A system for the assessment and training of temporal-order discrimination

Two programs were developed for psychophysical assessment and training of temporal-order thresholds in the visual and auditory modalities. Order threshold is defined as the minimum onset interval between two sensory events (stimulus onset asynchrony, SOA) that must exist before an observer is able to indicate the correct order of the events. Brain-injured patients with aphasia and children with language-learning impairments, i.e. those who have been diagnosed as performing poorly on temporal-order tasks and in discriminating stop-consonant vowel syllables, can effectively be trained by a feedback training procedure in which the SOA is manipulated. The performance in the temporal-order task and the ability to discriminate phonemes improves with this procedure. In the diagnostic program, the SOA is changed by an adaptive procedure that generates a sequence of SOAs converging to the threshold and is driven by the responses of the subject. The feedback-training program begins with the presentation of SOAs, which are slightly above the individual order threshold; they are subsequently varied according to the responses of the subject.