True and false memory priming of perceptual closure problems in healthy older adults and older adults with Alzheimer's disease.

OBJECTIVE: The present study set out to investigate whether false memories for pictures exhibit priming effects in older adult controls (OACs) and people with early onset Alzheimer's disease (AD). We conducted two studies to examine whether false memories for pictures had a priming effect on a perceptual closure task (PCT). METHOD: In Experiment 1, OACs and people with early onset AD were presented with pictorial versions of the Deese/Rodiger-McDermott lists and took part in a recognition task. This followed with a PCT, where both groups were shown degraded pictures that became clearer over time and participants had to identify the picture as quickly as possible. In Experiment 2, we manipulated the modality-verbal versus pictorial in both the study phase and PCT phase. RESULTS: Experiment 1 results indicated false memories for pictures did not serve as effective primes in the PCT. Experiment 2 results revealed pictorial false memories primed the PCT significantly slower than pictorial true memories in the visual PCT task, but the reverse finding was shown for the verbal PCT task. Finally, verbal false memories primed the verbal PCT reliably faster than true memories. CONCLUSIONS: Our findings show when solving pictorial problems, for both older adults and people with AD false memories may not activate the appropriate representation in memory for solving a pictorial problems whereas actually presented items do. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Continuidad de vínculos, hombres y mujeres en duelo por un ser querido: un análisis secundario / Continuing bonds, men, and women in bereavement: A secondary analysis

Introducción: El duelo es una respuesta compleja ante la pérdida de un ser querido que exhibe diferentes rutas para su ajuste, la continuidad de vínculos forma parte de su naturaleza. Objetivo: Analizar la experiencia de duelo por un ser querido en hombres y mujeres relacionada a percepción de cercanía con la persona fallecida, continuidad de vínculos y diagnósticos de Enfermería. Materiales y Métodos: Análisis secundario. Muestra a conveniencia de 251 dolientes, adultos, residentes de Canarias, hispanohablantes. Recolección con encuesta en línea compuesta por características sociodemográficas y de salud, y relacionadas con la pérdida, Escala de inclusión del otro en el yo, Escala de Continuidad de Vínculos y diagnósticos de Enfermería. Se utilizó análisis descriptivo, U de Mann-Whitney, coeficiente de Spearman. Nivel de significancia p<0,05. Resultados: Edad media de 45,09 años ±10,38. Un 22,70% (57) fue hombre, 77,30% (194) mujer. Se identificaron diferencias significativas entre hombres y mujeres en percepción de cercanía con el fallecido (p<0,05), y relaciones significativas entre percepción de cercanía con el fallecido, continuidad de vínculos y diagnósticos de Enfermería (p=0,001). Discusión: Al confrontar los resultados con otros estudios se presentan algunas consistencias y diferencias en el comportamiento de las variables demostrando el dinamismo del fenómeno. Conclusiones: Para este grupo de participantes, la experiencia de duelo no estaría ligada a construcciones sociales de género si no que contesta a una respuesta de afrontamiento según sus necesidades. La comprensión del proceso de duelo permite a la Enfermería de Salud Mental implementar acciones fundamentadas en el Proceso de Enfermería.

Introduction: Grief is a complex response to the loss of a loved one with different ways of adjustment, and Continuing Bonds are part of its nature. Objective: To analyze men's and women's experiences of grief in terms of perception of closeness to the deceased, Continuing Bonds, and Nursing diagnoses. Materials and Methods: Secondary analysis. A convenience sample of 251 Spanish-speaking adult mourners, residents of the Canary Islands, was used. Data was collected via an online survey consisting of socio-demographic, health, and loss-related characteristics, the Inclusion of Other in the Self scale, the Continuing Bonds Scale, and Nursing diagnoses. Descriptive analysis, Mann-Whitney U test, and Spearman's coefficient were used. Level of significance p<0.05. Results: The mean age was 45.09 years ±10.38 years; 22.70% (57) were male, and 77.30% (194) were female. Significant differences were found between men and women in the perception of closeness to the deceased (p<0.05), and significant relationships were found between the perception of closeness to the deceased, Continuing Bonds, and Nursing diagnoses (p=0.001). Discussion: A comparison of the results with other studies shows some consistencies and differences in the behavior of the variables, demonstrating the dynamism of the phenomenon. Conclusions: For this group of participants, the experience of grief would not be linked to social constructions of gender but instead respond to a coping response according to their needs. Understanding the grieving process allows Mental Health Nursing to implement interventions based on the Nursing Process.

