Ventral Area Research Articles

Symmetry of Respiration Induced Upper Body Movements

Abstract Many researchers have postulated inexpensive methods to estimate respiratory volumes from respirationinduced movements of the upper body. In the development of smart garments, the number and the optimal positioning of sensors is an essential aspect. Therefore, the symmetry of upper body respiratory movements was investigated based on the measurement data from a motion capture system. In the ventral central area, coefficients of determination above 0.99 regarding movements of symmetrical markers mean that sensors can be placed without restrictions in the position mirrored on the sagittal plane. This simplifies sensor positioning in a smart shirt and expands the range of applications of smart shirts for respiratory monitoring.

Morphological variation in the first vertebra among acanthomorph fishes – a guide for identifying fossil centra from microvertebrate sites

Innumerable fossil fish specimens have been recovered from fossil microvertebrate sites – areas in which small, isolated elements of the skeleton from multiple individuals have been amassed. The accumulated skeletal remains, often the result of transportation by moving waters, provide an important window on the fauna that was present in a wider area during a broader period of time than that represented by individual articulated specimens. Although microvertebrate localities provide important records of taxa, the disarticulated condition of the fossil elements can cause difficulties for taxonomic identification. This is particularly true for fish, which are most commonly represented in microfossil sites by vertebral centra; however, fish centra are notoriously difficult to identify at lower taxonomic levels, partly because of the vast numbers of living fish and lack of comparative collections. Arguably, the most distinctive vertebral centrum among all fish is the first abdominal centrum of Acanthomorpha. In acanthomorphs, in contrast to all other fishes, the first centrum bears two distinct (separate left and right) facets for articulation with the exoccipitals, which are normally positioned more or less dorsolateral to the articular facet for the basioccipital, forming a unique tri-partite morphology. We here document the first centrum of numerous acanthomorph fishes, and assess the morphologies for taxonomic or phylogenetic consistencies that would allow us to identify isolated centra to a particular acanthomorph group. Features we document include: whether the neural arch is fused to the centrum (as in the paracanthopterygians Lota lota and Percopsis omiscomaycus) or autogenous (most acanthopterygians); whether the left and right facets for the exoccipitals meet in the midline (e.g., Boops boops) or are widely separated (e.g., percids and scorpaenids); and the bone texture on the centrum which may be an anastomosed network forming many small spaces (e.g., Scomber spp.) or a more solid network with no spaces (e.g., Channidae), among others. From our examination of specimens, we note several unique features among the taxa examined: the first centrum of Monopterus alba is opisthocoelus and the first neural arch has processes extending posteriorly; the first centrum of Leiognathus equula has ventral process extending from the facets for articulation with the exoccipitals; there are anterior accessory processes on the neural arch of Parachanna obscura; the transverse processes of Chlorurus sp. and Scarus vetula extend from the ventral area of the centrum and form long triangular processes; and the neural arch of Siganus guttatus has ventrolateral processes that extend to the level of the ventral surface of the centrum. We also find that the overall morphology of the first centrum is conservative within a family, indicating that in many cases fossil material may be identified at least to the family level.

Outcome analysis of staged preputial graft technique for primary proximal hypospadias with and without post-operative vacuum physiotherapy

