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1.
Australas J Ageing ; 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38923185

RESUMO

OBJECTIVE: Population-based data on the required needs for palliative care in residential aged care have been highlighted as a key information gap. This study aimed to provide a comprehensive estimate of palliative care needs among Australia's residential aged care population using a validated algorithm based on causes of death. METHODS: A population-based retrospective cohort study was conducted using data from the Registry of Senior Australians of non-Indigenous residents of residential aged care services in New South Wales, Victoria, and South Australia aged older than 65 years, who died between 2016 and 2017 (n = 71,677). An internationally validated algorithm was used to estimate and characterise potential palliative care needs based on causes of death. This estimate was compared to palliative care needs identified from funding-based care needs assessment data. RESULTS: Ninety two per cent (n = 65,949) were estimated to have had potential palliative care needs prior to their death. Of these, 19% (n = 12,467) were assigned an end-of-life trajectory related to cancer, 61% (n = 40,511) to organ failure and 20% (n = 12,971) to frailty and dementia. By comparison, only 6% (n = 4430) of residents were assessed as needing palliative care by the funding-based care needs assessment. CONCLUSIONS: Over 90% of individuals dying in residential aged care may have benefited from a palliative approach to care. This need is substantially underestimated by the funding-based care needs assessment, which utilises a narrow definition of palliative care when death is imminent. There is a clear imperative to distinguish between palliative and end-of-life care needs within residential aged care to ensure appropriate and equitable access to palliative care.

2.
Brain Cogn ; 130: 11-19, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30622035

RESUMO

This study investigated electroencephalography (EEG) correlates of prediction error during probabilistic learning in pre-adolescents. The detection of prediction errors, the discrepancies between experienced and anticipated outcomes, is thought to be a critical mechanism that drives new learning. Thirty-three typically developing pre-adolescents (mean age = 10.62 years) participated in an associative learning task in which they learned the probabilistic relationships between cues and outcome stimuli in the absence of explicit feedback. We investigated whether three outcome-locked event-related potentials (ERPs) could reflect prediction error processing: the P3, the late positive potential (LPP), and the feedback-related negativity (FRN). All ERP components investigated were sensitive to the magnitude of hypothetical prediction errors that were estimated based on each individual's learning performance. Higher estimated prediction errors generated larger P3 and LPP components, and a more negative FRN. These findings indicate that pre-adolescents are capable of undergoing probabilistic learning in the absence of explicit feedback, much in the same way as adults, and that prediction error processing is physiologically indexed via the FRN, P3 and LPP following outcome stimuli.


Assuntos
Desenvolvimento do Adolescente/fisiologia , Aprendizagem por Associação/fisiologia , Córtex Cerebral/fisiologia , Desenvolvimento Infantil/fisiologia , Potenciais Evocados/fisiologia , Adolescente , Criança , Eletroencefalografia , Feminino , Humanos , Masculino
3.
Neuropsychologia ; 122: 76-87, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30468778

RESUMO

Repeated exposure to a stimulus leads to reduced responses of stimulus-selective sensory neurons, an effect known as repetition suppression or stimulus-specific adaptation. Several influential models have been proposed to explain repetition suppression within hierarchically-organised sensory systems, with each specifying different mechanisms underlying repetition effects. We manipulated temporal expectations within a face repetition experiment to test a critical prediction of the predictive coding model of repetition suppression: that repetition effects will be larger following stimuli that appear at expected times compared to stimuli that appear at unexpected times. We recorded event-related potentials from 18 participants and mapped the spatiotemporal progression of repetition effects using mass univariate analyses. We then assessed whether the magnitudes of observed face image repetition effects were influenced by temporal expectations. In each trial participants saw an adapter face, followed by a 500 ms or 1000 ms interstimulus interval (ISI), and then a test face, which was the same or a different face identity to the adapter. Participants' expectations for whether the test face would appear after a 500 ms ISI were cued by the sex of the adapter face. Our analyses revealed multiple repetition effects with distinct scalp topographies, extending until at least 800 ms from stimulus onset. An early (158-203 ms) repetition effect was larger for stimuli following surprising, rather than expected, 500 ms ISI durations, contrary to the model predictions of the predictive coding model of repetition suppression. During this time window temporal expectation effects were larger for alternating, compared to repeated, test stimuli. Statistically significant temporal expectation by stimulus repetition interactions were not found for later (230-609 ms) time windows. Our results provide further evidence that repetition suppression can reduce neural effects of expectation and surprise, indicating that there are multiple interactive mechanisms supporting sensory predictions within the visual hierarchy.


