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

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Health Promot Pract ; 19(3): 455-464, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-28548556

RESUMEN

PURPOSE: The purpose of this study was to measure effects of a modified physical education (PE) unit on leisure time physical activity (LTPA), relative autonomy, and known correlates of LTPA in seventh-grade boys and girls. METHOD: A seventh-grade mountain biking unit was modified to include instructional activities targeting known correlates of PA behavior following principles of Physical Education Dedicated to Physical Activity for Life (PEDAL). A three-group design (intervention, standard PE, no PE) was employed. Participants completed a survey at baseline, postintervention, and follow-up at 4 weeks. RESULTS: A total of 300 seventh graders (girls = 151) from two schools completed the surveys. Data suggest PE may influence certain correlates of and autonomous motivation for PA although results revealed no intervention main effects for continuous and noncontinuous dependent variables. Results also provide evidence of sport-specific skill being improved through physical education. CONCLUSION: While results of this study showed no main effects from the intervention, data suggest PE may influence certain correlates of and autonomous motivation for PA. This warrants attention toward autonomy supporting PE environments and instruction sensitive to autonomous motivation. Future studies should examine PEDAL-designed PE programs over an entire year or more.


Asunto(s)
Ejercicio Físico , Promoción de la Salud , Motivación , Educación y Entrenamiento Físico , Adolescente , Arizona , Curriculum , Femenino , Humanos , Actividades Recreativas , Masculino , Obesidad/prevención & control , Instituciones Académicas , Autoinforme
2.
Perception ; 46(7): 815-829, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28622756

RESUMEN

Palmer, Gardner, and Wickens studied aesthetic preferences for pictures of single objects and found a strong inward bias: Right-facing objects were preferred left-of-center and left-facing objects right-of-center. They found no effect of object motion (people and cars showed the same inward bias as chairs and teapots), but the objects were not depicted as moving. Here we measured analogous inward biases with objects depicted as moving with an implied direction and speed by having participants drag-and-drop target objects into the most aesthetically pleasing position. In Experiment 1, human figures were shown diving or falling while moving forward or backward. Aesthetic biases were evident for both inward-facing and inward-moving figures, but the motion-based bias dominated so strongly that backward divers or fallers were preferred moving inward but facing outward. Experiment 2 investigated implied speed effects using images of humans, horses, and cars moving at different speeds (e.g., standing, walking, trotting, and galloping horses). Inward motion or facing biases were again present, and differences in their magnitude due to speed were evident. Unexpectedly, faster moving objects were generally preferred closer to frame center than slower moving objects. These results are discussed in terms of the combined effects of prospective, future-oriented biases, and retrospective, past-oriented biases.


Asunto(s)
Percepción de Movimiento/fisiología , Reconocimiento Visual de Modelos/fisiología , Percepción Espacial/fisiología , Adulto , Femenino , Humanos , Masculino , Adulto Joven
3.
Cancer Cell ; 13(2): 167-80, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18242516

RESUMEN

By misdirecting the activity of Activation-Induced Deaminase (AID) to a conditional MYC transgene, we have achieved sporadic, AID-dependent MYC activation in germinal center B cells of Vk*MYC mice. Whereas control C57BL/6 mice develop benign monoclonal gammopathy with age, all Vk*MYC mice progress to an indolent multiple myeloma associated with the biological and clinical features highly characteristic of the human disease. Furthermore, antigen-dependent myeloma could be induced by immunization with a T-dependent antigen. Consistent with these findings in mice, more frequent MYC rearrangements, elevated levels of MYC mRNA, and MYC target genes distinguish human patients with multiple myeloma from individuals with monoclonal gammopathy, implicating a causal role for MYC in the progression of monoclonal gammopathy to multiple myeloma.


