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1.
The present study investigated neural mechanisms of moral judgment of lying in adults using high-density event-related potentials (ERPs). Participants were recruited to do moral judgment of 200 stories including two types of lying and their corresponding truth-telling. The results showed that both types of lying were judged more negative than their corresponding truth-telling, and moral judgment of black lying was more negative than that of modest lying. There were two main components of the ERPs evoked by the test stimuli. One was an early component, peaking at about 200 ms, and the other was a late component, peaking at about 400 ms. Over the frontal scalp sites, the early component was positive and the late component was negative, while they both reversed over the posterior sites. The ERPs of both types of lying was more positive than that of their corresponding truth-telling in the time window of 600—900 ms at the posterior sites.  相似文献   

2.
To investigate whether there is neural dissociation between processing Chinese nouns and verbs, event-related potentials (ERPs) were recorded from 17 healthy undergraduate students while they read sentences silently. The results revealed that the late negative component (LNC) generated by nouns and verbs was significantly different. The strongest effect was in the 200—300 ms and 400—550 ms time window. In the first window, the negativity generated by verbs was more positive than that by nouns over the centro-frontal electrodes. In the second window, the negativity elicited by verbs was more positive than that by nouns over anterior areas and more negative than that by nouns over posterior areas. The results indicated the neural dissociation of processing Chinese nouns and verbs.  相似文献   

3.
ERP evidence for neural dissociation of processing Chinese nouns and verbs   总被引:1,自引:0,他引:1  
To investigate whether there is neural dissociation between processing Chinese nouns and verbs, event-related potentials (ERPs) were recorded from 17 healthy undergraduate students while they read sentences silently. The results revealed that the late negative component (LNC) generated by nouns and verbs was significantly different. The strongest effect was in the 200—300 ms and 400—550 ms time window. In the first window, the negativity generated by verbs was more positive than that by nouns over the centro-frontal electrodes. In the second window, the negativity elicited by verbs was more positive than that by nouns over anterior areas and more negative than that by nouns over posterior areas. The results indicated the neural dissociation of processing Chinese nouns and verbs.  相似文献   

4.
The present study aims to investigate the neural correlates underlying humans’ sensitivity to valence differences in negative stimuli. Event-related potentials (ERPs) for highly negative (HN), moderately negative (MN), and Neutral pictures were recorded while subjects perform a standard/deviant categorization task, irrespective of the emotional valence of the deviants. The results show more negative ERP deflections during HN condition than during MN condition at each 50 ms interval from 350 to 650 ms after stimulus onset (at P3 and slow negative wave (SNW) components). Moreover, emotional effect was also observed for MN stimuli at P3 component (350—450 ms interval). Dipole analyses on the HN-MN difference wave during 350—450 ms interval (P3 component) and that during 450—650 ms interval (SNW component) were both localized to the right medial temporal lobe. Thus, the present study confirmed the human sensitivity to valence variations in emotionally negative stimuli, and further showed that the right medial temporal lobe, in particular, the right hippocampus/amygdala complex, may be the critical neural substrates underlying humans’ differential sensitivity to emotionally negative stimuli of varying valences.  相似文献   

5.
The present study aims to investigate the neural correlates underlying humans’ sensitivity to valence differences in negative stimuli. Event-related potentials (ERPs) for highly negative (HN), moderately negative (MN), and Neutral pictures were recorded while subjects perform a standard/deviant categorization task, irrespective of the emotional valence of the deviants. The results show more negative ERP deflections during HN condition than during MN condition at each 50 ms interval from 350 to 650 ms after stimulus onset (at P3 and slow negative wave (SNW) components). Moreover, emotional effect was also observed for MN stimuli at P3 component (350—450 ms interval). Dipole analyses on the HN-MN difference wave during 350—450 ms interval (P3 component) and that during 450—650 ms interval (SNW component) were both localized to the right medial temporal lobe. Thus, the present study confirmed the human sensitivity to valence variations in emotionally negative stimuli, and further showed that the right medial temporal lobe, in particular, the right hippocampus/amygdala complex, may be the critical neural substrates underlying humans’ differential sensitivity to emotionally negative stimuli of varying valences.  相似文献   

