Resting-state Functional Magnetic Resonance Imaging Study Of Eyes-open And Eyes-closed Changes After Early Visual Deprivation

BackgroundVolitional eye closure is observed only in conscious and awake humans,and is rare in animals or individuals in the vegetative state.It is believed that eye closure can focus one’s attention inward and facilitate activities such as meditation and mental imagery.Congenital blind individuals are also required to close their eyes for these activities.Resting-state functional magnetic resonance imaging(RS-fMRI)studies have found robust differences between the eyes-closed(EC)and eyes-open(EO)conditions in some brain regions in the sighted.MethodsThis study analyzed data from 21 congenital blind individuals and 21 sighted controls by using amplitude of low-frequency fluctuation(ALFF)as our main matrix of RS-fMRI.We used two-way repeated-measures ANOVA to analyze our data.ResultsThe blind group and the sighted group shared similar pattern of differences between the EC and EO condition:ALFF was higher in the EC condition compared to the EO condition in the bilateral primary sensorimotor cortex,bilateral supplementary motor area,and inferior occipital cortex,while ALFF was lower in the EC condition compared to the EO condition in the medial prefrontal cortex,highlighting the "nature" effect on the difference between the EC and EO conditions.Moreover,no significant difference was observed between the EC-EO pattern of the two subgroups of congenital blind(i.e.,with and without light perception),suggesting that the EC-EO difference is irrespective to residual light perception which reinforced the "nature" effect.We also found between-group differences,i.e.,more probably "nurture effect",in the posterior insula and fusiform.ConclusionOur results suggest that the acts of closing and opening the eyes are of importance for the congenital blind,and that these actions and their differences are inherent in the nature of humans.