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ABSTRACTIf spatial stimulus-response correspondence (SRC) effect results from automatic processes, cognitive load should not affect this effect. However, if spatial SRC effect is based on the interference of cognitive codes, cognitive load should influence it. Furthermore, the motion-based SRC effect should be affected by the cognitive load, as this SRC effect is related to the cognitive codes interference. In this study, participants performed combined tasks for space-based and motion-based SRC effects without working memory load (WML), or under spatial and verbal WML to see if cognitive load affects both SRC effects or just one. Results demonstrated that space-based SRC remained intact from WML, while the motion-based SRC was influenced by WML, although only in limited degree. This supports the notion that automatic processes underlie space-based SRC effect, whereas the motion-based SRC effect is related to cognitive codes interference, but the latter requires further investigation.

Multiple object tracking (MOT) and multiple identity tracking (MIT) each measure the ability to track moving objects visually. While prior investigators have mainly compared athletes and non-athletes on MOT, MIT more closely resembles dynamic real-life environments. Here we compared the performance and gaze behavior of handball players with non-athletes on both MOT and MIT. Since previous researchers have shown that MOT and MIT engage different eye movement strategies, we had participants track 3–5 targets among 10 moving objects. In MOT, the objects were identical, while in MIT they differed in shape and color. Although we observed no group differences for tracking accuracy, the eye movements of athletes were more target-oriented than those of non-athletes. We concluded that tasks and stimuli intended by researchers to demonstrate that athletes’ show better object tracking than non-athletes should be specific to the athletes’ type of sport and should use more perception-action coupled measures. An implication of this conclusion is that the differences in object tracking skills between athletes and non-athletes is highly specific to the skills demanded by the athletes’ sport.

Abstract.Previous research indicated that congruency between stimulus location and response position (spatial stimulus-response correspondence [SRC]) and stimulus motion and response movement congruency (motion SRC) are distinct SRC phenomena. This study further explored this issue and tested whether these two SRC effects are independent. This was conducted by investigating these two SRC effects in a single task. A stimulus with leftward or rightward motion was presented on the left or the right side of the screen and the participant had to move the joysticks held with the left and right hands leftward or rightward in response to the stimulus color. In this setting, the stimulus and response shared two types of correspondence: spatial and motion. The results demonstrated that two SRC effects occurred and interacted (interaction evident only in reaction times [RTs]). RT distribution analysis and accuracy delta plots for each SRC effect indicated that spatial and motion SRC are distinct phenomena based on different processes.

The time dependence of the dielectric permittivity of NH4HSeO4 under the application of mechanical stress is presented. The contribution of the domain structure changes and the relaxation of space charge to the relaxation of dielectric permittivity is discussed.

Time evolution of dielectric permittivity in [N(CH3)4]2ZnCl4 crystal was measured at the fixed temperature. In both incommensurate (II) and ferroelectric (III) phases, a long-term relaxation of permittivity has been confirmed. The gradual monotonic decreasing of ε with time obeys a stretch exponential law ε ∼ exp{-(t/τ)β}. In incommensurate phase the relaxation time τ rapidly increases if measurement takes place nearer and nearer of Tc, while in ferroelectric phase with approaching Tc, the slow decreasing of τ is found

Time dependence of the dielectric permittivity of NH4HSeO4 (AHSe) and RbHSeO4 (RbHSe) under the application of mechanical stress was investigated. The influence of: value and sign of the applied external forces, temperature and domain structure on the time dependence of ε were tested. Special attention was paid to the largest relaxation time τprime3 of AHSe related to the relaxation of space charge.

Splitting of the incommensurate-commensurate phase transition in NH4HSeO4 crystal hitherto was observed under uniaxial mechanical stress [image omitted]. The same effect under external bias electric field E or simultaneous action of mechanical stress and electric field was found. Dielectric permittivity data show that [image omitted] and E may compete or cooperate in the resulting effect. The obtained results throw new light on the problem and a possible mechanism of the splitting is proposed.

AbstractThe effect of electric field and mechanical stress (uniaxial or shear stress) on dielectric permittivity and spontaneous polarization in (TMA)2ZnC14crystals has been studied. The electric field Eshifts the transition point Tcl(IC ⇔ C) to higher temperature and the transition point Tc2(ferroelectric ⇔ ferroelastic) lower. It is found that the dielectric constant ϵ and the shift of the transition point are dependent on the uniaxial stresses σ11, σ22, and σ33in different ways, but they are affected mainly by the shear stress σ'. This stress can also induce a change of the crystal symmetry.

The incommensurate-commensurate (IC ⇔ C) phase transition of A2 BX4 type crystals can split under an electric field, as has been revealed by dielectric measurements. In this contribution, the splitting of the IC ⇔ C phase transition in NH4HSeO4 crystal is reported to occur under uniaxial mechanical stress. The individual components of the mechanical stress tensor contribute in a different way to the change of the dielectric permittivity and spontaneous polarization and are responsible for the splitting of the IC ⇔ C phase transition which is manifested by two maxima of ε instead of one.