Exploring structure and function of sensory cortex with 7 T MRI

Schluppeck, Denis; Sánchez-Panchuelo, Rosa-Maria; Francis, Susan T.

doi:10.1016/j.neuroimage.2017.01.081

Cited by 32 publications

(28 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the primary somatosensory cortex, we find no deviations from the homunculus model as shown previously in humans (Schluppeck 2017;Olman 2012;Kolasinski 2016;Shellekens 2018).…”

Section: Discussionsupporting

confidence: 89%

See 1 more Smart Citation

Sub-millimeter fMRI reveals multiple topographical digit representations that form action maps in human motor cortex

Huber¹,

Finn²,

Handwerker³

et al. 2018

Preprint

View full text Add to dashboard Cite

The human brain coordinates a wide variety of motor activities. On a large scale, the cortical motor system is topographically organized such that neighboring body parts are represented by neighboring brain areas. This homunculus-like somatotopic organization along the central sulcus has been observed using neuroimaging for large body parts such as the face, hands and feet. However, on a finer scale, invasive electrical stimulation studies show deviations from this somatotopic organization that suggest an organizing principle based on motor actions rather than body part moved. It has not been clear how the action-map organization principle of the motor cortex in the mesoscopic (sub-millimeter) regime integrates into a body map organization principle on a macroscopic scale (cm). Here we developed and applied advanced mesoscopic (sub-millimeter) fMRI and analysis methodology to non-invasively investigate the functional organization topography across columnar and laminar structures in humans. We find that individual fingers have multiple mirrored representations in the primary motor cortex depending on the movements they are involved in. We find that individual digits have cortical representations up to 3 mm apart from each other arranged in a column-like fashion. These representations are differentially engaged depending on whether the digits' muscles are used for different motor actions such as flexion movements like grasping a ball or retraction movements like releasing a ball. This research provides a starting point for noninvasive investigation of mesoscale topography across layers and columns of the human cortex and bridges the gap between invasive electrophysiological investigations and large coverage noninvasive neuroimaging. high-resolution fMRI | motor cortex | cortical layers | cortical columns | VASO

show abstract

“…In the primary somatosensory cortex, we find no deviations from the homunculus model as shown previously in humans (Schluppeck 2017;Olman 2012;Kolasinski 2016;Shellekens 2018).…”

Section: Discussionsupporting

confidence: 89%

“…Functional MRI signal changes in S1 show a linear arrangement of individual digits ( Fig. 1) as previously described in high-resolution fMRI (Olman 2012;Panchuelo 2016;Kolasinsky 2016;Schluppeck 2017;Siero 2014;Ejaz 2015). The distance between the representations of the thumb and the little finger in S1 is 16 ± 4 mm.…”

Section: Resultssupporting

confidence: 74%

Sub-millimeter fMRI reveals multiple topographical digit representations that form action maps in human motor cortex

Huber¹,

Finn²,

Handwerker³

et al. 2018

Preprint

View full text Add to dashboard Cite

show abstract

“…Initially, neuroscientists were forced to use highly invasive methods to probe the mechanisms of sensation, which limited the applicability of such studies to humans. [1][2][3][4][5] More recently, advances in functional neuroimaging over the past several decades have opened new avenues for investigating sensation and perception non-invasively [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Because of its non-invasive nature and because of the wealth of fundamental knowledge derived from homologous systems in other mammals and from humans undergoing surgical procedures, functional imaging of sensory systems currently provides the best foundation for understanding the functional organization of the brain in healthy humans.…”

Section: Introductionmentioning

confidence: 99%

Somatotopic Arrangement of Eight Distinct Skin Areas in the Human Primary Somatosensory Cortex Derived from Functional Magnetic Resonance Imaging

Willoughby

Thoenes

Bolding

2020

Preprint

View full text Add to dashboard Cite

Blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) was used to investigate cortical activity associated with peripheral tactile stimuli in a small cohort of healthy humans. MR-safe automated pneumatic stimulators modeled after the Wartenberg pinwheel were used to generate tactile stimuli at regular intervals on eight disparate areas of skin. The phase-encoded BOLD responses of voxels in the cerebral cortex were characterized by the maximal normalized cross-correlation coefficients at time delays between an idealized response and the measure time course. Overall at the group level, the somatotopic organization of the somatosensory cortex (SI) follows the accepted homunculus model, but a noticeable amount of variation was observed between individual study participants. The surface areas of cortical regions in SI activated by tactile stimulation of different body parts were calculated, giving an estimate of cortical magnification factors. Data collected with the participant actively attending the stimuli were compared to data collected before the attention task. No significant attention-related changes were observed in the somatotopic maps or in time courses of voxels well-correlated to stimuli.

