The association between income inequality and adult mental health at the subnational level-a systematic review.

PURPOSE: A systematic review was undertaken to determine whether research supports: (i) an association between income inequality and adult mental health when measured at the subnational level, and if so, (ii) in a way that supports the Income Inequality Hypothesis (i.e. between higher inequality and poorer mental health) or the Mixed Neighbourhood Hypothesis (higher inequality and better mental health). METHODS: Systematic searches of PsycINFO, Medline and Web of Science databases were undertaken from database inception to September 2020. Included studies appeared in English-language, peer-reviewed journals and incorporated measure/s of objective income inequality and adult mental illness. Papers were excluded if they focused on highly specialised population samples. Study quality was assessed using a custom-developed tool and data synthesised using the vote-count method. RESULTS: Forty-two studies met criteria for inclusion representing nearly eight million participants and more than 110,000 geographical units. Of these, 54.76% supported the Income Inequality Hypothesis and 11.9% supported the Mixed Neighbourhood Hypothesis. This held for highest quality studies and after controlling for absolute deprivation. The results were consistent across mental health conditions, size of geographical units, and held for low/middle and high income countries. CONCLUSIONS: A number of limitations in the literature were identified, including a lack of appropriate (multi-level) analyses and modelling of relevant confounders (deprivation) in many studies. Nonetheless, the findings suggest that area-level income inequality is associated with poorer mental health, and provides support for the introduction of social, economic and public health policies that ameliorate the deleterious effects of income inequality. CLINICAL REGISTRATION NUMBER: PROSPERO 2020 CRD42020181507.

Visual Population Receptive Fields in People with Schizophrenia Have Reduced Inhibitory Surrounds.

People with schizophrenia (SZ) experience abnormal visual perception on a range of visual tasks, which have been linked to abnormal synaptic transmission and an imbalance between cortical excitation and inhibition. However, differences in the underlying architecture of visual cortex neurons, which might explain these visual anomalies, have yet to be reported in vivo Here, we probed the neural basis of these deficits using fMRI and population receptive field (pRF) mapping to infer properties of visually responsive neurons in people with SZ. We employed a difference-of-Gaussian model to capture the center-surround configuration of the pRF, providing critical information about the spatial scale of the pRFs inhibitory surround. Our analysis reveals that SZ is associated with reduced pRF size in early retinotopic visual cortex, as well as a reduction in size and depth of the inhibitory surround in V1, V2, and V4. We consider how reduced inhibition might explain the diverse range of visual deficits reported in SZ.SIGNIFICANCE STATEMENT People with schizophrenia (SZ) experience abnormal perception on a range of visual tasks, which has been linked to abnormal synaptic transmission and an imbalance between cortical excitation/inhibition. However, associated differences in the functional architecture of visual cortex neurons have yet to be reported in vivo We used fMRI and population receptive field (pRF) mapping to demonstrate that the fine-grained functional architecture of visual cortex in people with SZ differs from unaffected controls. SZ is associated with reduced pRF size in early retinotopic visual cortex largely due to reduced inhibitory surrounds. An imbalance between cortical excitation and inhibition could drive such a change in the center-surround pRF configuration and ultimately explain the range of visual deficits experienced in SZ.

Enhanced integration of motion information in children with autism.

To judge the overall direction of a shoal of fish or a crowd of people, observers must integrate motion signals across space and time. The limits on our ability to pool motion have largely been established using the motion coherence paradigm, in which observers report the direction of coherently moving dots amid randomly moving noise dots. Poor performance by autistic individuals on this task has widely been interpreted as evidence of disrupted integrative processes. Critically, however, motion coherence thresholds are not necessarily limited only by pooling. They could also be limited by imprecision in estimating the direction of individual elements or by difficulties segregating signal from noise. Here, 33 children with autism 6-13 years of age and 33 age- and ability-matched typical children performed a more robust task reporting mean dot direction both in the presence and the absence of directional variability alongside a standard motion coherence task. Children with autism were just as sensitive to directional differences as typical children when all elements moved in the same direction (no variability). However, remarkably, children with autism were more sensitive to the average direction in the presence of directional variability, providing the first evidence of enhanced motion integration in autism. Despite this improved averaging ability, children with autism performed comparably to typical children in the motion coherence task, suggesting that their motion coherence thresholds may be limited by reduced segregation of signal from noise. Although potentially advantageous under some conditions, increased integration may lead to feelings of "sensory overload" in children with autism.

