Some methods to study information transmission through multi-channel neuronal systems.

Methods are proposed to isolate nearly simultaneous events or events with specific time relations to each other from two (or more) stimulus or spike trains. The methods can be implemented by means of a digital computer, but were implemented here with simple electronic hardware to present an alternative. The usefulness of these methods is demonstrated on data from cat experiments in which the influences of several motor units activated in parallel upon muscle spindle discharge patterns were studied by use of poststimulus time histograms (PSTHs). The contractions of one motor unit can interfere with the effects of others on muscle spindle discharges. In order to show this conditioning influence quantitatively, the integral of the PSTH is shown graphically as a function of the time interval between contractions of two motor units. These methods may help to elucidate some features of interactions between parallel neuronal channels bearing on the problem of the kind of information and how the latter is transmitted through complex multichannel systems.