Assuntos
Adaptação Fisiológica/fisiologia , Adaptação Psicológica/fisiologia , Antecipação Psicológica/fisiologia , Encéfalo/fisiologia , Reconhecimento Facial/fisiologia , Percepção do Tempo/fisiologia , Adolescente , Adulto , Potenciais Evocados , Feminino , Humanos , Masculino , Análise Espaço-Temporal , Adulto Jovem
4.
Sci Rep ; 8(1): 12661, 2018 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-30139950

RESUMO

Although the perception of faces depends on low-level neuronal processes, it is also affected by high-level social processes. Faces from a social in-group, such as people of a similar age, receive more in-depth processing and are processed holistically. To explore whether own-age biases affect subconscious face perception, we presented participants with the young/old lady ambiguous figure. Mechanical Turk was used to sample participants of varying ages from the USA. Results demonstrated that younger and older participants estimated the age of the image as younger and older, respectively. This own-age effect ties in with socio-cultural practices, which are less inclusive towards the elderly. Participants were not aware the study was related to ageing and the stimulus was shown briefly. The results therefore demonstrate that high-level social group processes have a subconscious effect on the early stages of face processing. A neural feedback model is used to explain this interaction.


Assuntos
Viés , Reconhecimento Visual de Modelos/fisiologia , Adulto , Fatores Etários , Conscientização , Reconhecimento Facial/fisiologia , Feminino , Humanos , Pessoa de Meia-Idade , Reconhecimento Psicológico
5.
Body Image ; 25: 133-138, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29567619

RESUMO

Thinspiration and fitspiration represent contemporary online trends designed to inspire viewers towards the thin ideal or towards health and fitness respectively. The aim of the present study was to compare thinspiration and fitspiration communities on Twitter. A total of 3289 English-language tweets with hashtags related to thinspiration (n = 1181) and fitspiration (n = 2578) were collected over a two-week period. Network analysis showed minimal overlap between the communities on Twitter, with the thinspiration community more closely-connected and having greater information flow than the fitspiration community. Frequency counts and sentiment analysis showed that although the tweets from both types of accounts focused on appearance and weight loss, fitspiration tweets were significantly more positive in sentiment. It was concluded that the thinspiration tweeters, unlike the fitspiration tweeters, represent a genuine on-line community on Twitter. Such a community of support may have negative consequences for collective body image and disordered eating identity.


Assuntos
Imagem Corporal/psicologia , Transtornos da Alimentação e da Ingestão de Alimentos/psicologia , Mídias Sociais , Apoio Social , Redução de Peso , Humanos , Rede Social
6.
Atten Percept Psychophys ; 80(1): 54-68, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28864874

RESUMO

Research suggests that the human brain codes manipulable objects as possibilities for action, or affordances, particularly objects close to the body. Near-body space is not only a zone for body-environment interaction but also is socially relevant, as we are driven to preserve our near-body, personal space from others. The current, novel study investigated how close proximity of a stranger modulates visuomotor processing of object affordances in shared, social space. Participants performed a behavioural object recognition task both alone and with a human confederate. All object images were in participants' reachable space but appeared relatively closer to the participant or the confederate. Results revealed when participants were alone, objects in both locations produced an affordance congruency effect but when the confederate was present, only objects nearer the participant elicited the effect. Findings suggest space is divided between strangers to preserve independent near-body space boundaries, and in turn this process influences motor coding for stimuli within that social space. To demonstrate that this visuomotor modulation represents a social phenomenon, rather than a general, attentional effect, two subsequent experiments employed nonhuman joint conditions. Neither a small, Japanese, waving cat statue (Experiment 2) nor a metronome (Experiment 3) modulated the affordance effect as in Experiment 1. These findings suggest a truly social explanation of the key interaction from Experiment 1. This study represents an important step toward understanding object affordance processing in real-world, social contexts and has implications broadly across fields of social action and cognition, and body space representation.


