ABSTRACT
Diagnostic tests, based on conditional reflex phenomena, foi psychiatric purposes are partly replicas of Pavlov's behavioral animal experiments in humans. Other procedures reveal information on the transmission from the first to the second signal system and/or second signal system functions. In human conditioning tests, a formerly indifferent stimulus to a specific activity is developed, under the conditions, into a specific stimulus for the specific function. While in delayed reflexes the conditional stimulus is prolonged and the reflex postponed to the end of this elongated stimulus, in a trace reflex the conditional stimulus remains unaltered, but the reflex appears following a time interval after the conditional stimulus. The number of associations required before the conditional reflex develops to the second (non-verbal) conditional stimulus alone is the measure of this function. The primary conditional stimulus thereafter is combined with the squeezing by the subject of a dynamometer to the command "Contract."