Management of proximal hypospadias remains challenging. We assessed the results of staged preputial graft repairs (SPG) for proximal hypospadias and hypothesize that post-operative vacuum physiotherapy (VP) improves graft suppleness and overall outcomes. Retrospective analysis of n=71 patients with proximal hypospadias and severe ventral penile curvature (PC) of ≥50° after degloving. PC was corrected using ventral transverse incisions of the tunica albuginea (VTITA) without applying a tourniquet, taking care to avoid injuring the underlying erectile tissue. The ventral raw area at the penile shaft, including VTITA, were covered with either divided and partially mobilized urethral plate, or with the inner preputial graft itself. During the second stage, a tunica vaginalis flap was often used to cover the tubularized neourethra. Outcomes and post-op complications were assessed after each stage, comparing patients who received vacuum physiotherapy (VP+, n=49) with those who did not (VP-, n=22). Mean PC was 66°, average follow-up duration was 13.01 months, and overall complication rate was 22.5%. Only 6 of 49 VP+patients experienced complications (12.24%; 4 fistulas; 2 urethral strictures) and no recurrence of PC after second stage was observed in this group. VP- patients displayed a significantly higher rate of complications, with 10 of 22 cases (45.45%) exhibiting fistula development (n=5) and glans dehiscence (n=5). Recurrence of mild PC after first-stage repair was comparable between patient groups (12% VP+, 18% VP-) and easily corrected by simple graft tubularization or dorsal plication during second-stage repair. Staged repair using VTITA is effective for correcting proximal hypospadias with severe chordee. VP appears to promote and expedite graft suppleness and significantly improves patient outcomes.

Visible-light optical coherence tomography platform for the characterization of the skin barrier.

We demonstrate a free-space, trolley-mountable Fourier domain visible-light optical coherence tomography (OCT) system for studying the stratum corneum in non-palmar human skin. An axial resolution of 1 µm in tissue and at least -75 dB sensitivity have been achieved. High-quality B-scans, containing 1600 A-scans, are acquired at a rate of 39 Hz. Images from the dorsal hand, ventral wrist and ventral forearm areas are obtained, with a clearly resolved stratum corneum layer (typically 5-15 µm thick) presenting as a hypoechogenic dark layer below the bright entrance signal, similar to that found in palmar skin with traditional OCT systems. We find that the appearance of the stratum corneum layer strongly depends on its water content, becoming brighter after occlusive hydration.

Architecture of the motor and premotor cortex of the capuchin monkey

IntroductionOver the last 65 million years, primates have evolved hind- and forelimbs capable of skilled grasping (e.g., tree branches) and manipulation of tools and other objects. The New World capuchin monkey and the Old World macaque monkey stand out among other primates for their manual dexterity. The capuchin monkey is distributed throughout the Amazon and the Atlantic Forests and is the only New World monkey to have evolved an opposable thumb and to have developed the capability of using tools in the wild.MethodsThe present work analyzes the cyto-, myelo- and immunoarchitecture of the motor and premotor areas of the capuchin monkey using Nissl, Gallyas and SMI-32 immunolabeling techniques.ResultsThese different staining techniques allowed for the parcellation of Brodmann area 4 into the ventral (F1v), medial (F1m) and dorsal (F1d) areas. Additionally, lateral area 6 was subdivided into the dorsal (F2 and F7) and ventral (F4 and F5) areas. Area F5 was subsequently subdivided into the convexity (F5c), anterior (F5a) and posterior (F5p) areas. Medial area 6 was subdivided into F3 and F6 areas.DiscussionThese motor and premotor areas of the capuchin monkey are similar to those of macaque and humans, and different from those of other New World monkeys. We argue that this is due to differences in manual dexterity across New World monkeys: capuchin monkeys have evolved different types of precision grips, while most of the other New World monkeys exclusively perform whole-hand grips during object manipulation.

Dystocia induced by ventral abdominal hernia in a peripaturient goat: A case report

A West African dwarf goat was presented to the Veterinary Teaching Hospital, University of Nigeria with the primary complaint of swollen abdomen and straining. Upon examination, the abdomen was observed to be enlarged and a fetus can be felt on abdominal ballottement. Presence of hernia ring was confirmed on the caudal ventral abdominal area before the umblicus. Caesarean section and consequent herniorrhaphy was adopted to correct thehernia. Three kid goats were delivered, and the animal survived uneventfully.

Oxycodone-induced dopaminergic and respiratory effects are modulated by deep brain stimulation.