Assuntos
Imagem Corporal/psicologia , Espaço Pessoal , Comportamento Social , Percepção Visual/fisiologia , Adulto , Animais , Gatos , Feminino , Humanos , Masculino , Desempenho Psicomotor , Adulto Jovem
7.
Laterality ; 23(4): 391-408, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28803507

RESUMO

The assessment of active language lateralization in infants and toddlers is challenging. It requires an imaging tool that is unintimidating, quick to setup, and robust to movement, in addition to an engaging and cognitively simple language processing task. Functional Transcranial Doppler Ultrasound (fTCD) offers a suitable technique and here we report on a suitable method to elicit active language production in young children. The 34-second "What Box" trial presents an animated face "searching" for an object. The face "finds" a box that opens to reveal a to-be-labelled object. In a sample of 95 children (1 to 5 years of age), 81% completed the task-32% with ≥10 trials. The task was validated (ρ = 0.4) against the gold standard Word Generation task in a group of older adults (n = 65, 60-85 years of age), though was less likely to categorize lateralization as left or right, indicative of greater measurement variability. Existing methods for active language production have been used with 2-year-old children while passive listening has been conducted with sleeping 6-month-olds. This is the first active method to be successfully employed with infants through to pre-schoolers, forming a useful tool for populations in which complex instructions are problematic.


Assuntos
Encéfalo/fisiologia , Linguagem Infantil , Lateralidade Funcional , Testes de Linguagem , Idoso , Idoso de 80 Anos ou mais , Velocidade do Fluxo Sanguíneo , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Circulação Cerebrovascular , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/diagnóstico por imagem , Artéria Cerebral Média/fisiologia , Fala/fisiologia , Ultrassonografia Doppler Transcraniana
8.
Neuroimage ; 169: 94-105, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29247805

RESUMO

Repeated stimulus presentation leads to reductions in responses of cortical neurons, known as repetition suppression or stimulus-specific adaptation. Circuit-based models of repetition suppression provide a framework for investigating patterns of repetition effects that propagate through cortical hierarchies. To further develop such models it is critical to determine whether (and if so, when) repetition effects are modulated by factors such as expectation and attention. We investigated whether repetition effects are influenced by perceptual expectations, and whether the time courses of each effect are similar or distinct, by presenting pairs of repeated and alternating face images and orthogonally manipulating expectations regarding the likelihood of stimulus repetition. Event-related potentials (ERPs) were recorded from n = 39 healthy adults, to map the spatiotemporal progression of stimulus repetition and stimulus expectation effects, and interactions between these, using mass univariate analyses. We also tested for another expectation effect that may contribute to repetition effects in many previous experiments: that repeated stimulus identities are predictable after seeing the first stimulus in a trial, but unrepeated stimulus identities cannot be predicted. Separate blocks were presented with predictable and unpredictable alternating face identities. Multiple repetition and expectation effects were identified between 99 and 800ms from stimulus onset, which did not statistically interact at any point and exhibited distinct spatiotemporal patterns of effects. Repetition effects in blocks with predictable alternating faces were smaller than in unpredictable alternating face blocks between 117-179 ms and 506-652ms, and larger between 246 and 428ms. The distinct spatiotemporal patterns of repetition and expectation effects support separable mechanisms underlying these phenomena. However, previous studies of repetition effects, in which the repeated (but not unrepeated) stimulus was predictable, are likely to have conflated repetition and stimulus predictability effects.


