disrupt attention, we would expect an increase (not a decrease) of bouncing percepts. The present study not only shows the involvement of the right PPC in the ABE, but also support the notion that cross-modal binding (and not attention) is at the origin of the ABE.
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Affiliation(s)
- Marcello Maniglia
- Dipartimento di Psicologia Generale, Università di Padova, Via Venezia 8, 35131 Padova, Italy
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14
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Palomar FJ, Díaz-Corrales F, Carrillo F, Fernández-del-Olmo M, Koch G, Mir P. Sensory perception changes induced by transcranial magnetic stimulation over the primary somatosensory cortex in Parkinson's disease. Mov Disord 2011; 26:2058-64. [DOI: 10.1002/mds.23779] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Revised: 03/30/2011] [Accepted: 04/11/2011] [Indexed: 11/08/2022] Open
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Gillebert CR, Mantini D, Thijs V, Sunaert S, Dupont P, Vandenberghe R. Lesion evidence for the critical role of the intraparietal sulcus in spatial attention. ACTA ACUST UNITED AC 2011; 134:1694-709. [PMID: 21576110 DOI: 10.1093/brain/awr085] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Based on lesion mapping studies, the inferior parietal lobule and temporoparietal junction are considered the critical parietal regions for spatial-attentional deficits. Lesion evidence for a key role of the intraparietal sulcus, a region featuring prominently in non-human primate studies and human functional imaging studies of the intact brain, is still lacking, probably due to the exceptional nature of isolated intraparietal sulcus lesions. We combined behavioural testing and functional imaging in two patients with a focal intraparietal sulcus lesion sparing the inferior parietal lobule and temporoparietal junction to examine the critical contribution of the intraparietal sulcus to spatial attention. Case H.H. had a focal ischaemic lesion (1.8 cm3) that was confined to the posterior segment of the left intraparietal sulcus, whereas Case N.V. had a partially reversible lesion of the middle segment of the right intraparietal sulcus extending into the superior parietal lobule (13.8 cm3). The performance of these cases was contrasted with five cases with a classical inferior parietal lesion, as well as with a group of 31 age-matched controls. In the behavioural study, the patients performed an orientation discrimination task on a peripheral target (eccentricity 7.6°) that was preceded by a central spatial cue. We manipulated both the cue validity (17% trials with an invalid spatial cue) and the presence of a competing distracter in the visual field contralateral to the target (17% double stimulation trials). The ability of the patients with an intraparietal sulcus lesion to reorient their spatial focus of attention and to select between competing stimuli was impaired for contralesional targets compared with controls, similarly to what we saw in the inferior parietal group. Furthermore, we could observe that the deficit in Case N.V. resolved with regression of the lesion. To further evaluate the correspondence between spatial-attentional deficits and the intraparietal sulcus lesions, we ascertained the functional integrity of the inferior parietal lobule and temporoparietal junction in Case H.H. using event-related functional magnetic resonance imaging with the same task as in the behavioural study. The intraparietal sulcus lesion of this patient did not affect the task-related activation of the inferior parietal lobule or temporoparietal junction. Additionally, a resting-state functional magnetic resonance imaging study in Case H.H. and 62 controls revealed that the lesion in Case H.H. did not affect the topology of the ventral attention network nor the strength of its main inter- and intrahemispheric connections. Our findings demonstrate that the human superior parietal cortex critically contributes to spatially selective attention.
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Affiliation(s)
- Céline R Gillebert
- Laboratory for Cognitive Neurology, Department of Neurosciences, K. U. Leuven, and Department of Neurology, University Hospitals, Herestraat 49-box 7003, B-3000 Leuven, Belgium
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Valero-Cabré A, Pascual-Leone A, Coubard OA. [Transcranial magnetic stimulation (TMS) in basic and clinical neuroscience research]. Rev Neurol (Paris) 2011; 167:291-316. [PMID: 21420698 PMCID: PMC3093091 DOI: 10.1016/j.neurol.2010.10.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2009] [Revised: 10/11/2010] [Accepted: 10/26/2010] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Non-invasive brain stimulation methods such as transcranial magnetic stimulation (TMS) are starting to be widely used to make causality-based inferences about brain-behavior interactions. Moreover, TMS-based clinical applications are under development to treat specific neurological or psychiatric conditions, such as depression, dystonia, pain, tinnitus and the sequels of stroke, among others. BACKGROUND TMS works by inducing non-invasively electric currents in localized cortical regions thus modulating their activity levels according to settings, such as frequency, number of pulses, train and regime duration and intertrain intervals. For instance, it is known for the motor cortex that low frequency or continuous patterns of TMS pulses tend to depress local activity whereas high frequency and discontinuous TMS patterns tend to enhance it. Additionally, local cortical effects of TMS can result in dramatic patterns in distant brain regions. These distant effects are mediated via anatomical connectivity in a magnitude that depends on the efficiency and sign of such connections. PERSPECTIVES An efficient use of TMS in both fields requires however, a deep understanding of its operational principles, its risks, its potential and limitations. In this article, we will briefly present the principles through which non-invasive brain stimulation methods, and in particular TMS, operate. CONCLUSION Readers will be provided with fundamental information needed to critically discuss TMS studies and design hypothesis-driven TMS applications for cognitive and clinical neuroscience research.
