A5067431984- Hearing Loss and Rehabilitation
- Visual perception and processing mechanisms
- Neuroscience and Music Perception
- EEG and Brain-Computer Interfaces
- Neural dynamics and brain function
- Functional Brain Connectivity Studies
- Advanced MRI Techniques and Applications
- Speech and Audio Processing
- Multisensory perception and integration
- Color perception and design
- Blind Source Separation Techniques
- Phonetics and Phonology Research
- Advanced Vision and Imaging
- Neural Networks and Applications
- Color Science and Applications
- Tactile and Sensory Interactions
- Computer Graphics and Visualization Techniques
- Language Development and Disorders
- Robotics and Automated Systems
- Atomic and Subatomic Physics Research
- Advanced Neuroimaging Techniques and Applications
- Reading and Literacy Development
- Neuroscience, Education and Cognitive Function
- Advanced Image Processing Techniques
- Neural and Behavioral Psychology Studies
RIKEN
2007-2023
RIKEN Center for Integrative Medical Sciences
2023
Faculty of Design
2022
Kyushu University
2021-2022
National Institute of Mental Health
2014-2022
National Center of Neurology and Psychiatry
2014-2022
RIKEN Center for Sustainable Resource Science
2022
RIKEN Nishina Center
2006-2015
RIKEN Center for Brain Science
1998-2012
The University of Tokyo
1990-2010
A novel noninvasive magnetic resonance imaging (MRI) method was developed to determine in vivo blood oxygen saturation and its changes during motor cortex activation small cerebral veins. Specifically, based on susceptibility measurements the resting states, pial veins were found have a mean of Yrest = 0.544 ± 0.029 averaged over 14 vessels 5 volunteers. During activation, revealed an change ΔYsusc 0.14 0.02. Independent evaluation from flow velocity yielded value ΔYflow 0.04 for this...
Our previous investigation on the effect of stretching spectrotemporally degraded and temporally interrupted speech stimuli showed remarkable intelligibility gains [Udea, Takeichi, Wakamiya (2022). J. Acoust. Soc. Am. 152(2), 970–980]. In this study, however, gap durations temporal resolution were confounded. current investigation, we therefore observed so-called mosaic while dissociating effects interruption resolution. The (20 frequency bands 20 ms segment duration) declined from 95% to...
Amodal completion of partly occluded figures is analyzed as natural computation. Here amodal shown to consist four subproblems: representation, parsing, correspondence, and interpolation. Second, each problem be basically solvable on the basis generic-viewpoint assumption. It also argued that interpolation might key because mutual interdependence among subproblems. Third, a theory described for problem, in which assumption curvature-consistency are presumed. The entails orientation curvature...
Understanding the neural mechanisms underlying speech production has a number of potential practical applications. Speech involves multiple feedback loops. An audio-vocal monitoring system plays an important role in production, based on auditory about speaker's own voice. Here we investigated mu-rhythm activity associated with by examining event-related desynchronization and synchronization conditions delayed (DAF) noise (Lombard). In Experiment 1, confirmed that mu-rhythms were detectable...
A novel kind of depth-spreading effect which should be distinguished in various aspects from the known interpolation, averaging, or ‘filling-in’ phenomena is reported. The demonstrations and experiments suggest that depth an uncrossed disparity can extrapolated from, not just interpolated between, illusory real contours to form perceptually a background surface. In addition, contour itself could drastically changed configuration sharpness, contingently with perceptual background-surface...
We conducted two event-related potential (ERP) experiments that examined the mechanisms of auditory temporal assimilation. Stimulus patterns consisted neighboring time intervals marked by three successive tone bursts (20 ms, 1000 Hz). Six stimuli were used in which first interval (T1) varied from 100 to 280 while second (T2) was fixed at 200 ms. Two other different T1/T2 combinations employed. Participants judged whether T1 and T2 had same duration or not pressing a button. ERPs recorded 11...
Two aspects of neon color spreading, local spreading (neon flank) and illusory contour, were investigated by dichoptic viewing. Neon flank was not observed under appropriate stimulation, suggesting that input to the process for is based on monocular configuration. However, contours formed according interocularly combined configuration rather than each configuration, responsible should be ocularly-nonselective binocular, monocular. The possibilities artifacts such as those arising from...
The study investigated how the brain activity changed when participants were engaged in a temporal production task known as "filled-duration illusion". Twelve right-handed asked to memorize and reproduce duration of time intervals (600 or 800 ms) bounded by two flashes. Random trials contained auditory stimuli form three 20-ms sounds between In one session, ignore presence sounds, other, they instructed pay attention sounds. behavioral results showed that reproduction was clearly affected...
Time is a fundamental dimension, but millisecond-level judgments sometimes lead to perceptual illusions. We previously introduced "time-shrinking illusion" using psychological paradigm that induces auditory temporal assimilation (ATA). In ATA, the duration of two successive intervals (T1 and T2), marked by three stimuli, can be perceived as equal when they are not. Here, we investigate spatiotemporal profile human magnetoencephalography (MEG). Behavioural results showed typical ATA:...
The effect of curvature on visual interpolation in partly occluded figures was examined. In experiments 1 and 2, the shape a visually interpolated contour measured by using partially triangle or circle as target figure. targets were cut off at both sides, with varying width from trial to trial. experiment 1, peak height, which supposed represent contour, for each size visible part. A significant curvature, difference height between targets, found when part 10 20 min. became stronger linearly...
Brain activity related to time estimation processes in humans was analyzed using a perceptual phenomenon called auditory temporal assimilation. In typical stimulus condition, two neighboring intervals (T1 and T2 this order) are perceived as equal even when the physical lengths of these considerably different. Our previous event-related potential (ERP) study demonstrated that slow negative component (SNCt) appears right-frontal brain area (around F8 electrode) after T2, which is associated...
Purpose This study aimed to use graph theoretical analysis of anatomical covariance derived from structural MRI reveal how the gray matter connectivity pattern is altered after corpus callosotomy (CC). Materials and methods We recruited 21 patients with epilepsy who had undergone CC. Enrollment criteria were applied: (1) no lesion identified on brain MRI; (2) history other surgery; (3) age not younger than 3 years older 18 at preoperative evaluation. The most common syndrome was...
It has been shown that the intelligibility of checkerboard speech stimuli, in which signals were periodically interrupted time and frequency, drastically varied according to combination number frequency bands (2-20) segment duration (20-320 ms). However, effects between 4 20 division parameters on have largely unknown. Here, we show was lowest four-band except for 320-ms duration. Then, temporally stimuli eight-band came this order (N = 19 20). At same time, U-shaped curves observed possibly...
The intelligibility of interrupted speech (interrupted over time) and checkerboard time-by-frequency), both which retained a half the original speech, was examined. stimuli decreased as segment duration increased. 20-band brought nearly 100% irrespective duration, whereas, with 2 4 frequency bands, trough 35%–40% appeared at 160-ms duration. Mosaic (power averaged time-frequency unit) yielded generally poor (⩽10%). results revealed limitations underlying auditory organization for cues...
To clarify the time course over which human brain processes information about durations up to ∼300 ms, we reanalyzed data that were previously reported by Mitsudo et al. (2009) using a multivariate analysis method. Event-related potentials recorded from 19 scalp electrodes on 11 (nine original and two additional) participants while they judged whether neighboring empty intervals - called t1 t2 marked three tone bursts had equal durations. There was also control condition in presented same...