A common visual metric for approximate number and density.

There is considerable interest in how humans estimate the number of objects in a scene in the context of an extensive literature on how we estimate the density (i.e., spacing) of objects. Here, we show that our sense of number and our sense of density are intertwined. Presented with two patches, observers found it more difficult to spot differences in either density or numerosity when those patches were mismatched in overall size, and their errors were consistent with larger patches appearing both denser and more numerous. We propose that density is estimated using the relative response of mechanisms tuned to low and high spatial frequencies (SFs), because energy at high SFs is largely determined by the number of objects, whereas low SF energy depends more on the area occupied by elements. This measure is biased by overall stimulus size in the same way as human observers, and by estimating number using the same measure scaled by relative stimulus size, we can explain all of our results. This model is a simple, biologically plausible common metric for perceptual number and density.

The online world as a means of connection and disconnection during the COVID-19 pandemic: A test of the interpersonal-connections-behaviour framework.

BACKGROUND: The interpersonal-connections-behaviour framework proposes that social media is helpful/unhelpful to the individual to the extent that it facilitates/hinders satisfaction of core needs for acceptance and belonging (connecting and disconnecting pathways). However, little research has, to date, explicitly tested this framework. METHODS: Both pathways were explored in a cross-sectional sample of UK adults at the start of the pandemic (N = 632) and in longitudinal (cross-lagged) analyses (N = 227-240). Participants completed measures of online and offline socialising with friends and family (connecting pathway), and online and offline social comparisons (disconnecting pathway), anxiety, depression and loneliness. RESULTS: In cross-sectional analyses higher levels of online comparisons were associated with poorer mental health, an effect that survived after controlling for offline comparisons, and was partially mediated by loneliness. Counter to our predictions, online socialising was also associated with poorer mental health. Longitudinal analyses did not support predicted directions of causality. LIMITATIONS: Limitations include a lack of testing of individual-level moderators, the use of single item questions to probe some constructs, and an inability to test for effects potentially operating at different time-scales. CONCLUSIONS: The findings reported partially support the interpersonal-connections-behaviour framework in highlighting a disconnecting (but not connecting) pathway between online engagement and mental health. From a clinical perspective they highlight the importance of including people's online lives when considering mental health risk and resilience, particularly (one might argue) during periods of social isolation.

Post-migration living difficulties and poor mental health associated with increased interpretation bias for threat.

Previous research has found associations between mental health difficulties and interpretation biases, including heightened interpretation of threat from neutral or ambiguous stimuli. Building on this research, we explored associations between interpretation biases (positive and negative) and three constructs that have been linked to migrant experience: mental health symptoms (Global Severity Index [GSI]), Post-Migration Living Difficulties (PMLD), and Perceived Ethnic Discrimination Questionnaire (PEDQ). Two hundred thirty students who identified as first- (n = 94) or second-generation ethnic minority migrants (n = 68), and first-generation White migrants (n = 68) completed measures of GSI, PEDQ, and PMLD. They also performed an interpretation bias task using Point Light Walkers (PLW), dynamic stimuli with reduced visual input that are easily perceived as humans performing an action. Five categories of PLW were used: four that clearly depicted human forms undertaking positive, neutral, negative, or ambiguous actions, and a fifth that involved scrambled animations with no clear action or form. Participants were asked to imagine their interaction with the stimuli and rate their friendliness (positive interpretation bias) and aggressiveness (interpretation bias for threat). We found that the three groups differed on PEDQ and PMLD, with no significant differences in GSI, and the three measured were positively correlated. Poorer mental health and increased PMLD were associated with a heightened interpretation for threat of scrambled animations only. These findings have implications for understanding of the role of threat biases in mental health and the migrant experience.

The association between sociodemographic inequalities, COVID-related impacts and mental health.

