Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.007
Filtrar
1.
PLoS One ; 15(12): e0244594, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33378385

RESUMO

Sense of body ownership is an immediate and distinct experience of one's body as belonging to oneself. While it is well-recognized that ownership feelings emerge from the integration of visual and somatosensory signals, the principles upon which they are integrated are still intensely debated. Here, we used the rubber hand illusion (RHI) to examine how the interplay of visual, tactile, and proprioceptive signals is governed depending on their spatiotemporal properties. For this purpose, the RHI was elicited in different conditions varying with respect to the extent of visuo-proprioceptive divergence (i.e., the distance between the real and fake hands) and differing in terms of the availability and spatiotemporal complexity of tactile stimulation (none, simple, or complex). We expected that the attenuating effect of distance on illusion strength will be more pronounced in the absence of touch (when proprioception gains relatively higher importance) and absent in the presence of complex tactile signals. Additionally, we hypothesized that participants with greater proprioceptive acuity-assessed using an elbow joint position discrimination task-will be less susceptible to the illusion, but only under the conditions of limited tactile stimulation. In line with our prediction, RHI was attenuated at the farthest distance only when tactile information was absent or simplified, but the attenuation was effectively prevented by the use of complex tactile stimulation-in this case, RHI was comparably vivid at both distances. However, passive proprioceptive acuity was not related to RHI strength in either of the conditions. The results indicate that complex-structured tactile signals can override the influence of proprioceptive signals in body attribution processes. These findings extend our understanding of body ownership by showing that it is primarily determined by informative cues from the most relevant sensory domains, rather than mere accumulation of multisensory evidence.


Assuntos
Ilusões/fisiologia , Propriocepção/fisiologia , Tato/fisiologia , Percepção Visual/fisiologia , Adulto , Feminino , Humanos , Masculino , Borracha , Adulto Jovem
2.
Nat Commun ; 11(1): 4853, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978377

RESUMO

In hypnotic responding, expectancies arising from imaginative suggestion drive striking experiential changes (e.g., hallucinations) - which are experienced as involuntary - according to a normally distributed and stable trait ability (hypnotisability). Such experiences can be triggered by implicit suggestion and occur outside the hypnotic context. In large sample studies (of 156, 404 and 353 participants), we report substantial relationships between hypnotisability and experimental measures of experiential change in mirror-sensory synaesthesia and the rubber hand illusion comparable to relationships between hypnotisability and individual hypnosis scale items. The control of phenomenology to meet expectancies arising from perceived task requirements can account for experiential change in psychological experiments.


Assuntos
Mãos , Hipnose/métodos , Ilusões/fisiologia , Manejo da Dor/métodos , Sinestesia/terapia , Adolescente , Adulto , Feminino , Humanos , Imaginação , Masculino , Pessoa de Meia-Idade , Dor , Sugestão , Adulto Jovem
3.
Nat Commun ; 11(1): 4518, 2020 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-32908146

RESUMO

The human brain is specialized for face processing, yet we sometimes perceive illusory faces in objects. It is unknown whether these natural errors of face detection originate from a rapid process based on visual features or from a slower, cognitive re-interpretation. Here we use a multifaceted approach to understand both the spatial distribution and temporal dynamics of illusory face representation in the brain by combining functional magnetic resonance imaging and magnetoencephalography neuroimaging data with model-based analysis. We find that the representation of illusory faces is confined to occipital-temporal face-selective visual cortex. The temporal dynamics reveal a striking evolution in how illusory faces are represented relative to human faces and matched objects. Illusory faces are initially represented more similarly to real faces than matched objects are, but within ~250 ms, the representation transforms, and they become equivalent to ordinary objects. This is consistent with the initial recruitment of a broadly-tuned face detection mechanism which privileges sensitivity over selectivity.