Asunto(s)
Citidina Desaminasa/metabolismo , Centro Germinal/patología , Mieloma Múltiple/enzimología , Mieloma Múltiple/patología , Proteínas Proto-Oncogénicas c-myc/genética , Transgenes/genética , Animales , Antígenos de Neoplasias/inmunología , Proliferación Celular , Codón de Terminación/genética , Análisis Mutacional de ADN , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Ensayos de Selección de Medicamentos Antitumorales , Perfilación de la Expresión Génica , Humanos , Inmunización , Ratones , Modelos Biológicos , Datos de Secuencia Molecular , Mieloma Múltiple/inmunología , Especificidad de Órganos , Paraproteinemias/patología , Células Plasmáticas/enzimología , Células Plasmáticas/patología , Ingeniería de Proteínas , Hipermutación Somática de Inmunoglobulina/genética
4.
Proc Natl Acad Sci U S A ; 110(22): 8836-41, 2013 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-23671106

RESUMEN

Experimental evidence demonstrates robust cross-modal matches between music and colors that are mediated by emotional associations. US and Mexican participants chose colors that were most/least consistent with 18 selections of classical orchestral music by Bach, Mozart, and Brahms. In both cultures, faster music in the major mode produced color choices that were more saturated, lighter, and yellower whereas slower, minor music produced the opposite pattern (choices that were desaturated, darker, and bluer). There were strong correlations (0.89 < r < 0.99) between the emotional associations of the music and those of the colors chosen to go with the music, supporting an emotional mediation hypothesis in both cultures. Additional experiments showed similarly robust cross-modal matches from emotionally expressive faces to colors and from music to emotionally expressive faces. These results provide further support that music-to-color associations are mediated by common emotional associations.


Asunto(s)
Cognición/fisiología , Color , Emociones , Cara , Modelos Psicológicos , Música/psicología , Análisis de Varianza , Humanos , México , Estados Unidos
5.
Blood ; 120(2): 376-85, 2012 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-22451422

RESUMEN

The attrition rate for anticancer drugs entering clinical trials is unacceptably high. For multiple myeloma (MM), we postulate that this is because of preclinical models that overemphasize the antiproliferative activity of drugs, and clinical trials performed in refractory end-stage patients. We validate the Vk*MYC transgenic mouse as a faithful model to predict single-agent drug activity in MM with a positive predictive value of 67% (4 of 6) for clinical activity, and a negative predictive value of 86% (6 of 7) for clinical inactivity. We identify 4 novel agents that should be prioritized for evaluation in clinical trials. Transplantation of Vk*MYC tumor cells into congenic mice selected for a more aggressive disease that models end-stage drug-resistant MM and responds only to combinations of drugs with single-agent activity in untreated Vk*MYC MM. We predict that combinations of standard agents, histone deacetylase inhibitors, bromodomain inhibitors, and hypoxia-activated prodrugs will demonstrate efficacy in the treatment of relapsed MM.


Asunto(s)
Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/genética , Animales , Antineoplásicos/farmacología , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Ácidos Borónicos/administración & dosificación , Ácidos Borónicos/farmacología , Bortezomib , Modelos Animales de Enfermedad , Resistencia a Antineoplásicos , Ensayos de Selección de Medicamentos Antitumorales , Genes myc , Humanos , Ratones , Ratones Congénicos , Ratones Endogámicos C57BL , Ratones Transgénicos , Mieloma Múltiple/sangre , Mieloma Múltiple/patología , Proteínas de Mieloma/metabolismo , Trasplante de Neoplasias , Valor Predictivo de las Pruebas , Pirazinas/administración & dosificación , Pirazinas/farmacología
6.
Blood ; 120(5): 1067-76, 2012 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-22498740

RESUMEN

Emerging evidence indicates that tumors can follow several evolutionary paths over a patient's disease course. With the use of serial genomic analysis of samples collected at different points during the disease course of 28 patients with multiple myeloma, we found that the genomes of standard-risk patients show few changes over time, whereas those of cytogenetically high-risk patients show significantly more changes over time. The results indicate the existence of 3 temporal tumor types, which can either be genetically stable, linearly evolving, or heterogeneous clonal mixtures with shifting predominant clones. A detailed analysis of one high-risk patient sampled at 7 time points over the entire disease course identified 2 competing subclones that alternate in a back and forth manner for dominance with therapy until one clone underwent a dramatic linear evolution. With the use of the Vk*MYC genetically engineered mouse model of myeloma we modeled this competition between subclones for predominance occurring spontaneously and with therapeutic selection.