Introduction: Opioids are the leading cause of overdose death in the United States, accounting for almost 70,000 deaths in 2020. Deep brain stimulation (DBS) is a promising new treatment for substance use disorders. Here, we hypothesized that VTA DBS would modulate both the dopaminergic and respiratory effect of oxycodone. Methods: Multiple-cyclic square wave voltammetry (M-CSWV) was used to investigate how deep brain stimulation (130Hz, 0.2ms, and 0.2mA) of the rodent ventral segmental area (VTA), which contains abundant dopaminergic neurons, modulates the acute effects of oxycodone administration (2.5mg/kg, i.v.) on nucleus accumbens core (NAcc) tonic extracellular dopamine levels and respiratory rate in urethane-anesthetized rats (1.5g/kg, i.p.). Results: I.V. administration of oxycodone resulted in an increase in NAcc tonic dopamine levels (296.9 ± 37.0nM) compared to baseline (150.7 ± 15.5nM) and saline administration (152.0 ± 16.1nM) (296.9 ± 37.0 vs. 150.7 ± 15.5 vs. 152.0 ± 16.1, respectively, p = 0.022, n = 5). This robust oxycodone-induced increase in NAcc dopamine concentration was associated with a sharp reduction in respiratory rate (111.7 ± 2.6min-1 vs. 67.9 ± 8.3min-1; pre- vs. post-oxycodone; p < 0.001). Continuous DBS targeted at the VTA (n = 5) reduced baseline dopamine levels, attenuated the oxycodone-induced increase in dopamine levels to (+39.0% vs. +95%), and respiratory depression (121.5 ± 6.7min-1 vs. 105.2 ± 4.1min-1; pre- vs. post-oxycodone; p = 0.072). Discussion: Here we demonstrated VTA DBS alleviates oxycodone-induced increases in NAcc dopamine levels and reverses respiratory suppression. These results support the possibility of using neuromodulation technology for treatment of drug addiction.

Sex differences in atypical fronto-subcortical structural connectivity among children with attention-deficit/hyperactivity disorder: Associations with delay discounting

PurposeAtypical fronto-subcortical neural circuitry has been implicated in the pathophysiology of attention-deficit/hyperactivity disorder (ADHD), including connections between prefrontal cortical regions involved in top-down cognitive control and subcortical limbic structures (striatum and amygdala) involved in bottom-up reward and emotional processing. The integrity of fronto-subcortical connections may also relate to interindividual variability in delay discounting, or a preference for smaller, immediate over larger, delayed rewards, which is associated with ADHD, with recent evidence of ADHD-related sex differences. MethodsWe applied diffusion tensor imaging to compare the integrity of the white matter connections within fronto-subcortical tracts among 187 8–12 year-old children either with ADHD ((n = 106; 29 girls) or typically developing (TD) controls ((n = 81; 28 girls). Analyses focused on diagnostic group differences in fractional anisotropy (FA) within fronto-subcortical circuitry implicated in delay discounting, connecting subregions of the striatum (dorsal executive and ventral limbic areas) and amygdala with prefrontal regions of interest (dorsolateral [dlPFC], orbitofrontal [OFC] and anterior cingulate cortex [ACC]), and associations with two behavioral assessments of delay discounting. ResultsChildren with ADHD showed reduced FA in tracts connecting OFC with ventral striatum, regardless of sex, whereas reduced FA in the OFC-amygdala and ventral ACC-amygdala tracts were specific to boys with ADHD. Across diagnostic groups and sex, reduced FA in the dorsal ACC-executive striatum tract correlated with greater game time delay discounting. ConclusionsThese results suggest a potential neurobiological substrate of heightened delay discounting in children with ADHD and support the need for additional studies including larger sample sizes of girls with ADHD to further elucidate ADHD-related sex differences in these relationships.

