Dr. Sanjay Gupta, a brain surgeon, writes for CNN that President Biden’s debate performance was “concerning” from a medical standpoint and called on the president to undergo cognitive and neurological testing. Said Gupta: “From a neurological standpoint, we were concerned with his confused rambling; sudden loss of concentration in the middle of a sentence; halting speech and absence of facial animation, resulting at times in a flat, open-mouthed expression.”