Visual Motion Research Articles

Validity and Reliability of OpenPose-Based Motion Analysis in Measuring Knee Valgus during Drop Vertical Jump Test.

OpenPose-based motion analysis (OpenPose-MA), utilizing deep learning methods, has emerged as a compelling technique for estimating human motion. It addresses the drawbacks associated with conventional three-dimensional motion analysis (3D-MA) and human visual detection-based motion analysis (Human-MA), including costly equipment, time-consuming analysis, and restricted experimental settings. This study aims to assess the precision of OpenPose-MA in comparison to Human-MA, using 3D-MA as the reference standard. The study involved a cohort of 21 young and healthy adults. OpenPose-MA employed the OpenPose algorithm, a deep learning-based open-source two-dimensional (2D) pose estimation method. Human-MA was conducted by a skilled physiotherapist. The knee valgus angle during a drop vertical jump task was computed by OpenPose-MA and Human-MA using the same frontal-plane video image, with 3D-MA serving as the reference standard. Various metrics were utilized to assess the reproducibility, accuracy and similarity of the knee valgus angle between the different methods, including the intraclass correlation coefficient (ICC) (1, 3), mean absolute error (MAE), coefficient of multiple correlation (CMC) for waveform pattern similarity, and Pearson's correlation coefficients (OpenPose-MA vs. 3D-MA, Human-MA vs. 3D-MA). Unpaired t-tests were conducted to compare MAEs and CMCs between OpenPose-MA and Human-MA. The ICCs (1,3) for OpenPose-MA, Human-MA, and 3D-MA demonstrated excellent reproducibility in the DVJ trial. No significant difference between OpenPose-MA and Human-MA was observed in terms of the MAEs (OpenPose: 2.4° [95%CI: 1.9-3.0°], Human: 3.2° [95%CI: 2.1-4.4°]) or CMCs (OpenPose: 0.83 [range: 0.99-0.53], Human: 0.87 [range: 0.24-0.98]) of knee valgus angles. The Pearson's correlation coefficients of OpenPose-MA and Human-MA relative to that of 3D-MA were 0.97 and 0.98, respectively. This study demonstrated that OpenPose-MA achieved satisfactory reproducibility, accuracy and exhibited waveform similarity comparable to 3D-MA, similar to Human-MA. Both OpenPose-MA and Human-MA showed a strong correlation with 3D-MA in terms of knee valgus angle excursion.

Analyzing the neurotoxic effects of anatoxin-a and saxitoxin in zebrafish larvae

Global warming due to climate change, as well as freshwater eutrophication caused by anthropogenic activities are responsible, among other factors, for an increasing occurrence of harmful algal blooms (HABs) in aquatic systems. These can lead to the generation of cyanotoxins, secondary metabolites coming from cyanobacteria, producing adverse effects in living organisms including death. This research aims to study the effects that two neurotoxins, anatoxin-a (ATX-a) and saxitoxin (STX), have on living organisms. Once the stability of both compounds in water was determined for a 24 h period using ultra-high-performance liquid chromatography coupled to a triple quadrupole mass spectrometer (UPLC-MS/MS), zebrafish larvae were exposed to different levels of toxins (1 ng L−1, 10 ng L−1, 100 ng L−1 and 1 μg L−1) during 24 h. Behavioral studies including vibrational startle response (VSR), habituation to vibrational stimuli, basal locomotor activity (BLM) and visual motor response (VMR) were performed using Danio Vision system, and neurotransmitters (NTs) from 15-head pools of control and exposed zebrafish larvae were extracted and analyzed by UPLC-MS/MS. Both compounds induced hypolocomotion in the individuals, while 10 and 100 ng L−1 of ATX-a significantly increased methionine (120 % and 126 %, respectively) and glutamate levels (118 % and 129 %, respectively). Saxitoxin enhanced 3-metoxytyramine (3-MT) levels at 1 ng L−1 by 185 %. The findings of this study show that both studied cyanotoxins influence the behavior of zebrafish larvae as well as their metabolism.

Slc4a7 Regulates Retina Development in Zebrafish.