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Affiliation(s)
- A Valero-Cabré
- CNRS UMR 7225-Inserm S975-UPMC, groupe de dynamiques cérébrales plasticité et rééducation, centre de recherche de l'institut du cerveau et la moelle, 47, boulevard de l'Hôpital, 75013 Paris, France.
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17
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Contributions of human parietal and frontal cortices to attentional control during conflict resolution: a 1-Hz offline rTMS study. Exp Brain Res 2010; 205:131-8. [DOI: 10.1007/s00221-010-2336-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Accepted: 06/13/2010] [Indexed: 01/01/2023]
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18
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Verleger R, Möller F, Kuniecki M, Śmigasiewicz K, Groppa S, Siebner HR. The left visual-field advantage in rapid visual presentation is amplified rather than reduced by posterior-parietal rTMS. Exp Brain Res 2010; 203:355-65. [DOI: 10.1007/s00221-010-2237-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Accepted: 03/24/2010] [Indexed: 12/01/2022]
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19
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Wolfe B, Rushmore RJ, Valero-Cabré A. Coping with spatial attention in real space: A low-cost portable testing system for the investigation of visuo-spatial processing in the human brain. J Neurosci Methods 2010; 187:190-8. [DOI: 10.1016/j.jneumeth.2010.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2009] [Revised: 01/06/2010] [Accepted: 01/08/2010] [Indexed: 10/20/2022]
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20
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Sack AT. Parietal cortex and spatial cognition. Behav Brain Res 2009; 202:153-61. [PMID: 19463696 DOI: 10.1016/j.bbr.2009.03.012] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2009] [Revised: 03/04/2009] [Accepted: 03/06/2009] [Indexed: 01/15/2023]
Affiliation(s)
- Alexander T Sack
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
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21
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Novel 'hunting' method using transcranial magnetic stimulation over parietal cortex disrupts visuospatial sensitivity in relation to motor thresholds. Neuropsychologia 2009; 47:3152-61. [PMID: 19651149 DOI: 10.1016/j.neuropsychologia.2009.07.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2008] [Revised: 07/19/2009] [Accepted: 07/24/2009] [Indexed: 11/23/2022]
Abstract
There is considerable inter-study and inter-individual variation in the scalp location of parietal sites where transcranial magnetic stimulation (TMS) may modulate visuospatial behaviours (e.g. see Ryan, Bonilha, & Jackson, 2006); and no clear consensus on methods for identifying such sites. Here we introduce a novel TMS "hunting paradigm" that allows rapid, reliable identification of a site over the right anterior intraparietal sulcus (IPS), where short trains (at 10 Hz for 0.5 s) of TMS disrupt performance of a visuospatial task. The task involves detection of a small peripheral gap (at 14 degrees eccentricity), on one or other (known) side of an extended (29 degrees ) horizontal line centred on fixation. Signal-detection analysis confirmed that TMS at the right IPS site reduced sensitivity (d') for gap targets in the left visual hemifield. A further experiment showed that the same right-parietal TMS increased sensitivity instead for gaps in the right hemifield. Comparing TMS across a grid of scalp locations around the identified 'hotspot' confirmed the spatial-specificity of the effective site. Assessment of the TMS intensity required to produce the phenomena found this was linearly related to individuals' resting motor TMS threshold over hand M1. Our approach provides a systematic new way to identify an effective site and intensity in individuals, at which TMS over right-parietal cortex reliably changes visuospatial sensitivity.
