An aspect of processing speed, usually measured with the help of visual masking. A test stimulus consisting of two vertical lines is exposed very briefly on each trial and is immediately followed by a masking stimulus. The task is to judge which line was shorter, and a person's inspection time is usually taken as the minimum exposure duration (up to the onset of the masking stimulus) required for a predetermined level of accuracy, such as 90 per cent correct responses. Inspection time is consistently though weakly correlated (approximately r = −.30) with psychometric measures of intelligence, especially with performance subtests. IT abbrev.