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Results 251 - 300 of 1565
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Hidaka Souta - - 2009
Audition provides important cues with regard to stimulus motion although vision may provide the most salient information. It has been reported that a sound of fixed intensity tends to be judged as decreasing in intensity after adaptation to looming visual stimuli or as increasing in intensity after adaptation to receding ...
Lange Joachim - - 2009
Prosopagnosia is a deficit in recognizing people from their faces. Acquired prosopagnosia results after brain damage, developmental or congenital prosopagnosia (CP) is not caused by brain lesion, but has presumably been present from early childhood onwards. Since other sensory, perceptual, and cognitive abilities are largely spared, CP is considered to ...
Nishina Shigeaki S Honda Research Institute Japan, Saitama 351-0188, Japan. - - 2009
Enhancement in perceptual learning of a visual stimulus can often be explained either by learning of integrated visual information that is processed in higher visual areas or by learning of component information that is processed in lower visual areas. It is not clear on which visual information perceptual learning is ...
Neveu Magella M - - 2009
Albino mammals exhibit a range of visual deficits including disrupted hemispheric pathways, an underdeveloped central retina, and nystagmus. Recently, it has been reported that albino animals also show deficits in the processing of visual motion, exhibiting higher motion coherence thresholds (MCTs; the proportion of coherently moving elements within a field ...
Hesselmann Guido - - 2009
A striking effect of selective attention on perception of first- and second-order motion has been termed 'attention-induced motion blindness' or AMB (Sahraie et al., 2001). The AMB paradigm is based on a rapid serial visual presentation (RSVP) task and causes a severe transient impairment of the detection of coherent motion ...
Arthur Joeanna C - - 2009
Non-sensory (cognitive) inputs can play a powerful role in monitoring one's self-motion. Previously, we showed that access to spatial memory dramatically increases response precision in an angular self-motion updating task [1]. Here, we examined whether spatial memory also enhances a particular type of self-motion updating - angular path integration. "Angular ...
Mercier Manuel - - 2009
A number of electrophysiological studies have been conducted in recent years in order to clarify the dynamics of visual motion processing in the human brain. Using a variety of event-related potential (ERP) measures, several parameters such as onset, offset, contrast and velocity have been investigated, while a critical aspect of ...
Ikeda Hanako - - 2009
The detection of biological motion and the detection of emotion from this motion are important visual functions with obvious survival and social values. The perception of biological motion is remarkably robust, and numerous studies have shown that the emotional states of a person can be deduced from point-light biological motion. ...
Collin Charles A - - 2009
Matching performance is better when pairs of visual stimuli are presented in bilateral conditions--in which one stimulus is presented to each side of the visual field--than in unilateral presentations-when both stimuli are presented to one side of the field. This is called the bilateral field advantage (BFA). The processing of ...
Wright W Geoffrey WG Brandeis University, Waltham, MA 02454, USA. - - 2009
Visual and gravitoinertial sensory inputs are integrated by the central nervous system to provide a compelling and veridical sense of spatial orientation and motion. Although it's known that visual input alone can drive this perception, questions remain as to how vestibular/ proprioceptive (i.e. inertial) inputs integrate with visual input to ...
Rider Andrew T - - 2009
Objects in motion appear shifted in space. For global motion stimuli we can ask whether the shift depends on the local or global motion. We constructed arrays of randomly oriented Gaussian enveloped drifting sine gratings (dynamic Gabors) whose speed was set such that the normal component of motion was consistent ...
Bentvelzen Adam - - 2009
We investigated audiovisual speed perception to test the maximum-likelihood-estimation (MLE) model of multisensory integration. According to MLE, audiovisual speed perception will be based on a weighted average of visual and auditory speed estimates, with each component weighted by its inverse variance, a statistically optimal combination that produces a fused estimate ...
Chiszar David - - 2009
Five hatchling Komodo Dragons (Varanus komodoensis) at Denver Zoo were observed in two experiments that studied the effects of visual and chemical cues arising from prey. Rate of tongue flicking was recorded in Experiment 1, and amount of time the lizards spent interacting with stimuli was recorded in Experiment 2. ...
Wallis Thomas S A - - 2009
Motion-defined form can seem to persist briefly after motion ceases, before seeming to gradually disappear into the background. Here we investigate if this subjective persistence reflects a signal capable of improving objective measures of sensitivity to static form. We presented a sinusoidal modulation of luminance, masked by a background noise ...
Rose David - - 2009
Biological motion stimuli contain a great deal of information about the person and action depicted. Here, we extend the known range by showing that viewers can see which member of a pair of conversing actors is talking. Moreover, the ability varies with the emotional content of the conversation. The implications ...
Saunders Daniel R - - 2009
Biological-motion perception consists of a number of different phenomena. They include global mechanisms that support the retrieval of the coherent shape of a walker, but also mechanisms which derive information from the local motion of its parts about facing direction and animacy, independent of the particular shape of the display. ...
Sprayberry Jordanna D H - - 2009
Hawkmoths rely on vision to track moving flowers during hovering-feeding bouts. Visually guided flight behaviors require a sensorimotor transformation, where motion information processed by the optic ganglia ultimately modifies motor axon activity. While a great deal is known about motion processing in the optic lobes of insects, there has been ...
McMullen Patricia A - - 2009
Traditional theories posit a ventral cortical visual pathway subserving object recognition regardless of the information defining the contour. However, functional magnetic resonance imaging (fMRI) studies have shown dorsal cortical activity during visual processing of static luminance-defined (SL) and motion-defined form (MDF). It is unknown if this activity is supported behaviorally, ...
Hesselmann Guido - - 2008
We have recently shown that intrinsic fluctuations of ongoing activity during baseline have an impact on perceptual decisions reported for an ambiguous visual stimulus (Hesselmann et al., 2008). To test whether this result generalizes from the visual object domain to other perceptual and neural systems, the current study investigated the ...
Badcock David R - - 2009
Geisler's [Geisler, W. S. (1999). Motion streaks provide a spatial code for motion direction. Nature, 400, 65-69] model of motion processing proposes that image smear arising from extended integration periods in Simple cells creates motion streaks which indicate the axis of motion. Orientation cues were provided using textured dot-pairs composed ...
Huang Xin X Vision Center Laboratory, Salk Institute for Biological Studies, La Jolla, California 92037, USA. - - 2008
The perceptual interpretation of a given visual feature depends on the surrounding context. To explore the neural mechanisms underlying such contextual interactions in the motion domain, we studied responses of neurons in the middle temporal area (MT) of macaque monkeys while presenting a variety of center-surround stimuli that stimulated both ...
Burr David C - - 2009
Humans are extremely sensitive to visual motion, largely because local motion signals can be integrated over a large spatial region. On the other hand, summation is often not advantageous, for example when segmenting a moving stimulus against a stationary or oppositely moving background. In this study we show that the ...
Amano Kaoru - - 2009
Human brain uses visual motion inputs not only for generating subjective sensation of motion but also for directly guiding involuntary actions. For instance, during arm reaching, a large-field visual motion is quickly and involuntarily transformed into a manual response in the direction of visual motion (manual following response, MFR). Previous ...
Salillas Elena - - 2009
In the present study, a group of patients with left-sided neglect performed a number comparison task that co-occurred either with coherent motion in different directions or with random motion. Their performance was compared to that of a healthy control group and to a group of patients with right hemisphere damage ...
Wibral Michael - - 2009
When 2 visual stimuli are presented one after another in different locations, they are often perceived as one, but moving object. Feedback from area human motion complex hMT/V5+ to V1 has been hypothesized to play an important role in this illusory perception of motion. We measured event-related responses to illusory ...
Lewald Jörg - - 2009
The perception of motion is an essential prerequisite to responding adequately to the dynamic aspects of sensory information in the environment. The neural substrates of auditory motion processing are, at present, still a matter of debate. It has been hypothesized that motion information is, as in the visual system, processed ...
Liang Pei - - 2008
Many response characteristics of neurons sensitive to visual motion depend on stimulus history and change during prolonged stimulation. Although the changes are usually regarded as adaptive, their functional significance is still not fully understood. With experimenter-defined stimuli, previous research on motion adaptation has mainly focused on enhancing the detection of ...
Kozak Lajos R - - 2009
PURPOSE: To study how central visual motion integration and segmentation processes are influenced by the congruence or incongruence of peripheral contextual moving surrounds and to determine their clinical relevance. METHODS: Nine subjects participated in experiments 1 and 2 (12-second blocks containing 2-second static fixation and 10-second surface plaid movement) and ...
Barnes G R GR Faculty of Life Sciences, University of Manchester, Moffat Building, Sackville St., Manchester M60 1QD, United Kingdom. - - 2008
Ocular pursuit movements allow moving objects to be tracked with a combination of smooth movements and saccades. The principal objective is to maintain smooth eye velocity close to object velocity, thus minimising retinal image motion and maintaining acuity. Saccadic movements serve to realign the image if it falls outside the ...
Moutoussis Konstantinos - - 2008
Several human and monkey studies have demonstrated a close relationship between motion perception and activation of area V5, leading to the general view that activity in this area correlates with the subjective experience of motion. In the present study, we investigate whether the responses of this area are still governed ...
Becker Hubertus G T - - 2008
The detection of coherent motion embedded in noise has been widely used as a measure of global visual motion processing. Animal studies have demonstrated that this performance is closely linked to the responses of direction-sensitive neurons in the macaque middle temporal (MT) and medial superior temporal (MST) areas. Despite the ...
Huddleston Wendy E - - 2008
A perception of coherent motion can be obtained in an otherwise ambiguous or illusory visual display by directing one's attention to a feature and tracking it. We demonstrate an analogous auditory effect in two separate sets of experiments. The temporal dynamics associated with the attention-dependent auditory motion closely matched those ...
Väljamäe A - - 2008
Information about the motion of objects can be extracted by multiple sensory modalities, and, as a consequence, object motion perception typically involves the integration of multi-sensory information. Often, in naturalistic settings, the flow of such information can be rather discontinuous (e.g. a cat racing through the furniture in a cluttered ...
Seno Takeharu T Intelligent Modeling Laboratory, Department of Psychology, Graduate School of Humanities and Sociology, University of Tokyo, Tokyo, 113-0033, Japan. - - 2009
We examined the biases in vection strength caused by motion direction (temporonasal vs. nasotemporal motion) and position of stimulus presentation (nasal and temporal semi-retinas) to investigate a subcortical contribution to vection. These biases have been identified for optokinetic nystagmus (OKN) and are acknowledged as evidence for a subcortical origin of ...
Getzmann Stephan - - 2008
The effect of velocity on auditory motion processing in combination with a motion-onset delay was investigated in two experiments. The detection of motion onset and discrimination of motion direction were studied, employing a psychophysical reaction time task. Listeners were presented with sounds moving along the frontal horizontal plane in a ...
Cattaneo Zaira - - 2008
The state-dependency approach of transcranial magnetic stimulation (TMS) enables differential stimulation of functionally distinct neural populations within the affected region of cortex. Here we tested the validity of a paradigm based on state-dependency, the TMS-adaptation paradigm, in the context of visual motion perception. Visual adaptation was used to induce an ...
Castelo-Branco Miguel - - 2009
Motion processing involves multiple hierarchical steps, from the magnocellular pathway, sensitive to high temporal frequency modulations, to subsequent motion integration within the visual cortical dorsal stream. We have tested whether motion integration deficits in mild Parkinson disease (PD) can be explained by visual deficits in earlier processing nodes. Contrast sensitivity ...
Cicchino Jessica B - - 2008
Three experiments investigated 5- through 8-month-olds' ability to encode self-propelled and caused motion and examined whether processing of motion onset changes when crawling begins. Infants were habituated (Experiments 1 and 2) or familiarized (Experiment 3) with simple causal and noncausal launching events. They then viewed the caused-to-move and self-propelled objects ...
Hall-Haro Cynthia C Center for Neural Science, New York University, New York, NY 10012, - - 2008
We studied the development of sensitivity to complex motion using plaid patterns. We hypothesized, based on neurophysiological data showing a dearth of pattern direction-selective (PDS) cells in area medial temporal (MT) of infant macaques, that sensitivity to pattern motion would develop later than other forms of global motion sensitivity. We ...
Paradis A-L - - 2008
This study aims at segregating the neural substrate for the 3D-form and 3D-motion attributes in structure-from-motion perception, and at disentangling the stimulus-driven and endogenous-attention-driven processing of these attributes. Attention and stimulus were manipulated independently: participants had to detect the transitions of one attribute--form, 3D motion or colour--while the visual stimulus ...
Linares Daniel - - 2008
When humans view a moving object, the spatial lag in perception expected from neural delays may be partially corrected by motion mechanisms biasing perceived position. The drifting-Gabor illusion seems to support this view: the perceived location of a static envelope filled with a moving pattern is shifted in the direction ...
Gold Joshua I JI University of Pennsylvania, Department of Neuroscience, 116 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104-6074, USA. - - 2008
Choice behavior on simple sensory-motor tasks can exhibit trial-to-trial dependencies. For perceptual tasks, these dependencies reflect the influence of prior trials on choices that are also guided by sensory evidence, which is often independent across trials. Here we show that the relative influences of prior trials and sensory evidence on ...
Deas Ross W RW Visual Neuroscience Group, School of Psychology, The University of Nottingham, University Park, Nottingham, UK. - - 2008
Adaptation to visual motion can induce marked distortions of the perceived spatial location of subsequently viewed stationary objects. These positional shifts are direction specific and exhibit tuning for the speed of the adapting stimulus. In this study, we sought to establish whether comparable motion-induced distortions of space can be induced ...
Freeman Elliot - - 2008
In temporal ventriloquism, auditory events can illusorily attract perceived timing of a visual onset [1-3]. We investigated whether timing of a static sound can also influence spatio-temporal processing of visual apparent motion, induced here by visual bars alternating between opposite hemifields. Perceived direction typically depends on the relative interval in ...
Hayashi Ryusuke R Department of Integrative Brain Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan. - - 2008
We have recently developed a new motion display in which the monocular and dichoptic motion components move in opposite directions (Hayashi et al. 2007). In the present paper, we estimated the difference between the integration times required to detect the dichoptic motion and monocular motion by changing the duration of ...
Pavan Andrea - - 2008
Motion perception influences perceived position. It has been shown that first-order (luminance defined) motion shifts perceived position across a wide range of spatial and temporal frequencies. On the other hand, second-order (contrast defined) motion shifts perceived position over a narrow range of temporal frequencies, regardless of spatial frequency [Bressler, D. ...
Welchman Andrew E - - 2008
Determining the approach of a moving object is a vital survival skill that depends on the brain combining information about lateral translation and motion-in-depth. Given the importance of sensing motion for obstacle avoidance, it is surprising that humans make errors, reporting an object will miss them when it is on ...
Kerzel Dirk D Faculté de Psychologie et des Sciences de l'Education, Université de Genève, 40 Boulevard du Pont d'Arve, 1205 Geneva, Switzerland. - - 2008
During smooth pursuit eye movements, briefly presented objects are mislocalized in the direction of motion. It has been proposed that the localization error is the sum of the pursuit signal and the retinal motion signal in a ~200 ms interval after flash onset. To evaluate contributions of retinal motion signals ...
McAleer Phil - - 2008
The impression of animacy from the motion of simple shapes typically relies on synthetically defined motion patterns resulting in pseudorepresentations of human movement. Thus, it is unclear how these synthetic motions relate to actual biological agents. To clarify this relationship, we introduce a novel approach that uses video processing to ...
Katsov Alexander Y - - 2008
Motion vision is an ancient faculty, critical to many animals in a range of ethological contexts, the underlying algorithms of which provide central insights into neural computation. However, how motion cues guide behavior is poorly understood, as the neural circuits that implement these computations are largely unknown in any organism. ...
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