The Cortical Site of Visual Suppression by Transcranial Magnetic Stimulation

Thielscher, Axel; Reichenbach, Alexandra; Uğurbil, Kâmil; Uludağ, Kâmil

doi:10.1093/cercor/bhp102

Cited by 68 publications

(61 citation statements)

References 54 publications

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“…It has sometimes been assumed that occipital TMS primarily targets the visual area V1 (Boyer et al 2005;Laycock et al 2007;Silvanto et al 2005a, b). However, a recent study (Thielscher et al 2010) found that the exact site of stimulation is likely to be V2d or even V3. In this study, we are largely agnostic with respect to the exact regions in the visual hierarchy that were stimulated, since the net effect of increased noise could be accomplished at several levels in the hierarchy.…”

Section: Summary Of Resultsmentioning

confidence: 99%

Direct injection of noise to the visual cortex decreases accuracy but increases decision confidence

Rahnev

Maniscalco

Luber

et al. 2012

Journal of Neurophysiology

117

131

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Rahnev DA, Maniscalco B, Luber B, Lau H, Lisanby SH. Direct injection of noise to the visual cortex decreases accuracy but increases decision confidence. J Neurophysiol 107: 1556 -1563, 2012. First published December 14, 2011 doi:10.1152/jn.00985.2011The relationship between accuracy and confidence in psychophysical tasks traditionally has been assumed to be mainly positive, i.e., the two typically increase or decrease together. However, recent studies have reported examples of exceptions, where confidence and accuracy dissociate from each other. Explanations for such dissociations often involve dual-channel models, in which a cortical channel contributes to both accuracy and confidence, whereas a subcortical channel only contributes to accuracy. Here, we show that a single-channel model derived from signal detection theory (SDT) can also account for such dissociations. We applied transcranial magnetic stimulation (TMS) to the occipital cortex to disrupt the internal representation of a visual stimulus. The results showed that consistent with previous research, occipital TMS decreased accuracy. However, counterintuitively, it also led to an increase in confidence ratings. The data were predicted well by a single-channel SDT model, which posits that occipital TMS increased the variance of the internal stimulus distributions. A formal model comparison analysis that used information theoretic methods confirmed that this model was preferred over single-channel models, in which occipital TMS changed the signal strength or dual-channel models, which assume two different processing routes. Thus our results show that dissociations between accuracy and confidence can, at least in some cases, be accounted for by a single-channel model.

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Section: Summary Of Resultsmentioning

confidence: 99%

Direct injection of noise to the visual cortex decreases accuracy but increases decision confidence

Rahnev

Maniscalco

Luber

et al. 2012

Journal of Neurophysiology

117

131

View full text Add to dashboard Cite

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“…One likely reason for such an effect is the presence of variations in brain anatomy and a resulting variability in the amount of direct magnetic stimulation received by each retinotopic region. Understanding how these differences in brain anatomy affect the amount of induced electrical field to each retinotopically defined region of early visual cortex was beyond the scope of this paper, but there has been a lot of exciting work in this direction (Kammer et al 2001;SalminenVaparanta et al 2012aSalminenVaparanta et al , 2012bThielscher et al 2010). Instead, here we focused on the functional consequences of stimulation rather than on the precise amount of stimulation induced in each region.…”

Section: Discussionmentioning

confidence: 99%

“…Following previous research (Boyer et al 2005), we chose the starting point of the hunting procedure to be 2 cm above and 1 cm left of the inion, but the final position was close to the midline for all subjects, and thus it is unlikely that one hemisphere was targeted preferentially. We could not estimate the induced electrical field in each retinotopically defined visual area as has been done before (Kammer et al 2001;SalminenVaparanta et al 2012aSalminenVaparanta et al , 2012bThielscher et al 2010), but instead focused on the functional consequences of stimulation rather than in the precise amount of stimulation induced in each region.…”

Section: Subjectsmentioning

confidence: 99%

Continuous theta burst transcranial magnetic stimulation reduces resting state connectivity between visual areas

