Interactions between the central nervous system(CNS)and autonomic nervous system(ANS)play a crucial role in modulating perception,cognition,and emotion production.Previous studies on CNS–ANS interactions,or heart–br...Interactions between the central nervous system(CNS)and autonomic nervous system(ANS)play a crucial role in modulating perception,cognition,and emotion production.Previous studies on CNS–ANS interactions,or heart–brain coupling,have often used heart rate variability(HRV)metrics derived from electrocardiography(ECG)recordings as empirical measurements of sympathetic and parasympathetic activities.Functional near-infrared spectroscopy(fNIRS)is a functional brain imaging modality that is increasingly used in brain and cognition studies.The fNIRS signals contain frequency bands representing both neural activity oscillations and heartbeat rhythms.Therefore,fNIRS data acquired in neuroimaging studies can potentially provide a single-modality approach to measure task-induced responses in the brain and ANS synchronously,allowing analysis of CNS–ANS interactions.In this proof-of-concept study,fNIRS was used to record hemodynamic changes from the foreheads of 20 university students as they each played a round of multiplayer online battle arena(MOBA)game.From the fNIRS recordings,neural and heartbeat frequency bands were extracted to assess prefrontal activities and shortterm pulse rate variability(PRV),an approximation for short-term HRV,respectively.Under the experimental conditions used,fNIRS-derived PRV metrics showed good correlations with ECG-derived HRV golden standards,in terms of absolute measurements and video game playing(VGP)-related changes.It was also observed that,similar to previous studies on physical activity and exercise,the PRV metrics closely related to parasympathetic activities recovered slower than the PRV indicators of sympathetic activities after VGP.It is concluded that it is feasible to use fNIRS to monitor concurrent brain and ANS activations during online VGP,facilitating the understanding of VGP-related heart–brain coupling.展开更多
BACKGROUND： Go, a traditional Chinese chess-like game, requires many unknown functions of the brain including attention, imaging, problem solving and processing of spatial working memory. To date, it remains uncertai...BACKGROUND： Go, a traditional Chinese chess-like game, requires many unknown functions of the brain including attention, imaging, problem solving and processing of spatial working memory. To date, it remains uncertain whether the intellectual activities required to play Go are related to the frontal lobe. OBJECTIVE： To investigate various patterns of brain region activity while schizophrenic patients and normal subjects engaged in memorizing piece placement in the Chinese game of Go. Spatial working memory was measured in order to validate whether the prefrontal lobe participates in this memory process. DESIGN, TIME AND SETTING： Non-randomized, concurrent control trial was performed at Second Xiangya Hospital of Central South University, between May and December 2004. PARTICIPANTS： A total of nine Chinese schizophrenic patients with no brain or bodily diseases and not undergoing electroshock treatment, who were in accordance with the DSM-Ⅳ criteria for schizophrenia, as well as thirteen healthy staffs and students with matched age, sex, and education were included. Patients and control subjects had no neurological disorders or mental retardation. In addition, all participants were right-handed. METHODS： The cognitive task for functional magnetic resonance imaging was a block design experiment. Both groups were asked to remember the placement of pieces in the Chinese game of Go on a computer screen. A brain activation map was analyzed in SPM99. MAIN OUTCOME MEASURES： Brain responses were compared with regard to activation region size, volume, and asymmetry indices. RESULTS： Compared with the control group, the reaction time was significantly delayed in schizophrenics performing the working memory task （P 〈 0.05）. When performing the tasks, normal subjects showed significant activation of the bilateral dorsolateral prefrontal lobe with left dominance; the asymmetry indices were： frontal lobe, ＋0.32; temporal lobe, 0.58; parietal lobe, 0.41 ; and occipital lobe, 0.34. On the other hand, sc展开更多