Assuntos
Reconhecimento Facial/fisiologia , Ilusões/fisiologia , Modelos Neurológicos , Lobo Temporal/fisiologia , Córtex Visual/fisiologia , Adolescente , Adulto , Mapeamento Encefálico , Simulação por Computador , Feminino , Humanos , Imagem por Ressonância Magnética , Magnetoencefalografia , Masculino , Neuroimagem , Estimulação Luminosa , Tempo de Reação , Lobo Temporal/diagnóstico por imagem , Córtex Visual/diagnóstico por imagem , Adulto Jovem
4.
Nat Commun ; 11(1): 3925, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32764538

RESUMO

Adaptation is a ubiquitous property of sensory systems. It is typically considered that neurons adapt to dominant energy in the ambient environment to function optimally. However, perceptual representation of the stimulus, often modulated by feedback signals, sometimes do not correspond to the input state of the stimulus, which tends to be more linked with feedforward signals. Here we investigated the relative contributions to cortical adaptation from feedforward and feedback signals, taking advantage of a visual illusion, the Flash-Grab Effect, to disassociate the feedforward and feedback representation of an adaptor. Results reveal that orientation adaptation is exclusively dependent on the perceived rather than the retinal orientation of the adaptor. Combined fMRI and EEG measurements demonstrate that the perceived orientation of the Flash-Grab Effect is indeed supported by feedback signals in the cortex. These findings highlight the important contribution of feedback signals for cortical neurons to recalibrate their sensitivity.


Assuntos
Adaptação Fisiológica , Ilusões/fisiologia , Orientação Espacial/fisiologia , Adulto , Eletroencefalografia , Potenciais Evocados Visuais , Retroalimentação Fisiológica , Feminino , Neuroimagem Funcional , Humanos , Imagem por Ressonância Magnética , Masculino , Ilusões Ópticas/fisiologia , Estimulação Luminosa , Psicofísica , Retina/fisiologia , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Adulto Jovem
5.
Proc Natl Acad Sci U S A ; 117(37): 23044-23053, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32839324

RESUMO

Visual motion detection is one of the most important computations performed by visual circuits. Yet, we perceive vivid illusory motion in stationary, periodic luminance gradients that contain no true motion. This illusion is shared by diverse vertebrate species, but theories proposed to explain this illusion have remained difficult to test. Here, we demonstrate that in the fruit fly Drosophila, the illusory motion percept is generated by unbalanced contributions of direction-selective neurons' responses to stationary edges. First, we found that flies, like humans, perceive sustained motion in the stationary gradients. The percept was abolished when the elementary motion detector neurons T4 and T5 were silenced. In vivo calcium imaging revealed that T4 and T5 neurons encode the location and polarity of stationary edges. Furthermore, our proposed mechanistic model allowed us to predictably manipulate both the magnitude and direction of the fly's illusory percept by selectively silencing either T4 or T5 neurons. Interestingly, human brains possess the same mechanistic ingredients that drive our model in flies. When we adapted human observers to moving light edges or dark edges, we could manipulate the magnitude and direction of their percepts as well, suggesting that mechanisms similar to the fly's may also underlie this illusion in humans. By taking a comparative approach that exploits Drosophila neurogenetics, our results provide a causal, mechanistic account for a long-known visual illusion. These results argue that this illusion arises from architectures for motion detection that are shared across phyla.


Assuntos
Drosophila/fisiologia , Ilusões/fisiologia , Percepção de Movimento/fisiologia , Animais , Humanos , Movimento (Física) , Neurônios/fisiologia , Visão Ocular/fisiologia , Vias Visuais/fisiologia
6.
PLoS One ; 15(8): e0237421, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32853272

RESUMO

Body image disorders in anorexia nervosa (AN) patients and recovered AN (RAN) patients have been suggested to stem from aberrant integration of sensory information. Previous research by Case et al. (2012) used the size-weight illusion (SWI) to study multisensory integration in AN. Their results showed a diminished SWI in AN patients, which they interpreted as evidence of decreased integration of visual and proprioceptive information. However, their method did not distinguish between visual and haptic size information, which was presented concurrently while making weight judgements. Therefore, the reported effect might be attributed to integrating visual, haptic size cues, or a combination of both processes with proprioceptive input. Here, we use the SWI to investigate the integration of visual and haptic object-related sensory information in a sample of AN patients (n = 30), RAN patients (n = 29) and healthy controls (HC) (n = 29). We aimed to distinguish the contribution of visual and haptic object size by including separate visual and haptic SWI conditions. In addition to explicit measures, we included grip force measurements to assess implicit expectations about object weight. We further analysed the correlation between the SWI and a visual body size estimation (VSE) task. In contrast to Case et al. (2012), we found no evidence of differential SWI experience between groups. All participants reported a stronger visual SWI compared to haptic SWI. Grip force rate (but not peak) showed evidence of motor adaptation for the larger object in the visual condition. Furthermore, there was no correlation between the VSE and SWI, indicating no relation between perceived object weight and body size estimation. These results do not support the hypothesised impairment of visual-haptic object related integration in AN.