6.
In the present study, high-density event-related potentials (ERPs) were recorded to examine the electrophysiologic correlates of "Aha!" effects in a guessing Chinese Iogogriph task by using a two-stage model for learning-testing. Results showed that: Firstly Successful Guessing elicited a more negative ERP deflection (N350) than Recognition did in the time window from 300--350 ms after onset of the stimuli. A voltage map of the difference wave (Successful Guessing minus Recognition) showed strong activity at the front-central region. Dipole analysis localized the generator of the N350 in the vicinity of the posterior cingulate cortex (PCC) and the inferior frontal gyrus. Secondly, a greater late positive component (LPC) in Successful Guessing than Recognition was found between 600 and 700 ms post-stimulus. Dipole analysis localized the generator of LPC in the right parahippocampal gyrus.  相似文献   

7.
The effect of mutation of strongly conserved porelining residues in the chloride channel EcClC on the electrostatic potential and binding free energy of the chloride ion was studied using explicit protein-membrane structures. Electrostatic potential distribution and binding free energy of the chloride ion at different binding sites in the wild-type and mutated EcClC were calculated with APBS. The potential data reveal that the electrostatic potential around the selectivity filter, especially around the site Sext and Scen becomes more negative as the residue R147 was mutated to C147. The electrostatic binding free energy shows that the binding free energy of the chloride ion at all binding sites becomes more positive as R147 was mutated. It follows that mutation of R147 decreases ion stabilization at binding sites and affects channel's gating.  相似文献   

8.
Event-related potential (ERP) was used to examine the interactions between working memory and se- lective attention. We combined two unrelated tasks, one requiring working memory and the other se- lective attention, which were performed by some undergraduates. The ERP results revealed that both congruent and incongruent stimuli in the selective attention task evoked an N400 component, reaching the peak point at around 500 ms. The N400 evoked by incongruent stimuli was more negative than that of congruent, which indicated the difference of semantic N400. Furthermore, working memory load had a significant influence on the N400 evoked by selective attention task in parietal region. And working memory load showed difference in the ERPs of working memory retrieval in central and parietal regions. The ERPs of probe under high working memory load were more positive from 350 to 550 ms post-stimulus; however, stimulus type of selective attention had no influence on working memory re- trieval. The present study shows that working memory does not play a major role in the selective at- tention, especially in ignoring distracter, but it influences the performance of the selective attention as the background. The congruency of target and distracter in the selective attention task does not influ- ence the working memory retrieval.  相似文献   

9.
A study-test paradigm was used to investigate the Dm (Differential memory) effect and the old/new effect of pictures. The participants were asked to judge whether the pictures were previously studied or not when they were presented with a series of pictures during the test phase. The event-related potentials (ERPs) were recorded during encoding and retrieval phases. The results showed that (1)during 400-700 ms of encoding, the remembered old pictures elicited more positive waveforms than the forgotten old pictures at frontal and central areas; (2) during 500-600 ms of retrieval, the correctly judged old pictures elicited more positive waveforms than the correctly judged new pictures at medial-midline in both hemispheres; (3) the duration of Dm effect was longer than that of old/new effect for picture. The present results suggest that the Dm effect of pictures is different from that of words and faces in spatial and temporal distributions. The neural mechanisms of picture encoding and picture retrieval are also different, which indicates that retrieval is not the simple recovery of encoding.  相似文献   

10.
Analyses of the correlation between hyperspectral reflectance and pigment content including chlorephyll-a, chlorephyll-b and carotenoid of leaves in different sites of rice were reported in this paper. The hyperspectral reflectance of late rice during the whole growing season was measured using a Spectroradiometer with spectral range of 350 - 1050 nm and resolution of 3 nm. The chlorophyll-a, chlorephyll-b and carotenoid contents in rice leaves in rice fields to which different levels of nitrogen were applied were measured. The chlorephyll-a content of upper leaves was well correlated with the spectral variables. However, the correlation between both chlorephyll-b and careteniod and the spectral variables was far from that of chlorophyll-a. The potential of hyperspectral reflectance measurement for estimating chlorophyll-a of upper leaves was evaluated using univariate correlation and multivariate regression analysis methods with different types of predictors. This study showed that the most suitable estimated model of chlorephyll-a of upper leaves was obtained by using some hyperspectral variables such as SDr , SDb and their integration.  相似文献   

11.
Carbon nanotube (CNT) bulbs made of decimeter-scale double-walled carbon nanotube (DWCNT) strands and films were fabricated and their luminescence properties, including the lighting efficiency, voltage-current relation and thermal stability were investigated. The results show that the DWCNT bulb has a comparable spectrum of visible light with tungsten bulb and its average efficiency is 40% higher than that of a tungsten filament at the same temperature (1400―2300 K). The nanotube filaments show both resistance and thermal stability over a large temperature region. No obvious damage was found for a nanotube bulb illuminating at 2300 K for more than 24 hours in vacuum.  相似文献   

