Objective Behavioral studies have suggested a low-frequency（0.05 Hz） fluctuation of sustained attention on the basis of the intra-individual variability of reaction-time.Conventional task designs for functional magn...Objective Behavioral studies have suggested a low-frequency（0.05 Hz） fluctuation of sustained attention on the basis of the intra-individual variability of reaction-time.Conventional task designs for functional magnetic resonance imaging（fMRI） studies are not appropriate for frequency analysis.The present study aimed to propose a new paradigm,real-time finger force feedback（RT-FFF）,to study the brain mechanisms of sustained attention and neurofeedback.Methods We compared the low-frequency fluctuations in both behavioral and fMRI data from 38 healthy adults（19 males;mean age,22.3 years）.Two fMRI sessions,in RT-FFF and sham finger force feedback（S-FFF） states,were acquired（TR 2 s,Siemens Trio 3-Tesla scanner,8 min each,counter-balanced）.Behavioral data of finger force were obtained simultaneously at a sampling rate of 250 Hz.Results Frequency analysis of the behavioral data showed lower amplitude in the lowfrequency band（0.004-0.104 Hz） but higher amplitude in the high-frequency band（27.02-125 Hz） in the RT-FFF than the S-FFF states.The mean finger force was not significantly different between the two states.fMRI data analysis showed higher fractional amplitude of low-frequency fluctuation（fALFF） in the S-FFF than in the RT-FFF state in the visual cortex,but higher fALFF in RT-FFF than S-FFF in the middle frontal gyrus,the superior frontal gyrus,and the default mode network.Conclusion The behavioral results suggest that the proposed paradigm may provide a new approach to studies of sustained attention.The fMRI results suggest that a distributed network including visual,motor,attentional,and default mode networks may be involved in sustained attention and/or real-time feedback.This paradigm may be helpful for future studies on deficits of attention,such as attention deficit hyperactivity disorder and mild traumatic brain injury.展开更多
基金supported by the National Natural Science Foundation of China (81020108022,30770594).
文摘Objective Behavioral studies have suggested a low-frequency（0.05 Hz） fluctuation of sustained attention on the basis of the intra-individual variability of reaction-time.Conventional task designs for functional magnetic resonance imaging（fMRI） studies are not appropriate for frequency analysis.The present study aimed to propose a new paradigm,real-time finger force feedback（RT-FFF）,to study the brain mechanisms of sustained attention and neurofeedback.Methods We compared the low-frequency fluctuations in both behavioral and fMRI data from 38 healthy adults（19 males;mean age,22.3 years）.Two fMRI sessions,in RT-FFF and sham finger force feedback（S-FFF） states,were acquired（TR 2 s,Siemens Trio 3-Tesla scanner,8 min each,counter-balanced）.Behavioral data of finger force were obtained simultaneously at a sampling rate of 250 Hz.Results Frequency analysis of the behavioral data showed lower amplitude in the lowfrequency band（0.004-0.104 Hz） but higher amplitude in the high-frequency band（27.02-125 Hz） in the RT-FFF than the S-FFF states.The mean finger force was not significantly different between the two states.fMRI data analysis showed higher fractional amplitude of low-frequency fluctuation（fALFF） in the S-FFF than in the RT-FFF state in the visual cortex,but higher fALFF in RT-FFF than S-FFF in the middle frontal gyrus,the superior frontal gyrus,and the default mode network.Conclusion The behavioral results suggest that the proposed paradigm may provide a new approach to studies of sustained attention.The fMRI results suggest that a distributed network including visual,motor,attentional,and default mode networks may be involved in sustained attention and/or real-time feedback.This paradigm may be helpful for future studies on deficits of attention,such as attention deficit hyperactivity disorder and mild traumatic brain injury.