Assuntos
Anorexia Nervosa/psicologia , Ilusões/fisiologia , Percepção de Tamanho , Percepção do Tato , Percepção Visual , Percepção de Peso , Adulto , Feminino , Força da Mão , Humanos , Masculino
7.
J Vis ; 20(6): 16, 2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32579673

RESUMO

Object-based warping is a powerful visual illusion wherein space between features within figural regions is regularly overestimated compared with those within ground regions. Originally, the effect was only examined in displays of two-dimensional (2D) stimuli. The present study sought to examine whether object-based warping persists in more naturalistic viewing conditions, where additional contextual cues are present. Stimuli were presented with either three-dimensional (3D) printed objects (Experiment 1) or 3D objects in virtual reality (Experiments 2-4). The testing metric was actual distance of features (dots) compared with estimated distances made by participants. Responses for the 3D printed stimuli were measured with replica dots on a slide ruler device. The virtual reality experiments collected responses either with a computer mouse or motion-tracked controller and included manipulations of object type, spatial separation, viewing distance of stimuli, and head motion. A standard warping effect in 3D was observed in all experiments, although the effect was not present in one condition that elicits warping in 2D (Occluded Rectangle). The final experiment resolves this discrepancy by reducing the multicomponent object (Occluded Rectangle) to a single component figure, while demonstrating the influence of depth cues on the warping effect under occlusion. Collectively, these experiments reveal that object-based warping is a powerful effect, even in naturalistic settings.


Assuntos
Ilusões/fisiologia , Imageamento Tridimensional , Percepção Visual/fisiologia , Atenção/fisiologia , Sinais (Psicologia) , Feminino , Humanos , Masculino , Realidade Virtual , Vias Visuais/fisiologia
8.
J Vis ; 20(6): 4, 2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32511665

RESUMO

Vision scientists have attempted to classify visual illusions according to certain aspects, such as brightness or spatial features. For example, Piaget proposed that visual illusion magnitudes either decrease or increase with age. Subsequently, it was suggested that illusions are segregated according to their context: real-world contexts enhance and abstract contexts inhibit illusion magnitudes with age. We tested the effects of context on the Müller-Lyer and Ponzo illusions with a standard condition (no additional context), a line-drawing perspective condition, and a real-world perspective condition. A mixed-effects model analysis, based on data from 76 observers with ages ranging from 6 to 66 years, did not reveal any significant interaction between context and age. Although we found strong intra-illusion correlations for both illusions, we found only weak inter-illusion correlations, suggesting that the structure underlying these two spatial illusions includes several specific factors.


Assuntos
Células Ependimogliais/fisiologia , Ilusões/fisiologia , Individualidade , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ilusões Ópticas , Adulto Jovem
9.
PLoS One ; 15(5): e0232349, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32365070

RESUMO

A popular model for sensory processing, known as predictive coding, proposes that incoming signals are iteratively compared with top-down predictions along a hierarchical processing scheme. At each step, error signals arising from differences between actual input and prediction are forwarded and recurrently minimized by updating internal models to finally be "explained away". However, the neuronal mechanisms underlying such computations and their limitations in processing speed are largely unknown. Further, it remains unclear at which step of cortical processing prediction errors are explained away, if at all. In the present study, human subjects briefly viewed the superposition of two orthogonally oriented gratings followed by abrupt removal of one orientation after either 33 or 200 milliseconds. Instead of strictly seeing the remaining orientation, observers report rarely but highly significantly an illusory percept of the arithmetic difference between previous and actual orientations. Previous findings in cats using the identical paradigm suggest that such difference signals are inherited from first steps of visual cortical processing. In light of early modeling accounts of predictive coding, in which visual neurons were interpreted as residual error detectors signaling the difference between actual input and its temporal prediction based on past input, our data may indicate continued access to residual errors. Such strategy permits time-critical perceptual decision making across a spectrum of competing internal signals up to the highest levels of processing. Thus, the occasional appearance of a prediction error-like illusory percept may uncover maintained flexibility at perceptual decision stages when subjects cope with highly dynamic and ambiguous visual stimuli.


