If You Are Old, Videos Look Slow. The Paradoxical Effect of Age-Related Motor Decline on the Kinematic Interpretation of Visual Scenes

Perception and action are tightly coupled. However, there is still little recognition of how individual motor constraints impact perception in everyday life. Here we asked whether and how the motor slowing that accompanies aging influences the sense of visual speed. Ninety-four participants aged between 18 and 90 judged the natural speed of video clips reproducing real human or physical motion (SoS, Sense-of-Speed adjustment task). They also performed a finger tapping task and a visual search task, which estimated their motor speed and visuospatial attention speed, respectively. Remarkably, aged people judged videos to be too slow (speed underestimation), as compared to younger people: the Point of Subjective Equality (PSE), which estimated the speed bias in the SoS task, was +4% in young adults (<40), +12% in old adults (40–70) and +16% in elders. On average, PSE increased with age at a rate of 0.2% per year, with perceptual precision, adjustment rate, and completion time progressively worsening. Crucially, low motor speed, but not low attentional speed, turned out to be the key predictor of video speed underestimation. These findings suggest the existence of a counterintuitive compensatory coupling between action and perception in judging dynamic scenes, an effect that becomes particularly germane during aging.

Gestures in ensemble performance

Gestures, defined as meaning-bearing bodily actions, play important and varied roles in ensemble performance. This chapter discusses how the term “gesture” differs from physical “motion” and perceived “action.” The functional differences between sound-producing, sound-facilitating, sound-accompanying, and communicative actions are presented, alongside how these can be performed and/or perceived as meaning-bearing gestures. The role of gestures in ensemble performance is examined from four perspectives: (1) ensemble size and setup; (2) the musical degrees of freedom of the ensemble; (3) the musical leadership; and (4) the role of machines in the musicianship. It is argued that the use of gestures varies between different types of ensembles and musical genres. The common denominator is the need for meaning-bearing bodily communication between performers, with such gestures also playing an important part in the musical communication with the audience.

Instructor-learner body coupling reflects instruction and learning

It is widely accepted that nonverbal communication is crucial for learning, but the exact functions of interpersonal coordination between instructors and learners remain unclear. Specifically, it is unknown what role instructional approaches play in the coupling of physical motion between instructors and learners, and crucially, how such instruction-mediated Body-to-Body Coupling (BtBC) might affect learning. We used a video-based, computer-vision Motion Energy Analysis (MEA) to quantify BtBC between learners and instructors who used two different instructional approaches to teach psychological concepts. BtBC was significantly greater when the instructor employed a scaffolding approach than when an explanation approach was used. The importance of instructional approach was further underscored by the fact that an increase in motion in the instructor was associated with boosted BtBC, but only during scaffolding; no such relationship between the instructor movements and BtBC was found during explanation interactions. Finally, leveraging machine learning approaches (i.e., support vector and logistic regression models), we demonstrated that both learning outcome and instructional approaches could be decoded based on BtBC. Collectively, these results show that the real-time interaction of teaching and learning bodies is important for learning and that instructional approach matters, with possible implications for both in-person and online learning.

Examining the Effect of Adverbs and Onomatopoeia on Physical Movement

Introduction: The effect of promoting a physical reaction by the described action is called the action-sentence compatibility effect (ACE). It has been verified that physical motion changes depending on the time phase and grammatical expression. However, it is unclear how adverbs and onomatopoeia change motion simulations and subsequent movements.Methods: The subjects were 35 healthy adults (11 females; mean age 21.3). We prepared 20 sentences each, expressing actions related to hands and feet. These were converted into 80 sentences (stimulus set A), with the words “Slow” or “Quick” added to the words related to the speed of movement, and 80 sentences (stimulus set B) with the words “Fast” and onomatopoeia “Satto” added. Additionally, 20 unnatural sentences were prepared for each stimulus set as pseudo sentences. Choice reaction time was adopted; subjects pressed the button with their right hand only when the presented text was correctly understood (Go no-go task). The reaction time (RTs) and the number of errors (NoE) were recorded and compared.Results: As a result of a two-way repeated ANOVA, an interaction effect (body parts × words) was observed in RTs and NoE in set A. “Hand and Fast” had significantly faster RTs than “Hand and Slow” and “Foot and Fast.” Furthermore, “Hand and Fast” had a significantly higher NoE than others. In set B, the main effects were observed in both RTs and NoE. “Hand” and “Satto” had significantly faster RTs than “Foot” and “Quick,” respectively. Additionally, an interaction effect was observed in NoE, wherein “Foot and Satto” was significantly higher than “Hand and Satto” and “Foot and Quick.”Conclusion: In this study, the word “Fast” promoted hand response, reaffirming ACE. The onomatopoeia “Satto” was a word that conveys the speed of movement, but it was suggested that the degree of understanding may be influenced by the body part and the attributes of the subject.

