Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Behav Res Methods ; 53(4): 1502-1514, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33245514

RESUMO

The portability of low-cost eye trackers makes them attractive for research outside of the laboratory. Such research may require independent eye-tracker use. The present work compared the data quality of the Gazepoint GP3 when used independently by research participants with expert eye-tracking users. Twenty participants completed a training and a testing session 1 week apart. At training visits, participants were taught how to set up and use eye-tracking hardware and software and how to complete two tasks: a calibration task to measure accuracy and precision, as well as a visual search task to assess target fixations. At the testing session, participants set up the Gazepoint eye tracker and completed the two tasks without assistance. Participant accuracy and precision and visual search performance were compared to values obtained from two expert eye-tracking users. Additionally, the eye-tracker sampling rate, which is sensitive to factors such as head motion, was assessed in both participants and the expert users. Participant accuracy and precision closely approximated expert user values. Participant target fixations were detected with a 92.5% sensitivity and 76.8% specificity, closely mirroring expert user sensitivity and specificity. The sampling rate distribution was also similar between the participants and expert user (the means of those distributions were 16.99 ± 3.0 ms and 16.43 ± 2.3 ms, respectively). When used independently, data quality obtained from a low-cost, portable eye-tracking setup closely approximated values obtained from an expert user and was adequate enough to be a feasible option for some studies that require independent use by study participants.


Assuntos
Confiabilidade dos Dados , Tecnologia de Rastreamento Ocular , Calibragem , Medições dos Movimentos Oculares , Humanos
2.
Public Health Nutr ; 23(15): 2793-2803, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32618235

RESUMO

OBJECTIVE: To evaluate the prevalence of food and beverage marketing on Twitch.tv (Twitch), a social media platform where individuals broadcast live audiovisual material to millions of daily users. DESIGN: Observational analysis of the prevalence of 238 food and beverage brands in five distinct categories (processed snacks; food delivery services and restaurants; candies, energy drinks/coffees/teas; and sodas and other sugar-sweetened beverages) over the course of 18 months. SETTING: Twitch streamer profiles and stream titles between January 2018 and July 2019. Twitch chat room messages during July 2019. PARTICIPANTS: None. RESULTS: There was a significant increase in brand exposure on Twitch both in stream titles (sodas and candies, P < 0·05) and on streamer profiles (sodas, restaurants/food delivery services, candies, and energy drinks/coffees/teas, P < 0·05) over the 18-month study period. Energy drinks, coffees and teas had the most exposure with 1·08 billion exposure hours from profiles and 83 million exposure hours from titles. Restaurants/food delivery services and sugar-sweetened beverages were the most frequently mentioned products in chat rooms with 1·24 million messages and 1·10 million messages, respectively. CONCLUSIONS: This study is the first to demonstrate the extent by which food and beverage brands garner millions of hours of exposure on Twitch. Future studies should evaluate the impact that this level of exposure to nutrient-poor, energy-dense products may have on behavioural and health outcomes.


Assuntos
Doces , Bebidas Gaseificadas , Bebidas Energéticas , Marketing , Lanches , Mídias Sociais , Humanos , Prevalência , Restaurantes
3.
Appetite ; 148: 104610, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31958480

RESUMO

OBJECTIVE: Attentional bias to food cues may be a risk factor for childhood obesity, yet there are few paradigms to measure such biases in young children. Therefore, the present work introduces an eye-tracking visual search task to measure attentional bias in young children. METHODS: Fifty-one 3-6-year-olds played a game to find a target cartoon character among food (experimental condition) or toy (control condition) distractors. Children completed the experimental and toy conditions on two separate visits in randomized order. Behavioral (response latencies) and eye-tracking measures (time to first fixation, initial gaze duration duration, cumulative gaze duration ) of attention to food and toy cues were computed. Regressions were used to test for attentional bias to food versus toy cues, and whether attentional bias to food cues was related to current BMI z-score. RESULTS: Children spent more cumulative time looking at food versus toy distractors and took longer to locate the target when searching through food versus toy distractors. The faster children fixated on their first food versus toy distractor was associated with higher BMI z-scores. CONCLUSIONS: Using a game-based paradigm employing eye-tracking, we found a behavioral attentional bias to food vs. toy distractors in young children. Further, attentional bias to food cues was associated with current BMI z-score.