Introdução: O luto é uma resposta complexa à perda de um ente querido que apresenta diferentes caminhos de ajustamento, a continuidade dos laços faz parte da sua natureza. Objetivo: Analisar a vivência do luto por um ente querido em homens e mulheres relacionada à percepção de proximidade com a pessoa falecida, continuidade de vínculos e diagnósticos de Enfermagem. Materiais e Métodos: Análise secundária. Amostra para conveniência de 251 enlutados, adultos, residentes nas Ilhas Canárias, falantes de espanhol. Coleção com inquérito online composto por características sociodemográficas e de saúde, e relacionadas à perda, Escala de inclusão do outro no eu, Escala de Continuidade de Vínculos e diagnósticos de Enfermagem. Foram utilizadas análise descritiva, U de Mann-Whitney, coeficiente de Spearman. Nível de significância p<0,05. Resultados: Idade média de 45,09 anos ±10,38. 22,70% (57) eram homens, 77,30% (194) eram mulheres. Foram identificadas diferenças significativas entre homens e mulheres na percepção de proximidade com o falecido (p<0,05), e relações significativas entre percepção de proximidade com o falecido, continuidade de vínculos e diagnósticos de Enfermagem (p=0,001). Discussão: Ao comparar os resultados com outros estudos, apresentam-se algumas consistências e diferenças no comportamento das variáveis, demonstrando o dinamismo do fenômeno. Conclusões: Para este grupo de participantes, a vivência do luto não estaria ligada a construções sociais de género, mas responde a uma resposta de enfrentamento de acordo com as suas necessidades. A compreensão do processo de luto permite à Enfermagem em Saúde Mental implementar ações pautadas no Processo de Enfermagem.

The sexual and reproductive health needs of school-going young people in the context of COVID-19 in rural KwaZulu-Natal, South Africa

Background: The impact of school closures due to COVID-19 raised widespread concerns about children's health and well-being. We examine the impact on the sexual health needs of learners in the context of COVID-19 related lockdowns in rural KwaZulu-Natal, South Africa.Methods: In july­November 2020 and August­November 2021 we conducted 24 in-depth interviews and 8 group discussions with teachers and learners from 4 schools, community members and key education stakeholders. All interviews were conducted by telephone. We used a thematic analysis approach and Nvivo 12 software to manage the data.Results: Four main themes related to the COVID-19 pandemic emerged from the data: the sexual and reproductive health (SRH) of learners in the lead-up to the pandemic; the impact of COVID-19 on learners' SRH and wellbeing; the opportunities schools provided to support sexual well-being of learners during the pandemic; and the role of schools in supporting SRH for learners during the pandemic. Learners and stakeholders reported that the SRH of young people was affected by alcohol misuse, poor SRH knowledge and few pathways to link learners with services. Stakeholders working with schools reported that a lack of access to biomedical interventions (e.g., contraception) increased learner pregnancies. Gender-based violence in learners' households was reported to have increased during the COVID-19 pandemic related to loss of income. School closures disrupted the provision of a safe space to provide SRH and HIV-education through Life Orientation lessons and school nurse talks. This loss of a safe space also left learners vulnerable to sexual and physical violence. However, once schools re-opened, daily COVID-19 screening in schools provided the opportunity to identify and support vulnerable children who had other social needs (food and uniforms). Conclusion: The COVID-19 pandemic may have increased SRH needs and vulnerability of school-going children in a high HIV-burden rural setting. School shutdowns reduced the opportunity for schools to provide a vital safe space and information to enhance SRH for adolescents. Schools play a vital health promotion and social protection role.