PURPOSE: There are concerns that the social, economic and health impacts of COVID-19 are unevenly distributed, exacerbating existing inequalities. Here we tested the hypotheses that: (H1) the magnitude of these impacts would be associated with symptoms of depression and anxiety early in the pandemic, and (H2) that these impacts would be associated with a range of sociodemographic risk factors. METHODS: Cross-sectional self-report data were collected from a UK sample (N = 632) between the 16th of May and 21st of July 2020, coinciding with the early stages of the pandemic and first UK lockdown. Data were collected on COVID-19 related impacts including financial and social stressors, symptoms of anxiety and depression, and sociodemographic/economic risk factors operationalised at multiple levels including the individual, familial, household and neighbourhood. RESULTS: Using regression analyses both financial and social impacts were independently associated with anxiety (R2 = 0.23) and depression scores (R2 = 0.24), as well as clinically significant generalised anxiety (R2 = 0.14) and depression (R2 = 0.11). In addition, many sociodemographic factors were associated with elevated levels of COVID-19 related impacts, including being younger, female, having lower educational attainment and lower income. LIMITATIONS: The main limitations of the study were its modest sample size, cross sectional design (which precluded inferences about directions of causality), and the relatively high socioeconomic status of the sample (which limited generalisability). CONCLUSIONS: These findings are consistent with a growing body of evidence that suggests that the pandemic has exacerbated existing inequalities, and further, point to particular groups that should be supported by post-COVID-19 recovery policies and initiatives.

Number and density discrimination rely on a common metric: Similar psychophysical effects of size, contrast, and divided attention.

While observers are adept at judging the density of elements (e.g., in a random-dot image), it has recently been proposed that they also have an independent visual sense of number. To test the independence of number and density discrimination, we examined the effects of manipulating stimulus structure (patch size, element size, contrast, and contrast-polarity) and available attentional resources on both judgments. Five observers made a series of two-alternative, forced-choice discriminations based on the relative numerosity/density of two simultaneously presented patches containing 16-1,024 Gaussian blobs. Mismatches of patch size and element size (across reference and test) led to bias and reduced sensitivity in both tasks, whereas manipulations of contrast and contrast-polarity had varied effects on observers, implying differing strategies. Nonetheless, the effects reported were consistent across density and number judgments, the only exception being when luminance cues were made available. Finally, density and number judgment were similarly impaired by attentional load in a dual-task experiment. These results are consistent with a common underlying metric to density and number judgments, with the caveat that additional cues may be exploited when they are available.

Integration of visual motion and orientation signals in dyslexic children: an equivalent noise approach.

Dyslexic individuals have been reported to have reduced global motion sensitivity, which could be attributed to various causes including atypical magnocellular or dorsal stream function, impaired spatial integration, increased internal noise and/or reduced external noise exclusion. Here, we applied an equivalent noise experimental paradigm alongside a traditional motion-coherence task to determine what limits global motion processing in dyslexia. We also presented static analogues of the motion tasks (orientation tasks) to investigate whether perceptual differences in dyslexia were restricted to motion processing. We compared the performance of 48 dyslexic and 48 typically developing children aged 8 to 14 years in these tasks and used equivalent noise modelling to estimate levels of internal noise (the precision associated with estimating each element's direction/orientation) and sampling (the effective number of samples integrated to judge the overall direction/orientation). While group differences were subtle, dyslexic children had significantly higher internal noise estimates for motion discrimination, and higher orientation-coherence thresholds, than typical children. Thus, while perceptual differences in dyslexia do not appear to be restricted to motion tasks, motion and orientation processing seem to be affected differently. The pattern of results also differs from that previously reported in autistic children, suggesting perceptual processing differences are condition-specific.

Visual metacontrast masking in migraine.

BACKGROUND: In visual metacontrast masking, the visibility of a brief target stimulus can be reduced substantially if it is preceded (forward masking) or followed (backward masking) by a non-overlapping mask. These effects have been attributed to inhibitory processes within the visual system. Two previous studies have used metacontrast masking to assess inhibitory function in migraine and control groups, however, each used different types of masking and obtained different results. SUBJECTS AND METHODS: Forward, backward and combined forward and backward masking were compared in migraine (15 with visual aura, 15 without) and control (n = 15) groups. Baseline trials were also included (target only). RESULTS: For all types of masking, both migraine groups were more accurate than the control group. When performance for the masking trials was expressed relative to baseline, however, there were no significant group differences. Performance in certain conditions nevertheless correlated significantly with migraine frequency and with the recency of the last attack. CONCLUSIONS: The inhibitory processes involved in the masking tasks employed in this study do not appear to be impaired in migraine. Their better overall performance may reflect a sensitivity difference, perhaps as a consequence of a heightened neuronal response, which varies with the migraine cycle.