Assuntos
Viés de Atenção , Índice de Massa Corporal , Sinais (Psicologia) , Alimentos , Obesidade Infantil/psicologia , Atenção , Viés , Criança , Pré-Escolar , Movimentos Oculares , Tecnologia de Rastreamento Ocular , Feminino , Humanos , Masculino , Obesidade Infantil/etiologia , Estimulação Luminosa , Tempo de Reação
4.
Public Health Nutr ; 19(12): 2128-34, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27022823

RESUMO

OBJECTIVE: Food packaging often pictures supplementary extras, such as toppings or frosting, that are not listed on the nutritional labelling. The present study aimed to assess if these extras might exaggerate how many calories† are pictured and if they lead consumers to overserve. DESIGN: Four studies were conducted in the context of fifty-one different cake mixes. For these cake mixes, Study 1 compared the calories stated on the nutrition label with the calories of the cake (and frosting) pictured on the box. In Studies 2, 3 and 4, undergraduates (Studies 2 and 3) or food-service professionals (Study 4) were given one of these typical cake mix boxes, with some being told that cake frosting was not included on the nutritional labelling whereas others were provided with no additional information. They were then asked to indicate what they believed to be a reasonable serving size of cake. Settings Laboratory setting. SUBJECTS: Undergraduate students and food-service professionals. RESULTS: Study 1 showed that the average calories of cake and frosting pictured on the package of fifty-one different cake mixes exceed the calories on the nutritional label by 134 %. Studies 2 and 3 showed that informing consumers that the nutritional information does not include frosting reduces how much people serve. Study 4 showed that even food-service professionals overserve if not told that frosting is not included on the nutritional labelling. CONCLUSIONS: To be less misleading, packaging should either not depict extras in its pictures or it should more boldly and clearly state that extras are not included in calorie counts.


Assuntos
Rotulagem de Alimentos , Tamanho da Porção de Referência , Viés , Ingestão de Energia , Humanos
5.
Eat Behav ; 53: 101874, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38636439

RESUMO

OBJECTIVE: To assess whether attentional bias to food cues and appetitive traits are independently and interactively associated with adiposity in adolescents. METHOD: Eighty-five adolescents, 14-17-years had their attentional bias to food images measured in a sated state by computing eye tracking measures of attention (first fixation duration, cumulative fixation duration) to food and control distractor images that bordered a computer game. Parents reported adolescent appetitive traits including the food approach domains of enjoyment of food, food responsiveness, emotional overeating, and the food avoidance domains of satiety responsiveness and emotional overeating through the Children's Eating Behavior Questionnaire. RESULTS: First fixation bias to food cues was positively associated with enjoyment of food, and negatively associated with satiety responsiveness. In a series of regression models adjusted for relevant covariates, first fixation bias to food cues (ß = 0.83, p = 0.007), higher food responsiveness (ß = 0.74, p < 0.001), higher emotional overeating (ß = 0.51, p = 0.002), and a composite appetite score (ß = 1.42, p < 0.001) were each significantly associated with greater BMI z-scores. In models assessing the interactive effects between attentional bias and appetitive traits, higher first fixation bias to food cues interacted synergistically with food responsiveness and emotional overeating in relation to BMI z-score. A synergistic interaction between first fixation bias to food cues and the composite appetite score in relation to BMI z-score was also observed. CONCLUSION: Individuals with high attentional bias to food cues and obesogenic appetitive traits may be particularly susceptible to weight gain.


