Automated System For Selecting Time‐Locked Signals From Analog Recorders

Abstract

ABSTRACTIn research centers where particular attention is paid to evoked potentials or event‐related slow potentials, e.g. contingent negative variation or motor potentials, the computer can facilitate the task of the researcher in distinguishing the numerous valid and non‐valid trials on a registration on‐line. A non‐valid trial is one that has been contaminated by artifacts such as eyeblinks, eye‐movements, etc. Many of them, however, still use magnetic tape for data storage for off‐line analysis. Simultaneous with the visual control of the EEG the valid trials are selected and then averaged by means of a special purpose computer (averager) I. These analyses are time‐consuming and quite fatiguing because in case of a heavily contaminated registration, one must stop and restart the averager continuously: for this reason tape speed is limited for off‐line analysis. This paper describes a system. Automatic Data Selector (A.D.S.), which can be programmed and then automatically selects the valid trials. See Fig. 1.