Reliability and validity of two tests for non-verbal memory.

Because of its lenient effects on memory, unilateral electroconvulsive therapy (ECT) on the non-dominant hemisphere is routinely used in most ECT units in the Scandinavian countries. Considering the neuropsychological peculiarities of the non-dominant hemisphere, two tests were constructed to evaluate the effect of ECT on non-verbal memory. The tests are characterized by visual mode of administration and complex figurative items. They can measure both immediate and delayed memory and exist in two parallel forms. Analysis of a number of studies on unilateral non-dominant and dominant ECT indicates that the two non-verbal memory tests have good reliability and validity. Convergent validity between the two non-verbal memory tests, discriminant validity against tests of verbal memory, and criterion-related validity in relation to the influence of different treatment modalities, indicate the tests as valid instruments for measuring non-verbal memory. The two test forms show satisfactory parallelism. Together with tests of verbal memory, the total battery provides an all-round instrument for studying memory functions after ECT or other cerebral influences.