Assuntos
Adiposidade , Viés de Atenção , Sinais (Psicologia) , Humanos , Adolescente , Feminino , Masculino , Viés de Atenção/fisiologia , Adiposidade/fisiologia , Apetite/fisiologia , Comportamento Alimentar/psicologia , Alimentos , Hiperfagia/psicologia , Pais/psicologia , Inquéritos e Questionários , Índice de Massa Corporal , Emoções/fisiologia
7.
Front Psychol ; 13: 992450, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36506992

RESUMO

Purpose: To measure attention to food cues following a multitask or a sustained attention single task, and further, to examine the associations with current weight status and excess consumption. Methods: Ninety-six 13-to 17-year-olds were fed a standardized meal and then had their attention to food cues measured following completion of a single sustained attention task, media multitask, or a passive viewing control task. Participants then completed an eating in the absence of hunger paradigm to measure their excess consumption. Adolescents completed each condition on separate visits in randomized order. Attention to food cues was measured by computing eye-tracking measures of attention, first fixation duration, and cumulative fixation duration to distractor images while participants played the video game, Tetris. Participants also had their height and weight measured. Results: Although not statistically significant, attention to food cues was greatest following a media multitask and weakest following a task that engaged sustained attention when compared to a control. First fixation duration was positively and statistically significantly associated with BMI-Z when measured following a multitask. Cumulative fixation duration was not associated with BMI-Z. There were no associations between BMI-Z and attention to food cues after the attention or control task, nor any association between attention to food cues and eating in the absence of hunger. Conclusion: Among adolescents, we found that current adiposity was related to attention to food cues following a multitask. Multitasking may perturb the cognitive system to increase attention to food cues.

8.
Proc Natl Acad Sci U S A ; 105(19): 6998-7003, 2008 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-18458324

RESUMO

Significant morbidity and mortality among patients with diabetes mellitus result largely from a greatly increased incidence of microvascular complications. Proliferative diabetic retinopathy (PDR) and end stage renal disease (ESRD) are two of the most common and severe microvascular complications of diabetes. A high concordance exists in the development of PDR and ESRD in diabetic patients, as well as strong familial aggregation of these complications, suggesting a common underlying genetic mechanism. However, the precise gene(s) and genetic variant(s) involved remain largely unknown. Erythropoietin (EPO) is a potent angiogenic factor observed in the diabetic human and mouse eye. By a combination of case-control association and functional studies, we demonstrate that the T allele of SNP rs1617640 in the promoter of the EPO gene is significantly associated with PDR and ESRD in three European-American cohorts [Utah: P = 1.91 x 10(-3); Genetics of Kidneys in Diabetes (GoKinD) Study: P = 2.66 x 10(-8); and Boston: P = 2.1 x 10(-2)]. The EPO concentration in human vitreous body was 7.5-fold higher in normal subjects with the TT risk genotype than in those with the GG genotype. Computational analysis suggests that the risk allele (T) of rs1617640 creates a matrix match with the EVI1/MEL1 or AP1 binding site, accounting for an observed 25-fold enhancement of luciferase reporter expression as compared with the G allele. These results suggest that rs1617640 in the EPO promoter is significantly associated with PDR and ESRD. This study identifies a disease risk-associated gene and potential pathway mediating severe diabetic microvascular complications.


Assuntos
Nefropatias Diabéticas/complicações , Nefropatias Diabéticas/genética , Retinopatia Diabética/complicações , Retinopatia Diabética/genética , Eritropoetina/genética , Polimorfismo de Nucleotídeo Único/genética , Regiões Promotoras Genéticas/genética , Alelos , Animais , Linhagem Celular , Estudos de Coortes , Eritropoetina/metabolismo , Regulação da Expressão Gênica , Genes Reporter , Predisposição Genética para Doença , Haplótipos , Humanos , Rim/metabolismo , Rim/patologia , Luciferases/metabolismo , Camundongos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Retina/metabolismo , Retina/patologia
9.
Front Psychol ; 12: 804931, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35197886

