Stimulus-Response Compatibility (SRC) refers to the fact that some tasks are performed easier and better than others because of the way stimuli and responses are paired with each other. To assess the brain responses t...Stimulus-Response Compatibility (SRC) refers to the fact that some tasks are performed easier and better than others because of the way stimuli and responses are paired with each other. To assess the brain responses to stimulus-response conflicts, we investigated the behavioral (accuracy and Reaction Times: RTs) as well as the physiological response (Lateralized Readiness Potentials: LRP) modulations in a positional blocked and a conditional mixed design in twelve university students. Results revealed that the performance was less accurate and the RTs, as well as the LRP onset, were delayed under the mixed conditional design. A greater compatibility effect was also noted on accuracy, RTs and LRP onset latency in the mixed design. Consistent with these findings, smaller peak activation at fronto-central areas suggests that more selective inhibition is needed in a mixed design context. Despite a smaller activation, the topographical distribution is similar in both designs. These results indicate that the translation time between stimulus- and response codes are greater under the mixed instruction, while the similar LRP topography suggests that common neural structures underlie LRPs in response to both type of designs.展开更多
The paper presents the neural decoding result of finger or wrist movements using the primary motor cortex(M1)neural activities prior to its movement.It is well known that the observations of motor commands in brain ar...The paper presents the neural decoding result of finger or wrist movements using the primary motor cortex(M1)neural activities prior to its movement.It is well known that the observations of motor commands in brain are in advance before motor movements in the central nerve system.Readiness potential(RP)for electroencephalogram(EEG)has become an important domain of research.Likewise,pre-movement neural responses in M1 primary motor cortex have been observed.The neural activity data before 1 s.were used for neural decoding when the actual movements happened around 1 s.The obtained decoding accuracy in novel method reaches as high as 95% with 30 randomly selected neurons.展开更多
A method of estimating hand and elbow movements using electrocorticogram(ECoG)signals is proposed.Using multiple channels,surface electromyogram(EMG)signals and ECoG signals were obtained from patients simultaneously....A method of estimating hand and elbow movements using electrocorticogram(ECoG)signals is proposed.Using multiple channels,surface electromyogram(EMG)signals and ECoG signals were obtained from patients simultaneously.The estimated movements were those to close and then open the hand and those to bend the elbow inward.The patients were encouraged to perform the movements in accordance with their free will instead of after being induced by external stimuli.Surface EMG signals were used to find movement time points,and ECoG signals were used to estimate the movements.To extract the characteristics of the individual movements,the ECoG signals were divided into a total of six bands(the entire band and the δ,θ,α,β and γ bands)to obtain the information entropy,and the maximum likelihood estimation method was used to estimate the movements.The results of the experiment show that the performance averages 74% when the ECoG of γ band is used,which is higher than that when other bands are used,and higher estimation success rates are shown in the γ band than in other bands.The time of the movements is divided into three time sections based on movement time points,and the "Before" section,which includes the readiness potential,is compared with the "Onset" section.In the "Before" section and the "Onset" section,estimation success rates are 66% and 65%,respectively,and thus it is determined that the readiness potential could can be used.展开更多
文摘Stimulus-Response Compatibility (SRC) refers to the fact that some tasks are performed easier and better than others because of the way stimuli and responses are paired with each other. To assess the brain responses to stimulus-response conflicts, we investigated the behavioral (accuracy and Reaction Times: RTs) as well as the physiological response (Lateralized Readiness Potentials: LRP) modulations in a positional blocked and a conditional mixed design in twelve university students. Results revealed that the performance was less accurate and the RTs, as well as the LRP onset, were delayed under the mixed conditional design. A greater compatibility effect was also noted on accuracy, RTs and LRP onset latency in the mixed design. Consistent with these findings, smaller peak activation at fronto-central areas suggests that more selective inhibition is needed in a mixed design context. Despite a smaller activation, the topographical distribution is similar in both designs. These results indicate that the translation time between stimulus- and response codes are greater under the mixed instruction, while the similar LRP topography suggests that common neural structures underlie LRPs in response to both type of designs.
基金MKE(the Ministry of Knowledge Economy),Korea,under the ITRC(Infor mation Technology Research Center)support program supervised by the NIPA(National ITIndustry Promotion Agency)(NIPA-2011-C1090-1121-0010)
文摘The paper presents the neural decoding result of finger or wrist movements using the primary motor cortex(M1)neural activities prior to its movement.It is well known that the observations of motor commands in brain are in advance before motor movements in the central nerve system.Readiness potential(RP)for electroencephalogram(EEG)has become an important domain of research.Likewise,pre-movement neural responses in M1 primary motor cortex have been observed.The neural activity data before 1 s.were used for neural decoding when the actual movements happened around 1 s.The obtained decoding accuracy in novel method reaches as high as 95% with 30 randomly selected neurons.
基金The MKE(The Ministry of Knowledge Economy),Korea,under the ITRC(Infor mation Technology Research Center)support program supervised by the NIPA(National IT Industry Promotion Agency)(NIPA-2012-H0301-12-2006)
文摘A method of estimating hand and elbow movements using electrocorticogram(ECoG)signals is proposed.Using multiple channels,surface electromyogram(EMG)signals and ECoG signals were obtained from patients simultaneously.The estimated movements were those to close and then open the hand and those to bend the elbow inward.The patients were encouraged to perform the movements in accordance with their free will instead of after being induced by external stimuli.Surface EMG signals were used to find movement time points,and ECoG signals were used to estimate the movements.To extract the characteristics of the individual movements,the ECoG signals were divided into a total of six bands(the entire band and the δ,θ,α,β and γ bands)to obtain the information entropy,and the maximum likelihood estimation method was used to estimate the movements.The results of the experiment show that the performance averages 74% when the ECoG of γ band is used,which is higher than that when other bands are used,and higher estimation success rates are shown in the γ band than in other bands.The time of the movements is divided into three time sections based on movement time points,and the "Before" section,which includes the readiness potential,is compared with the "Onset" section.In the "Before" section and the "Onset" section,estimation success rates are 66% and 65%,respectively,and thus it is determined that the readiness potential could can be used.