show abstract

“…To date, the majority of UHF fMRI studies have used reduced field‐of‐view (FOV) 2D‐and 3D echo planar imaging (EPI) acquisitions to study chosen primary sensory areas, such as the visual and sensorimotor cortices (Fracasso, Luijten, Dumoulin, & Petridou, ; Puckett, Bollmann, Barth, & Cunnington, ; Reithler, Peters, & Goebel, ; Schluppeck, Sanchez‐Panchuelo, & Francis, ), thus overcoming a number of challenges of B 0 and B 1 inhomogeneities associated with larger FOV acquisitions (Polimeni, Renvall, Zaretskaya, & Fischl, ; Uludag & Blinder, ). For example, the increase in BOLD CNR of UHF experiments has been used to provide detailed maps of individual subjects’ visual (Goncalves et al, ; Kemper, De Martino, Emmerling, Yacoub, & Goebel, ; Poltoratski, Ling, McCormack, & Tong, ; Rua et al, ) and somatosensory functional responses (Puckett et al, ; Sanchez Panchuelo et al, ; Sanchez Panchuelo, Schluppeck, Harmer, Bowtell, & Francis, ) and how these relate to individual brain anatomy (Besle, Sanchez‐Panchuelo, Bowtell, Francis, & Schluppeck, ; Sanchez‐Panchuelo et al, ; Sanchez‐Panchuelo et al, ).…”

Section: Introductionmentioning

confidence: 99%

Addressing challenges of high spatial resolution UHF fMRI for group analysis of higher‐order cognitive tasks: An inter‐sensory task directing attention between visual and somatosensory domains

Aquino

Sokoliuk

Pakenham

et al. 2018

Human Brain Mapping

Self Cite

View full text Add to dashboard Cite

Functional MRI at ultra‐high field (UHF, ≥7 T) provides significant increases in BOLD contrast‐to‐noise ratio (CNR) compared with conventional field strength (3 T), and has been exploited for reduced field‐of‐view, high spatial resolution mapping of primary sensory areas. Applying these high spatial resolution methods to investigate whole brain functional responses to higher‐order cognitive tasks leads to a number of challenges, in particular how to perform robust group‐level statistical analyses. This study addresses these challenges using an inter‐sensory cognitive task which modulates top‐down attention at graded levels between the visual and somatosensory domains. At the individual level, highly focal functional activation to the task and task difficulty (modulated by attention levels) were detectable due to the high CNR at UHF. However, to assess group level effects, both anatomical and functional variability must be considered during analysis. We demonstrate the importance of surface over volume normalisation and the requirement of no spatial smoothing when assessing highly focal activity. Using novel group analysis on anatomically parcellated brain regions, we show that in higher cognitive areas (parietal and dorsal‐lateral‐prefrontal cortex) fMRI responses to graded attention levels were modulated quadratically, whilst in visual cortex and VIP, responses were modulated linearly. These group fMRI responses were not seen clearly using conventional second‐level GLM analyses, illustrating the limitations of a conventional approach when investigating such focal responses in higher cognitive regions which are more anatomically variable. The approaches demonstrated here complement other advanced analysis methods such as multivariate pattern analysis, allowing UHF to be fully exploited in cognitive neuroscience.

show abstract

Exploring structure and function of sensory cortex with 7 T MRI

Cited by 32 publications

References 50 publications

Sub-millimeter fMRI reveals multiple topographical digit representations that form action maps in human motor cortex

Sub-millimeter fMRI reveals multiple topographical digit representations that form action maps in human motor cortex

Somatotopic Arrangement of Eight Distinct Skin Areas in the Human Primary Somatosensory Cortex Derived from Functional Magnetic Resonance Imaging

Addressing challenges of high spatial resolution UHF fMRI for group analysis of higher‐order cognitive tasks: An inter‐sensory task directing attention between visual and somatosensory domains

Contact Info

Product

Resources

About