330 research outputs found
Executive function after exhaustive exercise
PurposeFindings concerning the effects of exhaustive exercise on cognitive function are somewhat equivocal. The purpose of this study was to identify physiological factors that determine executive function after exhaustive exercise.MethodsThirty-two participants completed the cognitive tasks before and after an incremental exercise until exhaustion (exercise group: N = 18) or resting period (control group N = 14). The cognitive task was a combination of a Spatial Delayed-Response (Spatial DR) task and a Go/No-Go task, which requires executive function. Cerebral oxygenation and skin blood flow were monitored during the cognitive task over the prefrontal cortex. Venous blood samples were collected before and after the exercise or resting period, and blood catecholamines, serum brain-derived neurotrophic factor, insulin-like growth hormone factor 1, and blood lactate concentrations were analyzed.ResultsIn the exercise group, exhaustive exercise did not alter reaction time (RT) in the Go/No-Go task (pre: 861 ± 299 ms vs. post: 775 ± 168 ms) and the number of error trials in the Go/No-Go task (pre: 0.9 ± 0.7 vs. post: 1.8 ± 1.8) and the Spatial DR task (pre: 0.3 ± 0.5 vs. post: 0.8 ± 1.2). However, ΔRT was negatively correlated with Δcerebral oxygenation (r = −0.64, P = 0.004). Other physiological parameters were not correlated with cognitive performance. Venous blood samples were not directly associated with cognitive function after exhaustive exercise.ConclusionThe present results suggest that recovery of regional cerebral oxygenation affects executive function after exhaustive exercise
Precise estimation of spin drift velocity and spin mobility in the absence of synthetic Rashba spin-orbit field in a Si metal-oxide-semiconductor
The discovery of built-in and synthetic Rashba fields in Si spin channels [S. Lee et al., Nat. Mater. 20, 1228 (2021)] challenged the conventional understanding of spin transport physics in semiconducting materials and forced researchers to reconsider the procedures used for estimating spin drift velocity and spin mobility. A conventional procedure for the estimation involves the detection of the Hanle-type spin precession under the application of an external magnetic field perpendicular to the plane; however, the in-plane effective magnetic fields due to the built-in Rashba fields hamper precise estimation because of the additional spin precession. In this work, we establish a precise method to estimate spin drift velocity and spin mobility, in addition to the spin lifetime and spin diffusion constant, by appropriately tuning the Rashba fields. Beyond the emblematic case of Si, the established method can be applied to other semiconductors, such as Ge and GaAs
Modulation of Hanle magnetoresistance in an ultrathin platinum film by ionic gating
Hanle magnetoresistance (HMR) is a type of magnetoresistance where interplay
of the spin Hall effect, Hanle-type spin precession, and spin-dependent
scattering at the top/bottom surfaces in a heavy metal controls the effect. In
this study, we modulate HMR in ultrathin Pt by ionic gating, where the surface
Rashba field created by a strong electric field at the interface between the
ionic gate and Pt plays the dominant role in the modulation. This finding can
facilitate investigations of gate-tunable, spin-related effects and fabrication
of spin devices.Comment: 10 pages, 3 figures (To appear in Applied Physics Express
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