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1.
J Affect Disord ; 347: 533-540, 2024 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-38070743

RESUMEN

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.


Asunto(s)
COVID-19 , Adulto , Humanos , Pandemias , Estudios Transversales , Aislamiento Social/psicología , Soledad/psicología , Ansiedad/epidemiología , Ansiedad/psicología , Depresión/epidemiología , Depresión/psicología
2.
Q J Exp Psychol (Hove) ; : 17470218231191442, 2023 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-37477179

RESUMEN

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.

4.
J Affect Disord ; 325: 596-603, 2023 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-36669568

RESUMEN

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.


Asunto(s)
COVID-19 , Salud Mental , Humanos , Femenino , COVID-19/epidemiología , Control de Enfermedades Transmisibles , Estudios Transversales , Ansiedad/epidemiología , Depresión/epidemiología
5.
R Soc Open Sci ; 9(5): 200414, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35592763

RESUMEN

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.

6.
Soc Psychiatry Psychiatr Epidemiol ; 57(1): 1-24, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34386869

RESUMEN

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.


Asunto(s)
Trastornos Mentales , Salud Mental , Adulto , Humanos , Renta , Trastornos Mentales/epidemiología , Política Pública , Características de la Residencia
7.
Artículo en Inglés | MEDLINE | ID: mdl-34069973

RESUMEN

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.


Asunto(s)
Terapia Cognitivo-Conductual , Salud Mental , Adolescente , Trastornos de Ansiedad , Niño , Depresión , Hospitales Pediátricos , Humanos , Masculino
8.
BMJ Open ; 9(9): e030448, 2019 09 18.
Artículo en Inglés | MEDLINE | ID: mdl-31537571

RESUMEN

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.


Asunto(s)
Trastornos Psicóticos/etiología , Clase Social , Determinantes Sociales de la Salud , Adulto , Estudios Transversales , Etnicidad , Femenino , Humanos , Renta , Londres , Masculino , Densidad de Población , Pobreza , Características de la Residencia , Medio Social , Problemas Sociales , Adulto Joven
9.
Front Psychol ; 10: 1898, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31485211

RESUMEN

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

10.
11.
PLoS One ; 14(6): e0218466, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31188884

RESUMEN

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

12.
Psychiatry Res ; 270: 869-879, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30551337

RESUMEN

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.


Asunto(s)
Escalas de Valoración Psiquiátrica/estadística & datos numéricos , Trastornos Psicóticos/diagnóstico , Evaluación de Síntomas/métodos , Adolescente , Adulto , Análisis Factorial , Femenino , Humanos , Londres , Masculino , Persona de Mediana Edad , Psicometría , Síndrome , Adulto Joven
13.
J Neurosci ; 37(6): 1546-1556, 2017 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-28025253

RESUMEN

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.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Inhibición Neural/fisiología , Estimulación Luminosa/métodos , Esquizofrenia/fisiopatología , Corteza Visual/fisiología , Campos Visuales/fisiología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Esquizofrenia/diagnóstico por imagen , Corteza Visual/diagnóstico por imagen
14.
J Neurosci ; 35(18): 6979-86, 2015 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-25948250

RESUMEN

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.


Asunto(s)
Trastorno Autístico/diagnóstico , Trastorno Autístico/psicología , Percepción de Movimiento/fisiología , Estimulación Luminosa/métodos , Desempeño Psicomotor/fisiología , Adolescente , Niño , Femenino , Humanos , Masculino
15.
PLoS One ; 10(2): e0117951, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25689281

RESUMEN

Schizophrenia has been linked to impaired performance on a range of visual processing tasks (e.g. detection of coherent motion and contour detection). It has been proposed that this is due to a general inability to integrate visual information at a global level. To test this theory, we assessed the performance of people with schizophrenia on a battery of tasks designed to probe voluntary averaging in different visual domains. Twenty-three outpatients with schizophrenia (mean age: 40±8 years; 3 female) and 20 age-matched control participants (mean age 39±9 years; 3 female) performed a motion coherence task and three equivalent noise (averaging) tasks, the latter allowing independent quantification of local and global limits on visual processing of motion, orientation and size. All performance measures were indistinguishable between the two groups (ps>0.05, one-way ANCOVAs), with one exception: participants with schizophrenia pooled fewer estimates of local orientation than controls when estimating average orientation (p = 0.01, one-way ANCOVA). These data do not support the notion of a generalised visual integration deficit in schizophrenia. Instead, they suggest that distinct visual dimensions are differentially affected in schizophrenia, with a specific impairment in the integration of visual orientation information.


Asunto(s)
Percepción de Forma/fisiología , Percepción de Movimiento/fisiología , Esquizofrenia/fisiopatología , Psicología del Esquizofrénico , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Orientación/fisiología
16.
Dev Cogn Neurosci ; 10: 44-56, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25160679

RESUMEN

The development of motion processing is a critical part of visual development, allowing children to interact with moving objects and navigate within a dynamic environment. However, global motion processing, which requires pooling motion information across space, develops late, reaching adult-like levels only by mid-to-late childhood. The reasons underlying this protracted development are not yet fully understood. In this study, we sought to determine whether the development of motion coherence sensitivity is limited by internal noise (i.e., imprecision in estimating the directions of individual elements) and/or global pooling across local estimates. To this end, we presented equivalent noise direction discrimination tasks and motion coherence tasks at both slow (1.5°/s) and fast (6°/s) speeds to children aged 5, 7, 9 and 11 years, and adults. We show that, as children get older, their levels of internal noise reduce, and they are able to average across more local motion estimates. Regression analyses indicated, however, that age-related improvements in coherent motion perception are driven solely by improvements in averaging and not by reductions in internal noise. Our results suggest that the development of coherent motion sensitivity is primarily limited by developmental changes within brain regions involved in integrating motion signals (e.g., MT/V5).


