Protagonists of mental tests in clinical practice have hitherto shown a decided preference for methods of examination adapted to study capacities already developed or knowledge already acquired. Relatively little attention has been given to the study of learning, despite the fact that this function is so obviously affected in many and various neuropsychiatric conditions. One need only recall the widespread loss of plasticity so characteristic of the dementias and the more specific defects of learning associated with various types of focal lesion, e.g. of the language centres or the visual-association areas (cf. Cobb, 1944, pp. 214–5; Zangwill, 1945). It may therefore be urged that any technique of studying learning that is objective in character and easily adapted to the needs of routine clinical examination is worthy of attention. One technique which meets these demands will be described in the present paper, together with a small selection of the results obtained on routine psychological testing at the Brain Injuries Centre in Edinburgh.