Tag: nevin manimala

J Vis. 2025 Apr 1;25(5):38. doi: 10.1167/jov.25.5.38.

ABSTRACT

It has been suggested that objects are more likely to be warmer in colour, redder and more saturated than the background. Here, we investigate the colour statistics of objects, and the brain regions that are responsive to these statistics. First, we analysed the Natural Scenes Dataset (NSD), a 7T dataset in which 8 participants viewed up to 10,000 natural scenes. Our analysis of the chromaticities of the 80 segmented object classes and backgrounds confirmed that object pixels were warmer, redder, more saturated and darker than background pixels. The probability that pixels were from objects rather than backgrounds (the ‘Object Colour Probability’, OCP) was calculated for 240 hue bins. The mean OCP of images correlated with NSD BOLD responses mostly in the ventral visual pathway. Other image statistics (e.g., number of food pixels) better explained the responses of correlated voxels. A second fMRI study, in which colours were shown as a single patch on a grey background, was analysed to study whether ventral visual pathway is responsive to OCP in the absence of other scene statistics. To constrain our analyses to functionally relevant areas, we used independent functional localizers to identify colour- and object-selective areas and combined these with NSD defined OCP responsive areas. The OCP of the colour patches significantly correlated with BOLD in colour-selective but not object-selective visual regions. Implications for the role of colour in object vision are discussed.

PMID:40215031 | DOI:10.1167/jov.25.5.38

J Vis. 2025 Apr 1;25(5):41. doi: 10.1167/jov.25.5.41.

ABSTRACT

Visual discomfort describes an aversive subjective experience characterised by perceptual distortions, blurred vision, diplopia, pain in the eyes, headache and/or nausea. Previous laboratory studies have found that levels of visual discomfort can be predicted from some statistical properties of scenes, including the spectral slope (e.g. Penacchio & Wilkins, 2015) and colour contrast (Juricevic et al. 2010; Penacchio et al. 2021). Lighting flicker (e.g. Yoshimoto et al., 2017) and colour temperature (e.g. Kakitsuba 2015) have also been shown to trigger discomfort. We investigated everyday occurrences of visual discomfort using a visual survey method. Participants (N = 36) captured scenes which they found to be visually uncomfortable within a university library. Participants gave a narrative and discomfort rating for each image. We also surveyed the lighting in the photographed areas, measuring flicker and the spectral power distribution of the illumination. Analysis showed some support for the importance of the image statistical features identified in laboratory studies, although there was no interaction between these features and lighting flicker or colour temperature. Qualitative analysis of participant narratives revealed that experiences of discomfort were attributed to low-level features (e.g. pattern, contrast), but also structural features (e.g. depth, disorganisation). These results provide new insights into the causes of visual discomfort in the everyday environment.

PMID:40215028 | DOI:10.1167/jov.25.5.41

J Vis. 2025 Apr 1;25(5):43. doi: 10.1167/jov.25.5.43.

ABSTRACT

Stable visual ensemble statistics can support performance on a visual search task (e.g. Corbett and Melcher, 2014). Such results may indicate improvements in the efficiency of visual cognition in response to a more predictable environment. Observations of improved cognition when immersed in nature (e.g. Berman et al., 2008) have been related to concepts of perceptual fluency and Attention Restoration. We investigated whether the statistical stability of natural scenes could be the underlying mechanism supporting enhancements in visual cognition related to natural images. In experiment 1, we replicated the first study from Corbett and Melcher (2014), showing that sequences of trials with a stable mean size of Gabor elements results in enhanced visual search for an orientation singleton target, compared to sequences with an unstable mean size. In experiment 2, we embedded visual search targets within a set of natural scene images. We leveraged existing variation in the image statistics between images to present sequences where the slope of the Fourier amplitude spectrum was relatively stable (gradually increasing/decreasing) or unstable (randomly ordered). The results have implications for our understanding of the effect of the visual environment on visuo-cognitive functions and the extraction of image statistics by the visual system. We discuss the likely role for eye movements in sampling natural scenes.

PMID:40215026 | DOI:10.1167/jov.25.5.43

J Vis. 2025 Apr 1;25(5):54. doi: 10.1167/jov.25.5.54.

ABSTRACT

Exposure to the colour statistics of natural scenes can both induce and counteract individual differences in colour perception. If different people inhabit different chromatic environments, calibration of the visual system to the colour statistics of those environments can cause individual differences in colour perception. Conversely, exposure to common colour statistics in a common visual environment can reduce individual differences in colour perception that would otherwise be caused by individual differences in physiological factors such as macular pigment density, lens density and cone spectral sensitivities. I will present some examples of our research on these themes, including a cross-environmental study on colour perception between participants living in remote rural versus urban environments in Ecuador (Skelton et al. 2023, Proc. Roy. Soc. B), and studies that explore how the visual systems of anomalous trichromats compensate for their altered cone spectral sensitivities.