Asunto(s)
Evolución Clonal/genética , Variaciones en el Número de Copia de ADN , Genes Dominantes/fisiología , Mieloma Múltiple/genética , Mieloma Múltiple/patología , Animales , Células Cultivadas , Evolución Clonal/inmunología , Evolución Clonal/fisiología , Análisis por Conglomerados , Variaciones en el Número de Copia de ADN/genética , Progresión de la Enfermedad , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Análisis por Micromatrices , Modelos Biológicos , Mieloma Múltiple/inmunología , Recurrencia
7.
Annu Rev Psychol ; 64: 77-107, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23020642

RESUMEN

Human aesthetic preference in the visual domain is reviewed from definitional, methodological, empirical, and theoretical perspectives. Aesthetic science is distinguished from the perception of art and from philosophical treatments of aesthetics. The strengths and weaknesses of important behavioral techniques are presented and discussed, including two-alternative forced-choice, rank order, subjective rating, production/adjustment, indirect, and other tasks. Major findings are reviewed about preferences for colors (single colors, color combinations, and color harmony), spatial structure (low-level spatial properties, shape properties, and spatial composition within a frame), and individual differences in both color and spatial structure. Major theoretical accounts of aesthetic response are outlined and evaluated, including explanations in terms of mere exposure effects, arousal dynamics, categorical prototypes, ecological factors, perceptual and conceptual fluency, and the interaction of multiple components. The results of the review support the conclusion that aesthetic response can be studied rigorously and meaningfully within the framework of scientific psychology.


Asunto(s)
Belleza , Conducta de Elección , Estética/psicología , Percepción Visual , Humanos
8.
J Vis ; 14(8): 23, 2014 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-25074901

RESUMEN

A new illusion, called the configural shape illusion (CSI), is described in which the apparent shape of an object (the "target") is systematically distorted by the presence of an adjacent shape (the "inducer") that is distinct from, but perceptually grouped with, the target. The target is selectively elongated in a direction consistent with the extension of the larger configuration that includes both target and inducer. Experiments 1 and 2 show that the CSI magnitude varies systematically with factors known to influence grouping strength between configural elements, including proximity, good continuation, positional alignment, lightness similarity, hue similarity, and common fate. Experiments 3 through 5 examine the influence of relative inducer size and target size on illusion magnitude. We suggest that the CSI is caused by edge assimilation modulated by similarity between the target and inducer arising from population coding of edge positions. This assimilation account fits well with previous explanations of one-dimensional illusions of linear extent (e.g., the Müller-Lyer and Baldwin illusions), which are extended to account for the present two-dimensional illusion of shape.


Asunto(s)
Percepción de Forma/fisiología , Ilusiones/fisiología , Humanos , Luz , Reconocimiento Visual de Modelos/fisiología , Psicofísica
9.
Proc Natl Acad Sci U S A ; 107(19): 8877-82, 2010 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-20421475

RESUMEN

Color preference is an important aspect of visual experience, but little is known about why people in general like some colors more than others. Previous research suggested explanations based on biological adaptations [Hurlbert AC, Ling YL (2007) Curr Biol 17:623-625] and color-emotions [Ou L-C, Luo MR, Woodcock A, Wright A (2004) Color Res Appl 29:381-389]. In this article we articulate an ecological valence theory in which color preferences arise from people's average affective responses to color-associated objects. An empirical test provides strong support for this theory: People like colors strongly associated with objects they like (e.g., blues with clear skies and clean water) and dislike colors strongly associated with objects they dislike (e.g., browns with feces and rotten food). Relative to alternative theories, the ecological valence theory both fits the data better (even with fewer free parameters) and provides a more plausible, comprehensive causal explanation of color preferences.


