Figure 2.   Schematic illustration of  the methodology and parameters for single-sweep analysis. (1) Maximal peak-to-peak amplitudes of digitally filtered single sweeps (on the left; 6 sweeps filtered in the 4-7 Hz range are shown as examples).  (2) Phase-locking estimated on the base of the integral value (sum of absolute bar values) of single-sweep wave identification (SSWI) histograms (superimposed single sweeps and the corresponding SSWI-histogram are shown as examples).  (3) Enhancement factor (EF) of each filtered single sweep as a measure of the maximal amplitude ratio between post- and prestimulus theta activity. The formula for EF calculation is given and illustrated at the top. T1 and T2 designate early (0-300 ms) and late (300-600 ms) time windows.