“Select the matching medicine for the date”
The International Daily Symbol Substitution Test – Medicines is a continuous performance test and a well-validated measure of processing speed. In this test, a key is provided at the top of the screen pairing nine medicines with a date (FEB 1, FEB 2, FEB 3, FEB 4, FEB 5, FEB 6, FEB 7, FEB 8 and FEB 9). Each medicine has a unique shape and color and corresponds to a different date (e.g., a round red tablet may be allocated to FEB 3). In the middle of the screen, an empty pill box labelled with a date is presented and the subject is asked to select the medicine that corresponds to that date, as per the key at the top of the screen (e.g., if FEB 3 is the label on the empty box in the middle of the screen, the subject should select the red tablet). The four previous and four upcoming trials are also displayed either side of the current trial. The software records each selection as a correct or incorrect response, and once a response is made it cannot be changed. The medicines are randomly selected from a repository of 100 stimuli, therefore multiple administrations with new date/medicine pairs are possible.
The International Daily Symbol Substitution Test – Medicines is also available in a “Delayed Recall” version, which measures memory.
Cognitive Domain:
Processing Speed
Administration Time:
3 Minutes
Outcome Measures:
Total number of correct responses in matching the medicines with the appropriate dates.