Investigating the biological function of proteins is a key aspect of protein studies. Bioinformatic methods become important for studying the biological function of proteins. In this paper, we first give the chaos gam...Investigating the biological function of proteins is a key aspect of protein studies. Bioinformatic methods become important for studying the biological function of proteins. In this paper, we first give the chaos game representation （CGR） of randomly-linked functional protein sequences, then propose the use of the recurrent iterated function systems （RIFS） in fractal theory to simulate the measure based on their chaos game representations. This method helps to extract some features of functional protein sequences, and furthermore the biological functions of these proteins. Then multifractal analysis of the measures based on the CGRs of randomly-linked functional protein sequences are performed. We find that the CGRs have clear fractal patterns. The numerical results show that the RIFS can simulate the measure based on the CGR very well. The relative standard error and the estimated probability matrix in the RIFS do not depend on the order to link the functional protein sequences. The estimated probability matrices in the RIFS with different biological functions are evidently different. Hence the estimated probability matrices in the RIFS can be used to characterise the difference among linked functional protein sequences with different biological functions. From the values of the Dq curves, one sees that these functional protein sequences are not completely random. The Dq of all linked functional proteins studied are multifractal-like and sufficiently smooth for the Cq （analogous to specific heat） curves to be meaningful. Furthermore, the Dq curves of the measure μ based on their CCRs for different orders to link the functional protein sequences are almost identical if q 〉 0. Finally, the Ca curves of all linked functional proteins resemble a classical phase transition at a critical point.展开更多
Coordinated mission decision-making is one of the core steps to effectively exploit the capabilities of cooperative attack of multiple aircrafts. However, the situational assessment is an essential base to realize the...Coordinated mission decision-making is one of the core steps to effectively exploit the capabilities of cooperative attack of multiple aircrafts. However, the situational assessment is an essential base to realize the mission decision-making. Therefore, in this paper, we develop a mission decision-making method of multi-aircraft cooperatively attacking multi-target based on situational assessment. We have studied the situational assessment mathematical model based on the Dempster-Shafer(D-S) evidence theory and the mission decision-making mathematical model based on the game theory. The proposed mission decision-making method of antagonized airfight is validated by some simulation examples of a swarm of unmanned combat aerial vehicles(UCAVs)that carry out the mission of the suppressing of enemy air defenses(SEAD).展开更多
基金supported by a grant from the National Natural Science Foundation of China(Grant No.21790392).
文摘Interactions between the central nervous system(CNS)and autonomic nervous system(ANS)play a crucial role in modulating perception,cognition,and emotion production.Previous studies on CNS–ANS interactions,or heart–brain coupling,have often used heart rate variability(HRV)metrics derived from electrocardiography(ECG)recordings as empirical measurements of sympathetic and parasympathetic activities.Functional near-infrared spectroscopy(fNIRS)is a functional brain imaging modality that is increasingly used in brain and cognition studies.The fNIRS signals contain frequency bands representing both neural activity oscillations and heartbeat rhythms.Therefore,fNIRS data acquired in neuroimaging studies can potentially provide a single-modality approach to measure task-induced responses in the brain and ANS synchronously,allowing analysis of CNS–ANS interactions.In this proof-of-concept study,fNIRS was used to record hemodynamic changes from the foreheads of 20 university students as they each played a round of multiplayer online battle arena(MOBA)game.From the fNIRS recordings,neural and heartbeat frequency bands were extracted to assess prefrontal activities and shortterm pulse rate variability(PRV),an approximation for short-term HRV,respectively.Under the experimental conditions used,fNIRS-derived PRV metrics showed good correlations with ECG-derived HRV golden standards,in terms of absolute measurements and video game playing(VGP)-related changes.It was also observed that,similar to previous studies on physical activity and exercise,the PRV metrics closely related to parasympathetic activities recovered slower than the PRV indicators of sympathetic activities after VGP.It is concluded that it is feasible to use fNIRS to monitor concurrent brain and ANS activations during online VGP,facilitating the understanding of VGP-related heart–brain coupling.