Where there is no object formation, there is no perceptual organization: Evidence from the configural superiority effect.

Object formation is considered the aim of perceptual organization, but such a proposition has been neglected in empirical studies. In the current study, we investigated the role of object formation in configural superiority. Essentially, discrimination on bar orientations was enhanced by adding a right angle to each of the bars. Such facilitation is due to the emergent feature (EF) of closure formed by combining the bars with right angles. To study object formation, visual stimuli were generated by random dot stereograms to form objects or holes in 3D. Behaviorally, we found that the EF of closure facilitated oddball discrimination on objects, as demonstrated by previous studies, but did not facilitate oddball discrimination on holes with the same shape as objects. Multivariate pattern analysis of functional magnetic resonance imaging (fMRI) data showed that the EF of closure increased the object classification accuracy compared to the holes in the lateral occipital cortex (LOC), where object information is encoded, but not in the early visual cortex (EVC). The neural representations of objects and holes with and without EFs were further investigated using representational similarity analysis. The results demonstrate that in the LOC, the neural representations of objects with EFs showed a greater difference than those of the other three, that is, objects without EFs and holes with or without EFs. However, the uniqueness of objects with EFs was not observed in the EVC. Thus, our results suggest that the EF of closure, which leads to the configural superiority effect, only emerges for objects but not for holes, and only in the LOC but not the EVC. Our study provides the first empirical evidence suggesting that object formation plays an indispensable role in perceptual organization.

Perceptual Gains and Losses in Synesthesia and Schizophrenia.

Individual differences in perception are widespread. Considering inter-individual variability, synesthetes experience stable additional sensations; schizophrenia patients suffer perceptual deficits in, eg, perceptual organization (alongside hallucinations and delusions). Is there a unifying principle explaining inter-individual variability in perception? There is good reason to believe perceptual experience results from inferential processes whereby sensory evidence is weighted by prior knowledge about the world. Perceptual variability may result from different precision weighting of sensory evidence and prior knowledge. We tested this hypothesis by comparing visibility thresholds in a perceptual hysteresis task across medicated schizophrenia patients (N = 20), synesthetes (N = 20), and controls (N = 26). Participants rated the subjective visibility of stimuli embedded in noise while we parametrically manipulated the availability of sensory evidence. Additionally, precise long-term priors in synesthetes were leveraged by presenting either synesthesia-inducing or neutral stimuli. Schizophrenia patients showed increased visibility thresholds, consistent with overreliance on sensory evidence. In contrast, synesthetes exhibited lowered thresholds exclusively for synesthesia-inducing stimuli suggesting high-precision long-term priors. Additionally, in both synesthetes and schizophrenia patients explicit, short-term priors-introduced during the hysteresis experiment-lowered thresholds but did not normalize perception. Our results imply that perceptual variability might result from differences in the precision afforded to prior beliefs and sensory evidence, respectively.

The Time Course of Perceptual Closure of Incomplete Visual Objects: An Event-Related Potential Study.

Perceptual organization is an important part of visual and auditory information processing. In the case of visual occlusion, whether the loss of information in images could be recovered and thus perceptually closed affects object recognition. In particular, many elderly subjects have defects in object recognition ability, which may be closely related to the abnormalities of perceptual functions. This phenomenon even can be observed in the early stage of dementia. Therefore, studying the neural mechanism of perceptual closure and its relationship with sensory and cognitive processing is important for understanding how the human brain recognizes objects, inspiring the development of neuromorphic intelligent algorithms of object recognition. In this study, a new experiment was designed to explore the realistic process of perceptual closure under occlusion and intact conditions of faces and building. The analysis of the differences in ERP components P1, N1, and Ncl indicated that the subjective awareness of perceptual closure mainly occurs in Ncl, but incomplete information has been processed and showed different manners compared to complete stimuli in N170 for facial materials. Although occluded, faces, but not buildings, still maintain the specificity of perceptual processing. The Ncl by faces and buildings did not show significant differences in both amplitude and latency, suggesting a "completing" process regardless of categorical features.