Functional brain networks reorganization in the absence of medial temporal lobe structures: an example of neuroplasticity

AbstractBackgroundMedial temporal lobe structures are particularly vulnerable in age‐related neurodegenerative diseases. Here, we investigated the brain reorganization that allows maintaining relatively normal global cognitive functioning in patients with herpes simplex encephalitis (HSE) – an infectious neurological disease ‐ with marked focal atrophy most pronounced in the medial temporal lobes, particularly the hippocampus. Using rs‐fMRI we (i) characterized the patterns of functional network organization, and (ii) compared the intra‐/interhemispheric functional connectivity (FC) within each patient.MethodA total of nine HSE patients were included (see Table 1), four of them were affected mainly in the left (LH) and five in the right (RH) hemisphere. The rs‐fMRI data were acquired after a long‐term follow‐up (median 16 years) of the disease and were preprocessed using the AFNI software. For each patient, using different brain parcellations, we computed the intra‐ and inter‐FC strength for each hemisphere separately, yielding four measures of intra‐FC LH/RH and inter‐FC LH/RH . We grouped the subjects according to their lesion‐side and their performance (low, high) in a memory task.ResultWe observed, regardless of the lesion side, a highly variable pattern of disrupted FC in each patient. Left‐lesioned patients showed high intra‐FCLH/RH particularly in the precuneus/posterior cingulate (PPC) and the angular gyrus while right‐lesioned patients exhibited a high inter‐FCRH in the medial prefrontal cortex (MPFC) and PPC regions. Both left and right‐lesioned showed decreased intra‐FCLH/RH in ventral medial temporal areas, more pronounced in the left‐lesioned patients (Figure1). Right‐lesioned individuals who showed a pattern of inter‐FC within the right MPF and PPC performed consistently higher on the memory task (percentiles &gt; 50) (Figure2).ConclusionThe substantial HSE‐induced medial temporal lobe lesions induce a global network reorganization. However, the side of the lesion seems to determine a specific pattern of network reorganization that is associated with differential cognitive performance. Left‐lesioned patients exhibited high PPC intra‐ and inter‐FCLH/RH and low memory performance while the right‐lesioned exhibited a high inter‐FCRH on the PPC and MPFC and better memory performance. Left lesions may result in nonadaptive brain reorganizations, however, right lesions, when linked to prefrontal brain reorganizations, may result in cognitive benefits and therefore be adaptive.

Sequential sparse autoencoder for dynamic heading representation in ventral intraparietal area

To navigate in space, it is important to predict headings in real-time from neural responses in the brain to vestibular and visual signals, and the ventral intraparietal area (VIP) is one of the critical brain areas. However, it remains unexplored in the population level how the heading perception is represented in VIP. And there are no commonly used methods suitable for decoding the headings from the population responses in VIP, given the large spatiotemporal dynamics and heterogeneity in the neural responses. Here, responses were recorded from 210 VIP neurons in three rhesus monkeys when they were performing a heading perception task. And by specifically and separately modelling the both dynamics with sparse representation, we built a sequential sparse autoencoder (SSAE) to do the population decoding on the recorded dataset and tried to maximize the decoding performance. The SSAE relies on a three-layer sparse autoencoder to extract temporal and spatial heading features in the dataset via unsupervised learning, and a softmax classifier to decode the headings. Compared with other population decoding methods, the SSAE achieves a leading accuracy of 96.8% ± 2.1%, and shows the advantages of robustness, low storage and computing burden for real-time prediction. Therefore, our SSAE model performs well in learning neurobiologically plausible features comprising dynamic navigational information.

Computed Tomographic and Histopathologic Studies of Lung Function Immediately Post Natum in Canine Neonates.

