[Presentation of a new tachistoscopic test procedure for measuring functional hemisphere asymmetries of the optic field].

A newly developed tachistoscopic test using visual half-field-stimulation was tried on a clinical population of 178 primary school children. Words and geometric figures were presented. The results showed inconsistent effects of increased tiredness on the one hand and training effects on the other hand, while doing the test. The amount of asymmetry in the performance was not effected. The construction of the test was based on results of a previous study with similar items on a normal population of the same age. Therefore the items within a pair of simultaneously presented words or geometric figures in the two visual half-fields are generally of equal difficulty as perception is regarded. Therefore asymmetries in the perception are due to functional hemispheric asymmetry. Vertical oriented four-letterwords show no significant difference between reproduction from the right or left visual half-field. This discrepant finding regarding to the literature is discussed in respect of different methodology, different age distribution of the population, and different state of skills in reading and writing. Geometric figures showed marked asymmetries on the level of reproduction. Such items were much better recognized, if they were presented in the left visual half-field.