Processing Speed - This subtest is a timed activity designed to measure an individual's mental processing speed. The examinee is required to identify all of the pictures on the screen that are identical to the picture displayed on top.
This subtest is primarily a task of visual matching and visual memory, and the use of a computer to both generate test stimuli and record the response time allows analyses of both accuracy and speed. Accuracy is determined by taking into account the number of items identified correctly ("hits"), as well the number of items erroneously identified as having been seen previously ("false alarms"). The scoring of this subtest is a composite score taking into account both factors (hits and false alarms) as well as the timing of the response. Performance may be influenced by attention to detail as well as the ability to concentrate and attend to a task while being timed.