A Mental Health Drop-In Centre Offering Brief Transdiagnostic Psychological Assessment and Treatment in a Paediatric Hospital Setting: A One-Year Descriptive Study.

AIM: This study was part of a broader project to examine the acceptability, feasibility and impact of a transdiagnostic mental health drop-in centre offering brief psychological assessment and treatment for children and young people and/or their families with mental health needs in the context of long-term physical health conditions (LTCs). The aims of this investigation were to characterise: (i) the use of such a centre, (ii) the demographics and symptoms of those presenting to the centre, and (iii) the types of support that are requested and/or indicated. METHODS: A mental health "booth" was located in reception of a national paediatric hospital over one year. Characteristics of young people with LTCs and their siblings/parents attending the booth were defined. Emotional/behavioural symptoms were measured using standardised questionnaires including the Strengths and Difficulties Questionnaire (SDQ). Participants subsequently received one of four categories of intervention: brief transdiagnostic cognitive behaviour therapy (CBT), referral to other services, neurodevelopmental assessment or signposting to resources. RESULTS: One hundred and twenty-eight participants were recruited. The mean age of young people was 9.14 years (standard deviation: 4.28); 61% identified as white and 45% were male. Over half of young people recruited scored in the clinical range with respect to the SDQ. Presenting problems included: anxiety (49%), challenging behaviour (35%), low mood (22%) and other (15%). CONCLUSIONS: A considerable proportion of young people with LTC in a paediatric hospital scored in the clinical range for common mental health problems, indicating a potential for psychological interventions.

Oculomotor responses and visuospatial perceptual judgments compete for common limited resources.

While there is evidence for multiple spatial and attentional maps in the brain it is not clear to what extent visuoperceptual and oculomotor tasks rely on common neural representations and attentional mechanisms. Using a dual-task interference paradigm we tested the hypothesis that eye movements and perceptual judgments made to simultaneously presented visuospatial information compete for shared limited resources. Observers undertook judgments of stimulus collinearity (perceptual extrapolation) using a pointer and Gabor patch and/or performed saccades to a peripheral dot target while their eye movements were recorded. In addition, observers performed a non-spatial control task (contrast discrimination), matched for task difficulty and stimulus structure, which on the basis of previous studies was expected to represent a lesser load on putative shared resources. Greater mutual interference was indeed found between the saccade and extrapolation task pair than between the saccade and contrast discrimination task pair. These data are consistent with visuoperceptual and oculomotor responses competing for common limited resources as well as spatial tasks incurring a relatively high attentional cost.

Correction: Local and Global Limits on Visual Processing in Schizophrenia.

[This corrects the article DOI: 10.1371/journal.pone.0117951.].

Correction: Reduced Crowding and Poor Contour Detection in Schizophrenia Are Consistent with Weak Surround Inhibition.

[This corrects the article DOI: 10.1371/journal.pone.0060951.].

Are socioenvironmental factors associated with psychotic symptoms in people with first-episode psychosis? A cross-sectional study of a West London clinical sample.

OBJECTIVES: To determine whether neighbourhood-level socioenvironmental factors including deprivation and inequality predict variance in psychotic symptoms after controlling for individual-level demographics. DESIGN: A cross-sectional design was employed. SETTING: Data were originally collected from secondary care services within the UK boroughs of Ealing, Hammersmith and Fulham, Wandsworth, Kingston, Richmond, Merton, Sutton and Hounslow as part of the West London First-Episode Psychosis study. PARTICIPANTS: Complete case analyses were undertaken on 319 participants who met the following inclusion criteria: aged 16 years or over, resident in the study's catchment area, experiencing a first psychotic episode, with fewer than 12 weeks' exposure to antipsychotic medication and sufficient command of English to facilitate assessment. OUTCOME MEASURES: Symptom dimension scores, derived from principal component analyses of the Scale for the Assessment of Positive Symptoms and Scale for the Assessment of Negative Symptoms, were regressed on neighbourhood-level predictors, including population density, income deprivation, income inequality, social fragmentation, social cohesion, ethnic density and ethnic fragmentation, using multilevel regression. While age, gender and socioeconomic status were included as individual-level covariates, data on participant ethnicity were not available. RESULTS: Higher income inequality was associated with lower negative symptom scores (coefficient=-1.66, 95% CI -2.86 to -0.46, p<0.01) and higher levels of ethnic segregation were associated with lower positive symptom scores (coefficient=-2.32, 95% CI -4.17 to -0.48, p=0.01) after adjustment for covariates. CONCLUSIONS: These findings provide further evidence that particular characteristics of the environment may be linked to specific symptom clusters in psychosis. Longitudinal studies are required to begin to tease apart the underlying mechanisms involved as well as the causal direction of such associations.