Assuntos
Ilusões/fisiologia , Estimulação Luminosa/instrumentação , Percepção Visual/fisiologia , Adulto , Feminino , Humanos , Masculino , Orientação Espacial , Estimulação Luminosa/métodos , Adulto Jovem
10.
Acta Psychol (Amst) ; 206: 103076, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32278119

RESUMO

Patterns of two Ts, materializing different symmetry groups, were used to explore conditions that would lead to a modulation of the typically observed overestimation of the length of a T's undivided line relative to its divided line. Observers either had to compare the lengths of the lines of one or the other of the Ts in a pattern, or noncorresponding lines between the two Ts. For both tasks alike, the T-illusion was found to be markedly greater with twofold mirror-symmetric 2-T patterns than it usually is with individual Ts. A control experiment suggested that the effect was probably due to the collinearity of the two Ts' undivided lines in these patterns rather than the additional axis of mirror symmetry. Findings are interpreted in terms of interactions between orientation-sensitive neurons that respond to the Ts' individual lines.


Assuntos
Ilusões/fisiologia , Ilusões/psicologia , Orientação Espacial/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos
11.
Sci Rep ; 10(1): 6572, 2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32313001

RESUMO

Visual perception can be influenced by stimulus context, selective attention, and prior experience. Many previous studies have shown complex interactions among these influencing factors, but it remains unclear whether context-induced illusions could be reduced by perceptual training and whether such a change in perceptual fidelity is linked to improved perceptual discriminability. To address this question, we introduced a context-induced tilt illusion into an orientation discrimination training paradigm. This resulted in parallel and long-term improvements in the discriminability and fidelity of orientation perception. The improved discriminability was specific to the task-relevant target stimulus but nonspecific to the task-irrelevant context. By contrast, the improved perceptual fidelity was specific to the task-irrelevant contextual stimulus that induced the illusion, but not specific to the task-relevant target stimulus or task performed on one of its features. These results indicate two dissociable learning effects associated with the same training procedure. Such a dissociation was further supported by the observation that the sizes of the two learning effects were uncorrelated across the subjects. Our findings suggest two parallel learning processes: a task-dependent process giving rise to enhanced discriminability for the task-relevant stimulus attribute, and a context-dependent process leading to improved perceptual fidelity for the attended stimuli.


Assuntos
Atenção/fisiologia , Orientação Espacial/fisiologia , Comportamento Espacial/fisiologia , Percepção Visual/fisiologia , Discriminação Psicológica/fisiologia , Feminino , Humanos , Ilusões/fisiologia , Aprendizagem , Masculino , Estimulação Luminosa , Visão Ocular/fisiologia
12.
Sci Rep ; 10(1): 5706, 2020 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-32235881

RESUMO

Body ownership can be experimentally investigated with the rubber hand illusion (RHI), in which watching a rubber hand stroked synchronously with one's own hidden hand induces a feeling of ownership over the rubber hand. The aim of this study was to investigate response to the RHI in high (N = 21) and low (N = 19) hypnotizable individuals in normal waking state and in hypnosis. Response to the RHI was measured via a question on the illusory feeling of ownership and with proprioceptive drift. The Highs expressed an overall feeling of more ownership over the rubber hand in both the normal waking state and hypnosis, although both groups gave higher ownership scores after synchronous than after asynchronous stroking and the difference between conditions was similar across groups. Conversely, the proprioceptive drift appeared to be differentially modulated by hypnosis and hypnotic suggestibility: it was increased in the Highs and decreased in the Lows after hypnosis induction. These findings hint at an interplay between hypnotic suggestibility and hypnosis in modulating response to the RHI. The selective breakdown of proprioceptive drift among the Lows suggests resistance to recalibrate one's own limb in hypnosis.


