scholarly journals Bridging the gap: global disparity processing in the human visual cortex

2012 ◽  
Vol 107 (9) ◽  
pp. 2421-2429 ◽  
Author(s):  
Benoit R. Cottereau ◽  
Suzanne P. McKee ◽  
Anthony M. Norcia
Keyword(s):  
Spatial Distribution ◽  
Population Level ◽  
Neural Substrates ◽  
Regions Of Interest ◽  
Inverse Technique ◽  
Lateral Occipital Complex ◽  
Reference Information ◽  
Depth Discrimination ◽  
Edge Detectors ◽  
Stereoscopic System

The human stereoscopic system is remarkable in its ability to utilize widely separated features as references to support fine depth discrimination. In a search for possible neural substrates of this ability, we recorded high-density EEG and used a distributed inverse technique to estimate population-level disparity responses in five regions of interest (ROIs): V1, V3A, hMT+, V4, and lateral occipital complex (LOC). The stimulus was a central modulating disk surrounded by a correlated “reference” annulus presented in the fixation plane. We varied a gap separating the disk from the annulus parametrically from 0 to 5.5° as a test of long-range disparity integration. In the V1, LOC, and hMT+ ROIs, the responses with gaps >0.5° were equal to those obtained in a control condition where the surround was composed of uncorrelated noise (no reference). By contrast, in the V4 and V3A ROIs, responses with gaps as large as 5.5° were still significantly higher than the control. As a test of the spatial distribution of the disparity reference information, we manipulated the properties of the stimulus by placing noise between the center and the surround or throughout the surround. The V3A ROI was particularly sensitive to disparity noise between the center and annulus regions, suggesting an important contribution of disparity edge detectors in this ROI.

scholarly journals Optical Imaging of the Small Intestine Immune Compartments Across Scales

2021 ◽  
Author(s):  
Arielle Planchette ◽  
Cédric Schmidt ◽  
Olivier Burri ◽  
Mercedes Gomez de Agüero ◽  
Aleksandra Radenovic ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Small Intestine ◽  
High Resolution ◽  
Imaging Modality ◽  
Regions Of Interest ◽  
Label Free ◽  
3 Dimensional ◽  
Wide Range ◽  
Mouse Small Intestine ◽  
Made In

Abstract The limitations of 2D microscopy constrain our ability to observe and understand tissue-wide networks that are, by nature, 3-dimensional. Optical projection tomography enables the acquisition of large volumes (ranging from micrometres to centimetres) in various tissues, with label-free capacities for the observation of auto-fluorescent signals as well fluorescent-labelled targets of interest in multiple channels. We present a multi-modal workflow for the characterization of both structural and quantitative parameters of the mouse small intestine. As proof of principle, we evidence its applicability for imaging the mouse intestinal immune compartment and surrounding mucosal structures. We quantify the volumetric size and spatial distribution of Isolated Lymphoid Follicles (ILFs) and quantify density of villi throughout centimetre long segments of intestine. Furthermore, we exhibit the age- and microbiota-dependence for ILF development, and leverage a technique that we call reverse-OPT for identifying and homing in on regions of interest. Several quantification capabilities are displayed, including villous density in the autofluorescent channel and the size and spatial distribution of the signal of interest at millimetre-scale volumes. The concatenation of 3D image acquisition with the reverse-OPT sample preparation and a 2D high-resolution imaging modality adds value to interpretations made in 3D. This cross-modality referencing technique is found to provide accurate localisation of ROIs and to add value to interpretations made in 3D. Importantly, OPT may be used to identify sparsely-distributed regions of interest in large volumes whilst retaining compatibility with high-resolution microscopy modalities, including confocal microscopy. We believe this pipeline to be approachable for a wide-range of specialties, and to provide a new method for characterisation of the mouse intestinal immune compartment.

Spatial and temporal population patterns of Aonidiella aurantii (Maskell) (Hemiptera: Diaspididae) parasitoids (Hymenoptera: Aphelinidae and Encyrtidae) caught on yellow sticky traps in citrus

1986 ◽  
Vol 76 (2) ◽  
pp. 265-274 ◽  
Author(s):  
M. J. Samways
Keyword(s):  
Spatial Distribution ◽  
Management Practices ◽  
Host Density ◽  
Population Level ◽  
Sticky Trap ◽  
Aonidiella Aurantii ◽  
Final Population ◽  
Parasitoid Population ◽  
Yellow Sticky Trap ◽  
Seasonal Population

AbstractParasitoids of Aonidiella aurantii (Maskell) on citrus in South Africa were monitored using two types of yellow sticky trap. One of these traps was highly efficient, being fluorescent with peak reflectance at about 530 nm. Aphytis spp. populations were low before February and high thereafter. Citrus surrounded by natural bush was an isolated reservoir of high host and parasitoid population levels. Aphytis spatial distribution within the orchard was extremely patchy, with over 100-fold differences in population levels over a distance of a few metres. This patchiness mirrored that of its host. This contagious spatial pattern was maintained despite 1000-fold seasonal changes in population levels. These temporal changes were characteristic and general throughout an orchard, and independent of patchiness. Initial Aphytis population levels did not dictate the final population level at the end of the season. Comperiella bifasciata Howard and its hyperparasitoid Marietta javensis (Howard) also showed clear seasonal population trends, but not of the same magnitude as those of Aphytis. There was no statistically significant correlation between the spatial distribution of one parasitoid with that of another, even between C. bifasciata and M. javensis. The patchiness of these two species was not correlated with overall host density. Aphytis and C. bifasciata were partially mutually exclusive. Aphytis was by far the most economically important of the parasitoids. Pest management practices, therefore, should aim at conserving the pool of Aphytis within the orchard as far as practicable.

scholarly journals Can the Archaeology of Manual Specialization Tell Us Anything About Language Evolution? A Survey of the State of Play

2009 ◽  
Vol 19 (1) ◽  
pp. 97-110 ◽  
Author(s):  
James Steele ◽  
Natalie Uomini
Keyword(s):  
Language Evolution ◽  
Population Level ◽  
Neural Substrates ◽  
Archaeological Data ◽  
The Right ◽  
Fossil Records ◽  
Role Specialization ◽  
Hand Preferences ◽  
Human Primate ◽  
Bimanual Tasks

In this review and position paper we explore the neural substrates for manual specialization and their possible connection with language and speech. We focus on two contrasting hypotheses of the origins of language and manual specialization: the language-first scenario and the tool-use-first scenario. Each one makes specific predictions about hand-use in non-human primates, as well as about the necessity of an association between speech adaptations and population-level right-handedness in the archaeological and fossil records. The concept of handedness is reformulated for archaeologists in terms of manual role specialization, using Guiard's model of asymmetric bimanual coordination. This focuses our attention on skilled bimanual tasks in which both upper limbs play complementary roles. We review work eliciting non-human primate hand preferences in co-ordinated bimanual tasks, and relevant archaeological data for estimating the presence or absence of a population-level bias to the right hand as the manipulator in extinct hominin species and in the early prehistory of our own species.

scholarly journals Dynamics and cortical distribution of neural responses to 2D and 3D motion in human

2014 ◽  
Vol 111 (3) ◽  
pp. 533-543 ◽  
Author(s):  
Benoit R. Cottereau ◽  
Suzanne P. McKee ◽  
Anthony M. Norcia
Keyword(s):  
Parietal Cortex ◽  
Regions Of Interest ◽  
Lateral Motion ◽  
Neural Basis ◽  
Source Imaging ◽  
Lateral Occipital Complex ◽  
Motion In Depth ◽  
Eeg Source Imaging ◽  
Harmonic Components ◽  
Motor Actions