Inherited retinal degenerations (IRDs) are a group of genetic disorders characterized by the progressive degeneration of retinal cells, leading to irreversible vision loss. SLC4A7 has emerged as a candidate gene associated with IRDs, yet its mechanisms remain largely unknown. This study aims to investigate the role of slc4a7 in retinal development and its associated molecular pathogenesis in zebrafish. Morpholino oligonucleotide knockdown, CRISPR/Cas9 genome editing, quantitative RT-PCR, eye morphometric measurements, immunofluorescent staining, TUNEL assays, visual motor responses, optokinetic responses, rescue experiments, and bulk RNA sequencing were used to assess the impact of slc4a7 deficiency on retinal development. Our results demonstrated that the knockdown of slc4a7 resulted in a dose-dependent reduction in eye axial length, ocular area, and eye-to-body-length ratio. The fluorescence observations showed a significant decrease in immunofluorescence signals from photoreceptors and in mCherry fluorescence from RPE in slc4a7-silenced morphants. TUNEL staining uncovered the extensive apoptosis of retinal cells induced by slc4a7 knockdown. Visual behaviors were significantly impaired in the slc4a7-deficient larvae. GO and KEGG pathway analyses reveal that differentially expressed genes are predominantly linked to aspects of vision, ion channels, and phototransduction. This study demonstrates that the loss of slc4a7 in larvae led to profound visual impairments, providing additional insights into the genetic mechanisms predisposing individuals to IRDs caused by SLC4A7 deficiency.

Visual feedback and motor memory contributions to sustained motor control deficits in autism spectrum disorder across childhood and into adulthood.

Background Autistic individuals show deficits in sustained fine motor control which are associated with an over-reliance on visual feedback. Motor memory deficits also have been reported during sustained fine motor control in autism spectrum disorders (ASD). The development of motor memory and visuomotor feedback processes contributing to sustained motor control issues in ASD are not known. The present study aimed to characterize age-related changes in visual feedback and motor memory processes contributing to sustained fine motor control issues in ASD. Methods Fifty-four autistic participants and 31 neurotypical (NT) controls ages 10-25 years completed visually guided and memory guided sustained precision gripping tests by pressing on force sensors with their dominant hand index finger and thumb. For visually guided trials, participants viewed a stationary target bar and a force bar that moved upwards with increased force for 15s. During memory guided trials, the force bar was visible for 3s, after which participants attempted to maintain their force output without visual feedback for another 12s. To assess visual feedback processing, force accuracy, variability (standard deviation), and regularity (sample entropy) were examined. To assess motor memory, force decay latency, slope, and magnitude were examined during epochs without visual feedback. Results Relative to NT controls, autistic individuals showed a greater magnitude and steeper slope of force decay during memory guided trials. Across conditions, the ASD group showed reduced force accuracy (β = .41, R 2 = 0.043, t 79.3 =2.36, p = 0.021) and greater force variability (β=-2.16, R 2 = .143, t 77.1 =-4.04, p = 0.0001) and regularity (β=-.52, R 2 = .021, t 77.4 =-2.21, p = 0.030) relative to controls at younger ages, but these differences normalized by adolescence (age x group interactions). Lower force accuracy and greater force variability during visually guided trials and steeper decay slope during memory guided trials were associated with overall autism severity. Conclusions Our findings that autistic individuals show a greater rate and magnitude of force decay than NT individuals following the removal of visual feedback indicate that motor memory deficits contribute to fine motor control issues in ASD. Findings that sensorimotor differences in ASD were specific to younger ages suggest delayed development across multiple motor control processes.

Patterns of cortical thickness alterations in degenerative cervical myelopathy: associations with dexterity and gait dysfunctions.

