Animal studies have shown that sensory deprivation in one modality can have striking effects on the development of the remaining modalities. Although recent studies of deaf and blind humans have also provided convincing behavioural, electrophysiological and neuroimaging evidence of increased capabilities and altered organization of spared modalities, there is still much debate about the identity of the brain systems that are changed and the mechanisms that mediate these changes. Plastic changes across brain systems and related behaviours vary as a function of the timing and the nature of changes in experience. This specificity must be understood in the context of differences in the maturation rates and timing of the associated critical periods, differences in patterns of transiently existing connections, and differences in molecular factors across brain systems.

This functional magnetic resonance imaging study investigated the impact of early auditory deprivation and/or use of a visuospatial language [American sign language (ASL)] on the organization of neural systems important in visual motion processing by comparing hearing controls with deaf and hearing native signers. Participants monitored moving flowfields under different conditions of spatial and featural attention. Recruitment of the motion-selective area MT-MST in hearing controls was observed to be greater when attention was directed centrally and when the task was to detect motion features, confirming previous reports that the motion network is selectively modulated by different aspects of attention. More importantly, we observed marked differences in the recruitment of motion-related areas as a function of early experience. First, the lateralization of MT-MST was found to shift toward the left hemisphere in early signers, suggesting that early exposure to ASL leads to a greater reliance on the left MT-MST. Second, whereas the two hearing populations displayed more MT-MST activation under central than peripheral attention, the opposite pattern was observed in deaf signers, indicating enhanced recruitment of MT-MST during peripheral attention after early deafness. Third, deaf signers, but neither of the hearing populations, displayed increased activation of the posterior parietal cortex, supporting the view that parietal functions are modified after early auditory deprivation. Finally, only in deaf signers did attention to motion result in enhanced recruitment of the posterior superior temporal sulcus, establishing for the first time in humans that this polymodal area is modified after early sensory deprivation. Together these results highlight the functional and regional specificity of neuroplasticity in humans.

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Objective: This study compared older adults' gains in cognitive and everyday functioning after a 60-session home-based videogame intervention with gains seen under formal cognitive training and usual care/no intervention. Materials and Methods: Participants were randomized to one of three groups: one group played an off-the-shelf videogame (i.e., Crazy Taxi), the second group engaged in a computerized training program focused on visual attention and processing speed (i.e., PositScience InSight), and the third group received no training. Training in the two intervention conditions consisted of 60 training sessions of 1 hour each, which were completed in 3 months (5 hours a week). Participants received a broad battery of cognitive and everyday functioning assessments immediately before (pretest), after (post-test), and 3 months after (follow-up) training. Results: Both training conditions improved on direct assessments of trained outcomes. In the InSight-trained group, we found transfer to untrained measures of visual attention and processing speed that were similar to the trained tasks, and these gains endured for up to 3 months. Participants in the videogame condition showed small additional benefits, not emerging until 3 months after intervention completion, on a measure of both attention and mood. No trained groups showed gain on visuospatial skills or memory. Conclusion:Training effects were highly specific to the target of training. Training effects to visual attention and processing speed were, as expected, larger for InSight-trained participants but were also seen for videogame participants. Given that past research has shown that videogame training leads to greater engagement than cognitive training, videogame interventions may represent a choice for more modest gains in a more engaging context.