PMID:40215015 | DOI:10.1167/jov.25.5.54

J Vis. 2025 Apr 1;25(5):57. doi: 10.1167/jov.25.5.57.

ABSTRACT

Infants start to interact with their visual environment during the first postnatal months. Immaturities in gross motor responses and spatial vision constrain their visual behavior during this rapid development. Analyses of first-person video and eye-tracking data from infants were performed to understand key components of visual experience during this period of visual learning.

METHODS: Infants wore head-mounted scene and binocular eye-tracking cameras (modified Pupil Labs Core) while engaging in naturalistic behavior in an 8ftx8ft home-like environment. Calibrated eye movements were identified using standard approaches (e.g. Engbert & Mergenthaler, 2006) and image statistics were extracted at fixation locations (>200ms).

RESULTS: Recordings (10.5 hours) at ages 2-3 (n=24) 5-6 (35) 8-9 (27) & 11-12 (11) months were analyzed. Eye position and saccade amplitude distributions relative to the head were tighter for younger infants. The distribution of RMS contrast around fixation was also highest at younger ages.

CONCLUSIONS: The youngest infants with limited head and trunk control exhibited the most restricted range of eye movements, suggesting no gaze shift compensation for limited mobility. This likely leads to less active sampling of the scene, slower rates of change in input, and a tight link between head- and eye-centered frames of reference. Early experience also provides a concentration of contrast serving the development of foveal and parafoveal function.

PMID:40215012 | DOI:10.1167/jov.25.5.57

Psychooncology. 2025 Apr;34(4):e70146. doi: 10.1002/pon.70146.

ABSTRACT

OBJECTIVE: To identify the contribution of psychosocial characteristics, supportive care needs, or quality of life on breast cancer survival outcomes.

METHODS: This study used data from a population-based longitudinal study involving women diagnosed with invasive breast cancer (n = 3326, response rate = 71%) in Queensland, Australia, 2010-2013, and followed up to 2020. Flexible parametric survival models were used to identify which factors were associated with survival outcomes. Model fit was assessed using D and $R_D^2$ statistics.

RESULTS: Unmet physical and daily living needs, social support, age, stage at diagnosis, tumour grade, clinical subtype and mode of detection explained 39% of survival variability ( $R_D^2$ 0.39; 95% CI 0.33-0.44), with a Harrell’s C statistic of 0.84 (95% CI 0.81-0.86). Unmet physical and daily living needs and social support, which fall under the categories of supportive care needs and psychosocial characteristics respectively, were identified as key factors that predict breast cancer survival, explaining 3% of survival variability. When compared to women who had less unmet physical needs and adequate social support (5-year survival: 96.6%, 95% CI 92%-99%), those who had more unmet physical needs and limited social support had poorer breast cancer-specific survival (5-year survival: 86.8%, 95% CI 72%-95%).

CONCLUSION: The study found that unmet physical and daily living needs and social support play a marginal but significant role in influencing breast cancer outcomes. The findings enhance the current literature regarding the impact of psychosocial characteristics and supportive care needs on breast cancer survival and suggest that integrating psychosocial support and interventions alongside medical treatment may further improve the survival outcomes for women diagnosed with breast cancer.

PMID:40215001 | DOI:10.1002/pon.70146

Pediatr Blood Cancer. 2025 Apr 11:e31700. doi: 10.1002/pbc.31700. Online ahead of print.

ABSTRACT

BACKGROUND: Children with cancer face an increased risk of complications and death beyond the 5-year survival mark. National surveillance efforts facilitate the systematic tracking of long-term health outcomes, including treatment-related complications and late mortality, among childhood cancer survivors. We aimed to describe the population of 5-year childhood cancer survivors in Canada, quantify the risk of death among survivors relative to the general population, and identify characteristics associated with late mortality.

METHODS: This retrospective cohort study used the Canadian Cancer Registry linked to the Canadian Vital Statistics-Death database (excludes Quebec). Survivors were diagnosed with cancer before 15 years old (1992-2012) and still alive five years after diagnosis. We approximated the risk of late mortality relative to the general population using standardized mortality ratios (SMRs) and absolute excess ratios (AERs). Cumulative all-cause and cause-specific mortality and time-to-event models identified characteristics associated with late mortality.

RESULTS: Of the 10,800 5-year survivors, 405 (4%) had a late death by 2017 (median follow-up: 9.1 years). Cancer recurrence or progression caused most late deaths (64%), followed by subsequent primary neoplasms (11%) and other health-related causes (15%). Survivors had a higher risk of all-cause mortality than the general population (SMR = 9.4; 95% CI = 8.5-10.4; AER = 34.8, 95% CI = 30.8-38.8). Risk was highest in the first 5-9 years of follow-up. Cumulative mortality differed significantly by age at diagnosis, sex and cancer type.

