Washington, Nov 27 : Former US President Donald Trump, who mixed up his predecessor Barack Obama's name with current incumbent Joe Biden's while bragging about his cognitive functions, sharply reacted to those critics who had pointed this out as evidence of his mental decline, saying that he had "aced" all physical and mental tests and he was deliberately mixing up names. Trump defended his mixing up of Obama's name for Biden's on several occasions, saying he "sarcastically" swaps their names, rather than forgetting whom he is running against, to indicate Obama is pulling the strings behind the scenes, media reports said. To bolster his case, Trump cited a recent medical exam, which included a cognitive portion that he said he "aced." "Whenever I sarcastically insert the name Obama for Biden as an indication that others may actually be having a very big influence in running our Country, Ron DeSanctimonious and his failing campaign apparatus, together with the Democrat's Radical Left 'Disinformation Machine,' go wild saying that 'Trump doesn't know the name of our President, (CROOKED!) Joe Biden. He must be cognitively impaired,'" the 77-year-old wrote on Truth Social. "No, I know both names very well, never mix them up, and know that they are destroying our Country," Trump said. He then cited his recent physical exam results, released last week, showing his cognitive test results were "excellent," according to Dr. Bruce Aronwald. "I just took a cognitive test as part of my Physical Exam, and ACED it," Trump wrote. "Also ACED (a perfect score!) one taken while in the White House." Trump then suggested Biden should take his own competency exam to determine why he holds certain positions regarding immigration, energy, defence, and the Department of Justice, along with "so many other CRAZY things!!!" the Washington Examiner reported. The former President's social media post comes as his GOP rival in the Republican presidential primary, Florida Governor Ron DeSantis and Democratic opponent Biden, have started to highlight Trump's mistakes increasing concern among voters. Significant shares of voters have already indicated that Trump's age and competency are concerns in the 2024 election, but Biden's have proven to loom larger as he falters in his speech and often refers to his Vice P:resident Kamala Harris as President. However, strategists have suggested that if Trump's age grows to become a larger worry for voters, it could give Biden an advantage. Polls show that youths in the 18 to 35 age group want a younger President in 2024 and reject both Biden and Trump for a post in the White House. Trump will be 81 when he leaves the White House and Biden 85 after the 2024 elections in 2028. /IANS