Findings show how the pandemic altered young minds

Humans can judge grating orientation by touch. Previous studies indicate that the extrastriate cortex is involved in tactile orientation judgments, suggesting that this area is related to visual imagery. However, it has been unclear which neural mechanisms are crucial for the tactile processing of orientation, because visual imagery is not always required for tactile spatial tasks. We expect that such neural mechanisms involve multisensory areas, because our perception of space is highly integrated across modalities. The current study uses functional magnetic resonance imaging during the classification of grating orientations to evaluate the neural substrates responsible for the multisensory spatial processing of orientation. We hypothesized that a region within the intraparietal sulcus (IPS) would be engaged in orientation processing, regardless of the sensory modality. Sixteen human subjects classified the orientations of passively touched gratings and performed two control tasks with both the right and ...

Growing evidence from post-mortem studies suggests involvement of white matter abnormalities in the pathology of schizophrenia. The development of a new magnetic resonance imaging (MRI) technique, Diffusion Tensor Imaging (DTI), allows examination of white matter track integrity in vivo. We examined a group of chronic schizophrenia patients and age, gender, and education level matched controls. All participants underwent a MRI scan including a spin-echo EPI DTI sequence (TR/TE 5400/80ms, 40 slices, 1.8x1.8x2mm³ voxel size) on a 3T MRI Scanner (Siemens Allegra). Diffusion weighted images were acquired in 6 directions with b value = 1000s/mm². The original voxel size was interpolated to 1x1x1mm³. The data was aligned to high-resolution T1 weighted anatomical images and transformed into Talairach space. The resulting datasets were spatially smoothed with a 10mm Gaussian kernel. White matter differences between the two groups were evaluated by comparing fractional anisotropy (FA) values in a whole-brain analys...

Whereas zebra finch males produce song in a more sexual context, females rather use long calls for acoustic recognition of conspecific and affinitive birds. Recognition of biologically relevant information in acoustic signals is thought to be accomplished (partly) by NCM (caudomedial neostriatum or nidopallium), a telencephalic brain region with a maximum size of 3 mm3. In order to prepare in-vivo studies of NCM activation in response to acoustic stimuli, the hypercapnic response of NCM was explored with both optical imaging (non-invasive in-vivo broadband time-resolved spectroscopy) and functional MRI (Blood Oxygenation Level Dependent, BOLD). Subsequently, local variations in CBV and hemoglobin saturation levels obtained from optical data in songbird brain can be correlated with local BOLD signal variations which provide overall information on CBF, CBV and alterations in hemoglobin oxygenation. Female zebra finches were anesthetized with 2% isoflurane under spontaneously breathing, while they underwent t...

Attention can be voluntarily directed to a location or automatically summoned to a location by a salient stimulus. We compared the effects of voluntary and stimulus-driven shifts of spatial attention on the blood oxygenation level-dependent signal in humans, using a method that separated preparatory activity related to the initial shift of attention from the subsequent activity caused by target presentation. Voluntary shifts produced greater preparatory activity than stimulus-driven shifts in the frontal eye field (FEF) and intraparietal sulcus, core regions of the dorsal frontoparietal attention network, demonstrating their special role in the voluntary control of attention. Stimulus-driven attentional shifts to salient color singletons recruited occipitotemporal regions, sensitive to color information and part of the dorsal network, including the FEF, suggesting a partly overlapping circuit for endogenous and exogenous orienting. The right temporoparietal junction (TPJ), a core region of the ventral fro...

For an integrated understanding of the brain’s functional architecture, in vivo correlation between functional areas and the pattern of neuronal connectivity is necessary. Such correlation studies were difficult to perform in the past, as most anatomical techniques necessitated invasive or terminal procedures. In the present study, we used the technique of the Diffusion Tensor Magnetic Resonance Imaging (DT-MRI) in combination with high-resolution functional MRI in cat primary visual cortex. Retinotopic organization of the both hemispheres of the cat visual cortices was obtained using standard stimuli. We used 9.4T magnet (30 Gauss/cm). MR parameters for fMRI: gradient-echo Echo-Planar Imaging; TE=15ms; TR=150ms; 64x64 in a FOV of 3x3 cm2, resolution: 460x460 mm2/pixel. Parameters for DT-MRI: spin-echo EPI; TE=44ms; TR=1000ms; 128x128 in a FOV of 5x5 cm2, resolution: 200x200 mm2/pixel. Diffusion parameters were: d=6ms, D=16ms, g=17g/cm (b=1040s/mm2). Diffusion-weighted images were obtained for 6 gradient e...

Introduction: Resting state networks (RSNs) are typically derived from fMRI, but iEEG offers superior spatiotemporal resolution. However, iEEG samples from only a subset of brain regions of interest (ROIs), with non-uniform electrode coverage of each RO...

The primary motor hand area (M1HAND) and adjacent dorsal premotor cortex (PMd) form the so-called motor hand knob in the precentral gyrus. M1HAND and PMd are critical for dexterous hand use and are densely inter-connected via cortico-cortical axons, lacking a sharp demarcating border. In 24 young right-handed volunteers, we performed multi-modal mapping to delineate the relationship between structure and function in the right motor hand knob. Quantitative structural magnetic resonance imaging (MRI) at 3 Tesla yielded regional R1-maps as a proxy of cortical myelin content. Participants also underwent functional MRI. We mapped task-related activation and temporal precision, while they performed a visuo-motor synchronization task requiring visually cued abduction movements with the left index or little finger. We also performed sulcus-aligned transcranial magnetic stimulation (TMS) of the motor hand knob to localize the optimal site (hotspot) for evoking a motor evoked potential (MEP) in two intrinsic hand mu...

When it comes to detecting disease, the earlier, the better. Now neuroscientists are beginning to look earlier than ever: before birth.

Concomitant increase in activity within the mid-dorsolateral prefrontal cortex (MDLFC) and the posterior parietal cortex (PPC) is observed in most functional neuroimaging studies of working memory ([Collette et al., 1999][1]; [Gerton et al., 2004][2]; [Sun et al., 2005][3]; [Postle et al., 2006][4]; [Champod and Petrides, 2007][5]; [Emery et al., 2008][6]). Despite broad consensus on the importance of these two brain regions in working memory, their unique contribution, especially that of the PPC, remains a matter of heated debate ([Paulesu et al., 1993][7]; [Smith and Jonides, 1998][8]; [Postle et al., 1999][9]; [Berryhill and Olson, 2008][10]). The main objective of the present parametric event-related functional magnetic resonance imaging study was to examine the hypothesis that the cortex in the intraparietal sulcus region in the PPC is involved in the manipulation (i.e., rearrangement) of verbal information in working memory and to dissociate the involvement of this brain region from that of the MDLFC...