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22
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Woo SH, Kim KH, Lee KM. The role of the right posterior parietal cortex in temporal order judgment. Brain Cogn 2009; 69:337-43. [DOI: 10.1016/j.bandc.2008.08.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2007] [Revised: 08/02/2008] [Accepted: 08/04/2008] [Indexed: 10/21/2022]
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23
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Perturbation of visuospatial attention by high-frequency offline rTMS. Exp Brain Res 2008; 189:121-8. [DOI: 10.1007/s00221-008-1449-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2007] [Accepted: 05/27/2008] [Indexed: 10/21/2022]
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24
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Seemungal BM, Rizzo V, Gresty MA, Rothwell JC, Bronstein AM. Posterior parietal rTMS disrupts human Path Integration during a vestibular navigation task. Neurosci Lett 2008; 437:88-92. [PMID: 18440143 DOI: 10.1016/j.neulet.2008.03.067] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2007] [Revised: 02/28/2008] [Accepted: 03/25/2008] [Indexed: 11/24/2022]
Abstract
In contrast to vision, the neuro-anatomical substrates of vestibular perception are obscure. The vestibular apparati provide a head angular velocity signal allowing perception of self-motion velocity. Perceived change of angular position-in-space can also be obtained from the vestibular head velocity signal via a process called Path Integration (so-called since displacement is obtained by a mathematical temporal integration of the vestibular velocity signal). It is unknown however, if distinct cortical loci sub-serve vestibular perceptions of velocity versus displacement (i.e. Path Integration). Previous studies of human brain activity have not used head motion stimuli hence precluding localisation of vestibular cortical areas specialised for Path Integration distinct from velocity perception. We inferred vestibular cortical function by measuring the disrupting effect of repetitive transcranial magnetic stimulation on the performance of a displacement-dependent vestibular navigation task. Our data suggest that posterior parietal cortex is involved in encoding contralaterally directed vestibular-derived signals of perceived angular displacement and a similar effect was found for both hemispheres. We separately tested whether right posterior parietal cortex was involved in vestibular-sensed velocity perception but found no association. Overall, our data demonstrate that posterior parietal cortex is involved in human Path Integration but not velocity perception. We suggest that there are separate brain areas that process vestibular signals of head velocity versus those involved in Path Integration.
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Affiliation(s)
- Barry M Seemungal
- Division of Neurosciences and Mental Health, Imperial College, Charing Cross Hospital Campus, London W6 8RF, United Kingdom.
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25
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Ruff CC, Bestmann S, Blankenburg F, Bjoertomt O, Josephs O, Weiskopf N, Deichmann R, Driver J. Distinct causal influences of parietal versus frontal areas on human visual cortex: evidence from concurrent TMS-fMRI. Cereb Cortex 2007; 18:817-27. [PMID: 17652468 PMCID: PMC2601025 DOI: 10.1093/cercor/bhm128] [Citation(s) in RCA: 226] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
It has often been proposed that regions of the human parietal and/or frontal lobe may modulate activity in visual cortex, for example, during selective attention or saccade preparation. However, direct evidence for such causal claims is largely missing in human studies, and it remains unclear to what degree the putative roles of parietal and frontal regions in modulating visual cortex may differ. Here we used transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) concurrently, to show that stimulating right human intraparietal sulcus (IPS, at a site previously implicated in attention) elicits a pattern of activity changes in visual cortex that strongly depends on current visual context. Increased intensity of IPS TMS affected the blood oxygen level-dependent (BOLD) signal in V5/MT+ only when moving stimuli were present to drive this visual region, whereas TMS-elicited BOLD signal changes were observed in areas V1-V4 only during the absence of visual input. These influences of IPS TMS upon remote visual cortex differed significantly from corresponding effects of frontal (eye field) TMS, in terms of how they related to current visual input and their spatial topography for retinotopic areas V1-V4. Our results show directly that parietal and frontal regions can indeed have distinct patterns of causal influence upon functional activity in human visual cortex.
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Affiliation(s)
- Christian C Ruff
- UCL Institute of Cognitive Neuroscience, 17 Queen Square, London WC1N 3AR, UK.
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Sack AT, Kohler A, Bestmann S, Linden DEJ, Dechent P, Goebel R, Baudewig J. Imaging the brain activity changes underlying impaired visuospatial judgments: simultaneous FMRI, TMS, and behavioral studies. ACTA ACUST UNITED AC 2007; 17:2841-52. [PMID: 17337745 DOI: 10.1093/cercor/bhm013] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Damage to parietal cortex impairs visuospatial judgments. However, it is currently unknown how this damage may affect or indeed be caused by functional changes in remote but interconnected brain regions. Here, we applied transcranial magnetic stimulation (TMS) to the parietal cortices during functional magnetic resonance imaging (fMRI) while participants were solving visuospatial tasks. This allowed us to observe both the behavioral and the neural effects of transient parietal activity disruption in the active healthy human brain. Our results show that right, but not left, parietal TMS impairs visuospatial judgment, induces neural activity changes in a specific right-hemispheric network of frontoparietal regions, and shows significant correlations between the induced behavioral impairment and neural activity changes in both the directly stimulated parietal and remote ipsilateral frontal brain regions. The revealed right-hemispheric neural network effect of parietal TMS represents the same brain areas that are functionally connected during the execution of visuospatial judgments. This corroborates the notion that visuospatial deficits following parietal damage are brought about by a perturbation of activity across a specific frontoparietal network, rather than the lesioned parietal site alone. Our experiments furthermore show how concurrent fMRI and magnetic brain stimulation during active task execution hold the potential to identify and visualize networks of brain areas that are functionally related to specific cognitive processes.
