Infinity on High with a 54% decline during a post-Grammy week. The album rose to number three in its third week with 79,000 units sold. In its fourth week, the disc slipped to number four and sold 67,000 copies. "Infinity on High"s sales again fell in its fifth week, moving 58,000 copies and descending to number eight on the chart. In its sixth and last week in the top ten it fell to number nine and sold 43,000 copies. In April 2007, the album was certified Platinum by the Recording Industry Association of America (RIAA), denoting the shipment of one million copies. It
Digit symbol substitution test Digit symbol substitution test Digit symbol substitution test (DSST) is a neuropsychological test sensitive to brain damage, dementia, age and depression. The test is not sensitive to the location of brain-damage (except for damage comprising part of the visual field). It consists of (e.g. nine) digit-symbol pairs (e.g. 1/-,2/┴ ... 7/Λ,8/X,9/=) followed by a list of digits. Under each digit the subject should write down the corresponding symbol as fast as possible. The number of correct symbols within the allowed time (e.g. 90 or 120 sec) is measured. The DSST contained in the Wechsler Adult Intelligence Scale is called 'Digit