Rahnev

Kok

Munneke

et al. 2013

Journal of Neurophysiology

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Research to date has focused on the effect of cTBS on the target area, but less is known about its effects on the resting state functional connectivity between different brain regions. We investigated this issue by applying cTBS to the occipital cortex and probing its influence in retinotopically defined regions in early visual cortex using functional MRI. We found that occipital cTBS reliably decreased the resting state functional connectivity (i.e., the correlation of spontaneous activity) between regions of the early visual cortex. In the context of a perceptual task, such an effect could mean that cTBS affects the strength of the perceptual signal, its variability, or both. We investigated this issue in a second experiment in which subjects performed a perceptual discrimination task and indicated their level of certainty on each trial. The results showed that occipital cTBS decreased both subjects' accuracy and confidence. Signal detection modeling suggested that these impairments resulted primarily from a decreased strength of the perceptual signal, with a nonsignificant trend of a decrease in signal variability. We discuss the implications of these experiments for understanding the mechanisms by which cTBS influences brain activity and perceptual processes. cTBS; fMRI; visual cortex; perception; resting state connectivity; signal detection theory REPETITIVE TRANSCRANIAL MAGNETIC stimulation is a popular technique used to transiently affect neural activity in a noninvasive manner. One recently developed variant of repetitive transcranial magnetic stimulation (TMS), continuous theta burst stimulation (cTBS;Huang et al. 2005), has shown promise because of its rapid application (Ͻ1 min), its ability to produce behavioral effects for up to 1 h after stimulation, and its connection to known neuronal mechanisms, such as long-term potentiation and depression (LTD). Indeed, research has shown that cTBS reduces motor cortical excitability in a manner consistent with LTD effects (Allen et al. 2007;Di Lazzaro et al. 2005Gentner et al. 2008;Huang et al. 2005Huang et al. , 2007.When applied to the occipital cortex, cTBS has been found to increase phosphene thresholds (PTs), such that higher stimulation intensity is needed to produce conscious visual experience (Franca et al. 2006). One possibility is that such an increase in PTs is, at least in part, due to decreased connectivity between areas in the early visual cortex, which would make the Here we tested for this possibility by investigating the resting state connectivity between retinotopically defined regions in the early visual cortex after occipital application of cTBS. We identified areas V1, V2, and V3 as three separate regions of interest (ROIs) and found that cTBS decreased the resting state functional connectivity between each pair of regions. In separate analyses, we separated the left and right hemisphere of each of these areas and observed that cTBS decreased the inter-and intrahemispheric resting state connectivity between these retinotopically defined re...

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“…We cannot pinpoint though, at which time point exactly the posterior mIPS was crucial for information processing. TMS studies in primary visual (Amassian et al, 1989;Thielscher et al, 2010) and motor (Di Lazzaro et al, 1999;Ferbert et al, 1992) areas, and TMS connectivity studies between higher order and primary motor cortices (Koch et al, 2007;Mochizuki et al, 2004) succeeded in narrowing down chronometry of neural processing to time windows of few milliseconds. Those effects, however, are much more robust than TMS effects due to virtual lesions of higher cortical areas such as the posterior parietal cortex.…”

Section: Discussionmentioning

confidence: 99%

A key region in the human parietal cortex for processing proprioceptive hand feedback during reaching movements

et al. 2014

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Seemingly effortless, we adjust our movements to continuously changing environments. After initiation of a goal-directed movement, the motor command is under constant control of sensory feedback loops. The main sensory signals contributing to movement control are vision and proprioception. Recent neuroimaging studies have focused mainly on identifying the parts of the posterior parietal cortex (PPC) that contribute to visually guided movements. We used event-related TMS and force perturbations of the reaching hand to test whether the same sub-regions of the left PPC contribute to the processing of proprioceptive-only and of multi-sensory information about hand position when reaching for a visual target. TMS over two distinct stimulation sites elicited differential effects: TMS applied over the posterior part of the medial intraparietal sulcus (mIPS) compromised reaching accuracy when proprioception was the only sensory information available for correcting the reaching error. When visual feedback of the hand was available, TMS over the anterior intraparietal sulcus (aIPS) prolonged reaching time. Our results show for the first time the causal involvement of the posterior mIPS in processing proprioceptive feedback for online reaching control, and demonstrate that distinct cortical areas process proprioceptive-only and multi-sensory information for fast feedback corrections.

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The Cortical Site of Visual Suppression by Transcranial Magnetic Stimulation

Cited by 68 publications

References 54 publications

Direct injection of noise to the visual cortex decreases accuracy but increases decision confidence

Direct injection of noise to the visual cortex decreases accuracy but increases decision confidence

Continuous theta burst transcranial magnetic stimulation reduces resting state connectivity between visual areas

A key region in the human parietal cortex for processing proprioceptive hand feedback during reaching movements

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