Position-element frequency learning is dissociable from Hebb repetition learning

Position-element association has been extensively investigated as a mechanism for serial order memory and has been widely implemented in models of short-term memory. This study examined whether and how the position-element association is learned as a form of long-term knowledge dissociated from other forms of knowledge such as sequence knowledge acquired in the Hebb list repetition paradigm. Laboratory learning experiments demonstrated that repeated exposure to a specific position-element association facilitated subsequent recall of the position-element association with experimental control of other aspects of to-be-learned statistical structure of the artificial phonotactics. The experiments also demonstrated that the positional frequency learning was more gradual than Hebb list learning, suggesting a dissociation of the two forms of learning. Functional roles of these two forms of learning were discussed

The interaction between temporal grouping and phonotactic chunking in short-term serial order memory for novel verbal sequences

The current study investigated the ways long-term memory contributes to short-term serial order memory of novel verbal sequences, focusing on long-term knowledge of bi-element frequency, that is, co-occurrence frequency of two consecutive elements in a linguistic environment. Participants performed two types of immediate serial recall of nine-element (nine-mora) sequences: low bi-mora frequency sequences where all eight associations between the nine morae were low frequency, and mixed bi-mora frequency sequences, with high-frequency associations for six of the eight bi-morae. Experiment 1 confirmed the bi-directional bi-mora frequency effect, meaning better recall performance for morae having high-frequency association with either the preceding mora (forward association) or the following mora (backward association). In Experiment 2, two temporal pauses were inserted in each list to disrupt high-frequency associations with the preceding mora or the following mora. The results showed that the bi-element frequency effect diminished when the high-frequency backward association was disrupted but the effect remained when the high-frequency forward association was disrupted. We discuss possible mechanisms underlying the asymmetric influence of temporal pauses on interactions between short-term memory and linguistic long-term memory

Electromechanical Coupling in HHD

Background: There is a need to stratify patients who may develop heart failure because of the current “heart failure pandemic”. We hypothesized that noninvasive assessment of diastolic electromechanical coupling by electrocardiography and Doppler echocardiography may be clinically useful for risk stratification of hypertensive patients who may develop heart failure. Methods: We measured the time from the peak to end of the T-wave (TpTe) as an electrophysiological parameter, and peak early-diastolic mitral flow (E) and lateral annular (e’) velocities as mechanical parameters in 109 patients with hypertension. Relationships between these parameters and their association with the prognosis was evaluated. Results: The e’ was inversely correlated with TpTe (p 12. There were 24 cardiovascular events during follow-up (57 ± 20 months), and Kaplan-Meir analysis showed that outcome was worse (p=0.003) in patients with higher E/e’ than lower E/e’, however, there was no difference between patients with longer TpTe (≧72 msec) and shorter TpTe (<72 msec). Conclusions: The correlation of TpTe with e’ and E/e’ in hypertensive patients suggests that these parameters reflect diastolic ventricular electromechanical coupling. The E/e’ predicted outcome, and an elevated E/e’ should be suspected when TpTe is prolonged (> 72 msec). Noninvasive evaluation of diastolic electromechanical coupling is clinically useful in patients with hypertension

Tensile Properties of Forged Mg-Al-Zn-Ca Alloy

Continuously-casted Mg-9Al-1Zn-1Ca (in mass%) alloy (Mg-Ca alloy) and Mg-9Al-1Zn alloys (Ca-free Mg alloy) were forged at 573 K and their mechanical properties were investigated by tension tests at ambient temperature and 573 K. The forged Mg-Ca alloy showed higher 0.2% proof stress than the forged Ca-free Mg alloy. The high strength for the Mg-Ca alloy was attributed not only to grain refinement by hot forging, but also to the strengthening mechanisms arising from the difference in thermal expansion and geometrical incompatibility between Mg matrix and second phase. The Ca addition decreased the elongation to failure; however, the decrease was reduced for the forged specimens, compared to the unforged specimen. This results from segmentation of the second phases by the hot forging. Also, the forged Mg-Ca alloy showed a large elongation of 284% at 573 K

Effects of Homogenization Annealing on Dynamic Recrystallization

Compression tests were conducted at the temperature of 573 K with the true strain rates of 10 À3 -1 s À1 on as-cast and homogenized Mg6Al-2Ca-2RE (RE = rare earth) (in mass%) alloy specimens, and their dynamic recrystallization (DRX) behaviors were investigated. Strain hardening occurred after yielding, followed by strain softening. The flow stress of the as-cast specimen was higher than that of the homogenized specimen. The DRX grain size depended minimally on the Z-parameter in both of the as-cast and homogenized specimens. This is likely to be due to the particle-stimulated nucleation mechanism involving the second-phase particles. When the specimens were deformed to the true compressive strain of 1.6, non-recrystallized regions were not observed in the homogenized specimen; however, they were partially observed in the as-cast specimen. The grain size in the recrystallized region in the as-cast specimen was smaller than that in the homogenized specimen. Elemental analyses revealed Al segregation around the second-phase particles in the as-cast specimen. Therefore, it is suggested that DRX in the present Mg-Al-Ca-RE alloy is affected by not only the second-phase particles, but also the Al segregation