Assuntos
Imagem Corporal/psicologia , Hipnose , Ilusões/fisiologia , Percepção do Tato/fisiologia , Percepção Visual/fisiologia , Adulto , Feminino , Humanos , Masculino , Sugestão , Adulto Jovem
13.
Atten Percept Psychophys ; 82(2): 564-584, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32189233

RESUMO

We present new evidence about illusory conjunctions (ICs) suggesting that their current explanation requires revision. According to Feature Integration Theory (FIT; Treisman & Gelade Cognitive Psychology, 12, 97-136, 1980), focal attention to a single stimulus is required to bind its features into an integrated percept. FIT predicts that if attention is spread over multiple stimuli, features of these different stimuli can be combined into a single percept and produce ICs. Treisman and Schmidt (Cognitive Psychology, 14, 107-141, 1982) and Cohen & Ivry (Journal of Experimental Psychology: Human Perception and Performance, 15(4), 650-663, 1989) supported this prediction. In the latter study, participants viewed brief displays containing two digits and two colored letters. Digit locations were pre-cued, and participants were instructed to prioritize the digits and to spread their attention across the region encompassed by the digits. Cohen & Ivry found that reports of one letter (the 'target') produced ICs when both letters appeared between the digits. Expanding on Cohen & Ivry's paradigm, we find that both letters do not need to appear between the digits to produce ICs. While the target letter was highly susceptible to ICs if the target appeared inside the position of a nearby digit, the position of the other letter was largely irrelevant. Our experimental results also argue that these ICs were not due to mnemonic errors occurring while the digits are being reported. Based on our findings, we propose that attention to the digits casts an attentional 'shadow' projecting towards fixation, interfering with processing of target letters in that shadow and allowing color information from elsewhere in the display to be included in the resulting percept.


Assuntos
Atenção/fisiologia , Percepção de Cores/fisiologia , Ilusões/fisiologia , Ilusões/psicologia , Estimulação Luminosa/métodos , Adulto , Cor , Sinais (Psicologia) , Feminino , Humanos , Masculino , Memória/fisiologia , Adulto Jovem
14.
Sci Rep ; 10(1): 5412, 2020 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-32214171

RESUMO

Body ownership (the feeling that one's body belongs to oneself) is commonly studied with Rubber hand illusion (RHI) paradigm that allows inducing a temporary illusory feeling of ownership of a life-sized rubber hand. However, it remains unclear whether illusory ownership of the fake hand relies on the same mechanisms as ownership of one's own real hand. Here, we directly compared ownership of the own hand (OH) and fake hand (FH) in the same set of conditions within immersive virtual reality. We obtained behavioral (proprioceptive drift) and subjective (questionnaire) measures of ownership and disownership for virtual OH, FH and object (Obj) that were located congruently or incongruently with the participant's real hand and were stimulated synchronously or asynchronously with the real hand. Both OH and FH (but not Obj) were embodied after synchronous stimulation in both locations. Crucially, subjective ownership of the OH was stronger than of the FH in congruent location after synchronous stimulation. It was also present after asynchronous stimulation, being stronger when the virtual OH was subjectively more similar to the real hand. The results suggest that the detailed appearance of the body might act as an additional component in the construction of body ownership.


Assuntos
Mãos/fisiologia , Ilusões/fisiologia , Percepção Visual/fisiologia , Adulto , Imagem Corporal , Feminino , Humanos , Masculino , Propriocepção/fisiologia , Percepção do Tato/fisiologia , Adulto Jovem
15.
Acta Psychol (Amst) ; 204: 103028, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32062166