RESUMO

OBJECTIVE: To assess distracted attention and performance on a computer task following completion of a sustained attention and acute media multitasking task among adolescents with varying self-reported usual media multitasking. METHODS: Ninety-six 13- to 17-year-olds played the video game Tetris following completion of a Go/No-go paradigm to measure sustained attention in the presence of distractors, an acute media multitasking, or a passive viewing condition. Adolescents completed the conditions on separate visits in randomized order. Sustained attention was measured within the Go/No-go task by measuring errors of omission. Distracted attention while playing the Tetris task was measured by computing eye tracking measures of attention (first fixation duration, cumulative fixation duration) to irrelevant distractor images that bordered the Tetris game. Participants also self-reported their daily media multitasking. RESULTS: The Go/No-go task revealed important qualitative differences in sustained attention among low and high usual media multitaskers. There was a uniform improvement in sustained attention among low usual media multitaskers, demonstrated by a consistent linear decrease in omission errors (ß = -0.01; P < 0.05). Among high usual media multitaskers, there was initially a decrease in sustained attention (ß = -0.01; P = 0.05) followed by an increase (ß = 0.16; P < 0.001). Completing the Go/No-go task also statistically significantly reduced distractibility and increased performance while playing Tetris compared to the passive viewing condition, but only among those with low usual media multitasking (all Ps ≤ 0.05). There was a non-statistically significant trend that completing the acute media multitask increased subsequent distractibility and performance while playing Tetris among high media multitaskers. CONCLUSION: In this sample of adolescents, practicing a sustained attention task reduces distractibility and improves task performance among those who have low levels of usual media multitasking.

10.
J Am Med Dir Assoc ; 22(4): 865-872.e5, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-34248422

RESUMO

Objectives: The prevalence of obesity with sarcopenia is increasing in adults aged ≥65 years. This geriatric syndrome places individuals at risk for synergistic complications that leads to long-term functional decline. We ascertained the relationship between sarcopenic obesity and incident long-term impaired global cognitive function in a representative US population. Design: A longitudinal, secondary data set analysis using the National Health and Aging Trends Survey. Setting: Community-based older adults in the United States. Participants: Participants without baseline impaired cognitive function aged ≥65 years with grip strength and body mass index measures. Methods: Sarcopenia was defined using the Foundation for the National Institutes of Health Sarcopenia Project grip strength cut points (men <35.5 kg; women <20 kg), and obesity was defined using standard body mass index (BMI) categories. Impaired global cognition was identified as impairment in the Alzheimer's Disease-8 score or immediate/delayed recall, orientation, clock-draw test, date/person recall. Proportional hazard models ascertained the risk of impaired cognitive function over 8 years (referent = neither obesity or sarcopenia). Results: Of the 5822 participants (55.7% women), median age category was 75 to 80, and mean grip strength and BMI were 26.4 kg and 27.5 kg/m2, respectively. Baseline prevalence of sarcopenic obesity was 12.9%, with an observed subset of 21.2% participants having impaired cognitive function at follow-up. Compared with those without sarcopenia or obesity, the risk of impaired cognitive function was no different in obesity alone [hazard ratio (HR) 0.98; 95% confidence interval (CI) 0.82-1.16]), but was significantly higher in sarcopenia (HR 1.60; 95% CI 1.42-1.80) and sarcopenic obesity (HR 1.20; 95% CI 1.03-1.40). There was no significant interaction term between sarcopenia and obesity. Conclusions: Both sarcopenia and sarcopenic obesity are associated with an increased long-term risk of impaired cognitive function in older adults.


Assuntos
Sarcopenia , Idoso , Envelhecimento , Composição Corporal , Índice de Massa Corporal , Cognição , Estudos Transversais , Feminino , Humanos , Masculino , Obesidade/epidemiologia , Sarcopenia/epidemiologia
11.
J Am Geriatr Soc ; 69(5): 1257-1264, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33565618