Asunto(s)
Conducta de Elección/fisiología , Percepción de Color/fisiología , Fenómenos Ecológicos y Ambientales , Modelos Biológicos , Adolescente , Adulto , Anciano , Color , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
10.
J Cogn Neurosci ; 23(3): 631-44, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20146596

RESUMEN

Edge-assignment determines the perception of relative depth across an edge and the shape of the closer side. Many cues determine edge-assignment, but relatively little is known about the neural mechanisms involved in combining these cues. Here, we manipulated extremal edge and attention cues to bias edge-assignment such that these two cues either cooperated or competed. To index their neural representations, we flickered figure and ground regions at different frequencies and measured the corresponding steady-state visual-evoked potentials (SSVEPs). Figural regions had stronger SSVEP responses than ground regions, independent of whether they were attended or unattended. In addition, competition and cooperation between the two edge-assignment cues significantly affected the temporal dynamics of edge-assignment processes. The figural SSVEP response peaked earlier when the cues causing it cooperated than when they competed, but sustained edge-assignment effects were equivalent for cooperating and competing cues, consistent with a winner-take-all outcome. These results provide physiological evidence that figure-ground organization involves competitive processes that can affect the latency of figural assignment.


Asunto(s)
Potenciales Evocados Visuales/fisiología , Percepción de Forma/fisiología , Neuronas/fisiología , Corteza Visual/fisiología , Análisis de Varianza , Atención/fisiología , Señales (Psicología) , Electroencefalografía , Movimientos Oculares/fisiología , Femenino , Humanos , Masculino , Tiempo de Reacción/fisiología , Procesamiento de Señales Asistido por Computador , Adulto Joven
11.
J Clin Invest ; 118(5): 1750-64, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18431519

RESUMEN

Knockout and transgenic studies in mice demonstrate that normal somatic tissues redundantly express 3 cyclin D proteins, whereas tumor cells seem dependent on a single overexpressed cyclin D. Thus, selective suppression of the individual cyclin D deregulated in a tumor represents a biologically valid approach to targeted cancer therapy. In multiple myeloma, overexpression of 1 of the cyclin D proteins is a ubiquitous feature, unifying at least 7 different initiating genetic events. We demonstrate here that RNAi of genes encoding cyclin D1 and cyclin D2 (CCND1 and CCND2, respectively) inhibits proliferation and is progressively cytotoxic in human myeloma cells. By screening a chemical library using a cell-based assay for inhibition of CCND2 trans-activation, we identified the plant cytokinin kinetin riboside as an inhibitor of CCND2 trans-activation. Kinetin riboside induced marked suppression of CCND2 transcription and rapidly suppressed cyclin D1 and D2 protein expression in primary myeloma cells and tumor lines, causing cell-cycle arrest, tumor cell-selective apoptosis, and inhibition of myeloma growth in xenografted mice. Mechanistically, kinetin riboside upregulated expression of transcription repressor isoforms of cAMP-response element modulator (CREM) and blocked both trans-activation of CCND2 by various myeloma oncogenes and cis-activation of translocated CCND1, suggesting induction of an overriding repressor activity that blocks multiple oncogenic pathways targeting cyclin D genes. These data support targeted repression of cyclin D genes as a therapeutic strategy for human malignancies.


Asunto(s)
Antineoplásicos/metabolismo , Ciclinas , Cinetina/genética , Mieloma Múltiple , Nucleósidos , Animales , Ciclo Celular/fisiología , Línea Celular Tumoral/efectos de los fármacos , Ciclina D , Ciclina D2 , Ciclinas/genética , Ciclinas/metabolismo , Femenino , Regulación de la Expresión Génica , Humanos , Cinetina/metabolismo , Lentivirus/genética , Lentivirus/metabolismo , Ratones , Ratones Desnudos , Estructura Molecular , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/genética , Mieloma Múltiple/metabolismo , Células 3T3 NIH , Nucleósidos/genética , Nucleósidos/metabolismo , Nucleósidos/farmacología , Nucleósidos/uso terapéutico , Regiones Promotoras Genéticas , Interferencia de ARN , Trasplante Heterólogo
12.
Blood ; 113(17): 4027-37, 2009 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-19096011

