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During adolescence, major changes in brain mechanisms take place and differentiated representations of both the self and of others are developed. Although studies have investigated the neural mechanisms of self- and other-referential processing in adolescents, the development of these mechanisms remain largely unaddressed. Here, we report a three-year longitudinal study with annual measurements, and investigate the developmental trajectories of activity and connectivity underlying self- and other-referential processes in 34 participants from early to mid-adolescence (mean age timepoints 1, 2, 3 = 12.9, 13.9, 15.0 years). Moreover, we probe whether these correlates continue to develop from mid-adolescence to young adulthood by comparing neural correlates of the adolescents at the last measurement to an independent group of 42 young adults (mean age 22 years). Participants underwent functional MRI while performing a trait judgement task in which they indicated whether an adjective described themselves, a similar or a dissimilar peer. Brain activity within the dorsal medial prefrontal cortex (dMPFC) and right temporal parietal junction (TPJ) showed a quadratic change from early to mid-adolescence, with a peak in activity at the second measurement when evaluating the self, the similar and dissimilar peer. No differential activity was observed when comparing the adolescents to young adults. Functional connectivity did not change from early to mid-adolescence, however, connectivity of the dMPFC with a posterior midline region during self- and other-referential processing relative to the control condition reduced from mid-adolescence to young adulthood. Together, these findings provide insight in the developmental trajectories of brain activity and connectivity underlying the development of the self-concept and representations of peers in adolescence., Competing Interests: Declaration of Competing Interest None., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

In order to further our understanding of brain function and the underlying networks, more advanced diffusion weighted magnetic resonance imaging (DWI MRI) data are essential. Here we present freely available high-resolution multi-shell multi-directional 3 Tesla (T) DWI MRI data as part of the 'Amsterdam Ultra-high field adult lifespan database' (AHEAD). The 3T DWI AHEAD dataset include 1.28mm isotropic whole brain DWI data of 49 healthy adult participants between 18 and 90 years old. The acquired data include DWIs at three non-zero b-values (48 directions, b-value 700 s/mm 2 ; 56 directions, b-value 1000 s/mm 2 ; 64 directions, b-value 1600 s/mm 2 ) including a total of twelve volumes with a b-value of 0 s/mm 2 (b0 volumes). In addition, eight b0 volumes with a reversed phase encoding direction were acquired to correct for distortions. To facilitate future use, the DWI data have been denoised, corrected for eddy currents, susceptibility-induced off-resonance field distortions, bias fields, and are skull stripped., Competing Interests: Of the authors, M.W.A. Caan is shareholder of Nico.lab International Ltd. The other authors declare that they have no known competing financial interests or personal relationships which have or could be perceived to have influenced the work reported in this article. The data described here was acquired with financial support from STW/NWO (#14017, BUF, MJM and AA), Health∼Holland TKI-PPP (LL, MWAC), ERC Consolidator (BUF), ERC PoC (BUF), and the NWO Vici (BUF)., (© 2022 The Author(s). Published by Elsevier Inc.)

7 Tesla (7T) magnetic resonance imaging holds great promise for improved visualization of the human brain for clinical purposes. To assess whether 7T is superior regarding localization procedures of small brain structures, we compared manual parcellations of the red nucleus, subthalamic nucleus, substantia nigra, globus pallidus interna and externa. These parcellations were created on a commonly used clinical anisotropic clinical 3T with an optimized isotropic (o)3T and standard 7T scan. The clinical 3T MRI scans did not allow delineation of an anatomically plausible structure due to its limited spatial resolution. o3T and 7T parcellations were directly compared. We found that 7T outperformed the o3T MRI as reflected by higher Dice scores, which were used as a measurement of interrater agreement for manual parcellations on quantitative susceptibility maps. This increase in agreement was associated with higher contrast to noise ratios for smaller structures, but not for the larger globus pallidus segments. Additionally, control-analyses were performed to account for potential biases in manual parcellations by assessing semi-automatic parcellations. These results showed a higher consistency for structure volumes for 7T compared to optimized 3T which illustrates the importance of the use of isotropic voxels for 3D visualization of the surgical target area. Together these results indicate that 7T outperforms c3T as well as o3T given the constraints of a clinical setting., Competing Interests: The authors have declared that no competing interests exist.

Normative databases allow testing of novel hypotheses without the costly collection of magnetic resonance imaging (MRI) data. Here we present the Amsterdam Ultra-high field adult lifespan database (AHEAD). The AHEAD consists of 105 7 Tesla (T) whole-brain structural MRI scans tailored specifically to imaging of the human subcortex, including both male and female participants and covering the entire adult life span (18-80 yrs). We used these data to create probability maps for the subthalamic nucleus, substantia nigra, internal and external segment of the globus pallidus, and the red nucleus. Data was acquired at a submillimeter resolution using a multi-echo (ME) extension of the second gradient-echo image of the MP2RAGE sequence (MP2RAGEME) sequence, resulting in complete anatomical alignment of quantitative, R 1 -maps, R 2 *-maps, T 1 -maps, T 1 -weighted images, T 2 *-maps, and quantitative susceptibility mapping (QSM). Quantitative MRI maps, and derived probability maps of basal ganglia structures are freely available for further analyses., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)