Comparison of unilateral dominant and non-dominant ECT on verbal and non-verbal memory.

An intraindividual, double-blind cross-over comparison of the effects of dominant (D) and non-dominant (ND) temporo-parietal unilateral electroconvulsive therapy (ECT) was performed in connection with the second and third treatment, the type of electrode placement being allocated at random. Four memory tests were used. The 30 Word-Pair Test is an audio-visual verbal recall test, the 30 Figure Test is a mainly visual recognition test with easily verbalized items. The 30 Geometrical Figure Test and the 30 Face Test are nonverbal recognition tests of visual complex and unfamiliar material. Compared with dominant ECT, non-dominant ECT has a more negative influence in the complex non-verbal visual tests, whereas dominant ECT has a more negative effect on verbal memory. In the non-verbal tests, as compared with the verbal ones, the encoding (or learning) is relatively more influenced and the retention (or storage) relatively less. An impairment either of complex apperceptive function or of memory may be responsible for the relatively lower performance in non-verbal tests after non-dominant ECT.