12.
We investigated the reappraisal and the time course of negative emotion regulation by performing event-related potential (ERP) recordings. We found that negative pictures elicited more positive P2 and late positivity potential (LPP) deflections than neutral pictures. This effect occurred between 150-2000 ms post-stimulus. Compared to the emotion maintaining condition, the emotion enhancing condition was associated with higher arousal ratings and displayed increased P2 and LPP amplitudes. The decrease condition was also associated with reduced picture-induced arousal; however, it led to increased P2 and LPP amplitudes. Furthermore, when compared with the maintain condition, both the enhancing and decrease conditions significantly enhanced LPP in the early stage (350-750 ms). Compared to previous studies using western subjects, the negative emotion LPP effects of the present study were shorter in duration and the decrease-emotion condition elicited larger LPPs.  相似文献   

13.
The current work examined neural substrates of perceptual grouping in human visual cortex using event-related potential (ERP) recording. Stimulus arrays consisted of local elements that were either evenly spaced (uniform stimuli) or grouped into columns or rows by proximity or color similarity (grouping stimuli). High-density ERPs were recorded while subjects identified orientations of perceptual groups in stimulus arrays that were presented randomly in one of the four quadrants of the visual field.Both uniform and grouping stimulus arrays elicited an early ERP component (C1), which peaked at about 70ms after stimulus onset and changed its polarity as a function of stimulated elevations. Dipole modeling based on realistichead boundary-element models revealed generators of the C1 component in the calcarine cortex. The C1 was modulated by perceptual grouping of local elements based on proximity, and this grouping effect was stronger in the upper than in the lower visual field. The findings provide ERP evidence for the engagement of human primary visual cortex in the early stage of perceptual grouping.  相似文献   

14.
Male Chinese loaches were exposed to 17β-estradiol (E2) and nonylphenol (NP) both singly and in combination for 42 days using semi-static waterborne exposure system. Plasma vitellogenin (Vtg) was chosen as determining endpoint. The results demonstrated that 0.5 μg/L E2 could induce the enhancement of Vtg contents in male Chinese loaches after exposure for 21 days, which showed a time-related increasing manner; NP was also estrogenic to male Chinese loach, and the vitellogenic responses showed in a time-and dose-related manner, which was less potent than that of E2. The bi- nary mixtures of E2 and NP can significantly elicit the production of Vtg in male Chinese loaches, which was more potent than that of individual compounds, and Vtg induced in the binary mixture groups was higher than the summation of Vtg induced in the corresponding single-compound groups at the same concentration.  相似文献   

15.
In our previous research in purine metabolism in Salmonella typhimurium, it was observed that the mutation frequency of the PUR box was one order of magnitude higher than that of purR under mutagenesis. In order to investigate further into this phenomenon, large amounts of independent PUR box and purR spontaneous mutants were isolated on lactose minimal medium by using a super-repressing mutant of purR (purRs). The mutational regions of 5 PUR box mutants and 4 purR mutants were cloned. Nucleotide sequence analysis showed that all the mutants had mutations at the expected sites. The comparison of the two types of mutations indicated that, although the purR gene was two orders of magnitude larger than the box). Thus, we concluded that high mutation frequency of the PUR box did not result from mutagenesis. Under spontaneous conditions, the mutation frequency of PUR box was also high. Some tentative explanations of this interesting phenomenon are given in this report.  相似文献   

16.
The development of bone tissues is regulated by mechanical stimulation.Cyclic stretching was applied to the osteoblasts that were delivered from rat calvarie,The results showed that stretching at 500με increased the cell proliferation while loading at 1000με and 1500με inhabited cell growth ,Loading also increased the adhesive force between cells and substrate as well as spreading areas of osteobalsts.Furthermore,the fluorescence probe Fluo-3/AM was used to investigate the effect of stretching stimulation on the intracellular calcium concentration of osteoblasts.The intracellular calcium concentration of osteoblasts that were stretched at 500 με for 5 min was 92.9% higher than the control ,After being treated with the panax ontoginseng saponins,the streteched osteoblasts still expressed 28.6% higher intracellular calcium concentration than that of the control ,which proved that both the influx of extracellualr calcium and the release of intracellular calcium store were involved in the increase of intracellular calcium concentration when osteoblasts responded to the cyclic stretching And the influx of extracellular calcium through transmembrance channel played a main role.  相似文献   

