Publications by authors named "Souta Hidaka"

Introduction: Various genetic mutations have been implicated in autism spectrum disorder (ASD). Some candidate genes for ASD are known to be related to signal transduction and may be involved in hand development as well as neurodevelopment. Therefore, although subtle, anatomical variations in hand configurations may be observed in individuals with ASD.

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When we interact with objects using our hands, we derive their size through our skin. Prolonged exposure to an object leads to a perceptual size aftereffect: adapting to a larger/smaller object makes a subsequently perceived object to appear smaller/larger than its actual size. This phenomenon has been described as haptic as tactile sensations with kinesthetic feedback are involved.

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The brain integrates multisensory information to construct coherent perceptual representations based on spatial and temporal congruence. Intriguingly, multisensory timing perception can be flexibly calibrated. Repeated exposure to audiovisual asynchrony induces shifts in subjective simultaneity (temporal recalibration).

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Our minds frequently wander from a task at hand. This mind-wandering reflects fluctuations in our cognitive states. The phenomenon of perceptual rivalry, in which one of the mutually exclusive percepts automatically switches to an ambiguous sensory input, is also known as fluctuations in our perceptual states.

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People with autism spectrum disorder (ASD) or higher levels of autistic traits have atypical characteristics in sensory processing. Atypicalities have been reported for proprioceptive judgments, which are tightly related to internal bodily representations underlying position sense. However, no research has directly investigated whether self-bodily representations are different in individuals with ASD.

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The number of clinical diagnoses of autism spectrum disorder (ASD) is increasing annually. Interestingly, the human body temperature has also been reported to gradually decrease over the decades. An imbalance in the activation of the excitatory and inhibitory neurons is assumed to be involved in the pathogenesis of ASD.

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Orientation information contributes substantially to our tactile perception, such as feeling an object's shape on the skin. For vision, a perceptual adaptation aftereffect (tilt aftereffect; TAE), which is well explained by neural orientation selectivity, has been used to reveal fundamental perceptual properties of orientation processing. Neural orientation selectivity has been reported in somatosensory cortices.

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Vision of the body without task cues enhances tactile discrimination performance. This effect has been investigated only with static visual information, although our body usually moves, and dynamic visual and bodily information provides ownership (SoO) and agency (SoA) sensations to body parts. We investigated whether vision of body movements could enhance tactile discrimination performance.

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Our bodily sensation is a fundamental cue for our self-consciousness. Whereas experimental studies have uncovered characteristics of bodily sensation, these studies investigated bodily sensations through manipulating bodily sensations to be apart from one's own body and to be assigned to external, body-like objects. In order to capture our bodily sensation as it is, this questionnaire survey study explored the characteristics of bodily sensation using a large population-based sample (N = 580, comprising 20s to 70s age groups) without experimental manipulations.

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Autism spectrum disorder (ASD) is characterized by atypical social communication and restricted and repetitive behaviors; such traits are continuously distributed across nonclinical and clinical populations. Recently, relationships between ASD traits and low-level multisensory processing have been investigated, because atypical sensory reactivity has been regarded as a diagnostic criterion of ASD. Studies regarding an audiovisual illusion (the double-flash illusion) reported that social communication difficulties are related to temporal aspects of audiovisual integration.

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Perceptual completion is a fundamental perceptual function serving to maintain robust perception against noise. For example, we can perceive a vivid experience of motion even for the discrete inputs across time and space (apparent motion: AM). In vision, stimuli irrelevant to AM perception are suppressed to maintain smooth AM perception along the AM trajectory where no physical inputs are applied.

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We perceive the roughness of an object through our eyes and hands. Many crossmodal studies have reported that there is no clear visuo-tactile interaction in roughness perception using static visual cues. One exception is that the visual observation of task-irrelevant hand movements, not the texture of task-relevant objects, can enhance the performance of tactile roughness discrimination.

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Recent studies have demonstrated that mental representations of the hand dorsum are distorted even for healthy participants. Perceptual hand maps estimated by pointing to specific landmarks (e.g.

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Spatial distortions in touch have been investigated since the 19th century. For example, two touches applied to the hand dorsum feel farther apart when aligned with the mediolateral axis (i.e.

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Crossmodal studies have reported not only facilitatory but also inhibitory perceptual interactions. For instance, tactile stimulation to the index finger of a hand leads to the degradation of visual discrimination performance (touch-induced visual suppression, TIVS). It has been suggested that the magnitude of TIVS depends on the spatial congruency of visuo-tactile stimuli and on individual differences in task performance.

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When we hold thin metallic bars between the palms of our hands and rub the palms against each other, the feeling of touching smooth velvet occurs. Previous studies have shown that tactile motion and pressure on the palms are important for this velvet hand illusion. Interestingly, when we experience this illusion, we cannot feel the texture of our palms as we usually do.

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Our visual system briefly retains a trace of a stimulus after it disappears. This phenomenon is known as iconic memory and its contents are thought to be temporally integrated with subsequent visual inputs to produce a single composite representation. However, there is little consensus on the temporal integration between iconic memory and subsequent visual inputs.

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Autism spectrum disorder (ASD) includes characteristics such as social and behavioral deficits that are considered common across the general population rather than unique to people with the diagnosis. People with ASD are reported to have sensory irregularities, including crossmodal perception. Crossmodal correspondences are phenomena in which arbitrary crossmodal inputs affect behavioral performance.

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Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social communication and interaction, and restricted interests and behavior patterns. These characteristics are considered as a continuous distribution in the general population. People with ASD show atypical temporal processing in multisensory integration.

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Studies of crossmodal interactions in motion perception have reported activation in several brain areas, including those related to motion processing and/or sensory association, in response to multimodal (e.g., visual and auditory) stimuli that were both in motion.

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Crossmodal studies have demonstrated inhibitory as well as facilitatory neural effects in higher sensory association and primary sensory cortices. A recent human behavioral study reported touch-induced visual perceptual suppression (TIVS). Here, we introduced an experimental setting in which TIVS could occur and investigated brain activities underlying visuo-tactile interactions using a functional magnetic resonance imaging technique.

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Research regarding crossmodal interactions has garnered much interest in the last few decades. A variety of studies have demonstrated that multisensory information (vision, audition, tactile sensation, and so on) can perceptually interact with each other in the spatial and temporal domains. Findings regarding crossmodal interactions in the spatiotemporal domain (i.

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In a single modality, the percept of an input (e.g., voices of neighbors) is often suppressed by another (e.

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It has been reported that color can affect the judgment of taste. For example, a dark red color enhances the subjective intensity of sweetness. However, the underlying mechanisms of the effect of color on taste have not been fully investigated; in particular, it remains unclear whether the effect is based on cognitive/decisional or perceptual processes.

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