Flexible Wireless Passive LC Pressure Sensor with Design Methodology and Cost-Effective Preparation

Continuous monitoring of physical motion, which can be successfully achieved via a wireless flexible wearable electronic device, is essential for people to ensure the appropriate level of exercise. Currently, most of the flexible LC pressure sensors have low sensitivity because of the high Young’s modulus of the dielectric properties (such as PDMS) and the inflexible polymer films (as the substrate of the sensors), which don’t have excellent stretchability to conform to arbitrarily curved and moving surfaces such as joints. In the LC sensing system, the metal rings, as the traditional readout device, are difficult to meet the needs of the portable readout device for the integrated and planar readout antenna. In order to improve the pressure sensitivity of the sensor, the Ecoflex microcolumn used as the dielectric of the capacitive pressure sensor was prepared by using a metal mold copying method. The Ecoflex elastomer substrates enhanced the levels of conformability, which offered improved capabilities to establish intimate contact with the curved and moving surfaces of the skin. The pressure was applied to the sensor by weights, and the resonance frequency curves of the sensor under different pressures were obtained by the readout device connected to the vector network analyzer. The experimental results show that resonant frequency decreases linearly with the increase of applied pressure in a range of 0–23,760 Pa with a high sensitivity of −2.2 MHz/KPa. We designed a coplanar waveguide-fed monopole antenna used to read the information of the LC sensor, which has the potential to be integrated with RF signal processing circuits as a portable readout device and a higher vertical readout distance (up to 4 cm) than the copper ring. The flexible LC pressure sensor can be attached to the skin conformally and is sensitive to limb bending and facial muscle movements. Therefore, it has the potential to be integrated as a body sensor network that can be used to monitor physical motion.

Evidence of High-Detail Perceptual Modeling in the Visual Cortex

This informal but well-referenced description of an afterimage experiment called Ghost Tap provides persuasive and easily reproducible evidence that the visual cortex plays a significant role in certain classes of long-duration visual afterimages. Subjects of the experiment literally cannot discern the difference between the afterimage and reality, resulting in easy startling of the subjects when physical motion in the room no longer matches the persuasive afterimages they are perceiving. Anecdotal examples of less extreme versions of the same effect suggest that the Ghost Tap effect has, over centuries, intentionally and unintentionally helped persuade people of the existence of nominally “supernatural” effects that are just persuasive long-duration afterimages. While this description is informal, the easy reproducibility of the Ghost Tap makes it a good candidate for more precise and quantitative studies. One theory why Ghost Tap exists is that it is part of load reduction and speed enhancement strategy to compensate for the slow processing speeds of neurons. Maintaining a dynamic and predictive real-time model of likely sensory inputs from the external world would enable the brain to discard quickly and with minimal processing any sensory inputs that fall within the predictive tolerance limits to the current model state. A perceptive load reduction interpretation of the Ghost Tap argues that the ability of the brain to support dreaming in vivid detail is likely a direct corollary of its ability to create dream-like waking states for faster and more efficient processing of large sensory loads. If the brain regularly uses dream-like waking states to reduce data, more study of effects like Ghost Tap might help explain the frequency of pathologies in which perception becomes disconnected from reality.

Physically Based Soap Bubble Synthesis for VR

To experience a real soap bubble show, materials and tools are required, as are skilled performers who produce the show. However, in a virtual space where spatial and temporal constraints do not exist, bubble art can be performed without real materials and tools to give a sense of immersion. For this, the realistic expression of soap bubbles is an interesting topic for virtual reality (VR). However, the current performance of VR soap bubbles is not satisfying the high expectations of users. Therefore, in this study, we propose a physically based approach for reproducing the shape of the bubble by calculating the measured parameters required for bubble modeling and the physical motion of bubbles. In addition, we applied the change in the flow of the surface of the soap bubble measured in practice to the VR rendering. To improve users’ VR experience, we propose that they should experience a bubble show in a VR HMD (Head Mounted Display) environment.