The Set-Shifting Test uses a set shifting paradigm to measure executive function.
Administration Time (in healthy volunteers): 7 Minutes
Cognitive Domain Measured: Set Shifting (Executive Function)
Set-Shifting Test Description
The pre-test on-screen instructions ask: “Is this a target card?” The test supervisor will read full instructions to the subject from the test supervisor script. To begin the test, the test supervisor or subject must press the “Enter” key.
A playing card is presented in the center of the screen. At the start of this test, the subject literally has to guess whether the card is the ‘target’ or ‘correct’ card. The subject is being asked to determine whether the card contains a target stimulus dimension (a color or a number).
As the subject makes their guesses, the software provides feedback and will not display the next stimuli until a correct response has been made. For example, if the subject wants to guess that a card is correct he/she presses “Yes”. If the guess is correct, the card will flip over. If the guess is incorrect, the subject will hear an error sound and the card will not flip over, indicating that the card does not contain the target stimulus dimension. In this case the subject would guess again (e.g. choose “No” to indicate that the card is ‘incorrect’). In this way, the subject is taught that a specific dimension of the card (either a color or a number) is ‘correct’.
When the subject has made their way through a set of cards, the ‘target’ or ‘correct’ stimulus dimension changes, either to the opposing example within the same dimension (eg, from red to black – intra-dimensional shift) or to a different dimension of the stimuli altogether (eg, from color to number – extra-dimensional shift). The subject is not told when these intra-dimensional or extra-dimensional ‘set-shifts’ occur, and they must re-learn the new target ‘rule’ to proceed through the test. There are multiple set-shifts within the test, and the order of these set-shifts is pseudo-randomized to create multiple alternate forms of the test.
The subject should be encouraged to work as quickly as they can and be as accurate as possible.
Primary Outcome measure
Unit of measurement: Total number of errors
Description and interpretation of scores: Accuracy of performance; Total number of errors across five rounds. (Lower score = better performance)