scholarly journals Syllable is a synchronization mechanism that makes human speech possible

2020 ◽  
Author(s):  
Yi Xu

Speech is a highly skilled motor activity that shares a core problem with other motor skills: how to reduce the massive degrees of freedom (DOF) to the extent that the central nervous control and learning of complex motor movements become possible. It is hypothesized in this paper that a key solution to the DOF problem is to eliminate most of the temporal degrees of freedom by synchronizing concurrent movements, and that this is done in speech through the syllable—a mechanism that synchronizes consonantal, vocalic and laryngeal gestures. Under this hypothesis, gestures are articulatory movements toward underlying targets; the onsets and offsets of the gestures are synchronized at the syllable edges, although more so at syllable onset than at the offset; and the realization of the synchronization is facilitated by sensorimotor feedback, especially tactile feedback, during consonant closures. This synchronization theory of the syllable also offers a comprehensive account of coarticulation, as it explicates how various coarticulation-related phenomena, including coarticulation resistance, locus, locus equation, diphone etc., are byproducts of syllable formation. It also provides a theoretical basis for understanding how suprasegmental events such as tone, intonation, phonation, etc. are aligned to segmental events in speech. It may also have implications for understanding vocal learning, speech disorders and motor control in general.

2021 ◽  
Vol 8 ◽  
Author(s):  
Zubair Iqbal ◽  
Maria Pozzi ◽  
Domenico Prattichizzo ◽  
Gionata Salvietti

Collaborative robots promise to add flexibility to production cells thanks to the fact that they can work not only close to humans but also with humans. The possibility of a direct physical interaction between humans and robots allows to perform operations that were inconceivable with industrial robots. Collaborative soft grippers have been recently introduced to extend this possibility beyond the robot end-effector, making humans able to directly act on robotic hands. In this work, we propose to exploit collaborative grippers in a novel paradigm in which these devices can be easily attached and detached from the robot arm and used also independently from it. This is possible only with self-powered hands, that are still quite uncommon in the market. In the presented paradigm not only hands can be attached/detached to/from the robot end-effector as if they were simple tools, but they can also remain active and fully functional after detachment. This ensures all the advantages brought in by tool changers, that allow for quick and possibly automatic tool exchange at the robot end-effector, but also gives the possibility of using the hand capabilities and degrees of freedom without the need of an arm or of external power supplies. In this paper, the concept of detachable robotic grippers is introduced and demonstrated through two illustrative tasks conducted with a new tool changer designed for collaborative grippers. The novel tool changer embeds electromagnets that are used to add safety during attach/detach operations. The activation of the electromagnets is controlled through a wearable interface capable of providing tactile feedback. The usability of the system is confirmed by the evaluations of 12 users.


2014 ◽  
Vol 5 (3) ◽  
pp. 25-48
Author(s):  
Girish Sriram ◽  
Alex Jensen ◽  
Steve C. Chiu

The human hand along with its fingers possess one of the highest numbers of nerve endings in the human body. It thus has the capacity for the richest tactile feedback for positioning capabilities. This article shares a new technique of controlling slippage. The sensing system used for the detection of slippage is a modified force sensing resistor (FSR®). The control system is a fuzzy logic control algorithm with multiple rules that is designed to be processed on a mobile handheld computing platform and integrated/working alongside a traditional Electromyography (EMG) or Electroencephalography (EEG) based control system used for determining position of the fingers. A 5 Degrees of Freedom (DOF) hand, was used to test the slippage control strategy in real time. First a reference EMG signal was used for getting the 5 DOF hand to grasp an object, using position control. Then a slip was introduced to see the slippage control strategy at work. The results based on the plain tactile sensory feedback and the modified sensory feedback are discussed.


2008 ◽  
Vol 99 (2) ◽  
pp. 595-604 ◽  
Author(s):  
Ely Rabin ◽  
Paul DiZio ◽  
Joel Ventura ◽  
James R. Lackner

Lightly touching a stable surface with one fingertip strongly stabilizes standing posture. The three main features of this phenomenon are fingertip contact forces maintained at levels too low to provide mechanical support, attenuation of postural sway relative to conditions without fingertip touch, and center of pressure (CP) lags changes in fingertip shear forces by ∼250 ms. In the experiments presented here, we tested whether accurate arm proprioception and also whether the precision fingertip contact afforded by the arm's many degrees of freedom are necessary for postural stabilization by finger contact. In our first experiment, we perturbed arm proprioception and control with biceps brachii vibration (120-Hz, 2-mm amplitude). This degraded postural control, resulting in greater postural sway amplitudes. In a second study, we immobilized the touching arm with a splint. This prevented precision fingertip contact but had no effect on postural sway amplitude. In both experiments, the correlation and latency of fingertip contact forces to postural sway were unaffected. We conclude that postural control is executed based on information about arm orientation as well as tactile feedback from light touch, although precision fingertip contact is not essential. The consistent correlation and timing of CP movement and fingertip forces across conditions in which postural sway amplitude and fingertip contact are differentially disrupted suggests posture and the fingertip are controlled in parallel with feedback from the fingertip in this task.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2667
Author(s):  
Manuel Caeiro-Rodríguez ◽  
Iván Otero-González ◽  
Fernando A. Mikic-Fonte ◽  
Martín Llamas-Nistal

Smart gloves have been under development during the last 40 years to support human-computer interaction based on hand and finger movement. Despite the many devoted efforts and the multiple advances in related areas, these devices have not become mainstream yet. Nevertheless, during recent years, new devices with improved features have appeared, being used for research purposes too. This paper provides a review of current commercial smart gloves focusing on three main capabilities: (i) hand and finger pose estimation and motion tracking, (ii) kinesthetic feedback, and (iii) tactile feedback. For the first capability, a detailed reference model of the hand and finger basic movements (known as degrees of freedom) is proposed. Based on the PRISMA guidelines for systematic reviews for the period 2015–2021, 24 commercial smart gloves have been identified, while many others have been discarded because they did not meet the inclusion criteria: currently active commercial and fully portable smart gloves providing some of the three main capabilities for the whole hand. The paper reviews the technologies involved, main applications and it discusses about the current state of development. Reference models to support end users and researchers comparing and selecting the most appropriate devices are identified as a key need.


