89,706 research outputs found
Human fine motion analysis using biological signals
金沢大学理工研究域電子情報学系In the field of the interface research, confusion had been discussed since before. However, the research that focused on link of interface and confusion motion is very little. In contrast, in the field of the cognitive research, a lot of study about confusion is researching as a popular theme since before. These studies use video camera or motion capture system as a method to observation and analysis of confusion [1]. Consequently, in the study, we acquire and analyze confusion seen from aspect of the field of cognitive research, and we have aimed to create some application at the interface. In this regard, in the field of the cognitive research use very largescale system for observe to confusion motion. So, it is difficult to application to interface. For the reason, we experiment on surface Electromyogram. Surface Electromyogram (EMG) is researched new interface and can observe change in muscle force or fine motion for observe of confusion motion. In the result, we were able to confirm some tendency of the EMG in people puzzled. © 2010 IEEE
Fast, invariant representation for human action in the visual system
Humans can effortlessly recognize others' actions in the presence of complex
transformations, such as changes in viewpoint. Several studies have located the
regions in the brain involved in invariant action recognition, however, the
underlying neural computations remain poorly understood. We use
magnetoencephalography (MEG) decoding and a dataset of well-controlled,
naturalistic videos of five actions (run, walk, jump, eat, drink) performed by
different actors at different viewpoints to study the computational steps used
to recognize actions across complex transformations. In particular, we ask when
the brain discounts changes in 3D viewpoint relative to when it initially
discriminates between actions. We measure the latency difference between
invariant and non-invariant action decoding when subjects view full videos as
well as form-depleted and motion-depleted stimuli. Our results show no
difference in decoding latency or temporal profile between invariant and
non-invariant action recognition in full videos. However, when either form or
motion information is removed from the stimulus set, we observe a decrease and
delay in invariant action decoding. Our results suggest that the brain
recognizes actions and builds invariance to complex transformations at the same
time, and that both form and motion information are crucial for fast, invariant
action recognition
Interactions between motion and form processing in the human visual system
The predominant view of motion and form processing in the human visual system assumes that these two attributes are handled by separate and independent modules. Motion processing involves filtering by direction-selective sensors, followed by integration to solve the aperture problem. Form processing involves filtering by orientation-selective and size-selective receptive fields, followed by integration to encode object shape. It has long been known that motion signals can influence form processing in the well-known Gestalt principle of common fate; texture elements which share a common motion property are grouped into a single contour or texture region. However, recent research in psychophysics and neuroscience indicates that the influence of form signals on motion processing is more extensive than previously thought. First, the salience and apparent direction of moving lines depends on how the local orientation and direction of motion combine to match the receptive field properties of motion-selective neurons. Second, orientation signals generated by “motion-streaks” influence motion processing; motion sensitivity, apparent direction and adaptation are affected by simultaneously present orientation signals. Third, form signals generated by human body shape influence biological motion processing, as revealed by studies using point-light motion stimuli. Thus, form-motion integration seems to occur at several different levels of cortical processing, from V1 to STS
The role of fingerprints in the coding of tactile information probed with a biomimetic sensor
In humans, the tactile perception of fine textures (spatial scale <200
micrometers) is mediated by skin vibrations generated as the finger scans the
surface. To establish the relationship between texture characteristics and
subcutaneous vibrations, a biomimetic tactile sensor has been designed whose
dimensions match those of the fingertip. When the sensor surface is patterned
with parallel ridges mimicking the fingerprints, the spectrum of vibrations
elicited by randomly textured substrates is dominated by one frequency set by
the ratio of the scanning speed to the interridge distance. For human touch,
this frequency falls within the optimal range of sensitivity of Pacinian
afferents, which mediate the coding of fine textures. Thus, fingerprints may
perform spectral selection and amplification of tactile information that
facilitate its processing by specific mechanoreceptors.Comment: 25 pages, 11 figures, article + supporting materia
Complexity, rate, and scale in sliding friction dynamics between a finger and textured surface.
Sliding friction between the skin and a touched surface is highly complex, but lies at the heart of our ability to discriminate surface texture through touch. Prior research has elucidated neural mechanisms of tactile texture perception, but our understanding of the nonlinear dynamics of frictional sliding between the finger and textured surfaces, with which the neural signals that encode texture originate, is incomplete. To address this, we compared measurements from human fingertips sliding against textured counter surfaces with predictions of numerical simulations of a model finger that resembled a real finger, with similar geometry, tissue heterogeneity, hyperelasticity, and interfacial adhesion. Modeled and measured forces exhibited similar complex, nonlinear sliding friction dynamics, force fluctuations, and prominent regularities related to the surface geometry. We comparatively analysed measured and simulated forces patterns in matched conditions using linear and nonlinear methods, including recurrence analysis. The model had greatest predictive power for faster sliding and for surface textures with length scales greater than about one millimeter. This could be attributed to the the tendency of sliding at slower speeds, or on finer surfaces, to complexly engage fine features of skin or surface, such as fingerprints or surface asperities. The results elucidate the dynamical forces felt during tactile exploration and highlight the challenges involved in the biological perception of surface texture via touch
- …