Degenerative cervical myelopathy (DCM) can lead to significant brain structural reorganization. The association between the cortical changes and specific motor symptoms in DCM has yet to be fully elucidated. We investigated the associations between cortical thickness changes with neurological symptoms, such as dexterity and gait abnormalities, in patients with DCM in a case-control study. A 3 Tesla MRI scanner was used to acquire high-resolution T1-weighted structural scans from 30 right-handed patients with DCM and 22 age-matched healthy controls. Pronounced cortical thinning was observed in DCM patients relative to healthy controls, particularly in the bilateral precentral and prefrontal gyri, left pars triangularis, left postcentral gyrus, right transverse temporal and visual cortices (P ≤ 0.04). Notably, cortical thickness in these regions showed strong correlations with objective motor deficits (P < 0.0001). Specifically, the prefrontal cortex, premotor area and supplementary motor area exhibited significant thickness reductions correlating with diminished dexterity (R2 = 0.33, P < 0.0007; R2 = 0.34, P = 0.005, respectively). Similarly, declines in gait function were associated with reduced cortical thickness in the visual motor and frontal eye field cortices (R2 = 0.39, P = 0.029, R2 = 0.33, P = 0.04, respectively). Interestingly, only the contralateral precuneus thickness was associated with the overall modified Japanese Orthopaedic Association (mJOA) scores (R2 = 0.29, P = 0.003). However, the upper extremity subscore of mJOA indicated an association with the visual cortex and the anterior prefrontal (R2 = 0.48, P = 0.002, R2 = 0.33, P = 0.0034, respectively). In conclusion, our findings reveal patterns of cortical changes correlating with motor deficits, highlighting the significance of combining objective clinical and brain imaging assessments for understanding motor network dysfunction in DCM.

A developmental model of audio-visual attention (MAVA) for bimodal language learning in infants and robots

A social individual needs to effectively manage the amount of complex information in his or her environment relative to his or her own purpose to obtain relevant information. This paper presents a neural architecture aiming to reproduce attention mechanisms (alerting/orienting/selecting) that are efficient in humans during audiovisual tasks in robots. We evaluated the system based on its ability to identify relevant sources of information on faces of subjects emitting vowels. We propose a developmental model of audio-visual attention (MAVA) combining Hebbian learning and a competition between saliency maps based on visual movement and audio energy. MAVA effectively combines bottom-up and top-down information to orient the system toward pertinent areas. The system has several advantages, including online and autonomous learning abilities, low computation time and robustness to environmental noise. MAVA outperforms other artificial models for detecting speech sources under various noise conditions.

Visuomotor prediction during action planning in the human frontoparietal cortex and cerebellum.

The concept of forward models in the brain, classically applied to describing on-line motor control, can in principle be extended to action planning, i.e. assuming forward sensory predictions are issued during the mere preparation of movements. To test this idea, we combined a delayed movement task with a virtual reality based manipulation of visuomotor congruence during functional magnetic resonance imaging. Participants executed simple hand movements after a delay. During the delay, two aspects of the upcoming movement could be cued: the movement type and the visuomotor mapping (i.e. congruence of executed hand movements and visual movement feedback by a glove-controlled virtual hand). Frontoparietal areas showed increased delay period activity when preparing pre-specified movements (cued > uncued). The cerebellum showed increased activity during the preparation for incongruent > congruent visuomotor mappings. The left anterior intraparietal sulcus showed an interaction effect, responding most strongly when a pre-specified (cued) movement was prepared under expected visuomotor incongruence. These results suggest that motor planning entails a forward prediction of visual body movement feedback, which can be adjusted in anticipation of nonstandard visuomotor mappings, and which is likely computed by the cerebellum and integrated with state estimates for (planned) control in the anterior intraparietal sulcus.

Clinical Presentations and Outcomes of Pediatric Rhegmatogenous Retinal Detachment: 11 Years' Experience at a Tertiary Eye Center.

Background and Objectives: Pediatric rhegmatogenous retinal detachment (RRD) represents a challenge for ophthalmologists and vitreoretinal surgeons. In this study, we aim to review the clinical features, and surgical and visual outcomes of pediatric RRD in a tertiary referral center. Materials and Methods: This is a retrospective study using the review of charts for all patients who presented to King Abdul-Aziz University Hospital, Riyadh, Saudi Arabia, from 2005 to 2016. This study included patients 18 years old or younger, had undergone surgical repairs for RRD, and were followed up for 1 year or more. Results: Eighty-nine eyes of 70 children who underwent surgical repair for RRD were included in the current retrospective study. A previous history of intraocular surgeries was present in 31.5%. The majority of cases had known ocular disease or syndromes (n = 58, 65.2%). The majority of eyes which had a primary surgical intervention achieved anatomical success (n = 88). Corneal complications accounted for the majority of complications following primary and secondary surgical interventions. Forty-two percent of the eyes had vision better than 20/200, while thirty-five percent had vision of hand motion or worse. Conclusions: In conclusion, despite the variability in causes of RRD in children, successful anatomical outcomes can be achieved with the proper surgical approach. Visual outcomes are less predictable due to other ocular complications.

