The cognitive test on which Donald Trump received a perfect score is considered a good screening tool for mental decline in an otherwise healthy person, medical experts said. The US president asked to be administered a mental test and was given the Montreal Cognitive Assessment (MoCA) as part of a medical exam by Dr. Ronny Jackson, the White House physician, who on Tuesday said he had absolutely no concerns about Mr Trump's neurological function. The president scored 30 out of 30. Montreal Cognitive Assessment Cognitive testing looks for signs of mild cognitive impairment and/or Alzheimer’s disease. It focuses on cognitive functions including memory, attention, language, abstraction, delayed recall and orientation. Sample questions on the Montreal test include repeating a set of numbers in order both forwards and backwards and remembering a list of common words. Test takers are asked to identify animals, and draw a clock face, putting in all of the numbers and setting the clock hands to a specific time. It takes about 10 minutes to administer. One memory test involves memorising the words 'face', 'velvet', 'church', 'daisy', 'red' and recalling them after five minutes. Another test challenges participants to name as many words as they can in one minute that begin with the letter F. In general, patients with good or average memory forget one of the five words and can still be within the normal range, said Dr James Mastrianni, an expert in memory disorders and other neurodegenerative conditions at the University of Chicago Medicine. "It's a screening assessment that we use routinely in the clinics to determine whether someone has some degree of cognitive impairment or not," he said. "If they score poorly on that assessment, then usually there is more detailed evaluation that follows. But if they score well that usually indicates there is pretty good cognitive function. They are essentially intact," Mastrianni added. How the Presidents' physicals compare The test was was created by Dr Ziad Nasreddine, a neurologist who graduated from University of Sherbrooke, Québec, in 1996. Recognising the need for a more expeditious cognitive function test, he adapted his comprehensive screen and created a much quicker assessment which could be adapted to first line specialty clinics. The test is designed to precisely measure cognitive impairment, assess major cognitive domains by acting as a cognitive brain scan and help detect early stages of impairment for the most common neurodegenerative conditions such as Alzheimer’s disease. It is also been sensitively designed so that it does “not falsely label someone who is normal as being impaired”. The MoCA has been found to be useful to detect mild cognitive impairment in many conditions including Alzheimer’s disease, Vascular Cognitive Impairment, Parkinson’s disease, multiple sclerosis, Huntington’s disease and head trauma. Test instructions may be repeated once, however items listed in the memory section may not. The MoCA is used in 100 countries around the world. The standard version of the test is "pretty good" but "not definitive" said Dr. Ronald Petersen, an Alzheimer’s disease expert at the Mayo Clinic in Rochester, Minnesota. Petersen said he could not comment specifically on the president’s cognitive health. The test does not assess the president’s psychiatric fitness and the president did not undergo a psychiatric evaluation, according to his doctor. According to the Alzheimer's Association, there is no single test that proves a person has Alzheimer's disease. That diagnosis is made through a complete assessment that considers all possible causes.