RESUMO

Many researchers have proposed that when an individual observes the actions of another individual, the observer simulates the action using many of the same neural areas that are involved in action production. The present study was designed to test this simulation hypothesis by comparing the perception of multisensory stimuli during both the execution and observation of an aiming action. The present work used the fusion illusion - an audio-visual illusion in which two visual stimuli presented with one auditory stimulus are erroneously perceived as being one visual stimulus. Previous research has shown that, during action execution, susceptibly to this illusion is reduced early in the execution of the movement when visual information may be more highly weighted than other sensory information. We sought to determine whether or not a non-acting observer of an action showed a similar reduction in susceptibility to the fusion illusion. Participants fixated a target and either executed or observed a manual aiming movement to that target. Audiovisual stimuli were presented at 0, 100, or 200 ms relative to movement onset and participants reported the number of perceived flashes after the movement was completed. Analysis of perceived flashes revealed that participants were less susceptible to the fusion illusion when the stimuli were presented early (100 ms) relative to later in the movement (200 ms). Critically, this pattern emerged in both execution and observation tasks. These findings support the hypothesis that observers simulate the performance of the actor and experience comparable real-time alterations in multisensory processing.


Assuntos
Percepção Auditiva/fisiologia , Técnicas de Observação do Comportamento/métodos , Ilusões/fisiologia , Ilusões/psicologia , Movimento/fisiologia , Percepção Visual/fisiologia , Estimulação Acústica/métodos , Adulto , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos , Adulto Jovem
16.
Sci Rep ; 10(1): 1665, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-32020035

RESUMO

Prediction is the process by which future events are anticipated based on past events; in contrast, postdiction is the retrospective interpretation of past events based on latter, more recent events. The prediction and postdiction are suggested to be similar based on theoretical models. Previous studies suggest that prediction is impaired in individuals with autism spectrum disorder (ASD). However, it is unclear whether postdiction is also impaired in individuals with ASD. In this study, we evaluated postdiction in individuals with ASD using the cutaneous and stick rabbit illusion paradigms in which the perceived location of a touch shifts postdictively in response to a subsequent touch stimulus. We observed significant cutaneous and stick rabbit illusion in both typically developing (TD) and ASD groups; therefore, postdiction was functional in individuals with ASD. Our present results suggest that postdiction involves a different neuronal process than prediction. We also observed that the ASD group exhibited significantly larger individual difference compared with the TD group in the stick rabbit illusion, which is considered to reflect extension of body schema to external objects. We discuss implications of the individual difference among the ASD participants in the context of sports requiring interactions between the body and external objects.


Assuntos
Transtorno do Espectro Autista/fisiopatologia , Ilusões/fisiologia , Percepção do Tato/fisiologia , Tato/fisiologia , Adolescente , Adulto , Encéfalo/fisiopatologia , Feminino , Humanos , Masculino , Estimulação Física , Adulto Jovem
17.
J Exp Psychol Hum Percept Perform ; 46(2): 172-201, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31985252

RESUMO

Auditory stimuli have been shown to alter visual temporal perception. For example, illusory temporal order is perceived when an auditory tone cues one side of space prior to the onset of simultaneously presented visual stimuli. Competing accounts attempt to explain such effects. The spatial gradient account of attention suggests speeded processing of visual stimuli in the cued space, whereas the impletion account suggests a Gestalt-like process where an attempt is made to arrive at a "realistic" representation of an event given ambiguous conditions. Temporal ventriloquism-where visual temporal order judgment performance is enhanced when a spatially uninformative tone is presented prior to, and after, visual stimuli onset-argues that the temporal relationship of the auditory stimuli to visual stimuli, as well as the number of auditory stimuli equaling the visual stimuli, drives the mechanisms underlying these and related effects. Results from a series of experiments highlight putative inconsistencies in both the spatial gradient account of attention and the classical temporal ventriloquism account. We present novel behavioral effects-illusory temporal order via spatially uninformative tones, and illusory simultaneity via a single tone prior to visual stimuli onset-that can be accounted for by an expanded version of the impletion account. (PsycINFO Database Record (c) 2020 APA, all rights reserved).