Understanding visual perception in visual snow syndrome: a battery of psychophysical tests plus the 30-day clinical diary.

Patients with visual snow syndrome (VSS) experience uncountable flickering tiny dots in the entire visual field. Symptoms often persist over the years. Very little is known about altered perception in VSS. VSS is diagnosed based on subjective reports because there is no manual with objective measures. In this study, 20 patients with VSS and 17 healthy controls performed a battery of tests assessing visual acuity, contrast sensitivity, illusion perception, spatial-temporal vision, motion perception, visual attention, and selective attention. Surprisingly, except for one test, which is the honeycomb illusion, patients performed at the same level as controls. Patients reporting black and white visual snow performed better in the Stroop test compared to patients reporting other visual snow colours. In addition to a clinical visit, the 30-day clinical diary was administered to patients to broadly measure their symptom severity. We found that better performance in the tests, in particular in the contrast and coherent motion tests, was correlated with lower VSS symptoms, weaker VS characteristics (e.g. density and size) and lower VS severity. Our results suggest that, even if visual abilities are not deteriorated by VSS, they can determine how severe symptoms are, and show that VSS is an heterogenous disorder where symptoms and visual abilities vary between patients, for instance depending on the VS colour. The study was primarily designed to identify tests where performance differs between controls and patients. In addition, exploratory analyses were conducted to initiate an understanding of the overall pattern of relationships between patients' visual abilities and symptoms, which is of clinical relevance. Future studies with more power are necessary to validate our findings.

Visual-Motor Integration (VMI) Is Also Relevant for Computer, Smartphone, and Tablet Use by Adults: Introducing the Brief Box Clicking Test.

Visual-motor integration (VMI) is typically examined in children to promote handwriting, but it may also be relevant for adults' capacity for technology use. To examine the reliability and validity of speed of completion of the box clicking test, a web-based test of VMI. Participants in the Understanding America Study completed online surveys on a regular basis, including a very brief (less than 30 s) self-administered box clicking test. For validity testing, we examined whether box clicking speed was associated with constructs relevant to visual-perceptual skills and motor coordination, the skills underlying VMI. Test-retest reliability was examined by computation of intraclass correlation coefficients. A total of 11,114 adults. Measures included the completion time for the box clicking task and measures relevant to visual perception (e.g., perceptual speed) and motor coordination (e.g., self-reported functional limitation). Results suggested that the box clicking test was a VMI task. Slower test performance was associated with lower visual-perceptual speed and a greater likelihood of reporting difficulties with dressing, a motor coordination relevant task. Box clicking tests taken within at least 2 yr of one another had moderate test-retest stability, but future studies are needed to examine test-retest reliabilities over brief (e.g., 2-wk) time intervals. The box clicking test may serve both as a tool for research and to clinically observe whether clients have VMI difficulties that interfere with computer, smartphone, or tablet use. Plain-Language Summary: Use of devices such as smartphones and computers is increasingly becoming integral for daily functioning. Visual-motor integration (VMI) has often been addressed by occupational therapists to support handwriting of children, but it may also be important for technology use by adults. Prior literature supports the relevance of VMI to technology use, and adults with various chronic conditions have been found to have decrements in VMI. We tested the psychometric properties of a brief box clicking test of VMI that could be used to examine VMI underlying technology use among adults. Overall, results suggested that the box clicking test was a VMI task. Just as speed of gait has been used as an index of functional mobility, speed on the box clicking task seemed serviceable as an index of VMI ability. The box clicking test may also be used for clinical observation of whether VMI interferes with technology use.