Bouba and Kiki inside objects: Sound-shape correspondence for objects with a hole.

Visual holes (cutouts in a surface) have recently intrigued vision scientists as interesting and useful stimuli in the studies of shape perception and as a perceptual conundrum regarding figure/ground organization. Adopting the Bouba/Kiki paradigm, this study addressed a controversial issue of whether the perceived shape of a closed region alters when the region changes from a solid object to an empty hole, in a more direct manner than previous studies did. Observers were presented with two doughnut-like cardboard cutouts, one with a flower-shaped hole and the other with a star-shaped hole, and then matched them with two nonsense words. The curvature profile of the hole boundary was manipulated so that the shape of the interior region (i.e., a hole) and that of the exterior region (i.e., material edges) give rise to opposite shape impressions (i.e., one rounded and the other spiky). The results of Experiment 1 revealed that shape-name matching for holed objects is based on the interior shapes of holes, but not those of materially defined inner edges. The following three experiments replicated the same pattern of results even when holes appeared like oral apertures in animal character faces (Experiments 2-3) and when they were irregular, non-symmetric, and low in semantic association with familiar real-world objects (Experiment 4). Lastly, Experiment 5 showed that shape-name matching for "C"-shaped, negative-part stimuli is also interior-shape-based if the opening of the interior region is relatively small. These findings suggest that the interior shapes of holes are automatically accessible. I conclude with a discussion of my hypothesis that the only global-level, unitary shape representation of a bounded region of a single connected surface is that of the interior region for both objects and holes, imposing an important constraint in visual shape processing.

Illusory sound texture reveals multi-second statistical completion in auditory scene analysis.

Sound sources in the world are experienced as stable even when intermittently obscured, implying perceptual completion mechanisms that "fill in" missing sensory information. We demonstrate a filling-in phenomenon in which the brain extrapolates the statistics of background sounds (textures) over periods of several seconds when they are interrupted by another sound, producing vivid percepts of illusory texture. The effect differs from previously described completion effects in that 1) the extrapolated sound must be defined statistically given the stochastic nature of texture, and 2) the effect lasts much longer, enabling introspection and facilitating assessment of the underlying representation. Illusory texture biases subsequent texture statistic estimates indistinguishably from actual texture, suggesting that it is represented similarly to actual texture. The illusion appears to represent an inference about whether the background is likely to continue during concurrent sounds, providing a stable statistical representation of the ongoing environment despite unstable sensory evidence.

Robust effects of predictability across experimental contexts: Evidence from event-related potentials.

Many experiments have shown that comprehenders can generate predictions about upcoming inputs on the fly, but relatively little is known about whether and how comprehenders' sensitivity to predictability may be modulated by the experimental context. The present study used event-related potentials (ERPs) in two experiments to ask whether changing the overall predictive validity of the stimuli will affect comprehenders' brain responses to predictable as well as unpredictable words by manipulating the filler sentences, which made up 50% of the stimuli in each experiment. Contrary to the prediction that predictable words should be processed more easily and elicit a smaller N400 response in a more prediction-encouraging experimental context, we found that participants' N400 response to predictable as well as unpredictable words was smaller when the overall predictive validity of the stimuli was low (that is, when the filler items were incongruous compared to when they were predictable). Further, even though the use of different filler sentences did modulate comprehenders' ERP and behavioural responses, it did not modulate the effect of target word predictability on participants' ERP responses at all. We take the present findings to suggest that healthy young adults' brain responses are inherently sensitive to the predictability of the incoming linguistic stimuli, and that this robust sensitivity can be observed regardless of the make-up of the experimental stimuli.

