TMS of the occipital cortex induces tactile sensations in the fingers of blind Braille readers

Ptito, Maurice; Fumal, Arnaud; Noordhout, A. Martens de; Schoenen, Jean; Gjedde, Albert; Kupers, Ron

doi:10.1007/s00221-007-1091-0

Cited by 80 publications

(57 citation statements)

References 47 publications

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“…This happens in blindfolded sighted participants (Merabet et al, 2007(Merabet et al, , 2008 and blind participants (Sadato et al, 1996(Sadato et al, , 1998(Sadato et al, , 2002(Sadato et al, , 2004Cohen et al, 1999;Burton et al, 2002Burton et al, , 2006Ptito et al, 2005;Stilla et al, 2008). Several lines of evidence suggest a functional role for cross-modal plasticity: a congenitally blind Braille reader developed alexia for Braille after suffering a bilateral occipital stroke , occipital transcranial magnetic stimulation (TMS) impairs blind participants' tactile performance (Cohen et al, 1997(Cohen et al, , 1999Kupers et al, 2007), and occipital TMS elicits sensations on the fingers in some participants (Ptito et al, 2008).…”

Section: Possible Neural Mechanismsmentioning

confidence: 99%

Tactile Spatial Acuity Enhancement in Blindness: Evidence for Experience-Dependent Mechanisms

Wong¹,

Gnanakumaran²,

Goldreich³

2011

J. Neurosci.

150

115

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Tactile spatial acuity is enhanced in blindness, according to several studies, but the cause of this enhancement has been controversial. Two competing hypotheses are the tactile experience hypothesis (reliance on the sense of touch drives tactile-acuity enhancement) and the visual deprivation hypothesis (the absence of vision itself drives tactile-acuity enhancement). Here, we performed experiments to distinguish between these two hypotheses. We used force-controlled grating orientation tasks to compare the passive (finger stationary) tactile spatial acuity of 28 profoundly blind and 55 normally sighted humans on the index, middle, and ring fingers of each hand, and on the lips. The tactile experience hypothesis predicted that blind participants would outperform the sighted on the fingers, and that Braille reading would correlate with tactile acuity. The visual deprivation hypothesis predicted that blind participants would outperform the sighted on fingers and lips. Consistent with the tactile experience hypothesis, the blind significantly outperformed the sighted on all fingers, but not on the lips. Additionally, among blind participants, proficient Braille readers on their preferred reading index finger outperformed nonreaders. Finally, proficient Braille readers performed better with their preferred reading index finger than with the opposite index finger, and their acuity on the preferred reading finger correlated with their weekly reading time. These results clearly implicate reliance on the sense of touch as the trigger for tactile spatial acuity enhancement in the blind, and suggest the action of underlying experience-dependent neural mechanisms such as somatosensory and/or cross-modal cortical plasticity.

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Section: Possible Neural Mechanismsmentioning

confidence: 99%

Tactile Spatial Acuity Enhancement in Blindness: Evidence for Experience-Dependent Mechanisms

Wong¹,

Gnanakumaran²,

Goldreich³

2011

J. Neurosci.

150

115

View full text Add to dashboard Cite

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“…In blind subjects visual cortex TMS interferes with both Braille reading and general tactile perception (Zangaladze et al, 1999;Kupers et al, 2007). However, it is difficult to compare studies using blind subjects to those using sighted subjects, as visual cortex in blind subjects is often sensitive to inputs from other modalities (Ptito et al, 2008).…”

Section: Comparison To Prior Workmentioning

confidence: 99%

Modulation of Olfactory Perception by Visual Cortex Stimulation

Jadauji

Djordjević²,

Lundström³

et al. 2012

J. Neurosci.

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When attempting to identify an object based on smell alone, people often visualize the perceived source of the odorant. This close association between olfactory and visual functions is supported by neuroimaging studies demonstrating activation of visual cortex during performance of purely olfactory tasks. Such activation might simply reflect the correlation between olfactory percepts and the corresponding visual images, or it might reflect a causal contribution of visual processing to olfactory perception. Here we provide evidence in support of the latter possibility. Using repetitive transcranial magnetic stimulation, we show that stimulating human visual cortex improves performance on a task requiring discrimination among different odor qualities. No significant improvement is found for tasks involving discrimination between intensities of the same odor, from stimulation of auditory cortex, or from "sham" stimulation. These results are thus consistent with a specific visual cortical influence on high-level olfactory perception. They also demonstrate that unimodal perceptual tasks are influenced by processing within cortical areas of other, seemingly unrelated, sensory systems.

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“…The authors concluded that the subjective character of the percept would depend on the stimulated sensory channel and not on the activated cortex. In other words, according to these authors, the subjective experience associated with an activity in the visual cortex after sensory remapping is tactile and not visual (see also Ptito et al, 2008).…”

Section: Activation Of the Associated Brain Areasmentioning

confidence: 99%

Perception With Compensatory Devices: From Sensory Substitution to Sensorimotor Extension

Auvray¹,

Myin

2009

Cognitive Science

110

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Sensory substitution devices provide through an unusual sensory modality (the substituting modality, e.g., audition) access to features of the world that are normally accessed through another sensory modality (the substituted modality, e.g., vision). In this article, we address the question of which sensory modality the acquired perception belongs to. We have recourse to the four traditional criteria that have been used to define sensory modalities: sensory organ, stimuli, properties, and qualitative experience (Grice, 1962), to which we have added the criteria of behavioral equivalence (Morgan, 1977), dedication (Keeley, 2002), and sensorimotor equivalence (O'Regan & Noë, 2001). We discuss which of them are fulfilled by perception through sensory substitution devices and whether this favors the view that perception belongs to the substituting or to the substituted modality. Though the application of a number of criteria might be taken to point to the conclusion that perception with a sensory substitution device belongs to the substituted modality, we argue that the evidence leads to an alternative view on sensory substitution. According to this view, the experience after sensory substitution is a transformation, extension, or augmentation of our perceptual capacities, rather than being something equivalent or reducible to an already existing sensory modality. We develop this view by comparing sensory substitution devices to other ''mind-enhancing tools'' such as pen and paper, sketchpads, or calculators. An analysis of sensory substitution in terms of mind-enhancing tools unveils it as a thoroughly transforming perceptual experience and as giving rise to a novel form of perceptual interaction with the environment.

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TMS of the occipital cortex induces tactile sensations in the fingers of blind Braille readers

Cited by 80 publications

References 47 publications

Tactile Spatial Acuity Enhancement in Blindness: Evidence for Experience-Dependent Mechanisms

Tactile Spatial Acuity Enhancement in Blindness: Evidence for Experience-Dependent Mechanisms

Modulation of Olfactory Perception by Visual Cortex Stimulation

Perception With Compensatory Devices: From Sensory Substitution to Sensorimotor Extension

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