Think fast, stay healthy? A narrative review of neurocognitive performance and lower extremity injury

BackgroundLower extremity (LE) injury has been problematic in athletic populations. While previous research has identified biomechanical and neuromuscular risk factors, more recent efforts have determined that neurocognitive performance (NP) may influence LE injury risk. ObjectivesTo describe the present findings pertaining to the relationship between NP and LE injury. This review described potential cerebral neural mechanisms underpinning LE injury with a particular emphasis on the role of vision in sensorimotor integration. Lastly, newer technology such as stroboscopic eyewear, smartboards, and virtual/augmented reality were discussed for their utility in assessing and training NP. MethodsNarrative review that described NP and LE injury, as well as plausible mechanisms and training interventions. ResultsNP appears to influence both LE biomechanics and LE injury risk. Athletes with worse NP demonstrated decreased knee flexion and increased frontal plane knee loading compared to better performing athletes. Most studies determined an association between NP and LE injury risk. Visual motor reaction time, processing speed, and working memory appear to be useful NP measures for identifying athletes at risk for LE injury. Various brain regions including the precuneus and lingual gyrus may be implicated as neural signatures for LE injury. While recently developed technology offer promise, far-transfer effects to LE injury risk reduction have yet to be substantially investigated. ConclusionsNP should be considered an important component for identifying LE injury risk. Sports scientists and clinicians may consider a variety of assessments and interventions to quantify and train NP in conjunction with previously established protocols.

The Impact of Viewing Distance and Proprioceptive Manipulations on a Virtual Reality Based Balance Test.

Our ability to maintain our balance plays a pivotal role in day-to-day activities. This ability is believed to be the result of interactions between several sensory modalities including vision and proprioception. Past research has revealed that different aspects of vision including relative visual motion (i.e., sensed motion of the visual field due to head motion), which can be manipulated by changing the viewing distance between the individual and the predominant visual cues, have an impact on balance. However, only a small number of studies have examined this in the context of virtual reality, and none examined the impact of proprioceptive manipulations for viewing distances greater than 3.5m. To address this, we conducted an experiment in which 25 healthy adults viewed a dartboard in a virtual gymnasium while standing in narrow stance on firm and compliant surfaces. The dartboard distance varied with three different conditions of 1.5m, 6m, and 24m, including a blacked-out condition. Our results indicate that decreases in relative visual motion, due to an increased viewing distance, yield decreased postural stability- but only with simultaneous proprioceptive disruptions.

MED13L-related disorder characterized by severe motor speech impairment.

MED13L-related disorder is associated with intellectual disability, motor delay, and speech deficits. Previous studies have focused on broad clinical descriptions of individuals, but limited information regarding specific speech diagnoses and results of direct testing has been published to date. We conducted deep phenotyping to characterize the speech, language, motor, cognitive, and adaptive phenotypes of individuals with MED13L-related disorder. In this cross-sectional study, we administered standardized articulation, language, motor, and cognitive testing to 17 children and adolescents (mean age 9y 9m; SD 4y 5m; range 4y 2m to 19y 7m). In-person testing was supplemented with broad developmental, medical, and behavioral information collected virtually from a cohort of 67 individuals. All individuals who completed in-person articulation testing met diagnostic criteria for speech apraxia, dysarthria, or both. Language impairment was present in all of the in-person cohort and almost all (97%) of the virtual cohort. Those who were able to complete motor testing demonstrated significant deficits in visual motor integration (mean 57.08, SD 9.26). Full scale IQs fell in the borderline to intellectual disability range, consistent with reported cognitive impairment in 97% of the virtual cohort. Notable medical features included hypotonia (83%), vision problems (72%), recurrent otitis media (58%), gastrointestinal problems (57%), and seizures (31%). MED13L-related disorder is characterized by a high rate of motor speech disorders that occur in the context of globally impaired motor, language, and cognitive skills. Children would benefit from intensive, individualized speech therapy and the early adoption of augmentative communication strategies.

