Complex sentence: The P3a is suspected to also reflect interactions between the frontal lobe and the hippocampus, as patients with focal hippocampal lesions have reduced P3a amplitude from novel distracters.
Split into simpler sentences: The P3a is suspected to also reflect frontal lobe activity in relation to the hippocampus. Patients with focal hippocampal lesions have reduced P3a amplitude from novel distracters.