RESUMEN

As multiple myeloma tumors universally dysregulate cyclin D genes we conducted high-throughput chemical library screens for compounds that induce suppression of cyclin D2 promoter transcription. The top-ranked compound was a natural triterpenoid, pristimerin. Strikingly, the early transcriptional response of cells treated with pristimerin closely resembles cellular responses elicited by proteosome inhibitors, with rapid induction of heat shock proteins, activating transcription factor 3 (ATF3), and CHOP. Enzymatic assays and immunoblotting confirm that pristimerin rapidly (< 90 minutes) and specifically inhibits chymotrypsin-like proteosome activity at low concentrations (< 100 nM) and causes accumulation of cellular ubiquitinated proteins. Notably, cytotoxic triterpenoids including pristimerin inhibit NF-kappaB activation via inhibition of IKK alpha or IKK beta, whereas proteosome inhibitors instead suppress NF-kappaB function by impairing degradation of ubiquitinated I kappaB. By inhibiting both IKK and the proteosome, pristimerin causes overt suppression of constitutive NF-kappaB activity in myeloma cells that may mediate its suppression of cyclin D. Multiple myeloma is exquisitely sensitive to proteosome or NF-kappaB pathway inhibition. Consistent with this, pristimerin is potently and selectively lethal to primary myeloma cells (IC(50) < 100 nM), inhibits xenografted plasmacytoma tumors in mice, and is synergistically cytotoxic with bortezomib--providing the rationale for pharmaceutical development of triterpenoid dual-function proteosome/NF-kappaB inhibitors as therapeutics for human multiple myeloma and related malignancies.


Asunto(s)
Antineoplásicos/farmacología , Productos Biológicos/farmacología , Quimasas/antagonistas & inhibidores , Mieloma Múltiple/metabolismo , FN-kappa B/antagonistas & inhibidores , Inhibidores de Proteasoma , Triterpenos/farmacología , Animales , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Productos Biológicos/química , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Linaje de la Célula , Células Cultivadas , Quimasas/metabolismo , Técnicas de Cocultivo , Técnicas Químicas Combinatorias , Ciclina D , Ciclinas/genética , Ciclinas/metabolismo , Ensayos de Selección de Medicamentos Antitumorales , Activación Enzimática/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Ratones , Estructura Molecular , Mieloma Múltiple/patología , FN-kappa B/metabolismo , Triterpenos Pentacíclicos , Complejo de la Endopetidasa Proteasomal/metabolismo , Activación Transcripcional/efectos de los fármacos , Triterpenos/química , Ensayos Antitumor por Modelo de Xenoinjerto
13.
J Vis ; 10(8): 3, 2010 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-20884578

RESUMEN

Identifying the visual cues that determine relative depth across an image contour (i.e., figure-ground organization) is a central problem of vision science. In this paper, we compare flat cues to figure-ground organization with the recently discovered cue of extremal edges (EEs), which arise when opaque convex surfaces smoothly curve to partly occlude themselves. The present results show that EEs are very powerful pictorial cues to relative depth across an edge, almost entirely dominating the well-known figure-ground cues of relative size, convexity, shape familiarity, and surroundedness. These results demonstrate that natural shading and texture gradients in an image provide important information about figure-ground organization that has largely been overlooked in the past 75 years of research on this topic.


Asunto(s)
Percepción de Profundidad/fisiología , Área de Dependencia-Independencia , Percepción de Forma/fisiología , Reconocimiento Visual de Modelos/fisiología , Señales (Psicología) , Humanos , Estimulación Luminosa/métodos
14.
J Exp Psychol Hum Percept Perform ; 34(6): 1353-71, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19045980