The perception of motion-in-depth is important for avoiding collisions and for the control of vergence eye-movements and other motor actions. Previous psychophysical studies have suggested that sensitivity to motion-in-depth has a lower temporal processing limit than the perception of lateral motion. The present study used functional MRI-informed EEG source-imaging to study the spatiotemporal properties of the responses to lateral motion and motion-in-depth in human visual cortex. Lateral motion and motion-in-depth displays comprised stimuli whose only difference was interocular phase: monocular oscillatory motion was either in-phase in the two eyes (lateral motion) or in antiphase (motion-in-depth). Spectral analysis was used to break the steady-state visually evoked potentials responses down into even and odd harmonic components within five functionally defined regions of interest: V1, V4, lateral occipital complex, V3A, and hMT+. We also characterized the responses within two anatomically defined regions: the inferior and superior parietal cortex. Even harmonic components dominated the evoked responses and were a factor of approximately two larger for lateral motion than motion-in-depth. These responses were slower for motion-in-depth and were largely independent of absolute disparity. In each of our regions of interest, responses at odd-harmonics were relatively small, but were larger for motion-in-depth than lateral motion, especially in parietal cortex, and depended on absolute disparity. Taken together, our results suggest a plausible neural basis for reduced psychophysical sensitivity to rapid motion-in-depth.

scholarly journals Home alone: A population neuroscience investigation of brain morphology substrates

2021 ◽  
Author(s):  
MaryAnn P Noonan ◽  
Chris Zajner ◽  
Danilo Bzdok
Keyword(s):  
Population Level ◽  
Tobacco Consumption ◽  
Neural Substrates ◽  
Living Will ◽  
Brain Morphology ◽  
Public Health Decision ◽  
Solitary Living ◽  
Long Run ◽  
Health Decision ◽  
Tv Watching

As a social species, ready exchange with peers is a pivotal asset - our 'social capital'. Yet, single-person households have come to pervade metropolitan cities worldwide, with unknown consequences in the long run. Here, we systematically explore the morphological manifestations associated with singular living in ~40,000 UK Biobank participants. The uncovered population-level signature spotlights the highly associative default mode network, in addition to findings such as in the amygdala central, cortical and corticoamygdaloid nuclei groups, as well as the hippocampal fimbria and dentate gyrus. Sex-stratified analyses revealed male-specific neural substrates, including somatomotor, saliency and visual systems, while female-specific neural substrates centred on the dorsomedial prefrontal cortex. In line with our demographic profiling results, the discovered neural imprint of living alone is potentially linked to alcohol and tobacco consumption, anxiety, sleep quality as well as daily TV watching. The secular trend for solitary living will require new answers from public-health decision makers.

Amphibian mortality levels on Spanish country roads: descriptive and spatial analysis

2008 ◽  
Vol 29 (3) ◽  
pp. 337-347 ◽  
Author(s):  
Neftalí Sillero
Keyword(s):  
Spatial Distribution ◽  
Activity Patterns ◽  
Age Factors ◽  
Population Level ◽  
Distribution Patterns ◽  
Reproductive Period ◽  
Migration Routes ◽  
Amphibian Species ◽  
Spatial Distribution Patterns ◽  
The Road

Abstract Road-kills are the greatest source of direct human-induced wildlife mortality, especially in amphibians. Country roads could act as the most important source of mortality when main roads act as strong barriers hampering the migration movements of some species. Mortality patterns of amphibians on country roads (1380 km) were studied in Salamanca (Spain) in order to quantify the mortality levels, to test the effects of sex and age factors on road-kills, to determine the spatial distribution patterns of road-kills, and to identify routes of migration through a friction map and hotspots of road-kills. From a total of 819 records of amphibians, 38.1% were road-killed and 61.9% were live. Fourteen amphibian species were recorded during the surveys (10 anurans and four urodeles). The species more affected by road-kills were the anurans Bufo calamita, Pelobates cultripes and B. bufo (38.5, 23.4 and 11.9%, respectively). Females had higher incidence of road-kills than males, due to the differential activity patterns of both sexes during the reproductive period. Adults were the most common age period and also the most road-killed. The spatial distribution patterns of live and road-killed records were clustered. On the sampled roads, there were 0.23 road-kills per kilometre and 52 hotspots of road-kills. The friction map showed that most of the road-killed and live specimens were located on migration routes crossing suitable habitats. Conservation measures should be implemented in these areas, as these mortality patterns may be causing significant negative impacts at the population level.