Examining collaboration skills and influencing factors among secondary school students with autism spectrum disorder in general education settings

The collaboration skills of students with autism spectrum disorder (ASD) are receiving increasing attention from educators and parents. Adolescents with ASD often face difficulties in interacting, forming relationships, and solving problems collaboratively with their peers. This study aims to examine the current state of collaboration skills and the factors affecting these skills in secondary school students with ASD who are integrated into general education settings. We conducted a quantitative analysis to assess various dimensions of collaboration among these students. The results indicated that the ability to participate in and accept group assignments was of particular concern (M=2.42, SD=0.21). Similarly, skills related to conflict resolution and emotional regulation were also highlighted (M=2.37, SD=0.45). Additionally, students with ASD who also have other disabilities, such as visual or hearing impairments or motor disabilities, showed the most significant challenges in collaboration skills (M=4.22, SD=1.00), followed by those with severe ASD (M=4.13, SD=1.05). Our findings reveal alarming signs regarding the collaboration skills of students with ASD. These results underscore the need for targeted interventions and educational strategies to support these students effectively. The study provides a basis for educators and parents to propose and implement appropriate measures to support and educate secondary school students with ASD, focusing on enhancing their collaboration skills.

Assessment of cognition: dementia and delirium : In consideration of the AWMF guidelines 038-013 and 084-002LG

Cognitive disorders are multifaceted and the range of neuropsychological instruments is correspondingly extensive; however, most examiners have to limit themselves to asmall selection in order to master them safely. In geriatric patients the various forms and stages of dementia dominate. Delirium must be distinguished from these as an acute life-threatening event. The personal and external medical history as well as clinical observation are the first steps in the assessment of cognition; the selection of test procedures is graduated and bears the patient's benefit in mind. When compiling atoolbox for use in one's own field of work, in addition to instruments focusing on different degrees of severity, alternatives should also be considered for use in the presence of comorbidities that reduce the validity (visual, hearing and fine motor disorders) and the examination situation should be taken into account.

Effects of repetitive subconcussive head trauma on the neuropsychological functioning and symptom reporting of high school athletes in high and low contact sports: Age and sex.

The present study was designed to assess the neuropsychological test performances of non-concussed female and male high school athletes of different ages in high and low contact sports. Large samples of 2,510 high school athletes in High Contact sports (e.g., football) and 1,437 in Low Contact sports (e.g., basketball) were examined. The participants were administered a baseline Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) prior to their respective seasons. Multivariate linear regression showed that the High Contact athletes had significantly poorer results than the Low Contact athletes in all four ImPACT Composite scores and the Total Symptom scores. No age differences were found, but in all three age groups, the High Contact athletes had lower Visual Motor Speed scores than the Low Contact athletes. No test score differences were noted between the females in the High and Low Contact groups, but the High Contact males had poorer Visual Motor Speed and Reaction Time than the Low Contact males. The present results were consistent with prior studies of subconcussive head trauma, with High Contact athletes obtaining overall poorer neuropsychological test results than Low Contact athletes. More investigations in this age group seems is warranted.

Abnormal activation patterns in MT+ during visual motion perception in major depressive disorder.

Previous studies have found that patients with Major Depressive Disorder (MDD) exhibit impaired visual motion perception capabilities, and multi-level abnormalities in the human middle temporal complex (MT+), a key brain area for processing visual motion information. However, the brain activity pattern of MDD patients during the perception of visual motion information is currently unclear. In order to study the effect of depression on the activity and functional connectivity (FC) of MT+ during the perception of visual motion information, we conducted a study combining task-state fMRI and psychophysical paradigm to compare MDD patients and healthy control (HC). Duration threshold was examined through a visual motion perception psychophysical experiment. In addition, a classic block-design grating motion task was utilized for fMRI scanning of 24 MDD patients and 25 HC. The grating moved randomly in one of eight directions. We examined the neural activation under visual stimulation conditions compared to the baseline and FC. Compared to HC group, MDD patients exhibited increased duration threshold. During the task, MDD patients showed decreased beta value and percent signal change in left and right MT+. In the sample comprising MDD and HC, there was a significant negative correlation between beta value in right MT+ and duration threshold. And in MDD group, activation in MT+ were significantly correlated with retardation score. Notably, no such differences in activation were observed in primary visual cortex (V1). Furthermore, when left MT+ served as the seed region, compared to the HC, MDD group showed increased FC with right calcarine fissure and surrounding cortex and decreased FC with left precuneus. Overall, the findings of this study highlight that the visual motion perception function impairment in MDD patients relates to abnormal activation patterns in MT+, and task-related activity are significantly connected to the retardation symptoms of the disease. This not only provides insights into the potential neurobiological mechanisms behind visual motion perception disorder in MDD patients from the aspect of task-related brain activity, but also supports the importance of MT+ as a candidate biomarker region for MDD.