INTERPRETATION: Our results underline the importance of long-term surveillance of childhood cancer survivors, as mortality rates remain higher than the general population for at least two decades after diagnosis.

PMID:40214998 | DOI:10.1002/pbc.31700

JAMA Netw Open. 2025 Apr 1;8(4):e254516. doi: 10.1001/jamanetworkopen.2025.4516.

ABSTRACT

IMPORTANCE: Following decades-long declines, significant increases in abortion rates have been reported in some jurisdictions from 2020 to 2023, but it is not yet known whether these trends are occurring in Canada.

OBJECTIVE: To assess abortion rates in Ontario from 2012 to 2022 and to examine trend changes associated with mifepristone availability, the COVID-19 pandemic, and postpandemic periods.

DESIGN, SETTING, AND PARTICIPANTS: This population-based interrupted time series cohort study examined all medication and procedural abortions provided in Ontario from January 1, 2012, to December 31, 2022, to females aged 15 to 44 years with provincial insurance coverage, identified using linked health administrative data that included records from practitioner billings, inpatient and outpatient hospital services, same-day surgeries, and outpatient prescription dispensations.

EXPOSURE: Availability of mifepristone regulated as a normal (ie, prescribed by an authorized prescriber without additional certification or registration and dispensed by a pharmacist) prescription medication (in November 2017) and the COVID-19 pandemic period (from March 2020 to December 2021).

MAIN OUTCOMES AND MEASURES: The main outcome was the abortion rate (number of abortions per 1000 females per year) overall and within age strata, using an interrupted time series design.

RESULTS: Of 422 867 medication and procedural abortions identified using data from health records of 225 540 reproductive-aged females (mean [SD] age, 28.5 [6.6] years), the abortion rate declined steadily from 15.6 abortions per year per 1000 females, aged 15 to 44 years, in 2012 to 12.3 in 2021 and then increased to 14.1 in 2022. When mifepristone was introduced in 2017 as a normal prescription medication, no immediate change in the abortion rate (-0.1 [95% CI, -0.7 to 0.8]) and a nonsignificant slope increase (0.6 [95% CI, -0.5 to 0.7]) were found. However, this trend resulted in an additional 1.5 (95% CI, 0.3-2.6) abortions per 1000 females by the first quarter of 2020 compared with premifepristone trends; rates increased more among those aged 15 to 19 years, less among those aged 35 to 44 years, and did not increase for those aged 25 to 29 years. During the pandemic period, abortion rates decreased by 1.2 (95% CI, -2.5 to -0.8), most pronounced among those aged 20 to 34 years. Compared with expected rates based on premifepristone trends, 5-year availability of normally prescribed mifepristone was associated with a rate difference of 1.9 (95% CI, 0.7-5.4) in 2022, with a greater increase among those aged 20 to 24 years (4.2 [95% CI, 1.5-9.0]) and no change among those aged 25 to 29 years (1.0 [95% CI, -1.7 to 6.2]). The increased abortion rate in 2022 was consistent with 5-year trends following normally prescribed mifepristone, although social forces potentially impacting international rates may have contributed.

CONCLUSIONS AND RELEVANCE: This study found that, following longstanding declines, abortion rates in Ontario gradually increased with mifepristone availability in 2017 in Ontario. Following a pandemic-related decrease in rates (in 2020 and 2021), substantial increases in abortion rates reported elsewhere from 2020 to 2023 did not occur in Ontario as of 2022, suggesting that Ontario’s health services environment and Canada’s regulatory and policy approach to preserving reproductive health services may have helped stabilize abortion rates. Future research is needed to understand how sociocultural changes affecting abortion service use elsewhere may be affecting contraception access and use and thus abortion rates in Canada.

PMID:40214991 | DOI:10.1001/jamanetworkopen.2025.4516

JAMA Netw Open. 2025 Apr 1;8(4):e254666. doi: 10.1001/jamanetworkopen.2025.4666.

ABSTRACT

IMPORTANCE: A resurgence of respiratory syncytial virus (RSV)-associated acute respiratory tract infection (ARI) was observed in 2022 and 2023 after the COVID-19 pandemic. Changes in the demographic characteristics, disease severity, and outcomes of patients were observed, which could impact the identification of risk groups for interventions aimed at reducing the severity of RSV disease.

OBJECTIVES: To identify factors associated with severe clinical outcomes among children hospitalized with RSV-associated ARIs in 2022 and 2023.

DESIGN, SETTING, AND PARTICIPANTS: This observational cohort study, conducted at 2 large, Canadian, tertiary-level pediatric hospitals, comprised all 709 cases of RSV-associated ARI among children younger than 18 years who were admitted to the hospital or intensive care unit (ICU) from July 1, 2022, to June 30, 2023.