Assuntos
Adaptação Fisiológica/fisiologia , Antecipação Psicológica/fisiologia , Córtex Cerebral/fisiologia , Eletroencefalografia/métodos , Potenciais Evocados/fisiologia , Reconhecimento Facial/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Fatores de Tempo , Adulto Jovem
9.
Appl Neuropsychol Adult ; 25(5): 473-485, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-28594578

RESUMO

Cognitive reserve beneficially affects cognitive performance, even into advanced age. However, the benefits afforded by high cognitive reserve may not extend to all cognitive domains. This study investigated whether cognitive reserve differentially affects performance on cognitive tasks, in 521 cognitively healthy individuals aged 60 to 98 years (Mage = 68, SD = 6.22, 287 female); years of education was used to index cognitive reserve. Cognitive performance variables assessed attention, executive functions, verbal memory, motor performance, orientation, perception of emotion, processing speed, and working memory. Bootstrapped regression analyses revealed that cognitive reserve was associated with attention, executive functions, verbal and working memory, and orientation; and not significantly related to emotion perception, processing speed, or motor performance. Cognitive reserve appears to differentially affect individual cognitive domains, which extends current theory that purports benefits for all domains. This finding highlights the possibility of using tests not (or minimally) associated with cognitive reserve, to screen for cognitive impairment and dementia in late life; these tests will likely best track brain health, free of compensatory neural mechanisms.


Assuntos
Cognição/fisiologia , Reserva Cognitiva/fisiologia , Idoso , Idoso de 80 Anos ou mais , Atenção , Feminino , Humanos , Inibição Psicológica , Masculino , Aprendizagem em Labirinto , Memória/fisiologia , Pessoa de Meia-Idade , Testes Neuropsicológicos , Estimulação Luminosa , Desempenho Psicomotor , Estatística como Assunto , Aprendizagem Verbal
10.
PLoS One ; 12(10): e0186171, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29020027

RESUMO

When traversing through an aperture, such as a doorway, people characteristically deviate towards the right. This rightward deviation can be explained by a rightward attentional bias which leads to rightward bisections in far space. It is also possible, however, that left or right driving practices affect the deviation. To explore this possibility, Australian (left-side drivers) and Swiss (right-side drivers) participants (n = 36 & 34) walked through the middle of an aperture. To control for the sway of the body, participants started with either their left or right foot. Sway had a significant effect on participants' position in the doorway and the amount of sway was greater for Australians-perhaps due to national differences in gait. There was a significant rightward deviation for the Swiss, but not for the Australians. It is suggested that driving practices have a small additive effect on rightward attentional biases whereby the bias is increased for people who drive on the right and reduced in people who drive on the left.


Assuntos
Condução de Veículo , Caminhada/fisiologia , Análise de Variância , Austrália , Feminino , Humanos , Masculino , Suíça , Adulto Jovem
11.
Q J Exp Psychol (Hove) ; 70(3): 444-460, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26880348

RESUMO

Perceptual attention in healthy participants is characterized by two biases, one operating in the horizontal plane, which draws attention leftward, and the other operating in the vertical plane, which draws attention upward. Given that these biases are reliably found in the same individual, and appear similar at a surface level, a number of researchers have investigated the relationship between horizontal and vertical attentional biases. To date, these investigations have failed to find an association, and this may be due to the fact that one-dimensional vertical and horizontal stimuli were presented separately rather than being measured from a single, two-dimensional stimulus. Across three experiments, two dimensional stimuli were presented, and participants marked the centre of the stimuli. In addition, the shapes of the stimuli were manipulated to determine whether this produced the same modulation of the two biases. Across 13 stimuli and three experiments there were no correlations between the vertical and horizontal biases. In addition, manipulations of stimulus shape, which affected biases in one dimension, did not affect biases in the other dimension. There were, however, consistent correlations between the degree of bias within each dimension across the different stimuli. This study has produced converging evidence that horizontal and vertical biases in spatial judgments rely on separate cognitive mechanisms. To account for these results we discuss a model whereby horizontal asymmetries rely more on space-based mechanisms whereas vertical asymmetries rely more on object-based mechanisms.


