This paper studies the existence and uniqueness of solutions and the stability and convergence of a dynamic system for solving saddle point problems (SPP) in Hilbert spaces. The analysis first converts the SPP into a problem of searching for equilibriums of a dynamic system using a criterion for solutions of the SPP, then shows the existence and uniqueness of the solutions by creating a positive function whose Fréchet derivative is decreasing along any solution. The construction of positively invariant subsets gives the global stability and convergence of this dynamic system, that is, the dynamic system globally converges to some exact solution of the SPP. Finally, the paper also shows that the obtained results can be applied to neural computing for solving SPP.
{"title":"Dynamic System for Solving Saddle Point Problems in Hilbert Spaces and Its Application to Neural Computing","authors":"Xisheng Shen (沈喜生) , Xiaofang Wang (王晓芳) , Yueting Chai (柴跃廷)","doi":"10.1016/S1007-0214(11)70046-3","DOIUrl":"10.1016/S1007-0214(11)70046-3","url":null,"abstract":"<div><p>This paper studies the existence and uniqueness of solutions and the stability and convergence of a dynamic system for solving saddle point problems (SPP) in Hilbert spaces. The analysis first converts the SPP into a problem of searching for equilibriums of a dynamic system using a criterion for solutions of the SPP, then shows the existence and uniqueness of the solutions by creating a positive function whose Fréchet derivative is decreasing along any solution. The construction of positively invariant subsets gives the global stability and convergence of this dynamic system, that is, the dynamic system globally converges to some exact solution of the SPP. Finally, the paper also shows that the obtained results can be applied to neural computing for solving SPP.</p></div>","PeriodicalId":60306,"journal":{"name":"Tsinghua Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1007-0214(11)70046-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67841212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Analyses of dynamic systems with random oscillations need to calculate the system covariance matrix, but this is not easy even in the linear case if the random term is not a Gaussian white noise. A universal method is developed here to handle both Gaussian and compound Poisson white noise. The quadratic variations are analyzed to transform the problem into a Lyapunov matrix differential equation. Explicit formulas are then derived by vectorization. These formulas are applied to a simple model of flows and queuing in a computer network. A stability analysis of the mean value illustrates the effects of oscillations in a real system. The relationships between the oscillations and the parameters are clearly presented to improve designs of real systems.
{"title":"Covariances of Linear Stochastic Differential Equations for Analyzing Computer Networks","authors":"Hua Fan (樊 华) , Xiuming Shan (山秀明) , Jian Yuan (袁 坚) , Yong Ren (任 勇)","doi":"10.1016/S1007-0214(11)70038-4","DOIUrl":"10.1016/S1007-0214(11)70038-4","url":null,"abstract":"<div><p><span>Analyses of dynamic systems with random oscillations need to calculate the system covariance matrix, but this is not easy even in the linear case if the random term is not a </span>Gaussian white noise<span>. A universal method is developed here to handle both Gaussian and compound Poisson white noise. The quadratic variations are analyzed to transform the problem into a Lyapunov matrix differential equation. Explicit formulas are then derived by vectorization. These formulas are applied to a simple model of flows and queuing in a computer network. A stability analysis of the mean value illustrates the effects of oscillations in a real system. The relationships between the oscillations and the parameters are clearly presented to improve designs of real systems.</span></p></div>","PeriodicalId":60306,"journal":{"name":"Tsinghua Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1007-0214(11)70038-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68134807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-06-01DOI: 10.1016/S1007-0214(11)70041-4
Siqiang Fan , He Tang , Hui Zhao , Xin Wang , Albert Wang , Bin Zhao , Gary G Zhang
This paper presents a new combined AC/DC-coupled output averaging technique for input amplifier design of flash analog-to-digital converters (ADC). The new offset averaging design technique takes full advantage of traditional DC-coupled resistance averaging and AC-coupled capacitance averaging techniques to minimize offset-induced ADC nonlinearities. Circuit analysis allows selection of optimum resistance and capacitance averaging factors to achieve maximum offset reduction in ADC designs. The new averaging method is verified in designing a 4 bit 1 Gs/s flash ADC that is implemented in foundry 0.13 μm CMOS technology.
