The Timing Effects of Accent Production in Periodic Finger-Tapping Sequences

When subjects are required to produce short sequences of equally paced finger taps and to accentuate one of the taps, the interval preceding the forceful tap is shortened and the one that immediately follows the accent is lengthened. Assuming that the tapping movements are triggered by an internal clock, one explanation attributes the mistiming of the taps to central factors: The momentary rate of the clock is accelerated or decelerated as a function of motor preparation to, respectively, increase or decrease the movement force. This hypothesis predicts that the interre-sponse intervals measured between either tap movement onsets or movement terminations (taps) will show the same timing pattern. A second explanation for the observed interval effects is that the tapping movements are triggered by a regular internal clock but the timing of the successive taps is altered because the forceful movement is completed in less time than the other tap movements are. This “peripheral” hypothesis predicts regular timing of movement onsets but distorted timing of movement terminations. In the present study, the trajectories of the movements performed by subjects were recorded and the interresponse intervals were measured at the beginning and the end of the tapping movements. The results of Experiment 1 showed that neither model can fully explain the interval effects: The fast forceful movements were initiated with an additional delay that took into account the small execution time of these movements. Experiment 2 reproduced this finding and showed that the timing of the onset and contact intervals did not evolve with the repetition of trial blocks. Therefore, the assumption of an internal clock that would trigger the successive movements must be rejected. The results are discussed in the framework of a modified two-stage model in which the internal clock, instead of triggering the tapping movements, provides target time points at which the movements have to produce their meaningful effects, that is, contacts with the response key. The timing distortions are likely to reflect both peripheral and central components.     

The Stress Strategy Test in relation to personality traits and cognitive abilities

Federmann, R., Bäckström, M. & Goldsmith, R. (2010). The Stress Strategy Test in relation to personality traits and cognitive abilities. Scandinavian Journal of Psychology, 51 , 16–22.
Relations between results of the Stress Strategy Test (SST), a computerized test the first author developed partly involving the Stroop effect, and of an interview and an intelligence test used by the Swedish armed forces as selection instruments for placement of recruits in type of military service were investigated in a group of 3,205 recruits. The SST results were found able to explain 17.64% and 12.25% of the variance in results of the intelligence test and the interview, respectively. Emotional stability and psychological energy were the two interview variables most closely related to results of the SST. The usefulness of the SST in a selection context is discussed.     

不同手指表征方式对数量表征能力的影响

采用距离启动范式,考察中国文化背景下不同手指表征方式对数量表征能力的影响。实验首先验证单手表征中不同手指数量表征方式对小数字（1～5）认知表征的影响;实验2则进一步采用中国人特有的单手手指表征,考察其对大数字（5～9）认知表征的影响。结果表明,小数字中出现了标准手指表征方式语义层面的位置编码、非标准手指表征方式知觉层面总和编码的激活;但大数字中两种手指表征方式均出现了语义层面位置编码的激活。此结果与计算模型理论一致,说明当手指数量从少到多变化时,标准手指表征方式为语义性的符号数量表征;而非标准手指表征方式由知觉性的非符号向语义性符号数量表征过渡。     

Is the principle of minimization of secondary moments validated during various fingertip force production conditions?

During the application of fingertip forces with simultaneous flexion of the four fingers, namely index, middle, ring, and little fingers, a stable force sharing among fingers is adopted. Several studies have hypothesized that this stable force sharing is established to minimize unnecessary rotational moments (different from the main flexion moments). This principle labeled "minimization of secondary moments" is presented in the literature as a principle used by the central nervous system to solve musculoskeletal redundancy. However, this principle has only been tested with one solicited degree of freedom and in one finger posture. Our study tests this principle with various degrees of freedom solicited as secondary moments and in two different finger postures. Participants (n=6) were asked to apply a downward vertical force using their four fingers with the forearm placed in two different configurations: a "horizontal" condition (involving flexion/extension and pronation/supination at the wrist joint) and a "vertical" condition (involving flexion/extension and radial/ulnar deviation at the wrist joint). Additionally, two finger postures were tested in each forearm configuration: in the first, the distal inter-phalangeal joints (DIP) were extended and the proximal inter-phalangeal joints (PIP) highly flexed. In the second finger posture, both DIP and PIP joints were flexed. The resultant four-finger force and the relative involvement of each finger in the resultant four-finger force (force sharing) were analyzed. Results showed that the finger postures did not influence the finger force sharing, showing that the minimization of the secondary moment principle was stable among the finger joint angle configurations. Nonetheless, the relative involvement of each finger was dependent on the secondary degree of freedom solicited (pronation/supination vs. radial/ulnar). The modifications of the finger force sharing between the "horizontal" and "vertical" conditions were in accordance with the principle of minimization of the secondary moments.     

Normalized pulse volume and blood volume as separate indices of finger arterial and venous vascular tone: Examination under propofol

Abstract: This study examined the newly proposed indices for estimating finger vascular tone, which can be obtained from near infrared transmittance photoplethysmographic recordings; normalized pulse volume (NPV) and blood volume (BV). They were recorded for seven male and two female students under continuous infusion of and recovery from propofol. Concomitant hemodynamic measurements were made with a non-invasive impedance cardiograph and a continuous blood pressure monitor. Normalized pulse volume showed no apparent dose-dependency and was negatively correlated with total peripheral resistance. In contrast, BV increased dose-dependently with propofol concentration and was negatively correlated with cardiac preload index (PLI) and with stroke volume (SV) at higher concentrations. The supplementary structural equation modeling procedure effectively illustrated causal relationships between BV, PLI and SV. In conclusion, the present data suggest that NPV and BV independently reflect arterial and venous tone in the finger tip, respectively. Although the underlying mechanisms remain unclear, BV is more sensitive to vascular dilation under propofol anesthesia.     

企业核心竞争力与企业伦理品质

企业真正的核心竞争力来自企业伦理品质所产生的道德实力。企业的道德实力是企业遵循与市场经济理性相适应的道德准则,它一贯尊重和尽力满足利益相关人利益,并与利益相关人和谐交往共同发展而产生的道德凝聚力和影响力。与企业经营实力一样,企业道德实力是可以描述和量度的客观状态。具体可以从顾客忠诚度、员工忠诚度、股东忠诚度、融资资信度、同行联系度、供销稳定度、社区融洽度和社会美誉度等八个方面进行考量。     

Finger drawing by infant chimpanzees (<Emphasis Type="Italic">Pan troglodytes</Emphasis>)

We introduced a new technique to investigate the development of scribbling in very young infants. We tested three infant chimpanzees to compare the developmental processes of scribbling between humans and chimpanzees. While human infants start to scribble on paper at around the age of 18 months, our 13- to 23-month-old infant chimpanzees had never been observed scribbling prior to this study. We used a notebook computer with a touch-sensitive screen. This apparatus was able to record the location of the subjects touches on the screen. Each touch generated a fingertip-sized dot at the corresponding on-screen location. During spontaneous interactions with this apparatus, all three infants and two mother chimpanzees left scribbles with their fingers on the screen. The scribbles contained not only simple dots or short lines, but also curves and hook-like lines or loops, most of which were observed in the instrumental drawings of adult chimpanzees. The results suggest that perceptual-motor control for finger drawing develops in infant chimpanzees. Two of the infants performed their first scribble with a marker on paper at the age of 20–23 months. Just prior to this, they showed a rapid increase in combinatory manipulation of objects. These findings suggest that the development of combinatory manipulation of objects as well as that of perceptual-motor control may be necessary for the emergence of instrumental drawing on paper.