17.
An event-related potential study was conducted to make clear the relationships between perceptual and semantic levels of representation. Subjects judged the semantic relationship between a picture sample and a word match using the delayed match-to-sample paradigm. The experiment includes three types of matching trials, i.e., identical match trials, where the words had the same meanings as the pictures, categorical match trials where the words matched the pictures in category, and non-match trials where the words matched neither in identification nor in category with the pictures. The three conditions evoke significantly different N400-1ike and P300 ERP components. Specifically, for the N400-1ike negative responses, the averaged amplitude of the non-match condition is the largest and the most negative-going, that of the categorical match condition is less negative-going, and that of the identical match condition is the smallest among all three conditions. In addition, only the identical match condition evokes an early P300 component. As for the late P300 component, the averaged amplitude of the categorical match condition is more robust in the frontal brain areas. In contrast, ERPs of the non-match condition are stronger in the posterior brain areas. From 250 to 450 ms, the difference waves between the identical match and non-match conditions are located in the central areas, and the difference waves between categorical match and non-match conditions occur in the right frontal areas. Our results suggest that cross-form picture-word identical matching and categorical matching involve different underlying mechanisms. The existence of the early P300 component evokes by the identical match condition provides support for theories of template matching and facilitation model.  相似文献   

18.
Evaluation of virus removal in MBR using coliphages T4   总被引:1,自引:0,他引:1  
A membrane bioreactor (MBR) with gravity drain was tested for domestic wastewater for 65 days. Resultss howed that the effluent quality was excellent, and met with the reuse water standard of China (GB/T 18920-2002). Virus removal in the membrane separation process was investigated by employing coliphages T4 as a tracer. Two microfiltration membrane modules, with pore sizes of 0.22 and 0.1 μm, were used to investigate their effects on virus rejection at the transmembrane pressure of 8.5 kPa. It was found that 0.1 μm membrane had complete rejection of virus, and 0.22 μm membrane had significant rejection of virus. In the longterm operation of this MBR, no significant difference was observed between both pore sizes because the virus concentrations of the effluent in both cases were in the same order. Effluent virus concentration at steady state of MBR running was less than 2 PFU/mL. The removal ratios of coliphage T4 in MF processes were more than 10^5.5. The membrane surface deposits played an important role in the rejection of virus. The formation of cake clay on the membrane surface was the main cause of high rejection of colipbage T4 with MF of 0.22 μm.  相似文献   

19.
To understand the influence of structure and atom sites on the electrochemical properties of Sn-based anode materials,the lithium intercalation–deintercalation mechanisms into SnNi2Cu and SnNiCu2phases were studied using the first-principle plane wave pseudo-potential method.Calculation results showed that both SnNi2Cu and SnNiCu2were unsuitable anode materials for lithium ion batteries.The Sn-based anode structure related to the number of interstitial sites,theoretical specific capacity,and volume expansion ratio.Different atom sites led to different forces at interstitial sites,resulting in variations in formation energy,density of states,and hybrid orbital types.In order to validate the calculated model,the SnNi2Cu alloy anode material was synthesized through a chemical reduction-codeposition approach.Experimental results proved that the theoretical design was reasonable.Consequently,when selecting Snbased alloy anodes,attention should be paid to maximizing the number of interstitial sites and distributing atoms reasonably to minimize forces at these sites and facilitate the intercalation and deintercalation of lithium ion.  相似文献   

20.
To investigate age and sex distribution of vasovagal syncope (VVS) patients undergoing head-up tilt table test (HUTT) at a tertiary hospital. The details of syncope patients who underwent HUTT at our department of cardiac function from January 2004 to December 2010 were reviewed. Of the 1 799 patients who underwent the HUTT, 854 tested positive, of which 558 (65.3%) were women, which were more than the women in the negative group (450, 47.6%) (p<0.05). VVS patients showed a bimodal age distribution between 11 and 20 years of age and in the fourth decade. In almost all age groups, mixed response was the highest compared with vasodepressor and cardioinhibitory. VVS patients who underwent HUTT indicate bimodal distribution peaking before the second decade and the fourth decade. The incidence of females was twice that of males before the sixth decade, and old age occupies a small percentage of VVS with no other comorbidities.  相似文献   

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