{"title":"Enhanced Offset Averaging Technique for Flash ADC Design","authors":"Siqiang Fan , He Tang , Hui Zhao , Xin Wang , Albert Wang , Bin Zhao , Gary G Zhang","doi":"10.1016/S1007-0214(11)70041-4","DOIUrl":"10.1016/S1007-0214(11)70041-4","url":null,"abstract":"<div><p>This paper presents a new combined AC/DC-coupled output averaging technique for input amplifier design of flash analog-to-digital converters (ADC). The new offset averaging design technique takes full advantage of traditional DC-coupled resistance averaging and AC-coupled capacitance averaging techniques to minimize offset-induced ADC nonlinearities. Circuit analysis allows selection of optimum resistance and capacitance averaging factors to achieve maximum offset reduction in ADC designs. The new averaging method is verified in designing a 4 bit 1 Gs/s flash ADC that is implemented in foundry 0.13 μm CMOS technology.</p></div>","PeriodicalId":60306,"journal":{"name":"Tsinghua Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1007-0214(11)70041-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67841201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-06-01DOI: 10.1016/S1007-0214(11)70042-6
Yufeng Wang (王宇峰), Yi Yang (杨 轶), Xiangming Kong (孔祥明), Wenjun Liao (廖文俊), Ligang Wang (王利刚), Tianling Ren (任天令), Litian Liu (刘理天)
A handwriting input system was developed using three collinear ultrasonic transducers. These collinear polyvinylidene fluoride (PVDF) transducers were specially designed for the handwriting input system to give a large writeable area with writing in any direction. Driver and detection circuits were developed for the handwriting system. This handwriting input system based on 2-dimensional position tracing has large writeable area (A4 paper), low drive voltage (5 V), and is independent of the handwriting pad or the pen.
{"title":"Handwriting Input System Based on Ultrasonic Transducers","authors":"Yufeng Wang (王宇峰), Yi Yang (杨 轶), Xiangming Kong (孔祥明), Wenjun Liao (廖文俊), Ligang Wang (王利刚), Tianling Ren (任天令), Litian Liu (刘理天)","doi":"10.1016/S1007-0214(11)70042-6","DOIUrl":"10.1016/S1007-0214(11)70042-6","url":null,"abstract":"<div><p>A handwriting input system was developed using three collinear ultrasonic transducers. These collinear polyvinylidene fluoride (PVDF) transducers were specially designed for the handwriting input system to give a large writeable area with writing in any direction. Driver and detection circuits were developed for the handwriting system. This handwriting input system based on 2-dimensional position tracing has large writeable area (A4 paper), low drive voltage (5 V), and is independent of the handwriting pad or the pen.</p></div>","PeriodicalId":60306,"journal":{"name":"Tsinghua Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1007-0214(11)70042-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67841203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-06-01DOI: 10.1016/S1007-0214(11)70047-5
Hui Zhang (张 辉) , Wei Jiang (江 伟) , Jin Zhou (周 晋) , Zhen Chen (陈 震) , Jun Li (李 军)
The best-effort internet has inherent limitations on the end-to-end performance for interactive multimedia communications. This paper presents a multiple description coding (MDC) and forward error correction (FEC) based multiple path transmission schemes for interactive multimedia (M3FEC), which improves the end users' experience by maximizing a rate-distortion (R-D) based optimization problem. The proposed model considers both the network diversity and the application's stringent requirements, and combines the individual merits of the three promising technologies of multiple path overlay routing, MDC and FEC. Extensive numerical analysis and PlanetLab experiments demonstrate that M3FEC successfully combats packet losses, error propagation, and unpredictable network dynamics. This method also significantly increases distortion for interactive multimedia by over 10 dB than traditional IP-layer single path transmission in poor network environments, and outperforms the performance achieved by using MDC or FEC alone.