On the "blindness" of blindsight: What is the evidence for phenomenal awareness in the absence of primary visual cortex (V1)?

Blindsight has been central to theories of phenomenal awareness; that a lesion to primary visual cortex (V1) abolishes all phenomenal awareness while unconscious visual functions can remain has led to the view that this region plays a crucial role in generating visual consciousness. However, since the early 20th century, there have been reports, many of which controversial, of phenomenal awareness in patients with V1 lesions. These reports include selective sparing of motion awareness, hemianopic completion and visual aftereffects. More recently, there have been successful attempts of inducing visual qualia with noninvasive brain stimulation. Here we critically review this evidence and discuss their implications to theoretical understanding of phenomenal awareness.

Neuro-cognitive mechanisms of global Gestalt perception in visual quantification.

Recent neuroimaging studies identified posterior regions in the temporal and parietal lobes as neuro-functional correlates of subitizing and global Gestalt perception. Beyond notable overlap on a neuronal level both mechanisms are remarkably similar on a behavioral level representing both a specific form of visual top-down processing where single elements are integrated into a superordinate entity. In the present study, we investigated whether subitizing draws on principles of global Gestalt perception enabling rapid top-down processes of visual quantification. We designed two functional neuroimaging experiments: a task identifying voxels responding to global Gestalt stimuli in posterior temporo-parietal brain regions and a visual quantification task on dot patterns with magnitudes within and outside the subitizing range. We hypothesized that voxels activated in global Gestalt perception should respond stronger to dot patterns within than those outside the subitizing range. The results confirmed this prediction for left-hemispheric posterior temporo-parietal brain areas. Additionally, we trained a classifier with response patterns from global Gestalt perception to predict neural responses of visual quantification. With this approach we were able to classify from TPJ Gestalt ROIs of both hemispheres whether a trial requiring subitizing was processed. The present study demonstrates that mechanisms of subitizing seem to build on processes of high-level visual perception.

The role of temporal integration in auditory stream segregation.

Grouping distinct, temporally separated sounds is assumed to follow Gestalt principles, such as similarity or proximity. In the auditory streaming paradigm, the probability of perceiving all sounds as part of the same repeating pattern (the integrated percept) increases when the interstimulus interval (ISI) is increased from medium to long intervals. However, ISIs shorter than 50 ms have not been systematically explored. Here we show that below ca. 60-ms intervals the direction of the effect of ISI on perception is reversed compared to longer ISIs: Decreasing the ISI increases the probability of the integrated percept. This suggests that temporal proximity plays a different role in auditory stream segregation at very short than at longer ISIs. As the effect of temporal proximity may vary among individuals, we tested whether the proportion of the integrated reports with short ISIs could be associated with individual differences in the temporal resolution of the central auditory system. We found that individual differences in the temporal integration threshold (as measured by a temporal order judgment task) correlated with the percentage of integrated percept reports in some of the short-ISI regions. Although this result cannot be regarded as strong evidence, it is compatible with the notion that temporal integration plays a role in auditory stream segregation at short ISIs. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Temporal properties of amodal completion: Influences of knowledge.

We studied the influence of knowledge in the interpretation of partly occluded objects. In the past decades, amodal completion has often been studied by using abstract, meaningless outlines of rather stylistic, geometric shapes. It has been recognized that smooth continuation of partly occluded contours behind an occluding surface is a strong completion tendency. In the current study we contrast this structurally driven completion tendency with knowledge driven tendencies. We used a set of partly occluded well-known objects for which structure-based completions and knowledge-based completions resulted in either the same or different interpretations. We adopted the behavioural primed matching paradigm to measure differential priming effects due to these completion tendencies. Our results implied differential temporal properties for structure-based and knowledge-based effects during perception of partly occluded objects. Interestingly, knowledge has an influence as early as 150 ms after the onset of the prime.