2020 ◽  
Author(s):  
Guoying Gu ◽  
Ningbin Zhang ◽  
Haipeng Xu ◽  
Shaoting Lin ◽  
Yang Yu ◽  
...  

Abstract Mainly composed of electrical motors and sophisticated mechanical components, existing neuroprosthetic hands1,2 are typically heavy (>400 g) and expensive (>USD 10,000), and they lack the compliance and tactile feedback of human hands. These limitations hamper neuroprosthetic hands’ innovation and broad utility for amputees3-5. Here we report the design, fabrication and applications of a lightweight (292 g) and potentially low-cost (component cost below USD 500) soft neuroprosthetic hand with simultaneous myoelectric control and tactile feedback. The soft neuroprosthetic hand consists of five soft fingers and a palm to give six active degrees of freedom under pneumatic actuation, four electromyography sensors that measure the surface electromyogram signals to control the hand to deliver four common grasp types, and five hydrogel-elastomer capacitive sensors on the fingertips that measure the touch pressure and elicit electrical stimulation on the skin of the residual limb. The soft finger is made of a fiber-reinforced elastomeric structure embedded with rigid segments to mimic the soft-joint/rigid-bone anatomy of the human finger. We use a set of standardized tests6 to compare the speed and dexterity of the soft neuroprosthetic hand and a conventional rigid neuroprosthetic hand7 on two transradial amputees. The soft neuroprosthetic hand gives overall superior performances to the rigid hand. We further demonstrate that one transradial amputee wearing the soft neuroprosthetic hand can regain the versatile hand functions with primitive touch sensation and real-time closed-loop control in daily activities such as handling tools, eating, shaking hands, petting animals, and recognizing touch pressure. This work not only represents a new paradigm for designing soft neuroprosthetic devices but also opens an avenue to widespread applications of lightweight, low-cost, and compliant hand replacements for amputees.


2018 ◽  
Vol 20 (2) (1) ◽  
pp. 48-52
Author(s):  
Elvira Brătilă ◽  
Cătălin Bogdan Coroleucă

Objective . Robotic surgery has gained ground in recent years in benign and malignant gynecological interventions. The purpose of this article is to present the main indications of robotic surgery, to identify the advantages and disad­van­tages of this surgical technique and to present our ex­pe­rience in this field. Materials and method. An analysis of ar­ti­cles published in literature to observe the in­di­ca­tions of robotic surgery in gynecology, both for be­nign and ma­lig­nant interventions. Comparison of li­te­rature data with the main surgical indications found in the pa­tient group selected by us who received robotic sur­ge­ry. Results . The integration of robotic technology is a significant advance in the minimal invasive treatment techniques of the gynecological pathology used to treat both benign and malignant conditions. The advantages of robotic surgery are: 3D view of the operator field, superior dexterity, seven degrees of freedom for the movement of the brushes, superior capability of stitches and knots, superior ergonomics, elimination of the effect of the rebound, movement of the movements and reduction of tremor. The disadvantages of surgery are: the high cost of surgery, the lack of tactile feedback and the increased size of the device. Conclusions . Robotic surgery is an effective, safe and feasible method for the treatment of benign and malignant gynecological disorders. The optimal knowledge of trocars (adapted to the body mass index of each patient) is important in order to benefit from all the advantages of robotic surgery. Regarding the robotic surgical treatment group in which the feasibility of this procedure was observed, there are: oncological interventions, endometriosis, in reproductive medicine and in obese patients.


2012 ◽  
Vol 224 (3) ◽  
pp. 323-334 ◽  
Author(s):  
Julius Verrel ◽  
Steven Pologe ◽  
Wayne Manselle ◽  
Ulman Lindenberger ◽  
Marjorie Woollacott

1966 ◽  
Vol 25 ◽  
pp. 373
Author(s):  
Y. Kozai

The motion of an artificial satellite around the Moon is much more complicated than that around the Earth, since the shape of the Moon is a triaxial ellipsoid and the effect of the Earth on the motion is very important even for a very close satellite.The differential equations of motion of the satellite are written in canonical form of three degrees of freedom with time depending Hamiltonian. By eliminating short-periodic terms depending on the mean longitude of the satellite and by assuming that the Earth is moving on the lunar equator, however, the equations are reduced to those of two degrees of freedom with an energy integral.Since the mean motion of the Earth around the Moon is more rapid than the secular motion of the argument of pericentre of the satellite by a factor of one order, the terms depending on the longitude of the Earth can be eliminated, and the degree of freedom is reduced to one.Then the motion can be discussed by drawing equi-energy curves in two-dimensional space. According to these figures satellites with high inclination have large possibilities of falling down to the lunar surface even if the initial eccentricities are very small.The principal properties of the motion are not changed even if plausible values ofJ3andJ4of the Moon are included.This paper has been published in Publ. astr. Soc.Japan15, 301, 1963.


2020 ◽  
Vol 43 ◽  
Author(s):  
David Spurrett

Abstract Comprehensive accounts of resource-rational attempts to maximise utility shouldn't ignore the demands of constructing utility representations. This can be onerous when, as in humans, there are many rewarding modalities. Another thing best not ignored is the processing demands of making functional activity out of the many degrees of freedom of a body. The target article is almost silent on both.


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