As discussed above, P3 has multiple sources, with contributions from the frontal cortex and hippocampus. P3 consists of delta and theta oscillations with a higher proportion of delta oscillations from the posterior regions of the brain, and theta occurring in the frontal and central regions (Yordanova and Kolev 1996; Basar et al. 1999; Basar-Eroglu et al. 1992; Karakas et al. 2000). Synchronization occurs in the theta range between the hippocampus and frontal and parietal regions in the brain (figure 1) (i.e., these regions communicate with each other) during attention tasks.