The lung tissue in newborn canine neonates is still in a morphologically and functionally immature, canalicular-saccular stage. True alveoli are only formed postnatally. The aim of this study was to analyze the spatial and temporal development of the ventilation of the lung tissue in vital canine neonates during the first 24 h post natum (p.n.). Forty pups (birth weight Ø 424 g ± 80.1 g) from three litters of large dog breeds (>20 kg live weight) were included in the studies. Thirty-three pups (29 vital, 2 vitally depressed, 2 stillborn neonates) originated from controlled, uncomplicated births (n = 3); moreover, six stillborn pups as well as one prematurely deceased pup were birthed by other dams with delivery complications. Computed tomography (CT) was used in 39 neonates, and histopathologic tissue classification techniques (HALO) were used in 11 neonates (eight stillborn and three neonates died early post natum, respectively) to quantify the degree of aerated neonatal lung tissue. It was shown that, in vital born pups, within the first 10 min p.n., the degree of ventilation reached mean values of -530 (±114) Hounsfield units (HU) in the dorsal and -453.3 (±133) HU in the ventral lung area. This is about 75-80% of the final values obtained after 24 h p.n. for dorsal -648.0 (±89.9) HU and ventral quadrants -624.7 (±76.8) HU. The dorsal lung areas were always significantly better ventilated than the ventral regions (p = 0.0013). CT as well as histopathology are suitable to clearly distinguish the nonventilated lungs of stillborns from neonates that were initially alive after surviving neonatal respiratory distress syndrome but who died prematurely (p = 0.0398). The results of this study are clinically relevant since the lung tissue of canine neonates presents an aeration profile as early as 10 min after birth and continues progressively, with a special regard to the dorsal lung areas. This is the basis for resuscitation measures that should be performed, preferably with the pup in the abdomen-chest position.

Diverse bone microanatomy in cetaceans from the Eocene of Ukraine further documents early adaptations to fully aquatic lifestyle

Basilosauridae, fully aquatic archaeocetes from the Eocene, had osteosclerotic or pachyosteosclerotic structure of ribs and, sometimes, other bones. Such a structure is far different from osteoporotic-like bones of modern cetaceans. A microanatomical and histological study was conducted on axial and limb skeleton of several basilosaurid specimens assigned to the genus Basilotritus, from Bartonian (late middle Eocene) deposits of Ukraine, remarkable for its pachyostotic bones. The postcranial skeleton of these specimens is a complex mosaic of diverse types of bone structure, which include pachyosteosclerotic, osteosclerotic and cancellous elements. The vertebrae have a pachyostotic layered cortex reaching its greatest thickness in the lumbar region. This cortex was strongly vascularized, and its layered structure is due to concentric circles mostly made by longitudinal vascular canals, in addition to cyclical growth lines. Heavy bones are concentrated in the dorsal and ventral areas. Swollen distal ends of thoracic ribs are interpreted as serving as ballast in the ventral area, as also previously proposed for Basilosaurus cetoides. Cortical bone tissue in vertebrae and ribs showed signs of intensive resorption and remodeling. This indicates the use of the axial skeleton not only for buoyancy control but also possibly for calcium and phosphorus recycling.

25 Effect of Cyclic Monensin Feeding onin Situ Degradability of Low-Quality Forage Fed to Ruminally Cannulated Beef Steers