RESUMEN

Edge-region grouping (ERG) is proposed as a unifying and previously unrecognized class of relational information that influences figure-ground organization and perceived depth across an edge. ERG occurs when the edge between two regions is differentially grouped with one region based on classic principles of similarity grouping. The ERG hypothesis predicts that the grouped side will tend to be perceived as the closer, figural region. Six experiments are reported that test the predictions of the ERG hypothesis for 6 similarity-based factors: common fate, blur similarity, color similarity, orientation similarity, proximity, and flicker synchrony. All 6 factors produce the predicted effects, although to different degrees. In a 7th experiment, the strengths of these figural/depth effects were found to correlate highly with the strength of explicit grouping ratings of the same visual displays. The relations of ERG to prior results in the literature are discussed, and possible reasons for ERG-based figural/depth effects are considered. We argue that grouping processes mediate at least some of the effects we report here, although ecological explanations are also likely to be relevant in the majority of cases.


Asunto(s)
Atención , Percepción de Color , Percepción de Profundidad , Percepción de Distancia , Área de Dependencia-Independencia , Orientación , Reconocimiento Visual de Modelos , Aprendizaje Discriminativo , Femenino , Fusión de Flicker , Humanos , Masculino , Percepción de Movimiento , Ilusiones Ópticas , Psicofísica , Adulto Joven
15.
Iperception ; 9(6): 2041669518808535, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30479734

RESUMEN

When people make cross-modal matches from classical music to colors, they choose colors whose emotional associations fit the emotional associations of the music, supporting the emotional mediation hypothesis. We further explored this result with a large, diverse sample of 34 musical excerpts from different genres, including Blues, Salsa, Heavy metal, and many others, a broad sample of 10 emotion-related rating scales, and a large range of 15 rated music-perceptual features. We found systematic music-to-color associations between perceptual features of the music and perceptual dimensions of the colors chosen as going best/worst with the music (e.g., loud, punchy, distorted music was generally associated with darker, redder, more saturated colors). However, these associations were also consistent with emotional mediation (e.g., agitated-sounding music was associated with agitated-looking colors). Indeed, partialling out the variance due to emotional content eliminated all significant cross-modal correlations between lower level perceptual features. Parallel factor analysis (Parafac, a type of factor analysis that encompasses individual differences) revealed two latent affective factors- arousal and valence -which mediated lower level correspondences in music-to-color associations. Participants thus appear to match music to colors primarily in terms of common, mediating emotional associations.

16.
Vision Res ; 141: 95-108, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-28456532

RESUMEN

There are well-known and extensive differences in color preferences between individuals, but there are also within-individual differences from one time to another. Despite the seeming independence between these individual and temporal effects, we propose that they have the same underlying cause: people's ecological experiences with color-associated objects and events. Our approach is motivated by the Ecological Valence Theory (EVT; Palmer & Schloss, 2010) which states that preference for a given color is determined by the combined valence (liking/disliking) of all objects and events associated with that color. We define three ecologically-based hypotheses for explaining temporal and individual differences in color preferences concerning: (1) differences in object valences, (2) differences in color-object associations, and (3) differences in object activations in the mind when preferences are measured. We review prior studies that support these hypotheses and raise open research questions about untested predictions. We also extend the computational framework of the EVT by defining a single weighted average equation that captures both individual and temporal differences in color preferences. Finally, we consider other factors that potentially contribute to color preferences, including abstract symbolic associations, color in design, and psychophysical and/or physiological factors.


Asunto(s)
Conducta de Elección/fisiología , Percepción de Color/fisiología , Individualidad , Cognición/fisiología , Estética , Femenino , Humanos , Masculino , Modelos Teóricos
17.
Cogn Sci ; 41 Suppl 5: 1183-1201, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28000944

RESUMEN

How does the visual system recognize images of a novel object after a single observation despite possible variations in the viewpoint of that object relative to the observer? One possibility is comparing the image with a prototype for invariance over a relevant transformation set (e.g., translations and dilations). However, invariance over rotations (i.e., orientation invariance) has proven difficult to analyze, because it applies to some objects but not others. We propose that the invariant transformations of an object are learned by incorporating prior expectations with real-world evidence. We test this proposal by developing an ideal learner model for learning invariance that predicts better learning of orientation dependence when prior expectations about orientation are weak. This prediction was supported in two behavioral experiments, where participants learned the orientation dependence of novel images using feedback from solving arithmetic problems.