Assuntos
Atenção/fisiologia , Viés , Cognição/fisiologia , Orientação , Percepção Espacial/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa , Tempo de Reação/fisiologia , Estatística como Assunto , Adulto Jovem
12.
Brain Cogn ; 111: 134-143, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27923149

RESUMO

Pseudoneglect is the tendency for the general population to over-attend to the left. While pseudoneglect is classically demonstrated using line bisection, it also occurs for visual search. The current study explored the influence of eye movements and functional cerebral asymmetry on asymmetries for visual search. In Experiment 1, 24 participants carried out a conjunction search for a target within a rectangular array. A leftward advantage for detecting targets was observed when the eyes were free to move, but not when they were restricted by short exposure durations. In Experiment 2, the effect of functional cerebral asymmetry was explored by comparing 20 right-handers and 19 left-handers. Results showed a stronger leftward bias for the right-handers, consistent with a mechanism related to cerebral asymmetry. In Experiment 3, an eye-tracker directly controlled eye movements in 25 participants. A leftward advantage emerged when the eyes were still, but not when they were free to move. Experiments 1 and 3 produced contradictory results in relation to eye movements, which may be related to task-related demands. On balance, the data suggest that asymmetries in visual search can occur in the absence of eye movements and that they are related to right hemisphere specialisation for spatial attention.


Assuntos
Atenção/fisiologia , Movimentos Oculares/fisiologia , Lateralidade Funcional/fisiologia , Percepção Espacial/fisiologia , Percepção Visual/fisiologia , Adolescente , Adulto , Medições dos Movimentos Oculares , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
13.
J Exp Psychol Hum Percept Perform ; 42(10): 1643-53, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27668425

RESUMO

In object perception studies, a response advantage arises when the handle of an object is congruent with the responding hand. This handle effect is thought to reflect increased motor activation of the hand most suited to grasp the object, consistent with affordance theories of object representation. An alternative explanation has been proposed, however, which suggests that the handle effect is related to a simple spatial compatibility effect (the Simon effect). In 3 experiments, we determined whether the handle effect would emerge in the absence of explicit spatial compatibility between handle and response. Stimulus and response location was varied vertically and participants made horizontally orthogonal, bimanual responses to objects' kitchen/garage category, color (as in a traditional Simon effect) or upright/inverted orientation. Categorization and inversion tasks, which relied on object knowledge, elicited a handle effect and a vertical Simon effect regarding stimulus and response locations. When participants judged object color, as per standard Simon effect paradigms, the handle effect disappeared but the Simon effect strengthened. These data demonstrate a dissociation between affordance and spatial compatibility effects and prove that affordance plays an important role in the handle effect. Models that incorporate both affordance and spatial compatibility mechanisms are discussed. (PsycINFO Database Record


Assuntos
Atividade Motora/fisiologia , Desempenho Psicomotor/fisiologia , Percepção Espacial/fisiologia , Percepção Visual/fisiologia , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
14.
Exp Brain Res ; 234(11): 3381-3387, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27461110

RESUMO

When dividing attention between the left and right sides of physical space, most individuals pay slightly more attention to the left side. This phenomenon, known as pseudoneglect, may also occur for the left and right sides of mental representations of stimuli. Representational pseudoneglect has been shown for the recall of real-world scenes and for simple, briefly presented stimuli. The current study sought to investigate the effect of exposure duration and complexity using adaptations of the Rey-Osterrieth figures. Undergraduates (n = 97) were shown a stimulus for 20 s and asked to remember it. Participants were then shown a probe and indicated whether it was the same or different. Results showed that, irrespective of whether an element was added or subtracted, changes on the left side of the remembered image were better detected. These results are consistent with representational pseudoneglect and demonstrate that this effect occurs for complex stimuli when presented for an extended period of time. Representation neglect is therefore unlikely to be the result of an initial saccade to the left-but could be related to the formation or recall of the representation.


Assuntos
Atenção , Lateralidade Funcional/fisiologia , Testes Neuropsicológicos , Detecção de Sinal Psicológico/fisiologia , Percepção Visual/fisiologia , Adolescente , Adulto , Análise de Variância , Feminino , Humanos , Imaginação , Masculino , Pessoa de Meia-Idade , Transtornos da Percepção/fisiopatologia , Transtornos da Percepção/psicologia , Adulto Jovem
15.
Atten Percept Psychophys ; 78(5): 1351-62, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27150618

RESUMO

Clinical neglect patients overattend to stimuli on their right, whereas the general population overattend to the left (pseudoneglect). Both phenomena are affected by viewing distance, whereby the attentional biases are attenuated as the stimulus moves from near to far space. Both are also affected by stimulus length and reduce in strength, or even reverse (the crossover effect), as length decreases. To gain an insight into the cognitive/neural mechanisms that underlie the effects of viewing distance and stimulus length, in two experiments we examined the interaction between the variables. In Experiment 1 we asked university students (n = 20) to perform a horizontal landmark bisection task with lines presented at varying lengths (1.2°, 6.3°, and 18.4° of viewing angle) and distances (450 and 1,350 mm). A crossover effect and pseudoneglect were observed for the short and the long lines, respectively. An effect of viewing distance was only observed for long lines. Experiment 2 was the same, except that the lines were rotated to form vertical lines. No crossover effect was observed for the short lines, but an upward bias was observed for the long lines. Once again, an effect of viewing distance was only apparent for the long lines. These results demonstrate that the crossover effect is not a general property of short lines and is specific to the horizontal dimension. Models of crossover therefore need to incorporate processes related to left-right asymmetries. The results also demonstrate that viewing distance only affects long lines, and that this happens irrespective of orientation. A model of viewing distance is discussed that incorporates a right hemisphere mechanism specialized for an interaction between the ventral and dorsal streams.


Assuntos
Viés de Atenção , Estimulação Luminosa/métodos , Percepção Espacial , Processamento Espacial , Adulto , Feminino , Lateralidade Funcional , Humanos , Masculino , Orientação , Adulto Jovem
16.
Artigo em Inglês | MEDLINE | ID: mdl-25989367

RESUMO

Social and general cognitive abilities decline in late life. Those with high cognitive reserve display better general cognitive performance in old age; however, it is unknown whether this is also the case for social cognition. A total of 115 healthy older adults, aged 60-85 years (m = 44, f = 71) were assessed using The Awareness of Social Inference Test (TASIT-R; social cognition), the Lifetime of Experiences Questionnaire (LEQ; cognitive reserve), and the Wechsler Abbreviated Scale of Intelligence (WASI-II; general cognitive ability). The LEQ did not predict performance on any TASIT-R subtest: Emotion Evaluation Test (ß = -.097, p = .325), Social Inference - Minimal (ß = -.004, p = .972), or Social Inference - Enriched (ß = -.016, p = .878). Sensitivity analyses using two alternative cognitive reserve measures, years of education and the National Adult Reading Test, supported these effects. Cognitive reserve was strongly related to WASI-II performance. Unlike general cognitive ability, social cognition appears unaffected by cognitive reserve. Findings contribute to the emerging understanding that cognitive reserve differentially affects individual cognitive domains, which has implications for the theoretical understanding of cognitive reserve and its brain correlates. Cognitive measures unbiased by cognitive reserve may serve as best indicators of brain health, free of compensatory mechanisms.


