Current neuroengineering technologies have reached the stage where lost sensory or motor functions can be partially restored through electrical stimulation of the brain. However, higher cognitive functions such as memory and learning remain far more difficult to understand and manipulate because of the extraordinary complexity of the underlying neural activity. By achieving a deeper understanding of how the brain functions, could we move beyond treating cognitive disorders with engineered devices to directly modulate higher cognitive processes? Ultimately, could we create an internal brain reality that surpasses conventional virtual reality?