Reduced intrinsic visual cortical connectivity is associated with impaired perceptual closure in schizophrenia.

Sensory perceptual processing deficits, such as impaired visual object identification and perceptual closure, have been reported in schizophrenia. These perceptual impairments may be associated with neural deficits in visual association areas, including lateral occipital cortex and inferior temporal areas. However, it remains unknown if such deficits can be found in the intrinsic architecture of the visual system. In the current study, we measured perceptual closure performance and resting-state functional connectivity using functional magnetic resonance imaging (FMRI) in 16 schizophrenia patients and 16 matched healthy controls. We estimated intrinsic functional connectivity using self-organized grouping spatial ICA, which clusters component maps in the subject space according to spatial similarity. Patients performed worse than controls in the perceptual closure task. This impaired closure performance of patients was correlated with increased severity of psychotic symptoms. We also found that intrinsic connectivity of the visual processing system was diminished in patients compared to controls. Lower perceptual closure performance was correlated to lower visual cortical intrinsic connectivity overall. We suggest that schizophrenia is associated with impaired intrinsic connectivity of the visual system, and that it is a potential mechanism leading to impaired visual object perception. These findings contribute to increasing evidence for impairments of higher visual functions in schizophrenia.

The effects of Kanizsa contours on temporal integration and attention in rapid serial visual presentation.

Performance in rapid serial visual presentation tasks has been shown to depend on the temporal integration of target stimuli when they are presented in direct succession. Temporal target integration produces a single, combined representation of visually compatible stimuli, which is comparatively easy to identify. It is currently unknown to what extent target compatibility affects this perceptual behavior, because it has not been studied systematically to date. In the present study, the effects of compatibility on temporal integration and attention were investigated by manipulating the Gestalt properties of target features. Of particular interest were configurations in which a global illusory shape was formed when all stimulus features were present; a Kanizsa stimulus, which was expected to have a unifying effect on the perception of the successive targets. The results showed that although the presence of a Kanizsa shape can indeed enhance temporal integration, this also was observed for other good Gestalts, such as due to common fate and closure. Identification accuracy seemed to vary, possibly as a result of masking strength, but this did not seem associated with attentional processing per se. Implications for theories of Gestalt processing and temporal integration are discussed.

Impairment of perceptual closure in autism for vertex- but not edge-defined object images.

One of the characteristics of autism spectrum disorder (ASD) is atypical sensory processing and perceptual integration. Here, we used an object naming task to test the significance of deletion of vertices versus extended contours (edges) in naming fragmented line drawings of natural objects in typically developing and ASD children. The basic components of a fragmented image in perceptual closure need to be integrated to make a coherent visual perception. When vertices were missing and only edges were visible, typically developing and ASD subjects performed similarly. But typically developing children performed significantly better than ASD children when only vertex information was visible. These results indicate impairment of binding vertices but not edges to form a holistic representation of an object in children with ASD.

Differentiating global and local contour completion using a dot localization paradigm.

Competing theories of partially occluded object perception (amodal completion) emphasize either relatively local contour relationships or global factors such as symmetry. These disparate theories may reflect 2 separate processes: a low-level contour interpolation process and a higher-order global recognition process. The 2 could be distinguished experimentally if only the former produces precise representations of occluded object boundaries. Using a dot localization paradigm, we measured the precision and accuracy of perceived object boundaries for participants instructed to complete occluded objects with divergent local and global interpretations. On each trial, a small red dot was flashed on top of an occluder. Participants reported whether the dot fell inside or outside the occluded object's boundaries. Interleaved, 2-up, 1-down staircases estimated points on the psychometric function where the probability was .707 that the dot would be seen as either outside or inside the occluded object's boundaries. The results reveal that local contour interpolation produces precise and accurate representations of occluded contours, and consistency across observers, but completion according to global symmetry does not. These results support a distinction between local, automatic contour interpolation processes and global processes based on recognition from partial information. (PsycINFO Database Record