Assuntos
Envelhecimento/psicologia , Reserva Cognitiva , Percepção Social , Idoso , Idoso de 80 Anos ou mais , Escolaridade , Feminino , Humanos , Testes de Linguagem , Masculino , Pessoa de Meia-Idade , Testes Psicológicos , Leitura , Fatores Sexuais , Escalas de Wechsler
17.
Psychol Aging ; 30(3): 613-23, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26121286

RESUMO

The brain is dependent on the cerebrovascular system, particularly microvasculature, for a consistent blood supply; however, age-related changes in this system affect neuronal and therefore cognitive function. Structural vascular markers and vascular disease appear to preferentially affect fluid cognitive abilities, sparing crystallized abilities. We sought to investigate the relationships between cerebrovascular function and cognitive domains. Fifty individuals between 60 and 75 years of age (31 women, 19 men) underwent cognitive testing: Wechsler Vocabulary and Matrix Reasoning subtests (crystallized and fluid ability measures, respectively Wechsler, 2011), and the Addenbrooke's Cognitive Examination-Revised (ACE-R; general cognitive ability; Mioshi, Dawson, Mitchell, Arnold, & Hodges, 2006). Transcranial Doppler (TCD) measures were also collected at rest and during a cognitive word-generation task, from which a lateralization index was calculated. Lower pulsatility index at rest, and greater left lateralization during the TCD cognitive task were associated with better performance on the Matrix Reasoning but not the Vocabulary test; these effects were independent from each other and from any vascular comorbidity burden. These functional findings confirm previous structural studies, which revealed that fluid abilities are more vulnerable to cerebrovascular dysfunction than crystallized abilities, and identify two (likely related) mechanisms: degraded cerebrovascular integrity (indexed by pulsatility index) and a delateralization of function. Cerebrovascular dysfunction is a key contributor to cognitive aging that deserves further attention, particularly in relation to early diagnostic markers of impairment and monitoring of vascular (e.g., physical activity) interventions.


Assuntos
Envelhecimento/fisiologia , Envelhecimento/psicologia , Encéfalo/irrigação sanguínea , Encéfalo/fisiologia , Cognição/fisiologia , Ultrassonografia Doppler Transcraniana , Idoso , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/fisiopatologia , Transtornos Cognitivos/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Descanso/fisiologia , Vocabulário
18.
BMC Neurol ; 15: 64, 2015 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-25907452

RESUMO

BACKGROUND: A visual field defect (VFD) is a common consequence of stroke with a detrimental effect upon the survivors' functional ability and quality of life. The identification of effective treatments for VFD is a key priority relating to life post-stroke. Understanding the natural evolution of scanning compensation over time may have important ramifications for the development of efficacious therapies. The study aims to unravel the natural history of visual scanning behaviour in patients with VFD. The assessment of scanning patterns in the acute to chronic stages of stroke will reveal who does and does not learn to compensate for vision loss. METHODS/DESIGN: Eye-tracking glasses are used to delineate eye movements in a cohort of 100 stroke patients immediately after stroke, and additionally at 6 and 12 months post-stroke. The longitudinal study will assess eye movements in static (sitting) and dynamic (walking) conditions. The primary outcome constitutes the change of lateral eye movements from the acute to chronic stages of stroke. Secondary outcomes include changes of lateral eye movements over time as a function of subgroup characteristics, such as side of VFD, stroke location, stroke severity and cognitive functioning. DISCUSSION: The longitudinal comparison of patients who do and do not learn compensatory scanning techniques may reveal important prognostic markers of natural recovery. Importantly, it may also help to determine the most effective treatment window for visual rehabilitation.


Assuntos
Movimentos Oculares/fisiologia , Hemianopsia/fisiopatologia , Projetos de Pesquisa , Acidente Vascular Cerebral/fisiopatologia , Campos Visuais/fisiologia , Adulto , Hemianopsia/etiologia , Hemianopsia/reabilitação , Humanos , Estudos Observacionais como Assunto , Avaliação de Resultados em Cuidados de Saúde , Acidente Vascular Cerebral/complicações
19.
Int J Psychophysiol ; 96(1): 8-15, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25746937

