A patient blind in part of the visual field due to damage to the visual cortex reports conscious vision for moving, but not stationary, stimuli in the blind area. This completion effect is perceptual, not conceptual, and likely relies on spared representations in the striate cortex. fMRI shows brain activation only for moving stimuli, but on the same side of the brain as the stimulus rather than the opposite side, indicating a shift to the wrong hemisphere. This shift, explained by an imbalance of excitatory and inhibitory interactions between the striate cortices after injury, reveals neuroplasticity and offers new insights into visual system function and consciousness.
The default mode network processes mental states involving internal representations of subjective experiences, such as autobiographical memory retrieval and resting states. A novel analysis method called one-to-many dynamic functional connectivity analysis for fMRI was developed to detect how a single brain network's dynamics adapt depending on the mental state. Applied to a single late-blind subject with advanced mental imagery ability, the method examined the default mode network during three autobiographical memory retrieval states and a resting state. The posterior cingulate cortex as the center best depicted dynamic adaptation between mental states. The correlation between the posterior cingulate cortex and the right parahippocampal cortex varied most, contributing relatively more to dynamic adaptation.