Abstract Effects of cyclic monensin feeding on in situ disappearance kinetics of low-quality forage (LQF; 4.9% CP) were evaluated. Ruminally cannulated steers (n = 12; Bos taurus; 260 kg BW) consuming LQF were randomly assigned to of 3 treatments in a completely randomized design: CON (0 mg∙animal-1∙day-1 monensin; Rumensin 90, Elanco Animal Health, Greenfield, IN), 2) MON (200 mg∙animal-1∙day-1 monensin), or 3) CYC (200 mg∙animal-1∙day-1 monensin for 4 d and 0 mg∙animal-1∙day-1 monensin for subsequent 4 d). Steers were fed dried distillers’ grains with solubles (1 kg∙animal-1∙day-1) for monensin inclusion. Four 28-d replicated cycles were used allowing 9 days for treatment adaptation, 4 days for sampling, and 4 days for withdrawal of monensin within the CYC treatment group. Low-quality forage samples were weighed into 0 × 20 cm polyester bags in replicates of four for each sampling hour. On d 0, all replicates were placed into the ventral area of the rumen and replicates were removed 0, 4, 8,6, 24, 48, and 72 hours post feeding. Upon removal, bags were rinsed in ice water, and frozen until final replicates were removed. Subsequently, bags were washed utilizing a commercial washing machine, dried at 55°C to a constant weight and dried residues were analyzed for DM. Ruminal in situ DM degradation data over time were fitted to the first-order exponential model with discrete lag using the NLIN procedure of SAS 9.4, then model parameters were compared with PROC GLIMMIX model to compare dietary treatments with period included as a random variable. There was no effect of treatment (P ≥ 0.22) on potentially degradable DM, rate of DM degradation, DM residue, DM lag, or wash loss of DM. Results are consistent with findings in the concurrent in vivo study conducted by Hook et al. (2022). Further evaluation of NDF degradability is required to determine a clear effect of cyclic monensin feeding on steers consuming an LQF.

Acute intermittent hypoxia alters disease course and promotes CNS repair including resolution of inflammation and remyelination in the experimental autoimmune encephalomyelitis model of MS.

Remyelination and neurodegeneration prevention mitigate disability in Multiple Sclerosis (MS). We have shown acute intermittent hypoxia (AIH) is a novel, non-invasive and effective therapy for peripheral nerve repair, including remyelination. Thus, we posited AIH would improve repair following CNS demyelination and address the paucity of MS repair treatments. AIH's capacity to enhance intrinsic repair, functional recovery and alter disease course in the experimental autoimmune encephalomyelitis (EAE) model of MS was assessed. EAE was induced by MOG35-55 immunization in C57BL/6 female mice. EAE mice received either AIH (10 cycles-5 min 11% oxygen alternating with 5 min 21% oxygen) or Normoxia (control; 21% oxygen for same duration) once daily for 7d beginning at near peak EAE disease score of 2.5. Mice were followed post-treatment for an additional 7d before assessing histopathology or 14d to examine maintenance of AIH effects. Alterations in histopathological correlates of multiple repair indices were analyzed quantitatively in focally demyelinated ventral lumbar spinal cord areas to assess AIH impacts. AIH begun at near peak disease significantly improved daily clinical scores/functional recovery and associated histopathology relative to Normoxia controls and the former were maintained for at least 14d post-treatment. AIH enhanced correlates of myelination, axon protection and oligodendrocyte precursor cell recruitment to demyelinated areas. AIH also effected a dramatic reduction in inflammation, while polarizing remaining macrophages/microglia toward a pro-repair state. Collectively, this supports a role for AIH as a novel non-invasive therapy to enhance CNS repair and alter disease course following demyelination and holds promise as a neuroregenerative MS strategy.

Elevated estradiol during a hormone simulated pseudopregnancy decreases sleep and increases hypothalamic activation in female Syrian hamsters.

Sleep disruptions are a common occurrence during the peripartum period. While physical and environmental factors associated with pregnancy and newborn care account for some sleep disruptions, there is evidence that peripartum fluctuations in estrogens may independently impact sleep. However, the impact of these large fluctuations in estrogens on peripartum sleep is unclear because it is difficult to tease apart the effects of estrogens on sleep from effects associated with the growth and development of the fetus or parental care. We therefore used a hormone-simulated pseudopregnancy (HSP) in female Syrian hamsters to test the hypothesis that pregnancy-like increases in estradiol decrease sleep in the absence of other factors. Adult female Syrian hamsters were ovariectomized and given daily hormone injections that simulate estradiol levels during early pregnancy, late pregnancy, and the postpartum period. Home cage video recordings were captured at seven timepoints and videos were analyzed for actigraphy. During "late pregnancy," total sleep time and sleep efficiency were decreased in hormone-treated animals during the white light period compared to pretest levels. Likewise, during "late pregnancy," locomotion was increased in the white light period for hormone-treated animals compared to pretest levels. These changes continued into the "postpartum period" for animals who continued to receive estradiol treatment, but not for animals who were withdrawn from estradiol. At the conclusion of the experiment, animals were euthanized and cFos expression was quantified in the ventral lateral preoptic area (VLPO) and lateral hypothalamus (LH). Animals who continued to receive high levels of estradiol during the "postpartum" period had significantly more cFos in the VLPO and LH than animals who were withdrawn from hormones or vehicle controls. Together, these data suggest that increased levels of estradiol during pregnancy are associated with sleep suppression, which may be mediated by increased activation of hypothalamic nuclei.

