Bimanual Finger Tapping: Effects of Frequency and Auditory Information on Timing Consistency and Coordination

The authors' goal in this study was to probe the basis for an earlier, unexpected finding that preferred-frequency finger tapping tends to have higher frequencies and to be less stable for in-phase than for antiphase tasks. In follow-up experiments, 3 protocols were employed: a preferred-frequency replication in both coordination modes, a metronome-driven matching of the preferred frequencies to each of the coordination modes, and a frequency scaling of both modes. The original findings were affirmed for preferred frequency. Tapping to a metronome had a differential effect on in-phase and antiphase: A more stable coupling across frequencies was exhibited during in-phase. Under frequency scaling, the antiphase pattern decomposed at lower frequencies than did in-phase, but no phase transitions were observed. The loss of stable coordination in both modes was attended by sudden increases in frequency differences between fingers and by phase wandering. The emergence of those effects is discussed in light of asymmetric modifications to the Haken-Kelso-Bunz model (H. Haken, J. A. S. Kelso, & H. Bunz, 1985) and the task constraints of tapping.     

Influence of Strategy on Muscle Activity During Impact Movements

Participants (N = 10) made flexions or extensions about the elbow. Movements either were pointing (i.e., self-terminated) or terminated by impact on a barrier. The author examined how the trajectory and the electromyographic (EMG) patterns varied according to the distance moved, the instruction provided concerning speed, or the type of termination. Variations in kinematics induced by changes in the target distance or the instruction regarding speed were the same for impact and pointing movements. In comparison with a pointing movement of similar distance and speed instruction, an impact movement (a) accelerated longer and reached a higher velocity, (b) had a longer agonist EMG burst, and (c) had a low level of contraction that started slightly after the agonist burst and continued throughout the movement but had little or no antagonist burst. Because the different types of movements required different forces from the muscles, there were systematic, task-specific differences in EMG patterns that reflected task-specific differences in central control. The results of this experiment demonstrate that impact movements share some of the rules used in the control of other tasks, such as pointing and reversing movements. The sharing is not imposed by mechanical or physiological constraints but, rather, represents the imposition of internal constraints.     

An Examination of Rapid Positioning Movements with Spatiotemporal Constraints

Unidirectional positioning movements with spatiotemporal-constraints were examined as a test of impulse-timing theory (Schmidt, 1976; 1980; Wallace, 1981). Movements were examined at the kinematic, kinetic, and neuromuscular levels in three experiments. In the first experiment, displacement was held constant while five different movement times were examined. Both amplitudes and durations of the EMG and the kinetic variables were related to movement time. The results generally support the impulse-timing model. In the second experiment, movements were performed to a target at each of four distances in a constant movement time. EMG and force amplitudes and, unexpectedly, accelerative-force duration were modulated to achieve changes in displacement when movement time was constant. In the third experiment, movement time and displacement were simultaneously varied resulting in four conditions with equal average velocities. The results of this experiment were not as clear and exhibited individual differences. EMG duration did not always vary with changes in movement time. The results of all three experiments could not be adequately accounted for by the impulse-timing model.     

A review of existing measures of attentional biases in body image and eating disorders research

Cognitive theories emphasise the important role of attentional biases in the development and maintenance of body image issues and eating pathology. A wealth of research has been conducted to examine attentional biases toward body‐related information among individuals with eating pathology. However, there is considerable variability in the methods that have been used to measure attention and, importantly, these methods tap into different attentional processes. Given the multifaceted nature of attention, it is important for researchers to select the right tools to test their hypotheses. This review critically evaluates the attentional measures that have been used in previous research, primarily the modified Stroop task, dot probe task, visual search task, and eyetracking. The strengths and limitations of each measure will be discussed in order to provide a guide for researchers to further investigate the attentional mechanisms underlying body image issues and eating disorders. Overall, we recommend that researchers use a combination of eyetracking technology and specific reaction‐time measures that target the specific attentional mechanism of interest.     

Effects of aging and depression on mnemonic discrimination ability

Aging and depression have been found to be associated with poorer performance in mnemonic discrimination. In the current study, a two-response format mnemonic similarity test, Cognitive Drug Research MST, was used to compare these effects. Seventy-six participants were tested; with 52 participants in the young group, aged 18–35 years, and 24 participants in the elderly group, aged 55 years or older. Twenty-two young participants and 10 elderly participants met DSM-IV criteria for MDD or dysthymia. Age-related deficits were found for lure identification and speed of response. Differences in speed of responses to lure images were found for younger depressed participants, and depressive symptom severity was found to be negatively associated with lure identification accuracy in the elderly. These findings may be viewed as putative behavioral correlates of decreased pattern separation ability, which may be indicative of altered hippocampal neurogenesis in aging and depression.     

Fractal patterns in Au–Ta multilayer films upon ion beam mixing

Metallic glass has been formed in Au₅₀Ta₅₀ multilayer films upon 200?keV xenon ion mixing at an irradiation dose of 1?×?10¹⁵?Xe⁺/cm². Electron diffraction and high-resolution transmission electron microscopy analysis confirm that the metallic glass consists of two amorphous phases, evolved from Au and Ta lattices, respectively, and also reveal the formation of a fractal morphology with a fractal dimension of 1.73?±?0.05 in the dual-phase glass features. In similar Au₆₅Ta₃₅ multilayer films, a fractal pattern is also observed at a dose of 1?×?10¹⁵?Xe⁺/cm², while the pattern, with a fractal dimension of 1.74?±?0.05, is composed in this case of a crystalline Au-based solid solution and a Ta-based amorphous phase. Interestingly, the fractal dimensions of the two irradiation-induced fractal patterns match quite well with that expected on a cluster diffusion-limited aggregation model.     

现代阳痿辨治思路创立与思辨

阳痿是临床常见、难治性病症,自古以来多从肾论治,尤其是壮阳一法几乎成为辨治阳痿的代名词.在万艾可面市后,中医药辨治阳痿的市场日见萎退,表面看是中医缺乏速效性治疗手段,实质上是在辨治阳痿的理论及临床方面存在客观的问题.本文拟从心肝在勃起中的指令性调节、气血在勃起中的实质性支撑,以及肾精、天癸在勃起中的本质性作用等角度,从勃起生理、病理、治疗等方面构建中医现代阳痿辨治的临床思路.     

不同加工深度非符号数量信息的SNARC效应：眼动证据

通过两项眼动实验考察了个体在水平和垂直方向上对点阵数量进行较浅(浏览)和较深(数字比较)程度加工时的数量空间表征联系。结果显示：点阵在水平方向上出现了SNARC效应, 且SNARC效应的大小不受加工深浅的影响, 而在垂直方向上没有出现SNARC效应。表明(1)点阵数量SNARC效应的稳定性不如阿拉伯数字; (2)方向对点阵SNARC效应的影响更大, 加工程度的影响则不明显。结合加工程度、空间方向和点阵数量的自身特征等对研究发现进行了讨论, 认为数字的空间表征在多个因素的共同影响下可能呈现出多样性。     

Emotional intelligence (EI), conflict resolution patterns,and relationship satisfaction: Actor and partner effects revisited

This study tested for actor and partner effects in the relationship between ability-based EI and adaptive marital relationships and satisfaction employing a standard dyadic design involving 100 young heterosexual couples. Participants were assessed on the MSCEIT along with measures of conflict resolution patterns and perceived marital satisfaction. A series of path analyses provided support for actor effects—but not partner effects—in the association of EI, assessed as ability, and marital variables. Overall, the data provide only partial support for the common claim and some prior research suggesting that EI plays a pivotal role in marital relationships.