Corrigendum: Visual surround suppression in schizophrenia.

[This corrects the article DOI: 10.3389/fpsyg.2013.00088.].

Biases and sensitivities in the Poggendorff effect when driven by subjective contours.

PURPOSE: A consensus in the existing literature suggests that the Poggendorff effect (a perceptual misalignment of two collinear transversal segments when separated by a pair of parallel contours) persists when the parallels are defined by Kanizsa-like subjective contours. However, previous studies have often been complicated by a lack of quantitative measures of effect size, statistical tests of significance, appropriate measures of baseline and control biases, or stringent definition of subjective contours. The aim of this study was thus to determine whether subjective contours are capable of driving the Poggendorff effect once other factors are accounted for. METHODS: Twenty participants were tested on a number of test and control figures incorporating first-order (luminance-defined) and subjective parallels using the method of adjustment. All figures were tested at two different orientations, and observer sensitivities and observer biases were assessed. RESULTS: A systematic response bias (in the direction of the classical effect) was found for Poggendorff figures that incorporated subjective parallels. The effect was highly significant and greater than for control figures. There was no concomitant change in judgment sensitivity (positional certainty). Finally, there was a positive correlation between the effect size for figures incorporating first-order and subjective parallels. CONCLUSIONS: The findings reported demonstrate conclusively that true Kanizsa-like subjective contours are capable of driving the Poggendorff effect. Further, the data are consistent with a growing body of evidence that suggests both first-order and subjective contours are processed at early loci in the visual pathways when position is encoded.

The component structure of the scales for the assessment of positive and negative symptoms in first-episode psychosis and its dependence on variations in analytic methods.

A secondary analysis was undertaken on Scales for the Assessment of Positive and Negative Symptoms (SAPS/SANS) data from 345 first-episode psychosis (FEP) patients gathered in the West London FEP study. The purpose of this study was to determine: (i) the component structure of these measures in FEP (primary analyses), and (ii) the dependence of any findings in these primary analyses on variations in analytic methods. Symptom ratings were exposed to data reduction methods and the effects of the following manipulations ascertained: (i) level of analysis (individual symptom vs. global symptom severity ratings), (ii) extraction method (principal component vs. exploratory factor analysis) and (iii) retention method (scree test vs. Kaiser criterion). Whilst global ratings level analysis rendered the classic triad of psychotic syndromes (positive, negative and disorganisation), symptom level analyses revealed a hierarchical structure, with 11 first-order components subsumed by three second-order components, which also mapped on to this syndrome triad. These results were robust across data reduction but not component retention methods, suggesting that discrepancies in the literature regarding the component structure of the SAPS/SANS partly reflect the level of analysis and component retention method used. Further, they support a hierarchical symptom model, the implications of which are discussed.

Levels of transient gap junctions between the retinal pigment epithelium and the neuroblastic retina are influenced by catecholamines and correlate with patterns of cell production.

Retinal mitosis takes place at the interface between the retinal pigment epithelium (RPE) and the neural retina. Multiple studies have highlighted the essential role that gap junction-mediated communication plays in the regulation of retinal organogenesis. Here, the localization pattern and function of the gap junction protein connexin 43 were examined in vivo in the rat at the interface between the retina and RPE during the main phases of retinal cell production. Connexin 43 was expressed at this site from E15 onward, and levels were subsequently temporally regulated. When Cx43 protein levels were reduced experimentally, by using antisense oligodeoxynucleotides, mitotic activity in the retina decreased significantly. Conversely, in the hypopigmented eye elevated mitotic levels were associated with a significant increase of connexin 43. Both excess protein levels and elevated mitosis were corrected by the in vivo administration of L-DOPA (a dopamine precursor and intermediary compound in the melanin synthesis pathway). These findings suggest that connexin 43-mediated communication between the retina and RPE is essential for the correct pacing of retinal organogenesis. Furthermore, this pathway may be gated by levels of ocular catecholamines.