Figure 4. The grand average waveform of P1 elicited in the incomplete face condition and complete face condition . The four tests and four electrode sites (PO3/PO4/O1/O2) were averaged.
For the amplitude of the P1 component, the main effect of time was significant [F (1.72, 29.23) = 3.59, p = 0.02, ηp2=0.17], and the amplitude of P1 in Test 2 was larger than that in Test 3 (4.70 ± 0.49 vs. 3.92 ± 0.46, p = 0.013) and Test 4 (3.91± 0.48, p = 0.010) (Figure 3). The main effect of hemisphere was significant [F (1,17) = 19.64, p <0.001, ηp2 = 0.54], and the P1 amplitude in the right hemisphere was larger than that in the left hemisphere (4.51 ± 0.48 vs. 3.81 ± 0.41) (Table 2 and Figure 5). The main effect of face stimulus was significant [F (1,17) = 21.13,p <0.001, ηp2 = 0.55], and the P1 amplitude in the complete condition was larger than that in the incomplete condition (4.72 ± 0.43 vs. 3.60 ± 0.48) (Table 2 and Figure 4).