基金Supported by:the National Science Foundation for Distinguished Young Scholars,No.60225015the National Natural Science Foundation of China, No.30100054,30570609
文摘BACKGROUND： Go, a traditional Chinese chess-like game, requires many unknown functions of the brain including attention, imaging, problem solving and processing of spatial working memory. To date, it remains uncertain whether the intellectual activities required to play Go are related to the frontal lobe. OBJECTIVE： To investigate various patterns of brain region activity while schizophrenic patients and normal subjects engaged in memorizing piece placement in the Chinese game of Go. Spatial working memory was measured in order to validate whether the prefrontal lobe participates in this memory process. DESIGN, TIME AND SETTING： Non-randomized, concurrent control trial was performed at Second Xiangya Hospital of Central South University, between May and December 2004. PARTICIPANTS： A total of nine Chinese schizophrenic patients with no brain or bodily diseases and not undergoing electroshock treatment, who were in accordance with the DSM-Ⅳ criteria for schizophrenia, as well as thirteen healthy staffs and students with matched age, sex, and education were included. Patients and control subjects had no neurological disorders or mental retardation. In addition, all participants were right-handed. METHODS： The cognitive task for functional magnetic resonance imaging was a block design experiment. Both groups were asked to remember the placement of pieces in the Chinese game of Go on a computer screen. A brain activation map was analyzed in SPM99. MAIN OUTCOME MEASURES： Brain responses were compared with regard to activation region size, volume, and asymmetry indices. RESULTS： Compared with the control group, the reaction time was significantly delayed in schizophrenics performing the working memory task （P 〈 0.05）. When performing the tasks, normal subjects showed significant activation of the bilateral dorsolateral prefrontal lobe with left dominance; the asymmetry indices were： frontal lobe, ＋0.32; temporal lobe, 0.58; parietal lobe, 0.41 ; and occipital lobe, 0.34. On the other hand, sc
基金Project partially supported by the National Natural Science Foundation of China (Grant No.30570426)the Chinese Program for New Century Excellent Talents in University (Grant No.NCET-08-06867)+1 种基金Fok Ying Tung Education Foundation (Grant No.101004)Australian Research Council (Grant No.DP0559807)
文摘Investigating the biological function of proteins is a key aspect of protein studies. Bioinformatic methods become important for studying the biological function of proteins. In this paper, we first give the chaos game representation （CGR） of randomly-linked functional protein sequences, then propose the use of the recurrent iterated function systems （RIFS） in fractal theory to simulate the measure based on their chaos game representations. This method helps to extract some features of functional protein sequences, and furthermore the biological functions of these proteins. Then multifractal analysis of the measures based on the CGRs of randomly-linked functional protein sequences are performed. We find that the CGRs have clear fractal patterns. The numerical results show that the RIFS can simulate the measure based on the CGR very well. The relative standard error and the estimated probability matrix in the RIFS do not depend on the order to link the functional protein sequences. The estimated probability matrices in the RIFS with different biological functions are evidently different. Hence the estimated probability matrices in the RIFS can be used to characterise the difference among linked functional protein sequences with different biological functions. From the values of the Dq curves, one sees that these functional protein sequences are not completely random. The Dq of all linked functional proteins studied are multifractal-like and sufficiently smooth for the Cq （analogous to specific heat） curves to be meaningful. Furthermore, the Dq curves of the measure μ based on their CCRs for different orders to link the functional protein sequences are almost identical if q 〉 0. Finally, the Ca curves of all linked functional proteins resemble a classical phase transition at a critical point.
基金supported by the Aeronautical Science Foundation of China (No. 05D01002)
文摘Coordinated mission decision-making is one of the core steps to effectively exploit the capabilities of cooperative attack of multiple aircrafts. However, the situational assessment is an essential base to realize the mission decision-making. Therefore, in this paper, we develop a mission decision-making method of multi-aircraft cooperatively attacking multi-target based on situational assessment. We have studied the situational assessment mathematical model based on the Dempster-Shafer(D-S) evidence theory and the mission decision-making mathematical model based on the game theory. The proposed mission decision-making method of antagonized airfight is validated by some simulation examples of a swarm of unmanned combat aerial vehicles(UCAVs)that carry out the mission of the suppressing of enemy air defenses(SEAD).
