> The next level of manipulation would be to induce signals into the brain as if they are coming from the visual processing area without directly stimulating the visual processing center at all - this is far further into the future, if it is even possible.
There's a new wave of interesting work regarding inducing patterns of activity in the cortex using spatially precise two-photon excitation methods (two-photon holography). This paper does a relatively good job in controlling for the behavior of the animals in the study and shows that recalling patterns of activity can reliably reproduce a learned behavior based on the pattern of activity (and also probes at some aspects of general computations in the cortex): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6711485/
There's a new wave of interesting work regarding inducing patterns of activity in the cortex using spatially precise two-photon excitation methods (two-photon holography). This paper does a relatively good job in controlling for the behavior of the animals in the study and shows that recalling patterns of activity can reliably reproduce a learned behavior based on the pattern of activity (and also probes at some aspects of general computations in the cortex): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6711485/