Assuntos
Atenção/fisiologia , Percepção Auditiva/fisiologia , Ilusões/fisiologia , Percepção do Tempo/fisiologia , Percepção Visual/fisiologia , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
18.
Acta Psychol (Amst) ; 204: 103016, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32000063

RESUMO

Many aspects of an event can change perceived duration. A common example of this is the magnitude-duration illusion, in which a high magnitude (e.g. large or high value) stimulus will be perceived to last longer than a low magnitude stimulus. The effects of magnitude on perceived duration are normally considered in terms of global context effects; what is large depends on the stimuli used throughout the experiment. In the current article, we examine local context effects in the magnitude-duration illusion, how trial-by-trial changes in magnitude affect the subjective duration of an event. We performed two experiments in which numerical magnitude and stimulus size were varied within either the example phase or reproduction phase of a temporal reproduction task. We showed that in the current trial the combined value-size magnitude presented in the example phase affected subsequent reproductions, while the magnitude presented in the reproduction phase did not. The size magnitude presented in the reproduction phase also affected the reproduction in the following trial, such that a larger stimulus in the current reproduction phase resulted in shorter reproductions in the next reproduction phase. This indicates that low level stimulus properties (i.e. size) can act to contextualize subsequent stimulus properties, which in turn affect perceived duration. The findings of our experiments add local, low-level, context effects to the known modifiers of perceived duration, as well as provide evidence with regards to the role of magnitude in interval timing.


Assuntos
Ilusões/fisiologia , Ilusões/psicologia , Estimulação Luminosa/métodos , Percepção do Tempo/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
19.
Acta Psychol (Amst) ; 203: 102987, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31923880

RESUMO

Research has found that body illusions may be accompanied by consequences for the real body whereby various somatosensory and homeostatic bodily functions may be impaired. These findings stem from research where an experimenter induced the body illusions. In line with advances in the domains of videogames and virtual reality where the real body is used as a controller we investigate if these consequences also accompany self-generated body illusions. In two preregistered experiments we made use of a head-mounted display set-up to induce the full body illusion (FBI) whereby touch is felt to originate from a 3PP body, and examined effects in the simple detection of supra-threshold vibrotactile stimuli presented to the participants' back and head. Results of both experiments indicate that it is possible to induce a FBI through self-stroking of the neck and that the FBI is accompanied by reduced accuracy and delayed reaction times in detection of somatosensory stimuli. In an additional preregistered control experiment the alternative explanation that a difference in motion presented in the conditions was responsible for these findings was ruled out. Our findings corroborate previous studies that have found body illusions to be accompanied by bodily consequences and further extend these findings to the domain of self-induced body illusions. These results are relevant for video games and VR setups that are geared towards virtual embodiment as they advance our understanding of the conditions and mechanisms in which bodily consequences may express themselves.


Assuntos
Imagem Corporal/psicologia , Ilusões/fisiologia , Ilusões/psicologia , Tato/fisiologia , Vibração , Realidade Virtual , Adolescente , Adulto , Emoções/fisiologia , Feminino , Humanos , Masculino , Movimento (Física) , Tempo de Reação/fisiologia , Jogos de Vídeo/psicologia , Adulto Jovem
20.
Acta Psychol (Amst) ; 202: 102958, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31864215

RESUMO

A novel illusion entitled "the letter height superiority effect" has been demonstrated. This shows that letters are perceived as being taller than pseudoletters, while in reality their objective sizes are identical. An explanation of this illusion has been proposed in the framework of the Interactive Activation Model. Indeed, we postulated that the more a feature is activated, the taller a stimulus is perceived as being. The objective of the current study was to test this postulate by manipulating feature activation through signal-to-noise ratio. We presented gray stimuli (low signal-to-noise ratio) or black ones (high signal-to-noise ratio). In a first experiment, participants judged the size of pairs of either letters or pseudoletters presented as black or gray. In a second experiment we presented pairs consisting of a letter and a pseudoletter, of identical or different colors. In a third experiment, we presented pairs of letters or pseudoletters of identical or different colors by block to test the possible effect of previous exposure on perceptual judgments. The results showed that for identical objective size, participants perceive black stimuli to be taller than gray ones and that the effects of the nature of the stimuli and their color are cumulative. The results also indicated that the effects were not due to previous exposure to color or sizes. These results confirm the Interactive Activation Model as a credible explanation for the letter height superiority effect.


Assuntos
Percepção de Cores/fisiologia , Ilusões/fisiologia , Ilusões/psicologia , Reconhecimento Visual de Modelos/fisiologia , Estimulação Luminosa/métodos , Adolescente , Adulto , Feminino , Humanos , Julgamento/fisiologia , Masculino , Tempo de Reação/fisiologia , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...