Cerebral Vascular Toxicity after Developmental Exposure to Arsenic (As) and Lead (Pb) Mixtures.

Arsenic (As) and lead (Pb) are environmental pollutants found in common sites linked to similar adverse health effects. This study determined driving factors of neurotoxicity on the developing cerebral vasculature with As and Pb mixture exposures. Cerebral vascular toxicity was evaluated at mixture concentrations of As and Pb representing human exposures levels (10 or 100 parts per billion; ppb; µg/L) in developing zebrafish by assessing behavior, morphology, and gene expression. In the visual motor response assay, hyperactivity was observed in all three outcomes in dark phases in larvae with exposure (1-120 h post fertilization, hpf) to 10 ppb As, 10 ppb Pb, or 10 ppb mix treatment. Time spent moving exhibited hyperactivity in dark phases for 100 ppb As and 100 ppb mix treatment groups only. A decreased brain length and ratio of brain length to total length in the 10 ppb mix group was measured with no alterations in other treatment groups or other endpoints (i.e., total larval length, head length, or head width). Alternatively, measurements of cerebral vasculature in the midbrain and cerebellum uncovered decreased total vascularization at 72 hpf in all treatment groups in the mesencephalon and in all treatment groups, except the 100 ppb Pb and 10 ppb As groups, in the cerebellum. In addition, decreased sprouting and branching occurred in the mesencephalon, while only decreased branching was measured in the cerebellum. The 10 ppb Pb group showed several cerebral vasculature modifications that were aligned with a specific gene expression alteration pattern different from other treatment groups. Additionally, the 100 ppb As group drove gene alterations, along with several other endpoints, for changes observed in the 100 ppb mix treatment group. Perturbations assessed in this study displayed non-linear concentration-responses, which are important to consider in environmental health outcomes for As and Pb neurotoxicity.

Enhanced functional brain network integration in mild cognitive impairment during cognitive task performance: A compensatory mechanism or a result of neural disinhibition?

Although previous studies have observed increased global network integration during tasks in persons with mild cognitive impairment (MCI), the association between this integration and actual task performance has remained unexplored. Understanding this link is crucial for uncovering the underlying mechanism behind these changes in network integration and their potential role in MCI. Here, to find such a link, we investigated brain network integration derived from electroencephalography recordings during a visual motion discrimination task in older adults with MCI and those with normal cognition. We focused on a critical period just before stimulus presentation, which is known to be important for task performance. Our results revealed that during this period, MCI patients exhibited increased network integration compared to controls. Interestingly, increased integration was associated with worse task performance in the MCI group, suggesting it was not beneficial. No such association was found in the control group. Notably, this difference existed despite similar overall task performance between the groups. This suboptimal integration pattern during the cognitive task might reflect network de-differentiation due to disinhibition in MCI patients. Collectively, our study highlights the potential of analysing network integration during tasks to identify cognitive impairment and suggest a distinct role for network integration in MCI patients compared with healthy controls.

Unsupervised mapping and semantic user localisation from first-person monocular video

We propose an unsupervised probabilistic framework for learning a human-centred representation of a person’s environment from first-person video. Specifically, non-geometric maps modelled as hierarchies of probabilistic place graphs and view graphs are learned. Place graphs model a user’s patterns of transition between physical locations whereas view graphs capture an aspect of user behaviour within those locations. Furthermore, we describe an implementation in which the notion of place is divided into stations and the routes that interconnect them. Stations typically correspond to rooms or areas where a user spends time. Visits to stations are temporally segmented based on qualitative visual motion. We describe how to learn maps online in an unsupervised manner, and how to localise the user within these maps. We report experiments on two datasets, including comparison of performance with and without view graphs, and demonstrate better online mapping than when using offline clustering.