scholarly journals Using Live and Video Stimuli to Localize Face and Object Processing Regions of the Canine Brain

Animals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 108
Author(s):  
Kirsten D. Gillette ◽  
Erin M. Phillips ◽  
Daniel D. Dilks ◽  
Gregory S. Berns
Keyword(s):  
Random Order ◽  
Superior Temporal Sulcus ◽  
Regions Of Interest ◽  
Two Dimensional ◽  
Fusiform Face Area ◽  
Object Processing ◽  
Lateral Occipital Complex ◽  
Face Area ◽  
Static Images ◽  
Posterior Superior Temporal Sulcus

Previous research to localize face areas in dogs’ brains has generally relied on static images or videos. However, most dogs do not naturally engage with two-dimensional images, raising the question of whether dogs perceive such images as representations of real faces and objects. To measure the equivalency of live and two-dimensional stimuli in the dog’s brain, during functional magnetic resonance imaging (fMRI) we presented dogs and humans with live-action stimuli (actors and objects) as well as videos of the same actors and objects. The dogs (n = 7) and humans (n = 5) were presented with 20 s blocks of faces and objects in random order. In dogs, we found significant areas of increased activation in the putative dog face area, and in humans, we found significant areas of increased activation in the fusiform face area to both live and video stimuli. In both dogs and humans, we found areas of significant activation in the posterior superior temporal sulcus (ectosylvian fissure in dogs) and the lateral occipital complex (entolateral gyrus in dogs) to both live and video stimuli. Of these regions of interest, only the area along the ectosylvian fissure in dogs showed significantly more activation to live faces than to video faces, whereas, in humans, both the fusiform face area and posterior superior temporal sulcus responded significantly more to live conditions than video conditions. However, using the video conditions alone, we were able to localize all regions of interest in both dogs and humans. Therefore, videos can be used to localize these regions of interest, though live conditions may be more salient.

scholarly journals Lacking social support is associated with structural divergences in hippocampus-default network co-variation patterns

2021 ◽  
Author(s):  
Chris Zajner ◽  
Robert N Spreng ◽  
Danilo Bzdok
Keyword(s):  
Social Support ◽  
Social Isolation ◽  
Population Level ◽  
Neural Substrates ◽  
Default Network ◽  
Brain Scans ◽  
Brain Hemispheres ◽  
Social Lives ◽  
Variation Patterns ◽  
Left And Right

Elaborate social interaction is a pivotal asset of the human species. The complexity of peoples social lives may constitute the dominating factor in the vibrancy of many individuals environment. The neural substrates linked to social cognition thus appear especially susceptible when people endure periods of social isolation: here, we zoom in on the systematic inter-relationships between two such neural substrates, the allocortical hippocampus (HC) and the neocortical default network (DN). Previous human social neuroscience studies have focused on the DN, while HC subfields have been studied in most detail in rodents and monkeys. To bring into contact these two separate research streams, we directly quantified how DN subregions are coherently co-expressed with specific HC subfields in the context of social isolation. A two-pronged decomposition of structural brain scans from 37,000 UK Biobank participants linked lack of social support to mostly lateral subregions in the DN patterns. This lateral DN association co-occurred with HC patterns that implicated especially subiculum, presubiculum, CA2, CA3, and dentate gyrus. Overall, the subregion divergences within spatially overlapping signatures of HC-DN co-variation followed a clear segregation divide into the left and right brain hemispheres. Separable regimes of structural HC-DN co-variation also showed distinct associations with the genetic predisposition for lacking social support at the population level.

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