Asunto(s)
Percepción de Movimiento/fisiología , Adulto , Encéfalo/fisiología , Niño , Femenino , Humanos , Masculino , Estimulación Luminosa , Factores de Tiempo
17.
Invest Ophthalmol Vis Sci ; 55(4): 2539-46, 2014 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-24677099

RESUMEN

PURPOSE: People with migraine are relatively poor at judging the direction of motion of coherently moving signal dots when interspersed with noise dots drifting in random directions, a task known as motion coherence. Although this has been taken as evidence of impoverished global pooling of motion signals, it could also arise from unreliable coding of local direction (of each dot), or an inability to segment signal from noise (noise-exclusion). The aim of this study was to determine how these putative limits contribute to impoverished motion processing in migraine. METHODS: Twenty-two participants with migraine (mean age, 34.7 ± 8.3 years; 16 female) and 22 age- and sex-matched controls (mean age, 34.4 ± 6.2 years) performed a motion-coherence task and a motion-equivalent noise task, the latter quantifying local and global limits on motion processing. In addition, participants were tested on analogous equivalent noise paradigms involving judgments of orientation and size, so that the specificity of any findings (to visual dimension) could be ascertained. RESULTS: Participants with migraine exhibited higher motion-coherence thresholds than controls (P = 0.01, independent t-test). However, this difference could not be attributed to deficits in either local or global processing since they performed normally on all equivalent noise tasks (P > 0.05, multivariate ANOVA). CONCLUSIONS: These findings indicate that motion perception in the participants with migraine was limited by an inability to exclude visual noise. We suggest that this is a defining characteristic of visual dysfunction in migraine, a theory that has the potential to integrate a wide range of findings in the literature.


Asunto(s)
Percepción de Movimiento/fisiología , Ruido , Umbral Sensorial/fisiología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Trastornos Migrañosos/fisiopatología , Estimulación Luminosa , Adulto Joven
18.
Vision Res ; 89: 1-9, 2013 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-23820087

RESUMEN

Sensitivity to visual numerosity has previously been shown to predict human mathematical performance. However, it is not clear whether it is discrimination of numerosity per se that is predictive of mathematical ability, or whether the association is driven by more general task demands. To test this notion we had over 300 participants (ranging in age from 6 to 73 years) perform a symbolic mathematics test and 4 different visuospatial matching tasks. The visual tasks involved matching 2 clusters of Gabor elements for their numerosity, density, size or orientation by a method of adjustment. Partial correlation and regression analyses showed that sensitivity to visual numerosity, sensitivity to visual orientation and mathematical education level predict a significant proportion of shared as well as unique variance in mathematics scores. These findings suggest that sensitivity to visual numerosity is not a unique visual psychophysical predictor of mathematical ability. Instead, the data are consistent with mathematics representing a multi-factorial process that shares resources with a number of visuospatial tasks.


Asunto(s)
Conceptos Matemáticos , Percepción Visual/fisiología , Adolescente , Adulto , Factores de Edad , Anciano , Niño , Discriminación en Psicología/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estimulación Luminosa/métodos , Psicofísica , Análisis de Regresión , Umbral Sensorial/fisiología , Factores Sexuales , Adulto Joven
19.
PLoS One ; 8(4): e60951, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23585865

RESUMEN

BACKGROUND: Detection of visual contours (strings of small oriented elements) is markedly poor in schizophrenia. This has previously been attributed to an inability to group local information across space into a global percept. Here, we show that this failure actually originates from a combination of poor encoding of local orientation and abnormal processing of visual context. METHODS: We measured the ability of observers with schizophrenia to localise contours embedded in backgrounds of differently oriented elements (either randomly oriented, near-parallel or near-perpendicular to the contour). In addition, we measured patients' ability to process local orientation information (i.e., report the orientation of an individual element) for both isolated and crowded elements (i.e., presented with nearby distractors). RESULTS: While patients are poor at detecting contours amongst randomly oriented elements, they are proportionally less disrupted (compared to unaffected controls) when contour and surrounding elements have similar orientations (near-parallel condition). In addition, patients are poor at reporting the orientation of an individual element but, again, are less prone to interference from nearby distractors, a phenomenon known as visual crowding. CONCLUSIONS: We suggest that patients' poor performance at contour perception arises not as a consequence of an "integration deficit" but from a combination of reduced sensitivity to local orientation and abnormalities in contextual processing. We propose that this is a consequence of abnormal gain control, a phenomenon that has been implicated in orientation-selectivity as well as surround suppression.


Asunto(s)
Percepción de Forma , Inhibición Psicológica , Reconocimiento Visual de Modelos , Esquizofrenia/fisiopatología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Orientación , Estimulación Luminosa
20.
Front Psychol ; 4: 88, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23450069

RESUMEN

Compared to unaffected observers patients with schizophrenia (SZ) show characteristic differences in visual perception, including a reduced susceptibility to the influence of context on judgments of contrast - a manifestation of weaker surround suppression (SS). To examine the generality of this phenomenon we measured the ability of 24 individuals with SZ to judge the luminance, contrast, orientation, and size of targets embedded in contextual surrounds that would typically influence the target's appearance. Individuals with SZ demonstrated weaker SS compared to matched controls for stimuli defined by contrast or size, but not for those defined by luminance or orientation. As perceived luminance is thought to be regulated at the earliest stages of visual processing our findings are consistent with a suppression deficit that is predominantly cortical in origin. In addition, we propose that preserved orientation SS in SZ may reflect the sparing of broadly tuned mechanisms of suppression. We attempt to reconcile these data with findings from previous studies.

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