People have a tendency to unconsciously mimic other's actions. This mimicry has been regarded as a prosocial response which increases social affiliation. Previous research on social priming of mimicry demonstrated an assimilative relationship between mimicry and prosociality of the primed construct: prosocial primes elicit stronger mimicry whereas antisocial primes decrease mimicry. The present research extends these findings by showing that assimilative and contrasting prime-to-behavior effect can both happen on mimicry. Specifically, experiment 1 showed a robust contrast priming effect where priming antisocial behaviors induces stronger mimicry than priming prosocial behaviors. In experiment 2, we manipulated the self-relatedness of the pro/antisocial primes and further revealed that prosocial primes increase mimicry only when the social primes are self-related whereas antisocial primes increase mimicry only when the social primes are self-unrelated. In experiment 3, we used a novel cartoon movie paradigm to prime pro/antisocial behaviors and manipulated the perspective-taking when participants were watching these movies. Again, we found that prosocial primes increase mimicry only when participants took a first-person point of view whereas antisocial primes increase mimicry only when participants took a third-person point of view, which replicated the findings in experiment 2. We suggest that these three studies can be best explained by the active-self theory, which claims that the direction of prime-to-behavior effects depends on how primes are processed in relation to the ‘self’.

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Piezoelectric actuators are widely used in the optical field due to their high precision, compact structure, flexible design, and fast response. This paper presents a novel piezoelectric actuator with a bridge-type mechanism, which can be used to stabilize the images of an infrared imaging system. The bridge amplification mechanism is used to amplify the actuation displacement, and its structural parameters are optimized by the response surface method. The control strategy of the image stabilization system is formulated, and the overall structure of the infrared image stabilization system is designed according to the principle of image stabilization and the control strategy. The prototype was fabricated and verified by a series of experiments. In the test, the laminated piezoelectric ceramics are used as the driving element, and its maximum output displacement was about 17 μm under a voltage of 100 V. Firstly, the performance of the piezoelectric amplification mechanism was tested, and the maximum displacement of the piezoelectric micro-motion mechanism was 115 μm. The displacement amplification ratio of the mechanism was 5.7. Then, the step distance and response time of the micro-displacement mechanism were measured by inputting the stepping signal. When the input voltage increased to 3 V, 5 V, and 7 V, the stepping displacements of the mechanism were 2.4 μm, 4.1 μm, and 5.8 μm. Finally, the image stabilization effect of the designed mechanism was verified by imaging timing control and feedback signal processing.

As the carriers of electromagnetic information about the cardiac system, both magnetocardiography (MCG) and electrocardiography (ECG) are non-stationary signals (NSS). The essential and crucial features of NSS are the local time-frequency characteristics (LTFCH). Under the constraint of the uncertainty principle in the time-frequency domain (TFD), the LTFCH of those non-stationary signals can be determined by evolutionary spectrum analysis (ESA). In this paper, by analyzing the QRS complexes of both MCG and ECG data from healthy volunteers, we have derived some characteristic parameters (CHPs) in the TFD, such as the quality factor (Q) and center frequency (f z ). According to the experiment results, we believe that there are threshold ranges of Q and f z values in the dynamic behavior of the cardiac system for healthy projects. If the CHPs are in the proper ranges, the cardiac system is in a normal condition and homeostasis can be self-correcting. In contrast, if the values of the CHPs are less than the proper ranges, the homeostasis of the cardiac system is lost and some cardiac diseases may result. The assumption of the threshold ranges is verified by sample data from different cardiac diseases, and the results support the assumption. The CHPs are not only a kind of new reference criterion for ECG in clinical diagnosis, but also afford a technological route for the application of MCGs in cardiology. The heart is the dynamic organ of the blood circulation system. The transmembrane potential changes during myocardial cells' vital processes are a biological electromagnetic signal source within living matter. Electrocardiography (ECG) and magnetocardiography (MCG), which are the carriers of electromagnetic information about the human cardiac system, can be acquired by non-invasive detection devices [1][2][3][4]. ECG and MCG signals, which are both NSS [5], have similar shapes. They both consist of a P-wave (atrial depolarization), QRS complex (ventricular depolarization) and T-wave (ventricular repolarization): the S-T segment reflects the repolarization status of myocardial cells. Transient information contained in the QRS complex *Corresponding author (email: xinyuanliu@pku.edu.cn)is extremely important for identifying changes of electromagnetic status in the cardiac system, and it can also provide clues about some cardiovascular diseases. Theoretically, in the TFD the frequency spectrum of a NSS is time-dependent, which means that traditional Fourier transform and the common wavelet transform methods are not suitable for analyzing LTFCH of those signals [6]. The evolutionary spectrum and the corresponding methods are used for detecting time-frequency domain features of NSS [7,8]. We have analyzed the features of the evolutionary spectrum from the QRS complex of healthy subjects' MCG and ECG signals, and then obtained the time-frequency domain characteristic parameters, that is the quality factor Q and the center frequency f z . The results show that the MCG and ECG are both information carriers of cardiac elec...