{"title":"M3FEC: Joint Multiple Description Coding and Forward Error Correction for Interactive Multimedia in Multiple Path Transmission","authors":"Hui Zhang (张 辉) , Wei Jiang (江 伟) , Jin Zhou (周 晋) , Zhen Chen (陈 震) , Jun Li (李 军)","doi":"10.1016/S1007-0214(11)70047-5","DOIUrl":"10.1016/S1007-0214(11)70047-5","url":null,"abstract":"<div><p>The best-effort internet has inherent limitations on the end-to-end performance for interactive multimedia communications. This paper presents a multiple description coding (MDC) and forward error correction<span> (FEC) based multiple path transmission schemes for interactive multimedia (M3FEC), which improves the end users' experience by maximizing a rate-distortion (R-D) based optimization problem. The proposed model considers both the network diversity and the application's stringent requirements, and combines the individual merits of the three promising technologies of multiple path overlay routing, MDC and FEC. Extensive numerical analysis and PlanetLab experiments demonstrate that M3FEC successfully combats packet losses, error propagation, and unpredictable network dynamics. This method also significantly increases distortion for interactive multimedia by over 10 dB than traditional IP-layer single path transmission in poor network environments, and outperforms the performance achieved by using MDC or FEC alone.</span></p></div>","PeriodicalId":60306,"journal":{"name":"Tsinghua Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1007-0214(11)70047-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67841213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-04-01DOI: 10.1016/S1007-0214(11)70032-3
Chang Shu (舒 畅), Xiaoqing Ding (丁晓青), Chi Fang (方 驰)
The histogram of oriented gradient has been successfully applied in many research fields with excellent performance especially in pedestrian detection. However, the method has rarely been applied to face recognition. Aimed to develop a fast and efficient new feature for face recognition, the original HOG and its variations were applied to evaluate the effects of different factors. An information theory-based criterion was also developed to evaluate the potential classification power of different features. Comparative experiments show that even with a relatively simple feature descriptor, the proposed HOG feature achieves almost the same recognition rate with much lower computational time than the widely used Gabor feature on the FRGC and CAS-PEAL databases.
{"title":"Histogram of the Oriented Gradient for Face Recognition","authors":"Chang Shu (舒 畅), Xiaoqing Ding (丁晓青), Chi Fang (方 驰)","doi":"10.1016/S1007-0214(11)70032-3","DOIUrl":"10.1016/S1007-0214(11)70032-3","url":null,"abstract":"<div><p>The histogram of oriented gradient has been successfully applied in many research fields with excellent performance especially in pedestrian detection. However, the method has rarely been applied to face recognition. Aimed to develop a fast and efficient new feature for face recognition, the original HOG and its variations were applied to evaluate the effects of different factors. An information theory-based criterion was also developed to evaluate the potential classification power of different features. Comparative experiments show that even with a relatively simple feature descriptor, the proposed HOG feature achieves almost the same recognition rate with much lower computational time than the widely used Gabor feature on the FRGC and CAS-PEAL databases.</p></div>","PeriodicalId":60306,"journal":{"name":"Tsinghua Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1007-0214(11)70032-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68033362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-04-01DOI: 10.1016/S1007-0214(11)70027-X
Xuguang Sun (孙旭光), Chun Zhang (张 春), Lili Gao (高立力), Yongming Li (李永明), Zhihua Wang (王志华)
Modeling of Schottky diodes in the CMOS process is a key step in ultra-high frequency (UHF) radio frequency identification (RFID) transponder designs. Accurate Schottky diode models need both DC and RF models. Conventional DC models of the Schottky diode fail to predict the forward leakage current, which is crucial for precise simulation results. This paper presents a Schottky diode model with an additional diode which gives the correct forward leakage current. The RF model of the Schottky diode is constructed based on the measured S-parameters. Then, an on-chip de-embedding process is needed to remove the parasitics due to the pads and interconnection lines in the S-parameter test. A flexible “open-through” on-chip de-embedding method is proposed which only requires an “open” dummy and a “through” dummy, with all the lumped and distributed parasitics equivalent to two-port networks to give sufficient high-frequency de-embedding accuracy. By the help of this de-embedding method and the new DC model, the accuracy of the established diode model could be guaranteed. The Schottky diode model is verified by comparison between measurements and simulations and successfully applied to an RFID transponder design.
{"title":"Modeling of a Schottky Diode in CMOS Process with a Flexible “Open-Through” On-Chip De-embedding Method","authors":"Xuguang Sun (孙旭光), Chun Zhang (张 春), Lili Gao (高立力), Yongming Li (李永明), Zhihua Wang (王志华)","doi":"10.1016/S1007-0214(11)70027-X","DOIUrl":"10.1016/S1007-0214(11)70027-X","url":null,"abstract":"<div><p><span>Modeling of Schottky diodes in the CMOS process is a key step in ultra-high frequency (UHF) radio frequency identification<span> (RFID) transponder designs. Accurate Schottky diode models need both DC and RF models. Conventional DC models of the Schottky diode fail to predict the forward leakage current, which is crucial for precise simulation results. This paper presents a Schottky diode model with an additional diode which gives the correct forward leakage current. The RF model of the Schottky diode is constructed based on the measured </span></span><em>S</em>-parameters. Then, an on-chip de-embedding process is needed to remove the parasitics due to the pads and interconnection lines in the <em>S</em>-parameter test. A flexible “open-through” on-chip de-embedding method is proposed which only requires an “open” dummy and a “through” dummy, with all the lumped and distributed parasitics equivalent to two-port networks to give sufficient high-frequency de-embedding accuracy. By the help of this de-embedding method and the new DC model, the accuracy of the established diode model could be guaranteed. The Schottky diode model is verified by comparison between measurements and simulations and successfully applied to an RFID transponder design.</p></div>","PeriodicalId":60306,"journal":{"name":"Tsinghua Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1007-0214(11)70027-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68147857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A method was developed to estimate EEPROM device life based on the consistency for breakdown charge, QBD, for constant voltage time dependent dielectric breakdown (TDDB) and constant current TDDB stress tests. Although an EEPROM works with a constant voltage, QBD for the tunnel oxide can be extracted using a constant current TDDB. Once the charge through the tunnel oxide, ΔQFG, is measured, the lower limit of the EEPROM life can be related to QBD/ΔQFG. The method is reached by erase/write cycle tests on an EEPROM.
{"title":"Estimates of EEPROM Device Lifetime","authors":"Leilei Li (李蕾蕾) , Zongguang Yu (于宗光) , Yue Hao (郝 跃)","doi":"10.1016/S1007-0214(11)70026-8","DOIUrl":"10.1016/S1007-0214(11)70026-8","url":null,"abstract":"<div><p>A method was developed to estimate EEPROM device life based on the consistency for breakdown charge, <em>Q</em><sub>BD</sub>, for constant voltage time dependent dielectric breakdown (TDDB) and constant current TDDB stress tests. Although an EEPROM works with a constant voltage, <em>Q</em><sub>BD</sub> for the tunnel oxide can be extracted using a constant current TDDB. Once the charge through the tunnel oxide, Δ<em>Q</em><sub>FG</sub>, is measured, the lower limit of the EEPROM life can be related to <em>Q</em><sub>BD</sub>/Δ<em>Q</em><sub>FG</sub>. The method is reached by erase/write cycle tests on an EEPROM.</p></div>","PeriodicalId":60306,"journal":{"name":"Tsinghua Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1007-0214(11)70026-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68033364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-04-01DOI: 10.1016/S1007-0214(11)70024-4
Yunbo Zhou (周云波) , Yu Yang (杨 煜) , Yueer Shan (单悦尔) , Huafeng Cao (曹华锋) , Bing Yang (杨 兵) , Zongguang Yu (于宗光)
An ultra-low power complementary metal-oxide-semiconductor (CMOS) front-end readout ASIC was developed for a portable digital radiation detector. The ASIC having a charge sensitive amplifier and a semi-Gaussian pulse-shaper was produced using the CSMC 0.5 μm DPDM process. The ENC noise of 363 e at 0 pF with a noise slope of 23 e/pF complies with the stringent low noise requirements. The peaking time was 250 ns at a 100 mV/fC conversion gain (detector capacitance is 20 pF). By operating this front-end readout ASIC in the weak inversion region, the ultra-low power dissipation is only 0.1 mW/channel (3.0 V). Simulations and test results suggest that this design gives lower power consumption than the front-end readout ASICs working in the strong inversion and is appropriate for the portable digital radiation detectors.