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Affiliation(s)
- Alexander T Sack
- Department of Cognitive Neuroscience, Faculty of Psychology, Maastricht University, 6200 MD Maastricht, The Netherlands.
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Koch G, Franca M, Mochizuki H, Marconi B, Caltagirone C, Rothwell JC. Interactions between pairs of transcranial magnetic stimuli over the human left dorsal premotor cortex differ from those seen in primary motor cortex. J Physiol 2006; 578:551-62. [PMID: 17124263 PMCID: PMC2075160 DOI: 10.1113/jphysiol.2006.123562] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
A single TMS pulse (110% resting motor threshold, RMT) to the left dorsal premotor cortex (PMd) (CS2) suppresses the amplitude of motor evoked potentials (MEPs) from a test pulse (TS) over the right motor cortex (M1), and facilitates MEPs from the left motor cortex. We probed how this interaction was changed by a prior conditioning pulse over PMd (CS1) using a paired pulse TMS design. In the main experiments, the intensity of CS1 was 80% RMT. Basal suppression of right M1 was removed when CS1-CS2 was 1 ms or 5 ms with a similar tendency at 15 ms. Basal facilitation of left M1 was suppressed at CS1-CS2 of 5 ms. A similar time course was seen if CS2 was increased to 100% RMT, but there was no significant effect if CS1 was 70% RMT. Preconditioning PMd with continuous or intermittent theta burst repetitive TMS (cTBS, iTBS) abolished the basal CS2-TS interaction between premotor and motor cortices. Finally, if very short interstimulus intervals between CS1 and CS2 were explored to detect interactions similar to I-wave facilitation in M1, we found that the basal suppression of right M1 was abolished at CS1-CS2 intervals of 1.8 and 2.8 ms. We suggest that paired pulse TMS may be capable of investigating properties of intrinsic circuits in PMd and that their properties differ from those in the nearby M1. Paired TMS may be a useful method of studying the excitability of intrinsic circuits in non-primary areas of the motor system.
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Affiliation(s)
- Giacomo Koch
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
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Fierro B, Brighina F, Giglia G, Palermo A, Francolini M, Scalia S. Paired pulse TMS over the right posterior parietal cortex modulates visuospatial perception. J Neurol Sci 2006; 247:144-8. [PMID: 16730028 DOI: 10.1016/j.jns.2006.04.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2005] [Revised: 02/14/2006] [Accepted: 04/11/2006] [Indexed: 11/29/2022]
Abstract
OBJECTIVE We previously observed a relative contralateral neglect by right parietal single-pulse TMS given 150 ms after visual stimulus presentation. Here we investigated the effects of parietal paired TMS in normal subjects performing a visuospatial task. METHODS Thirteen right-handed healthy subjects underwent a line-length judgement task during single-pulse and paired (1, 3, 5, 10 ms ISIs) TMS, delivered on the right parietal cortex 150 ms after visual stimulus. RESULTS Single pulse TMS over the right parietal cortex induced a significant rightward bias compared to the baseline condition. At 1 and 3 ms ISIs, paired-pulse TMS did not show any effect in comparison with single pulse TMS. More importantly, 5 ms ISI was able to restore baseline levels, thus inducing a significant improvement of the performance compared to single-pulse TMS and 1-3 ms ISIs. CONCLUSIONS Paired TMS seems able to modulate activity of the right posterior parietal cortex in healthy subjects performing a cognitive visuospatial task.