EXPOSURE: Diagnosis of RSV-associated ARI.

MAIN OUTCOMES AND MEASURES: The primary outcome of severe disease was defined as requiring noninvasive or invasive ventilation or death. Risk factors for severe disease and ICU admission (secondary outcome) were assessed using multivariable Poisson regression, and results were reported as adjusted risk ratios (ARRs) with 95% CIs, with age-stratified models (<2 years and ≥2 years).

RESULTS: A total of 709 cases (median age, 13.1 months [IQR, 2.0-36.6 months]; 442 boys [62.3%]) were admitted with RSV-associated ARI; 452 (63.8%) were younger than 2 years, and 257 (36.2%) were aged 2 years or older. Severe disease was documented for 204 cases (28.8%). Patients with severe disease were younger than those with nonsevere disease (median age, 2.6 months [IQR, 1.3-16.0 months] vs 18.6 months [IQR, 4.5-39.1 months]; P < .001). Pulmonary disease and use of home oxygen (ARR, 2.47 [95% CI, 1.30-4.68]) and neurologic, neuromuscular, and developmental conditions (ARR, 1.89 [95% CI, 1.03-3.49]) were associated with severe disease among children aged 2 years or older. Among children younger than 2 years, age younger than 3 months (ARR, 2.34 [95% CI, 1.43-3.84]), age 3 to less than 6 months (ARR, 2.79 [95% CI, 1.65-4.70]), and prematurity (ARR, 1.40 [95% CI, 1.03-1.89]) were associated with severe disease.

CONCLUSIONS AND RELEVANCE: In this cohort study of children hospitalized with RSV in 2022 and 2023, severe RSV disease was more likely among those aged 2 years or older with pulmonary and neurologic, neuromuscular, or developmental conditions. For children younger than 2 years, age younger than 6 months and prematurity were the main risk factors. These findings support prevention strategies for all younger children, including premature infants, with potential benefit for children aged 2 years or older in specific high-risk groups.

PMID:40214990 | DOI:10.1001/jamanetworkopen.2025.4666

JAMA Netw Open. 2025 Apr 1;8(4):e254689. doi: 10.1001/jamanetworkopen.2025.4689.

ABSTRACT

IMPORTANCE: Variations in perioperative dexamethasone dosing are common in brain metastasis resection, but their impact on patient outcomes remains unclear.

OBJECTIVE: To evaluate the association between perioperative dexamethasone dosing and patient outcomes, focusing on overall survival (OS) and progression-free survival (PFS).

DESIGN, SETTING, AND PARTICIPANTS: This retrospective multicenter comparative effectiveness study used data collected from January 2010 to December 2023. Patients with symptomatic brain metastases undergoing primary surgical resection at 7 neurological centers in Germany and 1 in Austria and who had complete records of perioperative dexamethasone dosing were included. Propensity score matching (PSM) was used to control for confounders. Analysis was conducted from March to June 2024.

EXPOSURES: Cumulative perioperative dexamethasone administration over 27 days, dichotomized at 122 mg using maximally selected rank statistics.

MAIN OUTCOMES AND MEASURES: The primary outcome was OS. Secondary outcomes included extracranial PFS (ecPFS) and intracranial PFS (icPFS) as well as incidence of wound revision surgery after brain metastasis resection. Hazard ratios (HRs) were calculated using Cox proportional hazards models.

RESULTS: A total of 1064 patients were included in the analysis. The median (IQR) age was 64 (56-72) years, with 489 female patients (49%) and 541 male patients (51%). Non-small cell lung cancer (NSCLC) was the most common tumor entity (564 patients [53%]), followed by breast cancer (146 patients [14%]) and melanoma (138 patients [13%]). After PSM, patients receiving cumulative dexamethasone doses less than 122 mg had a median OS of 19.1 (95% CI, 15.2-22.4) months compared with 12.0 (95% CI, 9.1-14.7) months for those receiving 122 mg or more (P = .002). Multivariable analysis showed an independent association between higher cumulative dexamethasone doses and reduced OS (HR, 1.40; 95% CI, 1.18-1.66; P < .001). Secondary analyses demonstrated consistent findings with icPFS and ecPFS and a dose-response association between cumulative dexamethasone and hazard for death.

CONCLUSIONS AND RELEVANCE: In this study, higher cumulative perioperative dexamethasone was associated with reduced OS, icPFS, and ecPFS in patients undergoing brain metastasis resection. These findings suggest that stricter dosing protocols could improve outcomes. Prospective trials are warranted to confirm these associations and guide evidence-based practice.

PMID:40214989 | DOI:10.1001/jamanetworkopen.2025.4689