Spatial and Motor Aspects in the “Action-Sentence Compatibility Effect”

The Action-sentence Compatibility Effect (ACE) is often taken as supporting the fundamental role of the motor system in understanding sentences that describe actions. This effect would be related to an internal “simulation,” i.e., the reactivation of past perceptual and motor experiences. However, it is not easy to establish whether this simulation predominantly involves spatial imagery or motor anticipation. In the classical ACE experiments, where a real motor response is required, the direction and motor representations are mixed. In order to disentangle spatial and motor aspects involved in the ACE, we performed six experiments in different conditions, where the motor component was always reduced, asking participants to judge the sensibility of sentences by moving a mouse, thus requiring a purely spatial representation, compatible with nonmotor interpretations. In addition, our experiments had the purpose of taking into account the possible confusion of effects of practice and of compatibility (i.e., differences in reaction times simultaneously coming from block order and opposite motion conditions). Also, in contrast to the usual paradigm, we included no-transfer filler sentences in the analysis. The ACE was not found in any experiment, a result that failed to support the idea that the ACE could be related to a simulation where spatial aspects rather than motor ones prevail. Strong practice effects were always found and were carved out from results. A surprising effect was that no-transfer sentences were processed much slower than others, perhaps revealing a sort of participants’ awareness of the structure of stimuli, i.e., their finding that some of them involved motion and others did not. The relevance of these outcomes for the embodiment theory is discussed.

Perceived direction of deformation flow

In everyday circumstances, human observers can easily discriminate the direction of transparent liquid flow. However, the mechanism of direction discrimination is not so straightforward. The present study focused on the flow of image deformation, which is closely related to the flow of transparent liquid in the natural world. To determine what image information is important in discriminating the direction of deformation flow, a natural image in a stimulus clip was deformed by using a deformation vector map that translated leftward or rightward. The task of the observers was to judge whether the transparent liquid in the clip flowed leftward or rightward. Manipulating the amplitude of deformation, we found that the discrimination performance improved with the amplitude. Interestingly, the observers’ performance was high overall only when shearing deformation was applied to the stimuli, while the observers reported an opposite-motion direction when only compressive deformation was applied. We computationally analyzed motion statistics of stimuli and found that the combination of mean and skewness of horizontal motion vectors reliably predicted the performance. The results indicate that human observers use global motion directions in order to determine the direction of deformation flow.

A Monolithic Force-Balanced Oscillator

Usage of compliant micromechanical oscillators has increased in recent years, due to their reliable performance despite the growing demand for miniaturization. However, ambient vibrations affect the momentum of such oscillators, causing inaccuracy, malfunction, or even failure. Therefore, this paper presents a compliant force-balanced mechanism based on rectilinear motion, enabling usage of prismatic oscillators in translational accelerating environments. The proposed mechanism is based on the opposite motion of two coplanar prismatic joints along noncollinear axes via a shape-optimized linkage system. Rigid-body replacement with shape optimized X-bob, Q-LITF, and LITF joints yielded a harmonic (R > 0.999), low frequency (f=27 Hz) single piece force-balanced micromechanical oscillator (∅ 35 mm). The experimental evaluation of large-scale prototypes showed a low ratio of the center of mass (CoM) shift compared to the stroke of the device (≈ 0.01) and proper decoupling of the mechanism from the base, as the oscillating frequency of the balanced devices during ambient disturbances was unaffected, whereas unbalanced devices had frequency deviations up to 1.6%. Moreover, the balanced device reduced the resultant inertial forces transmitted to the base by 95%.

Onboard scanning system for photodetector with time delay and charge accumulation

The study describes scanning space-based assets which, by means of a flat scanning mirror and an optical system, provides the transformation of the object space into a temporal sequence of electronic signals of a photodetector with a time delay and charge accumulation. High accuracy of photodetector elements polling and scanning of the object space is due to the movement of the scanning mirror according to the indications of a non-contact interferometric angle sensor. The reciprocating rotary scanning by a flat mirror is kinetically compensated by the opposite motion of the flywheel, which minimizes residual perturbations on the space platform. To reduce the impulse energy consumption and the time of reversal between the scanning mirror and the compensating flywheel, magnetic reversal energy recuperators are used.

Extended Macroscopic Study of Dilute Gas Flow within a Microcavity

The behaviour of monatomic and dilute gas is studied in the slip and early transition regimes using the extended macroscopic theory. The gas is confined within a two-dimensional microcavity where the longitudinal sides are in the opposite motion with constant velocity ±Uw. The microcavity walls are kept at the uniform and reference temperature T0. Thus, the gas flow is transported only by the shear stress induced by the motion of upper and lower walls. From the macroscopic point of view, the regularized 13-moment equations of Grad, R13, are solved numerically. The macroscopic gas proprieties are studied for different values of the so-called Knudsen number (Kn), which gives the gas-rarefaction degree. The results are compared with those obtained using the classical continuum theory of Navier-Stokes and Fourier (NSF).

A Novel Continuous Alternate Motion Mechanism With Two Input Wheels

This paper presents the design of a mechanism with the following specifications: continuous alternate motion, wide motion phases with constant angular velocity, parallel input and output shafts, and great strokes. Those specifications derive from a possible application in the textile field. The mechanism is composed of two star wheels properly coupled together: there are two counter-rotating input wheels, alternately coupling with slots first, then teeth at each side of the output wheel. As usual for star wheels, pins and slots handle the acceleration and deceleration phases, while the constant velocity phase is performed by coupling sectors of toothed gears. A proper design of pins and slots is performed, so that at the same time when a pin from one input wheel is releasing a slot, a pin from the other input wheel engages a slot on the other side of the output wheel, forcing the latter to an opposite motion. In this way the output wheel has a continuous and smooth alternate motion. By annihilating the arrest phases typical of star wheels, the proposed system eliminates the discontinuities in the acceleration diagram. The paper develops a complete parametrical analysis of the device, underlining the effect of the constraints on the shape of the motion laws with particular emphasis on the acceleration and deceleration phases. In this way the output wheel has a continuous and smooth alternate motion. With respect to an analogous mechanism realizing the same laws of motion, e.g., cams, this device is very compact and economical, also presenting parallel input and output shafts, and significantly reduces sliding and wear.