RESUMO

Neural adaptation paradigms have been used in the electrophysiological and neuroimaging literature to characterise neural populations underlying face and object perception. It was recently reported by Nemrodov and Itier (2012) that adaptation of the N170 event-related potential (ERP) component is not stimulus category-specific over rapid adapting stimulus durations (S1 durations) and interstimulus intervals (ISIs). We therefore tested the category-specificity of adaptation over a range of S1 durations and ISIs. Faces and chairs were presented at S1 (for 200, 500 or 1000 ms) and S2 (for 200 ms), over a variable ISI (200 or 500 ms). Mean amplitudes of the P1, N170 and P2 visual ERP components were measured following S1 and S2 stimuli. Faces at S1 led to the smallest (i.e., most adapted) N170 amplitudes to both faces and chairs at S2, more than chairs at S1. N170s at S2 were smallest after a 500ms S1 duration; but N170 amplitude did not vary over ISI. Effects were also seen for the two surrounding positive components, the P1 and P2. Presenting faces at S1 led to enhanced P1 amplitudes evoked by S2 chair stimuli. The P2 showed the smallest amplitudes following the shorter 200 ms ISI. These results indicate that adaptation of the N170 is not actually category-specific but instead dependent on the S1 category (regardless of S2 category), and may also be influenced by earlier effects at the P1 (i.e., not specific to the N170). This challenges the assumption that N170 category adaptation indexes effects on distinct neural populations that differ between faces and non-face objects.


Assuntos
Adaptação Fisiológica/fisiologia , Mapeamento Encefálico , Potenciais Evocados/fisiologia , Adulto , Análise de Variância , Eletroencefalografia , Feminino , Humanos , Masculino , Reconhecimento Visual de Modelos/fisiologia , Estimulação Luminosa , Tempo de Reação , Fatores de Tempo , Adulto Jovem
20.
Clin Neurophysiol ; 126(6): 1141-1158, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25306210

RESUMO

OBJECTIVE: To systematically evaluate evidence for configural and affective face processing abnormalities as measured by the N170 and Vertex Positive Potential (VPP) event-related potential components, and analogous M170 magnetoencephalography (MEG) component, in neurological and psychiatric disorders. METHODS: 1251 unique articles were identified using PsychINFO and PubMed databases. Sixty-seven studies were selected for review, which employed various tasks to measure the N170, M170 or VPP; the 13 neurological/psychiatric conditions were Attention-Deficit Hyperactivity Disorder (ADHD), Alcohol Dependence, Alzheimer's Disease, Autism Spectrum Disorders (ASDs), Bipolar Disorder, Bulimia Nervosa, Fibromyalgia, Huntington's Disease, Major Depressive Disorder, Parkinson's Disease, Prosopagnosia, Schizophrenia and Social Phobia. RESULTS: Smaller N170 and VPP amplitudes to faces compared to healthy controls were consistently reported in Schizophrenia but not in ASDs. In Schizophrenia N170 and VPP measures were not correlated with clinical symptoms. Findings from other disorders were highly inconsistent; however, reported group differences were almost always smaller amplitudes or slower latencies to emotional faces in disordered groups regardless of diagnosis. CONCLUSIONS: Results suggest that N170/VPP abnormalities index non-specific facial affect processing dysfunction in these neurological and psychiatric conditions, reflecting social impairments being broadly characteristic of these groups. SIGNIFICANCE: The N170 and analogous components hold promise as diagnostic and treatment monitoring biomarkers for social dysfunction.


Assuntos
Expressão Facial , Transtornos Mentais/fisiopatologia , Doenças do Sistema Nervoso/fisiopatologia , Percepção Visual , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/fisiopatologia , Doença de Alzheimer/psicologia , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Transtorno Bipolar/diagnóstico , Transtorno Bipolar/fisiopatologia , Transtorno Bipolar/psicologia , Eletroencefalografia/métodos , Potenciais Evocados/fisiologia , Humanos , Magnetoencefalografia/métodos , Transtornos Mentais/diagnóstico , Transtornos Mentais/psicologia , Doenças do Sistema Nervoso/diagnóstico , Doenças do Sistema Nervoso/psicologia , Esquizofrenia/fisiopatologia , Percepção Visual/fisiologia
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