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Affiliation(s)
- Brigida Fierro
- Dipartimento di Neurologia, Oftalmologia, Otorinolaringoiatria e Psichiatria, Università di Palermo, Via G. La Loggia, 90129, Palermo, Italy
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29
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Rossi S, Pasqualetti P, Zito G, Vecchio F, Cappa SF, Miniussi C, Babiloni C, Rossini PM. Prefrontal and parietal cortex in human episodic memory: an interference study by repetitive transcranial magnetic stimulation. Eur J Neurosci 2006; 23:793-800. [PMID: 16487159 DOI: 10.1111/j.1460-9568.2006.04600.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Neuroimaging findings, including repetitive transcranial magnetic stimulation (rTMS) interference, point to an engagement of prefrontal cortex (PFC) in learning and memory. Whether parietal cortex (PC) activity is causally linked to successful episodic encoding and retrieval is still uncertain. We compared the effects of event-related active or sham rTMS (a rapid-rate train coincident to the very first phases of memoranda presentation) to the left or right intraparietal sulcus, during a standardized episodic memory task of visual scenes, with those obtained in a fully matched sample of subjects who received rTMS on left or right dorsolateral PFC during the same task. In these subjects, specific hemispheric effects of rTMS included interference with encoding after left stimulation and disruption of retrieval after right stimulation. The interference of PC-rTMS on encoding/retrieval performance was negligible, lacking specificity even when higher intensities of stimulation were applied. However, right PC-rTMS of the same intensity lengthened reaction times in the context of a purely attentive visuospatial task. These results suggest that the activity of intraparietal sulci shown in several functional magnetic resonance studies on memory, unlike that of the dorsolateral PFC, is not causally engaged to a useful degree in memory encoding and retrieval of visual scenes. The parietal activations accompanying the memorization processes could reflect the engagement of a widespread brain attentional network, in which interference on a single 'node' is insufficient for an overt disruption of memory performance.
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Affiliation(s)
- Simone Rossi
- Dipartimento di Neuroscienze, Sezione Neurologia, Università di Siena, Policlinico le Scotte, Viale Bracci, I-53100, Siena, Italy.
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Koch G, Franca M, Albrecht UV, Caltagirone C, Rothwell JC. Effects of paired pulse TMS of primary somatosensory cortex on perception of a peripheral electrical stimulus. Exp Brain Res 2006; 172:416-24. [PMID: 16523332 DOI: 10.1007/s00221-006-0359-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2005] [Accepted: 01/03/2006] [Indexed: 10/24/2022]
Abstract
Paired pulse transcranial magnetic stimulation (paired TMS) was introduced to study local inhibitory or facilitatory intracortical circuits of the primary motor cortex. However, similar interactions can be shown in other areas of cortex. The current study tests the effects of paired pulse TMS of the right primary somatosensory cortex (S1) on the sensory perception of electrical stimuli applied on the contralateral thumb finger. In the main experiment a subthreshold conditioning stimulus (CS) preceded a suprathreshold test stimulus (TS) at different inter-stimulus intervals. We found that perception of a peripheral electrical stimulus was markedly attenuated by paired TMS in comparison to single pulse TMS when the ISIs was 10 or 15 ms, while there was no effect at shorter ISIs. There was no additional effect of the CS pulse if the intensity of the TS was subthreshold. In control experiments we observed that the effect vanished when the delay between the peripheral stimulus and the TS was 10 or 30 ms rather than 20 ms or if the pairs of pulses were applied over the vertex rather than the hand area. Furthermore, there was no change at longer ISIs when paired TMS was applied over the posterior parietal cortex of the same hemisphere. These results demonstrate that paired pulse TMS is able to probe intracortical circuits in S1 and that the intrinsic properties of these circuits differ even between closely adjacent areas of the cortex.
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Affiliation(s)
- Giacomo Koch
- Laboratorio di Neurologia Clinica e Comportamentale, Fondazione Santa Lucia IRCCS, Via Ardeatina, 306, 00179 Rome, Italy.
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Rushworth MFS, Taylor PCJ. TMS in the parietal cortex: updating representations for attention and action. Neuropsychologia 2006; 44:2700-16. [PMID: 16455113 DOI: 10.1016/j.neuropsychologia.2005.12.007] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2005] [Revised: 12/09/2005] [Accepted: 12/15/2005] [Indexed: 11/25/2022]
Abstract
Transcranial magnetic stimulation (TMS) is one of the most recent techniques to have been used in investigations of the parietal cortex but already a number of studies have employed it as a tool in investigations of attentional and sensorimotor processes in the human parietal cortices. The high temporal resolution of TMS has proved to be a particular strength of the technique and the experiments have led to hypotheses about when circumscribed regions of parietal cortex are critical for specific attentional and sensorimotor processes. A consistent theme that runs through many reports is that of a critical contribution of parietal areas when attention or movements are re-directed and representations for attention or action must be updated.
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Affiliation(s)
- M F S Rushworth
- Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford OX1 3UD, United Kingdom.
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