Mind the blind brain to understand the sighted one! Is there a supramodal cortical functional architecture?

Ricciardi, Emiliano; Bonino, Daniela; Pellegrini, Silvia; Pietrini, Pietro

doi:10.1016/j.neubiorev.2013.10.006

Cited by 139 publications

(129 citation statements)

References 149 publications

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“…In contrast, Jiang et al (46) reported only a weak (2% of voxels) response to tactile stimulation. Given the high sensitivity of intracranial recordings, we were able to show that indeed somatosensory information reaches pMSTv, suggesting a possible integration between tactile and visual information (47). If pMSTv functions in the same capacity as its monkey counterpart, this integration may serve to control tracking of moving objects not only with eyes, as described by Newsome et al (48), but also with arms (49).…”

Section: Responsiveness Maps Document the Wide Extent Of The Corticalmentioning

confidence: 67%

Four-dimensional maps of the human somatosensory system

Avanzini

Abdollahi

Sartori

et al. 2016

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

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A fine-grained description of the spatiotemporal dynamics of human brain activity is a major goal of neuroscientific research. Limitations in spatial and temporal resolution of available noninvasive recording and imaging techniques have hindered so far the acquisition of precise, comprehensive four-dimensional maps of human neural activity. The present study combines anatomical and functional data from intracerebral recordings of nearly 100 patients, to generate highly resolved four-dimensional maps of human cortical processing of nonpainful somatosensory stimuli. These maps indicate that the human somatosensory system devoted to the hand encompasses a widespread network covering more than 10% of the cortical surface of both hemispheres. This network includes phasic components, centered on primary somatosensory cortex and neighboring motor, premotor, and inferior parietal regions, and tonic components, centered on opercular and insular areas, and involving human parietal rostroventral area and ventral medial-superior-temporal area. The technique described opens new avenues for investigating the neural basis of all levels of cortical processing in humans.A detailed description of the spatiotemporal dynamics of human brain activity is a major goal of neuroscientific research. However, it has been impossible so far to attain both high spatial and temporal resolution using the available noninvasive recording and imaging techniques. Hence, a precise and comprehensive four-dimensional cartography of human neural activity has not yet been obtained. High spatial resolution, provided by neuroimaging techniques such as functional magnetic resonance imaging (fMRI), is crucial for highlighting the topographical organization of specific areas (e.g., somatotopy of sensorimotor areas) as well as identifying the nodes of brain networks endowed with specific functional properties (1). It is not sufficient, however, to know which nodes are active; information is also needed about the local dynamics of the nodes, as well as the relative timing of their activity, to fully understand human brain functions (2, 3). Even if the temporal resolution of electroencephalography (EEG) and magnetoencephalography (MEG) allowed one to observe the intra-and interareal dynamics, to date such recordings remain too poor in localization power (1-2 cm) (3, 4). Combining EEG and fMRI has been suggested as a solution, using EEG to determine the temporal dynamics within and between the areas identified with fMRI (5). However, the disparate nature of the two signals recorded (hemodynamic for fMRI, electrical for EEG) creates discrepancies in the results that prevent precise matching of these methods (3).Invasive intracranial EEG offers a unique opportunity to observe human brain activity with an unparalleled combination of spatial and temporal resolution. Depending on the electrodes used, two kinds of recordings can be made: (i) intraparenchymal recordings, also called stereo-EEG (sEEG) (6), obtained using stereotactically inserted needle-like electrodes...

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Section: Responsiveness Maps Document the Wide Extent Of The Corticalmentioning

confidence: 67%

Four-dimensional maps of the human somatosensory system

Avanzini

Abdollahi

Sartori

et al. 2016

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

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“…In this case, the functional specificity of VTC is merely an extension of this principle, which would make testable predictions about the computational mechanisms that underlie visual categorical processing (36,37). Alternatively, the development of categorical selectivity in VTC could be driven in part by multimodal or supramodal principles (38). In this view, a particular categorical sensitivity is hard-wired in the extrastriate cortex from birth.…”

Section: Discussionmentioning

confidence: 99%

“…First, what neural pathways mediate the categorical representations activated in VTC through auditory stimulation? Earlier work has demonstrated that nonvisual sensory input can be conveyed into the visual cortex in both blind and sighted (albeit to a smaller extent) individuals (38,40). These nonvisual signals might reach visual cortex through thalamocortical projections or corticocortical connections, transferring information directly from primary sensory areas or indirectly from higher-order (multisensory) areas (e.g., the superior temporal sulcus).…”

Section: Discussionmentioning

confidence: 99%

Development of visual category selectivity in ventral visual cortex does not require visual experience

