Expertise with unfamiliar objects ('greebles') recruits face-selective areas in the fusiform gyrus (FFA) and occipital lobe (OFA). Here we extend this finding to other homogeneous categories. Bird and car experts were tested with functional magnetic resonance imaging during tasks with faces, familiar objects, cars and birds. Homogeneous categories activated the FFA more than familiar objects. Moreover, the right FFA and OFA showed significant expertise effects. An independent behavioral test of expertise predicted relative activation in the right FFA for birds versus cars within each group. The results suggest that level of categorization and expertise, rather than superficial properties of objects, determine the specialization of the FFA.

Part of the ventral temporal lobe is thought to be critical for face perception, but what determines this specialization remains unknown. We present evidence that expertise recruits the fusiform gyrus 'face area'. Functional magnetic resonance imaging (fMRI) was used to measure changes associated with increasing expertise in brain areas selected for their face preference. Acquisition of expertise with novel objects (greebles) led to increased activation in the right hemisphere face areas for matching of upright greebles as compared to matching inverted greebles. The same areas were also more activated in experts than in novices during passive viewing of greebles. Expertise seems to be one factor that leads to specialization in the face area.

Our data indicate that preterm birth is associated with regionally specific, long-term reductions in brain volume and that morphological abnormalities are, in turn, associated with poorer cognitive outcome. JAMA. 2000;284:1939-1947.

Individuals with autism spectrum disorders demonstrate a pattern of brain activity during face discrimination that is consistent with feature-based strategies that are more typical of nonface object perception.

This document on the CMB-S4 Science Case, Reference Design, and Project Plan is the product of a global community of scientists who are united in support of advancing CMB-S4 to cross key thresholds in our understanding of the fundamental nature of space and time and the evolution of the Universe. CMB-S4 is planned to be a joint National Science Foundation (NSF) and Department of Energy (DOE) project, with the construction phase to be funded as an NSF Major Research Equipment and Facilities Construction (MREFC) project and a DOE High Energy Physics (HEP) Major Item of Equipment (MIE) project. At the time of this writing, an interim project office has been constituted and tasked with advancing the CMB-S4 project in the NSF MREFC Preliminary Design Phase and toward DOE Critical Decision CD-1. DOE CD-0 is expected imminently.CMB-S4 has been in development for six years. Through the Snowmass Cosmic Frontier planning process, experimental groups in the cosmic microwave background (CMB) and broader cosmology communities came together to produce two influential CMB planning papers, endorsed by over 90 scientists, that outlined the science case as well as the CMB-S4 instrumental concept [1, 2]. It immediately became clear that an enormous increase in the scale of ground-based CMB experiments would be needed to achieve the exciting thresholdcrossing scientific goals, necessitating a phase change in the ground-based CMB experimental program. To realize CMB-S4, a partnership of the university-based CMB groups, the broader cosmology community, and the national laboratories would be needed.The community proposed CMB-S4 to the 2014 Particle Physics Project Prioritization Process (P5) as a single, community-wide experiment, jointly supported by DOE and NSF. Following P5's recommendation of CMB-S4 under all budget scenarios, the CMB community started in early 2015 to hold biannual workshops -open to CMB scientists from around the world -to develop and refine the concept. Nine workshops have been held to date, typically with 150 to 200 participants. The workshops have focused on developing the unique and vital role of the future ground-based CMB program. This growing CMB-S4 community produced a detailed and influential CMB-S4 Science Book [3] and a CMB-S4 Technology Book [4]. Over 200 scientists contributed to these documents. These and numerous other reports, workshop and working group wiki pages, email lists, and much more may be found at the website http://CMB-S4.org.Soon after the CMB-S4 Science Book was completed in August 2016, DOE and NSF requested the Astronomy and Astrophysics Advisory Committee (AAAC) to convene a Concept Definition Taskforce (CDT) to conduct a CMB-S4 concept study. The resulting report was unanimously accepted in late 2017. 1 One recommendation of the CDT report was that the community should organize itself into a formal collaboration. An Interim Collaboration Coordination Committee was elected by the community to coordinate this process. The resulting draft bylaws were refined at the Spring 2018 CMB-S4...

According to modular models of cortical organization, many areas of the extrastriate cortex are dedicated to object categories. These models often assume an early processing stage for the detection of category membership. Can functional imaging isolate areas responsible for detection of members of a category, such as faces or letters? We consider whether responses in three different areas (two selective for faces and one selective for letters) support category detection. Activity in these areas habituates to the repeated presentation of one exemplar more than to the presentation of different exemplars of the same category, but only for the category for which the area is selective. Thus, these areas appear to play computational roles more complex than detection, processing stimuli at the individual level. Drawing from prior work, we suggest that face-selective areas may be involved in the perception of faces at the individual level, whereas letter-selective regions may be tuning themselves to font information in order to recognize letters more efficiently.

High angular resolution measurements of diffusion are used to estimate the angular distribution and diffusion anisotropy of fibers in a voxel. A simple, axially symmetric model of diffusion in white matter fibers is used to relate diffusion measurements to fiber properties. The new technique is called fiber orientation estimated using continuous axially symmetric tensors (FORE-CAST). It is tested using both numerical simulation and in vivo measurements. The new method agrees with other methods in voxels containing single fibers, but resolves crossing fibers better, at least at the level of diffusion weighting used in this study ( Diffusion tensor imaging (DTI) has been remarkably successful in detecting subtle changes in white matter tissue structure associated with brain development, degeneration, and injury (1-6). Typically, a decrease in fractional anisotropy (FA) (7) is associated with disability, although the biophysical basis of the change is usually uncertain. Two possible mechanisms of reduced FA are (1) changes in the intrinsic properties (e.g., cell densities) of a fiber and (2) changes in the angular distribution of fibers that share a voxel. The importance of partial volume averaging of fibers has been demonstrated by several techniques that can resolve crossing fibers, which a conventional tensor description cannot. Diffusion spectrum imaging (DSI) (8) and q-ball imaging (QBI) (9) provide relatively model-free descriptions of spin displacement. Similarly, the spherical harmonic decomposition (SHD) of apparent diffusion quantifies the higher order dependence of diffusion on orientation (10). Persistent angular structure MRI extracts directional information from diffusion data using a maximum entropy approach (11). While these and other methods can identify multiple directions corresponding to relatively fast diffusion, and by hypothesis the axes of multiple component fibers, they do not provide estimates of the intrinsic diffusion properties of any of the fibers or a quantitative description of the distribution of fiber axis orientations.The method described here takes the middle ground between a conventional, single tensor model of diffusion and "model-free" high angular resolution and q-space methods. The new method estimates the continuous distribution of fiber orientations within a voxel and distinguishes between fiber coherence (differences in orientation between fibers) and intrinsic fiber diffusivity. The method is named fiber orientation estimated using continuous axially symmetric tensors (FORECAST). This report presents the theoretical background to the technique and then describes numerical simulations that illustrate its use. Finally, the results of the new method, applied to in vivo human data, are compared to those obtained using other techniques. Some of this work has appeared in abstract form (12-14). A similar method, which estimates fiber orientations by spherical deconvolution, has been proposed recently by Tournier and colleagues (15). THEORYThe dependence of the NMR signal on the...

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