Visual event-related potentials reveal the early whole-word lexical processing of Chinese two-character words

Morphologically complex words are common across different languages, especially in Chinese, because more than 90% of common modern Chinese words are complex words. Many behavioral studies have suggested the whole-word processing of Chinese complex words, but the neural correlates of whole-word processing remain unclear. Previous electrophysiological studies revealed automatic and early (∼250 ms) access to the orthographic forms of monomorphic words in the ventral occipitotemporal area. In this study, we investigated whether there is also automatic and early orthographic recognition of Chinese complex words (as whole units) by recording event-related potentials (ERPs). A total of 150 two-character words and 150 two-character pseudowords composed of the same 300 characters (morphemes) were pseudorandomly presented to proficient Chinese readers. Participants were required to determine the color of each stimulus in the color decision task and to determine whether each stimulus was a word in the lexical decision task. The two constituent characters of each stimulus were horizontally arranged in Experiment 1 and vertically arranged in Experiment 2. The results revealed a significant early ERP difference between words and pseudowords approximately 250–300 ms after stimulus onset in the parieto-occipital scalp region. The early ERP difference was more prominent in the color decision task than in the lexical decision task, more prominent in Experiment 1 than in Experiment 2, and more prominent in the left parieto-occipital scalp region than in the right. Source analysis results showed that the early ERP difference originated from the left ventral occipitotemporal cortex. These results reflected early and automatic access to whole-word orthographic representations of Chinese complex words in the left ventral occipitotemporal cortex.

Visual adaptation reveals multichannel coding for numerosity.

Visual numerosity is represented automatically and rapidly, but much remains unknown about the computations underlying this perceptual experience. For example, it is unclear whether numerosity is represented with an opponent channel or multichannel coding system. Within an opponent channel system, all numerical values are represented via the relative activity of two pools of neurons (i.e., one pool with a preference for small numerical values and one pool with a preference for large numerical values). However, within a multichannel coding system, all numerical values are represented directly, with separate pools of neurons for each (discriminable) numerical value. Using an adaptation paradigm, we assessed whether the visual perception of number is better characterized by an opponent channel or multichannel system. Critically, these systems make distinct predictions regarding the pattern of aftereffects exhibited when an observer is adapted to an intermediate numerical value. Opponent channel coding predicts no aftereffects because both pools of neurons adapt equally. By contrast, multichannel coding predicts repulsive aftereffects, wherein numerical values smaller than the adapter are underestimated and those larger than the adapter are overestimated. Consistent with multichannel coding, visual adaptation to an intermediate value (50 dots) yielded repulsive aftereffects, such that participants underestimated stimuli ranging from 10-50 dots, but overestimated stimuli ranging from 50-250 dots. These findings provide novel evidence that the visual perception of number is supported by a multichannel, not opponent channel, coding system, and raise important questions regarding the contributions of different cortical regions, such as the ventral and lateral intraparietal areas, to the representation of number.

Tracking the temporal dynamics of the face-like inversion effect as revealed by Chinese characters using magnetoencephalography.

