| SWM is a test of the subject’s ability to retain spatial information and to manipulate remembered items in working memory. It is a self-ordered task, which also assesses heuristic strategy. This test is a sensitive measure of frontal lobe and ‘executive’ dysfunction. It has been shown in recent studies that impaired performance on SWM emerges as a common factor in prepsychosis. |
Administration time
Around 8 minutes, depending on level of impairment
Task
The test begins with a number of coloured squares (boxes) being shown on the screen. The aim of this test is that, by touching the boxes and using a process of elimination, the subject should find one blue ‘token’ in each of a number of boxes and use them to fill up an empty column on the right hand side of the screen. The number of boxes is gradually increased, until it is necessary to search a total of eight boxes. The colour and position of the boxes used are changed from trial to trial to discourage the use of stereotyped search strategies.
Test modes
Clinical mode.
Outcome measures
The twenty-four outcome measures for SWM include errors (touching boxes that have been found to be empty, and revisiting boxes which have already been found to contain a token), a measure of strategy, and latency measures.
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