Studies of the negative symptoms of schizophrenia seem to be of intere
st. However, the description of these symptoms is problematic. Some co
gnitive tests seem able to establish data that can be used to help dis
criminate among schizophrenic syndromes and to understand their differ
ent pathophysiology. Some of the main tests are described. Remarks con
cerning their value and the conditions of their interpretations are ma
de.