RESUMO

BACKGROUND/OBJECTIVES: It is unknown whether older adults at high risk of falls but without cognitive impairment have higher rates of subsequent cognitive impairment. DESIGN: This was an analysis of cross-sectional and longitudinal data from National Health and Aging Trends Study (NHATS). SETTING: NHATS, secondary analysis of data from 2011 to 2019. PARTICIPANTS: Community dwelling adults aged 65 and older without cognitive impairment. MEASUREMENTS: Participants were classified at baseline in three categories of fall risk (low, moderate, severe) using a modified algorithm from the Center for Disease Control's STEADI (Stop Elderly Accidents, Deaths, and Injuries) and fall risk from data from the longitudinal NHATS. Impaired global cognition was defined as NHATS-derived impairment in either the Alzheimer's Disease-8 score, immediate/delayed recall, orientation, clock-drawing test, or date/person recall. The primary outcome was the first incident of cognitive impairment in an 8 year follow-up period. Cox-proportional hazard models ascertained time to onset of cognitive impairment (referent = low modified STEADI incidence). RESULTS: Of the 7,146 participants (57.8% female), the median age category was 75 to 80 years. Prevalence of baseline fall modified STEADI risk categories in participants was low (51.6%), medium (38.5%), and high (9.9%). In our fully adjusted model, the risk of developing cognitive impairment was hazard ratio (HR) 1.18 [95% CI = 1.08, 1.29] in the moderate risk category, and HR 1.74 [95% CI = 1.53, 1.98] in the high-risk category. CONCLUSION: Older, cognitively intact adults at high fall risk at baseline had nearly twice the risk of cognitive decline at 8 year follow-up.


Assuntos
Acidentes por Quedas/estatística & dados numéricos , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/etiologia , Vida Independente/psicologia , Vida Independente/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Avaliação Geriátrica , Humanos , Incidência , Estudos Longitudinais , Masculino , Testes Neuropsicológicos , Prevalência , Modelos de Riscos Proporcionais , Fatores de Risco
12.
Front Psychol ; 10: 2534, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31798499

RESUMO

Obesity rates among children have climbed dramatically in the past two decades, a time period in which children also experienced greater exposure to portable media devices and smartphones. In the present study, we provide evidence of a potential link between media multitasking - using and switching between unrelated forms of digital media - and risk for obesity, as indexed by body mass index (BMI). Specifically, we recruited 179 pre-adolescent children (aged 9-11 years, 88 females) to participate in a study in which we assessed their media multitasking (MMT) tendencies, as well as BMI. Controlling for the influence of a known genetic risk factor for obesity and other covariates, including physical activity, we found a positive association between the frequency of children's MMT behaviors and age- and sex-standardized BMI z-scores, b = 1.07, p = 0.011. These findings are consistent with other recent work showing similar patterns of covariation between MMT and risk for obesity in young adults. The present work can also inform future work in this realm, such as the design of longitudinal studies that prospectively measure children's MMT behaviors and body composition to begin to identify directionality in the association.

13.
Front Psychol ; 10: 2256, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31649589

RESUMO

OBJECTIVE: To assess the associations between dietary cognitive restraint, disinhibited eating, and how taste and health perceptions relate to food preference; and further, whether cognitive restraint and disinhibited eating are associated with food preference decision reaction time. METHODS: Five hundred and seventeen adults participated in the study. Dietary cognitive restraint and disinhibited eating were assessed using the shortened Three-Factor Eating Questionnaire (TFEQ-R18). Participants also completed a dietary decision-making task to examine their food-related decisions. Participants were presented with 50 food items and asked to rate them for health and for taste. Participants were then presented with a reference food item and comparison items one at a time and asked to indicate which of the two foods they would prefer to eat. RESULTS: Participants with higher levels of cognitive restraint were more sensitive to health perceptions whereas those with higher levels of disinhibited eating were more sensitive to taste perceptions when indicating food preference. Reaction time analysis corroborated these results. Being classified as high for cognitive restraint was associated with faster reaction times if the preferred food was rated as healthier than the referent food. Conversely, being classified as high for disinhibited eating was associated with faster reaction times if the preferred food was rated as tastier than the referent food. CONCLUSION: The dietary decision-making task appears to capture distinct aspects of dietary restraint and disinhibition and may be useful in future studies to measure and/or alter levels of dietary restraint and disinhibition.

14.
Vision Res ; 48(5): 685-9, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18207215

RESUMO

Age-related macular degeneration (AMD) is a complex disorder with genetic and environmental influences. The genetic influences affecting AMD are not well understood and few genes have been consistently implicated and replicated for this disease. A polymorphism (rs11200638) in a transcription factor binding site of the HTRA1 gene has been described, in previous reports, as being most significantly associated with AMD. In this paper, we investigate haplotype association and individual polymorphic association by genotyping additional variants in the AMD risk-associated region of chromosome 10q26. We demonstrate that rs11200638 in the promoter region and rs2293870 in exon 1 of HTRA1, are among the most significantly associated variants for advanced forms of AMD.