Asunto(s)
Juicio/fisiología , Conocimiento , Reconocimiento en Psicología/fisiología , Percepción Visual/fisiología , Percepción de Forma/fisiología , Humanos , Orientación/fisiología
18.
Cogn Sci ; 41(6): 1589-1612, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27859560

RESUMEN

We investigated how color preferences vary according to season and whether those changes could be explained by the ecological valence theory (EVT). To do so, we assessed the same participants' preferences for the same colors during fall, winter, spring, and summer in the northeastern United States, where there are large seasonal changes in environmental colors. Seasonal differences were most pronounced between fall and the other three seasons. Participants liked fall-associated dark-warm colors-for example, dark-red, dark-orange (brown), dark-yellow (olive), and dark-chartreuse-more during fall than other seasons. The EVT could explain these changes with a modified version of Palmer and Schloss' (2010) weighted affective valence estimate (WAVE) procedure that added an activation term to the WAVE equation. The results indicate that color preferences change according to season, as color-associated objects become more/less activated in the observer. These seasonal changes in color preferences could not be characterized by overall shifts in weights along cone-contrast axes.


Asunto(s)
Conducta de Elección/fisiología , Cognición/fisiología , Percepción de Color/fisiología , Color , Estaciones del Año , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
19.
Psychon Bull Rev ; 13(4): 563-9, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17201352

RESUMEN

We investigated whether the lower region effect on figure-ground organization (Vecera, Vogel, and Woodman, 2002) would generalize to contextual depth planes in vertical orientations, as is predicted by a theoretical analysis based on the ecological statistics of edges arising from objects that are attached to surfaces of support. Observers viewed left/right ambiguous figure-ground displays that occluded middle sections of four types of contextual inducers: two types of attached, receding, vertical planes (walls) that used linear perspective and/or texture gradients to induce perceived depth and two types of similar trapezoidal control figures that used either uniform color or random texture to reduce or eliminate perceived depth. The results showed a reliable bias toward seeing as "figure" the side of the figure-ground display that was attached to the receding depth plane, but no such bias for the corresponding side in either of the control conditions. The results are interpreted as being consistent with the attachment hypothesis that the lower region cue to figure-ground organization results from ecological biases in edge interpretation that arise when objects are attached to supporting surfaces in the terrestrial gravitational field.


Asunto(s)
Percepción de Color , Fijación Ocular , Percepción Visual , Señales (Psicología) , Percepción de Profundidad , Gravitación , Humanos
20.
Atten Percept Psychophys ; 78(2): 636-46, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26637235

RESUMEN

Extremal edges (EEs) are borders consisting of luminance gradients along the projected edge of a partly self-occluding curved surface (e.g., a cylinder), with equiluminant contours (ELCs) that run approximately parallel to that edge. Gradient cuts (GCs) are similar luminance gradients with ELCs that intersect (are "cut" by) an edge that could be due to occlusion. EEs are strongly biased toward being seen as closer/figural surfaces (Palmer & Ghose, Psychological Science, 19(1), 77-83, 2008). Do GCs produce a complementary bias toward being seen as ground? Experiment 1 shows that, with EEs on the opposite side, GCs produce a ground bias that increases with increasing ELC angles between ELCs and the shared edge. Experiment 2 shows that, with flat surfaces on the opposite side, GCs do not produce a ground bias, suggesting that more than one factor may be operating. We suggest that two partially dissociable factors may operate for curved surfaces-ELC angle and 3-D surface convexity-that reinforce each other in the figural cues of EEs but compete with each other in GCs. Moreover, this figural bias is modulated by the presence of EEs and GCs, as specified by the ELC angle between ELCs and the shared contour.


Asunto(s)
Señales (Psicología) , Percepción de Profundidad/fisiología , Percepción de Forma/fisiología , Estimulación Luminosa/métodos , Humanos , Percepción Visual/fisiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA