Patients with vestibular dysfunction have visual, perceptual, and postural deficits. While there is considerable evidence that a semicircular canal prosthesis that senses angular head velocity and stimulates canal ampullary nerves can improve vision by augmenting the vestibulo-ocular reflex, no information is available regarding the potential utility of a canal prosthesis ...

Amplitude modulation encoding is critical for human speech perception and complex sound processing in general. The modulation transfer function (MTF) is a staple of auditory psychophysics, and has been shown to predict speech intelligibility performance in a range of adverse listening conditions and hearing impairments, including cochlear implant-supported hearing. Although ...

We recently demonstrated that the latency of a component of the event-related brain potential, the topographical N170 (NT170), is sensitive to the spatial location of reward-related stimuli in a virtual maze environment, occurring earlier for rewards found following rightward turns compared to leftward turns. We suggested that this NT170 latency ...

How is visual space represented in cortical area MT+? At a relatively coarse scale, the organization of MT+ is debated; retinotopic, spatiotopic, or mixed representations have all been proposed. However, none of these representations entirely explain the perceptual localization of objects at a fine spatial scale-a scale relevant for tasks ...

I lose track of time when I climb a mountain. My biggest motivation is to reach the summit.

Current knowledge about the precise timing of visual input to the cortex relies largely on spike timings in monkeys and evoked-response latencies in humans. However, quantifying the activation onset does not unambiguously describe the timing of stimulus-feature-specific information processing. Here, we investigated the information content of the early human visual ...

Novel techniques for sound waveform visualization and real-time pitch tracking are presented. The use of techniques is demonstrated on vocal sounds such as singing and speech. The visualization of a sound waveform in two- or three-dimensional reconstructed phase space obtained via signal time-delay embedding provides a compelling alternative to traditional ...

The nonvisual self-touch rubber hand paradigm elicits the compelling illusion that one is touching one's own hand even though the two hands are not in contact. In four experiments, we investigated spatial limits of distance (15cm, 30cm, 45cm, 60cm) and alignment (0°, 90° anti-clockwise) on the nonvisual self-touch illusion and ...

Objective. Our goal was to identify spatial filtering methods that would improve decoding of continuous arm movements from epidural field potentials as well as demonstrate the use of the epidural signals in a closed-loop brain-machine interface (BMI) system in monkeys. Approach. Eleven spatial filtering options were compared offline using field ...

The dorsal and ventral streams model of action and perception suggests that reaching to grasp a tool for use involves integrated operation of the two streams. Few attempts have been made to test the limits of this integration in normal subjects. Twenty normal subjects reached for tools or geometric objects ...

The central position and universality of music in human societies raises the question of its phylogenetic origin. One of the most important properties of music involves harmonic musical intervals, in response to which humans show a spontaneous preference for consonant over dissonant sounds starting from early human infancy. Comparative studies ...

The Zeitraffer phenomenon is the altered perception of the speed of moving objects. A single case is reported using the subject's own description of a transient alteration of the visual perception of motion. The literature on the subject is reviewed. The Zeitraffer phenomenon probably arises from dysfunction of brain networks ...

PURPOSE: To determine whether high light levels, which have a protective effect against form-deprivation myopia, also retard the development of lens-induced myopia in primates. METHODS: Hyperopic defocus was imposed on 27 monkeys by securing -3 D lenses in front of one eye. The lens-rearing procedures were initiated at 24 days ...

IPS18800 is a partial skeleton attributed to the fossil great ape Hispanopithecus laietanus, and dated to 9.6 Ma (millions of years ago). Previous studies on the postcranial anatomy of this taxon have shown that it displayed a derived, extant great ape-like orthograde body plan with suspensory adaptations, uniquely coupled with adaptations ...

Visual input is remarkably diverse. Certain sensory inputs are more probable than others, mirroring statistical regularities of the visual environment. The visual system exploits many of these regularities, resulting, on average, in better inferences about visual stimuli. However, by incorporating prior knowledge into perceptual decisions, visual processing can also result ...

Adapting to visual collisions increases the tendency to see the colliding objects as sliding over one another, rather than as one 'launching' another, but only in the adapted retinal location. This demonstrates a low-level perceptual component to the interpretation of the causes of visual events.

We employed a virtual environment to examine the postural behaviors of adults with cerebral palsy (CP). Four adults with CP (22-32 years) and nine healthy adults (21-27 years) were tested with a Rod and Frame protocol. They then stood quietly on a platform within a three-wall virtual environment. The platform ...

Previous research has shown that retinal slip can be a significant factor in causing motion sickness. Stroboscopic illumination may prevent retinal slip by providing snapshots of the visual environment that are brief enough so each image is stationary on the retina. The purpose of this study was to determine the ...

Although it is increasingly accepted that temporal expectation can modulate early perceptual processing, the underlying neural computations remain unknown. In the present study, we combined a psychophysical paradigm with electrophysiological recordings to investigate the putative contribution of low-frequency oscillatory activity in mediating the modulation of visual perception by temporal expectation. ...

Expertise in sports enhances the ability to anticipate forthcoming events from the observation of a player's actions. In the present study, we investigated whether this ability is applicable to deceptive action. In three experiments, performance at anticipating the direction change of a running opponent was examined with experienced rugby players ...

It is widely argued that the ability to recognize and identify manipulable objects depends on the retrieval and simulation of action-based information associated with using those objects. Evidence for that view comes from fMRI studies that have reported differential BOLD contrast in dorsal visual stream regions when participants view manipulable ...

In the present study, we investigated the effect of weightlessness on the ability to perceive and remember self-motion when passing through virtual 3D tunnels that curve in different direction (up, down, left, right). We asked cosmonaut subjects to perform the experiment before, during and after long-duration space flight aboard the ...

We investigated perceptual learning in self-motion perception. Blindfolded participants were displaced leftward or rightward by means of a motion platform and asked to indicate the direction of motion. A total of eleven participants underwent 3,360 practice trials, distributed over twelve (Experiment 1) or 6 days (Experiment 2). We found no improvement ...

Collagen fiber content and orientation affect the viscoelastic properties of the vocal folds, determining oscillation characteristics during speech and other vocalization. The investigation and reconstruction of the collagen network in vocal folds remains a challenge, because the collagen network requires at least micron-scale resolution. In this study, we used polarized ...

We have investigated the relation between visuo-tactile interactions and the self-other distinction. In the Visual Enhancement of Touch (VET) effect, non-informative vision of one's own hand improves tactile spatial perception. Previous studies suggested that looking at another person's hand could also enhance tactile perception, but did not systematically investigate the ...

The pattern of shading across an image can provide a rich sense of object shape. Our ability to use shading information is remarkable given the infinite possible combinations of illumination, shape and reflectance that could have produced any given image. Illumination can change dramatically across environments (e.g. indoor vs. outdoor) ...

For each saccade, we select an object to direct gaze and to specify the direction and amplitude of eye movement. Although these 2 processes are inevitably interdependent when visual stimuli are held stationary, several lines of evidence suggest that the neuronal signals in the frontal eye fields (FEF) that underlie ...

Does the nervous system continuously realign the senses so that objects are seen and felt in the same place? Conflicting answers to this question have been given. Research imposing a sensory mismatch has provided evidence that the nervous system realigns the senses to reduce the mismatch. Other studies have shown ...

Multisensory signals can enhance the spatial perception of objects and events in the environment. Changes of visual size and auditory intensity provide us with the main cues about motion direction in depth. However, frequency changes in audition and binocular disparity in vision also contribute to the perception of motion in ...

Human speech universally exhibits a 3- to 8-Hz rhythm, corresponding to the rate of syllable production, which is reflected in both the sound envelope and the visual mouth movements. Artificial perturbation of the speech rhythm outside the natural range reduces speech intelligibility, demonstrating a perceptual tuning to this frequency band. ...

Multiple visual signals are relevant to perception of heading direction. While the role of optic flow and depth cues has been studied extensively, little is known about the visual effects of gravity on heading perception. We used fMRI to investigate the contribution of gravity-related visual cues on the processing of ...

We easily recover the causal properties of visual events, enabling us to understand and predict changes in the physical world. We see a tennis racket hitting a ball and sense that it caused the ball to fly over the net; we may also have an eerie but equally compelling experience ...

Recent stimulus history-adaptation-alters neuronal responses and perception. Previous electrophysiological and perceptual studies suggest that prolonged adaptation strengthens and makes more persistent the effects seen after briefer exposures. However, no systematic comparison has been made between the effects of adaptation lasting hundreds of milliseconds, which might arise during a single fixation, ...

BACKGROUND:Adequate light is essential for vision during direct laryngoscopy. The ISO 7376:2009 standard specifies the minimal illuminance for laryngoscopes. No studies have objectively examined the relationship between laryngoscope illumination and visual acuity during laryngoscopy.METHODS:We measured the near visual performance of 50 anesthesiologists during direct laryngoscopy using near vision charts located ...

Information received from different sensory modalities profoundly influences human perception. For example, changes in the auditory flutter rate induce changes in the apparent flicker rate of a flashing light (Shipley, 1964). In the present study, we investigated whether auditory information would affect the perceived offset position of a moving object. ...

Neurons in the middle temporal area (MT) are often viewed as motion detectors that prefer a single direction of motion in a single region of space. This assumption plays an important role in our understanding of visual processing, and models of motion processing in particular. We used extracellular recordings in ...

Recent studies have emphasized the functional role of neuronal activity underlying oscillatory local field potential (LFP) signals during visual processing in natural conditions. While functionally relevant components in multiple frequency bands have been reported, little is known about whether and how these components interact with each other across the dominant ...

We used the perceptual reports of nonhuman primates to perform psychophysical calibrations of S-cone isolating stimuli. S-cone stimuli were calibrated separately at several spatial locations for each monkey. To do this we exploited the effect of transient tritanopia, which causes a selective decrease of sensitivity in the observer's S-cone channel. ...

Many neurons in the macaque ventral intraparietal area (VIP) are multimodal, i.e., they respond not only to visual but also to tactile, auditory and vestibular stimulation. Anatomical studies have shown distinct projections between area VIP and a region of premotor cortex controlling head movements. A specific function of area VIP ...

Humans show spontaneous synchronization of movements during social interactions; this coordination has been shown to facilitate smooth communication. Although human studies exploring spontaneous synchronization are increasing in number, little is known about this phenomenon in other species. In this study, we examined spontaneous behavioural synchronization between monkeys in a laboratory ...

The present study was motivated by a theory, which proposes that speech includes articulatory gestures that are connected to particular hand actions. We hypothesized that certain articulatory gestures would be more associated with the precision grip than with the power grip, and vice versa. In the study, the participants pronounced ...

Cognitive control requires the suppression of distracting information in order to focus on task-relevant information. We applied EEG source reconstruction via time-frequency linear constrained minimum variance beamforming to help elucidate the neural mechanisms involved in spatial conflict processing. Human subjects performed a Simon task, in which conflict was induced by ...

Many locomotor tasks involve interactions with moving objects. When observer (i.e., self-)motion is accompanied by object motion, the optic flow field includes a component due to self-motion and a component due to object motion. For moving observers to perceive the movement of other objects relative to the stationary environment, the ...

The optic flow generated when a person moves through the environment can be locally decomposed into several basic components, including radial, circular, translational and spiral motion. Since their analysis plays an important part in the visual perception and control of locomotion and posture it is likely that some brain regions ...

Transmission of neural signals in the brain takes time due to the slow biological mechanisms that mediate it. During such delays, the position of moving objects can change substantially. The brain could use statistical regularities in the natural world to compensate neural delays and represent moving stimuli closer to real ...

Humans show a spontaneous tendency to increase the velocity of their movements depending on the linear extent of their trajectory in order to keep execution time approximately constant. Termed the isochrony principle, this compensatory mechanism refers to the observation that the velocity of voluntary movements increases proportionally with their linear ...

It has now been well established that the point of subjective synchrony for audio and visual events can be shifted following exposure to asynchronous audio-visual presentations, an effect often referred to as temporal recalibration. Recently it was further demonstrated that it is possible to concurrently maintain two such recalibrated estimates ...

Several studies suggest that numerical and spatial representations are intrinsically linked. Recent findings demonstrate that also motor actions interact with number magnitude processing, showing a motor-to-semantic effect. The current study assesses whether calculation processes can be modulated by motions performed with the whole body. Participants were required to make additions ...

Intra-modal apparent motion has been shown to be affected or 'captured' by information from another, task-irrelevant modality, as shown in cross-modal dynamic capture effect. Here we created inter-modal apparent motion between visual and tactile stimuli and investigated whether there are mutual influences between auditory apparent motion and inter-modal visual/tactile apparent ...

Information obtained from multiple sensory modalities, such as vision and touch, is integrated to yield a holistic percept. As a haptic approach usually involves cross-modal sensory experiences, it is necessary to develop an apparatus that can characterize how a biological system integrates visual-tactile sensory information as well as how a ...