Assuntos
Cromossomos Humanos Par 10/genética , Degeneração Macular/genética , Polimorfismo de Nucleotídeo Único , Serina Endopeptidases/genética , Idoso , Idoso de 80 Anos ou mais , Mapeamento Cromossômico/métodos , Feminino , Predisposição Genética para Doença , Genótipo , Haplótipos , Serina Peptidase 1 de Requerimento de Alta Temperatura A , Humanos , Masculino , Pessoa de Meia-Idade
15.
Artigo em Inglês | MEDLINE | ID: mdl-15772601

RESUMO

OBJECTIVE: This study compared the accuracy of D- and F-speed intraoral radiographs and digital and enhanced digital radiographic images for endodontic file length determination. STUDY DESIGN: Size 15 K-files were bonded in 51 canals of 34 human cadaver teeth. The distance from file tip to root apex was measured on D- and F-speed film and on unenhanced and enhanced digital images. The quality of the images was rated by the observers. Overlying cadaver bone and root structure were subsequently removed to expose the file tip for actual measurement to the apex. The distance measured on each image was compared with the actual measurement. ANOVA, Kruskal-Wallis, sign test, and Pearson correlation statistical analyses were applied. RESULTS: There were no significant differences in measurement accuracy among the 4 image types (P < or = .05). Subjective ratings showed a preference for the quality of enhanced digital images. Conclusion All 4 image types were similar in accuracy of file measurement. The image quality of enhanced digital images was subjectively superior to the others.


Assuntos
Cavidade Pulpar/anatomia & histologia , Cavidade Pulpar/diagnóstico por imagem , Odontometria/métodos , Radiografia Dentária/métodos , Filme para Raios X , Análise de Variância , Dente Pré-Molar/anatomia & histologia , Dente Pré-Molar/diagnóstico por imagem , Humanos , Dente Molar/anatomia & histologia , Dente Molar/diagnóstico por imagem , Intensificação de Imagem Radiográfica , Radiografia Dentária Digital , Reprodutibilidade dos Testes , Estatísticas não Paramétricas , Raiz Dentária/anatomia & histologia , Raiz Dentária/diagnóstico por imagem
16.
Artigo em Inglês | MEDLINE | ID: mdl-12847452

RESUMO

OBJECTIVES: We sought to compare the sensitometric characteristics of 3 intraoral film types processed in an automated roller solution with the characteristics of the films processed in 4 automated nonroller solutions. STUDY DESIGN: Eastman Kodak Ultra-Speed, Flow X-ray EV-57, and Eastman Kodak InSight films were exposed to varying levels of radiation and processed in 1 automated roller solution and in 4 nonroller solutions. Speed and contrast were measured at various density levels and ranges. RESULTS: With the exception of 1 nonroller solution, there was little difference in speed between roller and nonroller processing chemicals at various density levels. Some nonroller solutions were faster than the roller chemicals for all films. Nonroller processing mostly increased contrast compared with roller processing over various ranges. CONCLUSIONS: Sensitometric properties of films processed in automatic nonroller solutions are comparable in many cases to those in roller solutions, sometimes resulting in greater speed and contrast. Different adjustments in exposure factors are required for specific film/processing combinations.


Assuntos
Radiografia Dentária/métodos , Filme para Raios X , Análise de Variância , Meios de Contraste , Doses de Radiação , Soluções
17.
Front Psychol ; 5: 1274, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25520675

RESUMO

In four experiments, we investigated how attention to local and global levels of hierarchical Navon figures affected the selection of diagnostic spatial scale information used in scene categorization. We explored this issue by asking observers to classify hybrid images (i.e., images that contain low spatial frequency (LSF) content of one image, and high spatial frequency (HSF) content from a second image) immediately following global and local Navon tasks. Hybrid images can be classified according to either their LSF, or HSF content; thus, making them ideal for investigating diagnostic spatial scale preference. Although observers were sensitive to both spatial scales (Experiment 1), they overwhelmingly preferred to classify hybrids based on LSF content (Experiment 2). In Experiment 3, we demonstrated that LSF based hybrid categorization was faster following global Navon tasks, suggesting that LSF processing associated with global Navon tasks primed the selection of LSFs in hybrid images. In Experiment 4, replicating Experiment 3 but suppressing the LSF information in Navon letters by contrast balancing the stimuli examined this hypothesis. Similar to Experiment 3, observers preferred to classify hybrids based on LSF content; however and in contrast, LSF based hybrid categorization was slower following global than local Navon tasks.