The neural basis of configural processing has been extensively studied by exploiting face inversion during recognition, and growing evidence has revealed that word inversion also involves changes in configuration. However, the neural dynamics of face-like inversion effects remain unclear. Here, we tracked the temporal dynamics of neural responses that were sensitive to inversion during Chinese character recognition as they occurred during face recognition using multivariate decoding and temporal generalization analyses. We recorded magnetoencephalography while participants performed a one-back task for faces, compound characters, and simple characters with upright and inverted orientations. We showed that the inversion effect (inverted versus upright) can be decoded at occipitotemporal sensors for all stimulus types over and across time points, with a stronger impact on faces and compound characters than on simple characters. The inversion effect occurred earlier and lasted longer for faces than for characters, and the effect was also stronger for compound characters than for simple characters. Finally, we demonstrated inversion effects in the event-related field for all stimulus types and identified their sources in the ventral occipitotemporal areas. Overall, this study provides novel evidence for the temporal dynamics of the face-like inversion effect occurring during Chinese character recognition.

The Architecture of Object-Based Attention

The allocation of attention to objects raises several intriguing questions: What are objects, how does attention access them, what anatomical regions are involved? Here, we review recent progress in the field to determine the mechanisms underlying object-based attention. First, findings from unconscious priming and cueing suggest that the preattentive targets of object-based attention can be fully developed object representations that have reached the level of identity. Next, the control of object-based attention appears to come from ventral visual areas specialized in object analysis that project downward to early visual areas. How feedback from object areas can accurately target the object's specific locations and features is unknown but recent work in autoencoding has made this plausible. Finally, we suggest that the three classic modes of attention may not be as independent as is commonly considered, and instead could all rely on object-based attention. Specifically, studies show that attention can be allocated to the separated members of a group-without affecting the space between them-matching the defining property of feature-based attention. At the same time, object-based attention directed to a single small item has the properties of space-based attention. We outline the architecture of object-based attention, the novel predictions it brings, and discuss how it works in parallel with other attention pathways.

Changes in ventilation distribution during general anesthesia measured with EIT in mechanically ventilated small children

BackgroundAtelectasis during general anesthesia is a risk for perioperative complications. EIT measurements were performed in mechanically ventilated healthy children during elective surgery to demonstrate the changes in ventilation distribution during general anesthesia. The ventilation distribution was quantified by calculating the Global Inhomogeneity index (GI).MethodsEIT measurements were performed in 23 children (9 weeks—10 years) without lung disease to detect changes in regional ventilation during elective surgery. Three previously defined time points were marked during the measurement: after intubation and start of pressure-controlled ventilation (PCV), change to pressure support ventilation (PSV), and after extubation (spontaneous breathing—SB). Ventilation distribution based on regions of interest (ROI) and changes in end-expiratory volume (∆EELV) were collected at these time points and compared. The Global Inhomogeneity index was calculated at the beginning of pressure-controlled ventilation (PCV).ResultsWith increasing spontaneous breathing, dorsal recruitment of atelectasis occurred. The dorsal ventilation fraction increased over the time of general anesthesia with increasing spontaneous breathing, whereas the ventral fraction decreased relatively (Difference ± 5.5 percentage points respectively; 95% CI; 3.5—7.4; p < 0.001). With the onset of spontaneous breathing, there was a significant reduction in end-expiratory volume (Difference: 105 ml; 95% CI, 75–135; p < 0.001). The GI of the lung-healthy ventilated children is 47% (SD ± 4%).ConclusionControlled ventilation of healthy children resulted in increased ventilation of the ventral and collapse of the dorsal lung areas. Restart of spontaneous breathing after cessation of surgery resulted in an increase in ventilation in the dorsal with decrease in the ventral lung areas. By calculating the GI, representing the ratio of more to less ventilated lung areas, revealed the presumed homogeneous distribution of ventilation.Trial registrationClinicalTrials.gov Registration ID: NCT04873999. First registration: 05/05/2021.