In this review, we describe the current models of dorsal and ventral streams in vision, audition and touch. Available theories take their first steps from the model of Milner and Goodale, which was developed to explai...In this review, we describe the current models of dorsal and ventral streams in vision, audition and touch. Available theories take their first steps from the model of Milner and Goodale, which was developed to explain how human actions can be efficiently carried out using visual information. Since then, similar concepts have also been applied to other sensory modalities. We propose that advances in the knowledge of brain functioning can be achieved through models explaining action and perception patterns independently from sensory modalities.展开更多
Objective: The present study aimed to investigate and to compare the electrophysiological changes in bipolar patients and healthy subjects during the execution of a saccade task. Materials and Methods: The subjects ha...Objective: The present study aimed to investigate and to compare the electrophysiological changes in bipolar patients and healthy subjects during the execution of a saccade task. Materials and Methods: The subjects had to respond to a fixed visual stimulus presented by a LEDs bar. We executed an ANOVA (one-way) and post hoc Scheffé test to examine the difference of absolute alpha power and reaction time among four groups: control, depression, manic and euthymic. We observed the frontal, parietal and occipital regions. The paired t test was realized on each electrode and group to compare the pre and post moment in the task. Results: We observed a statistical difference among the groups for the behavioral variable—saccade reaction time. For the electrophysiological variable—absolute alpha power, we did not find significant difference between the moments (pre and post stimulus presentation) for none of the electrodes of each bipolar group. However, the results pointed out to a difference between the moments for F3, P3, O1 and O2 electrodes for control group. Conclusion: We cannot affirm that the task influences the cortical activity of the patients. It is possible that the method used to analyze the data is not the adequate. The time-frequency analysis could be better to analyze the present data. We also observed that the absolute alpha power could be considered a marker of bipolar disorder, but not of the different states (i.e., mania, depression, euthymia).展开更多
Background:Visual input significantly influences cerebral activity related to locomotor navigation,although the underlying mechanism remains unclear.This study aimed to analyze the effects of chronic visual impairment...Background:Visual input significantly influences cerebral activity related to locomotor navigation,although the underlying mechanism remains unclear.This study aimed to analyze the effects of chronic visual impairment and its rehabilitation on sensorimotor integration during level walking in patients with age-related cataract.Methods:This prospective case series enrolled 14 female patients(68.4±4.7 years)with age-related cataract,scheduled for consecutive cataract surgeries at the Department of Ophthalmology in Peking University Third Hospital from June 2019 to June 2020.Electroencephalogram(EEG)signals during level walking were recorded using a portable EEG system before and 4 weeks after visual restoration.Walking speed was assessed using the Footscan system.Spectral power of the theta and alpha bands was analyzed with repeated-measures analysis of variance,with Assignment(rest and walking),Phase(preoperative and postoperative),and Electrode sites(F3,Fz,F4,O1,and O2)as within-subject factors.Results:Compared to the visual impairment state,theta band power significantly decreased after visual restoration(13.16±1.58μV^(2) vs.23.65±3.48μV^(2),P=0.018).Theta activity was notably reduced during walking(17.24±2.43μV^(2) vs.37.86±6.62μV^(2),P=0.017),while theta power at rest was not significantly different between the two phases(9.44±1.24μV^(2) vs.9.08±1.74µV^(2),P=0.864).Changes in walking speed were correlated with alterations in theta power at electrode sites of O1(r=-0.574,P=0.032)and O2(r=-0.648,P=0.012).Alpha band power remained stable during walking and was unaffected by visual status.Conclusions:Chronic visual impairment from age-related cataract triggers enhanced cerebral activation of sensorimotor integration to compensate for visual decline during locomotion.This cerebral over-activation is effectively alleviated by visual restoration.展开更多
文摘In this review, we describe the current models of dorsal and ventral streams in vision, audition and touch. Available theories take their first steps from the model of Milner and Goodale, which was developed to explain how human actions can be efficiently carried out using visual information. Since then, similar concepts have also been applied to other sensory modalities. We propose that advances in the knowledge of brain functioning can be achieved through models explaining action and perception patterns independently from sensory modalities.
文摘Objective: The present study aimed to investigate and to compare the electrophysiological changes in bipolar patients and healthy subjects during the execution of a saccade task. Materials and Methods: The subjects had to respond to a fixed visual stimulus presented by a LEDs bar. We executed an ANOVA (one-way) and post hoc Scheffé test to examine the difference of absolute alpha power and reaction time among four groups: control, depression, manic and euthymic. We observed the frontal, parietal and occipital regions. The paired t test was realized on each electrode and group to compare the pre and post moment in the task. Results: We observed a statistical difference among the groups for the behavioral variable—saccade reaction time. For the electrophysiological variable—absolute alpha power, we did not find significant difference between the moments (pre and post stimulus presentation) for none of the electrodes of each bipolar group. However, the results pointed out to a difference between the moments for F3, P3, O1 and O2 electrodes for control group. Conclusion: We cannot affirm that the task influences the cortical activity of the patients. It is possible that the method used to analyze the data is not the adequate. The time-frequency analysis could be better to analyze the present data. We also observed that the absolute alpha power could be considered a marker of bipolar disorder, but not of the different states (i.e., mania, depression, euthymia).
基金supported by a grant from the National Natural Science Foundation of China(No.81600760).
文摘Background:Visual input significantly influences cerebral activity related to locomotor navigation,although the underlying mechanism remains unclear.This study aimed to analyze the effects of chronic visual impairment and its rehabilitation on sensorimotor integration during level walking in patients with age-related cataract.Methods:This prospective case series enrolled 14 female patients(68.4±4.7 years)with age-related cataract,scheduled for consecutive cataract surgeries at the Department of Ophthalmology in Peking University Third Hospital from June 2019 to June 2020.Electroencephalogram(EEG)signals during level walking were recorded using a portable EEG system before and 4 weeks after visual restoration.Walking speed was assessed using the Footscan system.Spectral power of the theta and alpha bands was analyzed with repeated-measures analysis of variance,with Assignment(rest and walking),Phase(preoperative and postoperative),and Electrode sites(F3,Fz,F4,O1,and O2)as within-subject factors.Results:Compared to the visual impairment state,theta band power significantly decreased after visual restoration(13.16±1.58μV^(2) vs.23.65±3.48μV^(2),P=0.018).Theta activity was notably reduced during walking(17.24±2.43μV^(2) vs.37.86±6.62μV^(2),P=0.017),while theta power at rest was not significantly different between the two phases(9.44±1.24μV^(2) vs.9.08±1.74µV^(2),P=0.864).Changes in walking speed were correlated with alterations in theta power at electrode sites of O1(r=-0.574,P=0.032)and O2(r=-0.648,P=0.012).Alpha band power remained stable during walking and was unaffected by visual status.Conclusions:Chronic visual impairment from age-related cataract triggers enhanced cerebral activation of sensorimotor integration to compensate for visual decline during locomotion.This cerebral over-activation is effectively alleviated by visual restoration.