Hurk

Baelen

Beeck

2017

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

128

103

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To what extent does functional brain organization rely on sensory input? Here, we show that for the penultimate visual-processing region, ventral-temporal cortex (VTC), visual experience is not the origin of its fundamental organizational property, category selectivity. In the fMRI study reported here, we presented 14 congenitally blind participants with face-, body-, scene-, and object-related natural sounds and presented 20 healthy controls with both auditory and visual stimuli from these categories. Using macroanatomical alignment, response mapping, and surface-based multivoxel pattern analysis, we demonstrated that VTC in blind individuals shows robust discriminatory responses elicited by the four categories and that these patterns of activity in blind subjects could successfully predict the visual categories in sighted controls. These findings were confirmed in a subset of blind participants born without eyes and thus deprived from all light perception since conception. The sounds also could be decoded in primary visual and primary auditory cortex, but these regions did not sustain generalization across modalities. Surprisingly, although not as strong as visual responses, selectivity for auditory stimulation in visual cortex was stronger in blind individuals than in controls. The opposite was observed in primary auditory cortex. Overall, we demonstrated a striking similarity in the cortical response layout of VTC in blind individuals and sighted controls, demonstrating that the overall category-selective map in extrastriate cortex develops independently from visual experience.ategory selectivity in human and primate visual cortex is a striking example of how the brain encodes the outer world. Mostly found on the lateral and ventral parts of the temporal lobe, several distinct macroscopic brain regions are known to have a preference for a particular category of visual objects, including faces [fusiform face area, occipital face area (1)], body parts [extrastriate body area (2), fusiform body area (3)], artificial objects [lateral occipital complex (4)], and scenes [parahippocampal place area (5)]. The exact computational mechanisms that drive these regions are still largely unknown: Do these regions operate as distinct functional modules (1, 6), or is category selectivity fully distributed across ventral-temporal cortex (VTC) (7), ora combination of both-do category-selective regions reflect peaks in a broad tuning map for visual object features (8)?A prominent question is whether this functional architecture develops independently of visual input or relies on visual experience during early infancy and the following years. As an example of the latter, a key hypothesis indicates that the global functional organization of VTC starts out as a protomap with a retinotopic layout (9-11). Through visual experience, regions within this protomap develop selectivity for the visual categories that often appear in the retinotopic region that is represented. According to this perspective, because faces most likely appear...

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“…reviewed in Bavelier and Neville, 2002;Sadato, 2006;Renier et al, 2014;Ricciardi et al, 2014). These effects include both auditory as well as haptic responses within visual cortices.…”

Section: The Anatomic Scaffolding For Multisensory Processes In the Pmentioning

confidence: 99%

“…For example, primary visual cortex appears to be causally linked to the accuracy of reading Braille by early-blind individuals (Cohen et al, 1997;Sadato et al, 2002) and to also correlate with performance on tasks completed either via touch or sound (e.g. Amedi et al, 2003;Raz et al, 2005; reviewed in Ricciardi et al, 2014).…”

Section: The Anatomic Scaffolding For Multisensory Processes In the Pmentioning

confidence: 99%

The multisensory function of the human primary visual cortex

et al. 2016

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2It has been nearly ten years since Ghazanfar and Schroeder (2006) proposed that the neocortex is essentially multisensory in nature. However, it is only recently that sufficient and hard evidence that supports this proposal has accrued. We review evidence that activity within the human primary visual cortex plays an active role in multisensory processes and directly impacts behavioural outcome. This evidence emerges from a full pallet of human brain imaging and brain mapping methods with which multisensory processes are quantitatively assessed by taking advantage of particular strengths of each technique as well as advances in signal analyses. Several general conclusions about multisensory processes in primary visual cortex of humans are supported relatively solidly. First, haemodynamic methods (fMRI/PET) show that there is both convergence and integration occurring within primary visual cortex. Second, primary visual cortex is involved in multisensory processes during early post-stimulus stages (as revealed by EEG/ERP/ERFs as well as TMS). Third, multisensory effects in primary visual cortex directly impact behaviour and perception, as revealed by correlational (EEG/ERPs/ERFs) as well as more causal measures (TMS/tACS). While the provocative claim of Ghazanfar and Schroeder (2006) that the whole of neocortex is multisensory in function has yet to be demonstrated, this can now be considered established in the case of the human primary visual cortex.

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Mind the blind brain to understand the sighted one! Is there a supramodal cortical functional architecture?

Cited by 139 publications

References 149 publications

Four-dimensional maps of the human somatosensory system

Four-dimensional maps of the human somatosensory system

Development of visual category selectivity in ventral visual cortex does not require visual experience

The multisensory function of the human primary visual cortex

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