{"title":"Ultra-low Power CMOS Front-End Readout ASIC for Portable Digital Radiation Detector","authors":"Yunbo Zhou (周云波) , Yu Yang (杨 煜) , Yueer Shan (单悦尔) , Huafeng Cao (曹华锋) , Bing Yang (杨 兵) , Zongguang Yu (于宗光)","doi":"10.1016/S1007-0214(11)70024-4","DOIUrl":"10.1016/S1007-0214(11)70024-4","url":null,"abstract":"<div><p><span><span>An ultra-low power complementary metal-oxide-semiconductor (CMOS) front-end readout ASIC was developed for a portable digital radiation detector. The ASIC having a charge sensitive amplifier and a semi-Gaussian pulse-shaper was produced using the CSMC 0.5 μm DPDM process. The ENC noise of 363 e at 0 pF with a noise slope of 23 e/pF complies with the stringent low noise requirements. The peaking time was 250 ns at a 100 mV/fC conversion gain (detector capacitance is 20 pF). By operating this front-end readout ASIC in the weak inversion region, the ultra-low </span>power dissipation is only 0.1 mW/channel (3.0 V). Simulations and test results suggest that this design gives </span>lower power consumption<span> than the front-end readout ASICs working in the strong inversion and is appropriate for the portable digital radiation detectors.</span></p></div>","PeriodicalId":60306,"journal":{"name":"Tsinghua Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1007-0214(11)70024-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68033366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-04-01DOI: 10.1016/S1007-0214(11)70021-9
Andreas Marschner , Raffael Kalisch , Bram Vervliet , Debora Vansteenwegen , Christian Büchel
Lesion studies in animals have associated the amygdala mainly with aversive conditioning, both cued and contextual. However, neurophysiological studies indicate that the amygdala has a role in the processing of positive emotions in some kinds of stimulus-reward learning. The aim of the current study was to extend these findings to humans. Functional magnetic resonance imaging was applied to investigate the neural basis of aversive and appetitive conditioning. In the first study, aversive electrical shocks were delivered as either cue or context related. The second study integrated appetitive and aversive conditioning using electric shocks as aversive and monetary rewards as appetitive reinforcers. Differential responses in the amygdala were observed during both cue and contextual conditioning, whereas context conditioning additionally recruited the hippocampus. Amygdala activity was higher for reinforced acoustic stimuli. The findings underline the importance of the amygdala in associative learning, irrespective of the stimulus valence and stimulus type.
{"title":"Neural Correlates of Human Associative Learning","authors":"Andreas Marschner , Raffael Kalisch , Bram Vervliet , Debora Vansteenwegen , Christian Büchel","doi":"10.1016/S1007-0214(11)70021-9","DOIUrl":"10.1016/S1007-0214(11)70021-9","url":null,"abstract":"<div><p>Lesion studies in animals have associated the amygdala mainly with aversive conditioning, both cued and contextual. However, neurophysiological studies indicate that the amygdala has a role in the processing of positive emotions in some kinds of stimulus-reward learning. The aim of the current study was to extend these findings to humans. Functional magnetic resonance imaging was applied to investigate the neural basis of aversive and appetitive conditioning. In the first study, aversive electrical shocks were delivered as either cue or context related. The second study integrated appetitive and aversive conditioning using electric shocks as aversive and monetary rewards as appetitive reinforcers. Differential responses in the amygdala were observed during both cue and contextual conditioning, whereas context conditioning additionally recruited the hippocampus. Amygdala activity was higher for reinforced acoustic stimuli. The findings underline the importance of the amygdala in associative learning, irrespective of the stimulus valence and stimulus type.</p></div>","PeriodicalId":60306,"journal":{"name":"Tsinghua Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1007-0214(11)70021-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68034840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}