18.
Acta Psychol (Amst) ; 153: 129-38, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25463553

RESUMO

Hodsoll and Humphreys (2001) have assessed the relative contributions of stimulus-driven and user-driven knowledge on linearly- and nonlinearly separable searches. However, the target feature used to determine linear separability in their task (i.e., target size) was required to locate the target. In the present work, we investigated the contributions of stimulus-driven and user-driven knowledge when a linearly- or a nonlinearly-separable feature is available but not required for target identification. We asked observers to complete a series of standard color×orientation conjunction searches in which target size was either linearly- or nonlinearly separable from the size of the distractors. When guidance by color×orientation and guidance by size information are both available, observers rely on whichever information results in the best search efficiency. This is the case irrespective of whether we provide target foreknowledge by blocking stimulus conditions, suggesting that feature information is used in both a stimulus-driven and a user-driven fashion.


Assuntos
Atenção/fisiologia , Percepção de Cores/fisiologia , Sinais (Psicologia) , Desempenho Psicomotor/fisiologia , Percepção Espacial/fisiologia , Adulto , Feminino , Humanos , Masculino , Percepção de Tamanho/fisiologia , Adulto Jovem
19.
Vision Res ; 79: 8-16, 2013 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-23274647

RESUMO

Research suggests that subjects can compute the mean size of two sets of interspersed objects concurrently, but that doing so incurs a cost of dividing attention across the two sets. Alternatively, costs may arise from failing to exclude irrelevant items from the calculation of mean size. Here, we examined whether attention can be selectively deployed to prevent the inclusion of items from an irrelevant, concurrently displayed set in the computation of the relevant set's mean size. The results suggest that mean size is computed prior to the deployment of attention, failing to exclude processing of items that are irrelevant to the task. The influence of the irrelevant items is evident both with brief exposures of the set (200ms) and in a simultaneous judgment task with unlimited viewing time, suggesting that attention cannot be effectively deployed to facilitate selective averaging of the size of the relevant set. Size averaging appears to precede the deployment of selective attention, suggesting that it may be carried out automatically, without intention.


Assuntos
Atenção/fisiologia , Percepção de Tamanho/fisiologia , Adolescente , Adulto , Análise de Variância , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos , Adulto Jovem
20.
J Rehabil Res Dev ; 50(6): 757-68, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24203539

RESUMO

Although traumatic brain injury (TBI) can happen to anyone at any time, the wars in Iraq and Afghanistan have brought it renewed attention. Fortunately, most cases of TBI from the recent conflicts are mild TBI (mTBI). Still, many physical, psychological, and social problems are associated with mTBI. Among the difficulties encountered are oculomotor and vision problems, many of which can impede daily activities such as reading. Therefore, correct diagnosis and treatment of these mTBI-related vision problems is an important part of patient recovery. Numerous eye care providers in the Department of Veterans Affairs, in military settings, and in civilian practices specialize and are proficient in examining patients who have a history of TBI. However, many do not have this level of experience working with and treating patients with mTBI. Recognizing this, we used a modified Delphi method to derive expert opinions from a panel of 16 optometrists concerning visual examination of the patient with mTBI. This process resulted in a clinical tool containing 17 history questions and 7 examination procedures. This tool provides a set of clinical guidelines that can be used as desired by any eye care provider either as a screening tool or adjunct to a full eye examination when seeing a patient with a history of mTBI. The goal of this process was to provide optimal and uniform vision care for the patient with mTBI.


Assuntos
Lesões Encefálicas/complicações , Anamnese , Transtornos da Visão/diagnóstico , Transtornos da Visão/etiologia , Testes Visuais , Técnica Delphi , Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA