Studying single-trials of phase synchronous activity in the brain

This paper introduces a new method, single-trial phase locking statistics ( S-PLS) to estimate phase locking in single trials of brain signals between two electrodes. The possibility of studying single trials removes an import ant limitation in the study of long-range synchrony in brain signals. S-PLS is closely related to our previous method, phase locking statistics (PLS) that estimates phase locking over a set of trials. The S-PLS method is desc ribed in detail and applied to human surface recordings during the task of face-recognition. We compare these results with those provided by PLS and s how that they are qualitatively very similar, although S-PLS provides bette r discrimination of synchronic episodes.