How does the Spatial Working Memory Test work?
Boxes are scattered over a 5 × 5 board, and a token is hidden in one of them. Tap boxes to open them until you find it. Then the next token is hidden, but never in a box that has already given you one, so you keep searching until every box has given up exactly one token.
There are three boards, of 4, 6 and 8 boxes, 18 tokens in all. Opened boxes close again after a moment, and a box that gave a token looks just like the rest: remembering which ones did is the test. It isn't timed, though the result shows how long you took.
How is the Spatial Working Memory Test scored?
Your result is your errors, and 0 is perfect. Opening a box that already gave a token is a between-search error: it can't hold another one. Opening a box you already found empty in the same search is a within-search error. A box that is both counts once, as between-search. Errors aren't shown until the end.
Errors are separate from luck. Even with a perfect memory you have to open boxes to find each token, and how many depends on where it happens to be. On average, a perfect memory opens:
| Board | Tokens | Boxes a perfect memory opens, on average |
|---|---|---|
| 4 boxes | 4 | 7 |
| 6 boxes | 6 | 13.5 |
| 8 boxes | 8 | 22 |
That is 42.5 boxes over the three boards, worked out from the rule that a token is equally likely in any box still able to hide one, and checked by simulating that player.
Where does the Spatial Working Memory Test come from?
From Adrian Owen and colleagues (1990), who designed this search task to study planning and spatial working memory after damage to the frontal lobes. It later became part of CANTAB, a set of computerized tests used in clinics and research. This is a recreational version with its own boards and rules, not CANTAB, and it gives no diagnosis.
How do you do well on the Spatial Working Memory Test?
- Search in the same order every time. Start from the same box and follow the same route, so “where have I looked?” becomes “how far along am I?”
- Skip the boxes that have paid out. As the tokens pile up, more of your route is boxes to step over: on the 8-box board, the last search has 7 of them.
- Don't rush. Nothing is timed, and a second of thought is cheaper than an error.
What can affect your Spatial Working Memory result?
The number of boxes most of all: each extra box is one more place to remember, both as searched and as paid out. Where the tokens hide is luck, but it changes how many boxes you open, not how many errors you make. Interruptions hurt, because the boxes you have checked are held only in mind. To remember places once rather than track them, try the Object Location Test; for numbers that vanish once you start, the Chimp Test.