title: Hippocampal-prefrontal connectivity predicts midfrontal oscillations and long-term memory performance.
abstract: The hippocampus and prefrontal cortex interact to support working memory (WM) and long-term memory [1-3]. Neurophysiologically, WM is thought to be subserved by reverberatory activity of distributed networks within the prefrontal cortex (PFC) [2, 4-8], which become synchronized with reverberatory activity in the hippocampus [1, 4]. This electrophysiological synchronization is difficult to study in humans because noninvasive electroencephalography (EEG) cannot measure hippocampus activity. Here, using a novel integration of EEG and diffusion-weighted imaging, it is shown that individuals with relatively stronger anatomical connectivity linking the hippocampus to the right ventrolateral PFC (ventral Brodmann area 46) exhibited slower frequency neuronal oscillations during a WM task. Furthermore, subjects with stronger hippocampus-PFC connectivity were better able to encode the complex pictures used in the WM task into long-term memory. These findings are consistent with models suggesting that electrophysiological oscillations provide a mechanism of long-range interactions [9] and link hippocampus-PFC structural connectivity to PFC rhythmic electrical dynamics and memory performance. More generally, these results highlight the importance of incorporating individual differences when linking structure and function to cognition.
authors: Department of Psychology, University of Amsterdam, Weesperplein 4, Amsterdam 1018 XA, The Netherlands. mikexcohen@gmail.com
authors: Michael X
authors: MX
authors: Cohen
mesh_terms: D004569:Electroencephalography / Q000379:methods*; D005260:Female; D006624:Hippocampus / Q000033:anatomy & histology / Q000502:physiology*; D006801:Humans; D008297:Male; D057567:Memory, Long-Term; D008570:Memory, Short-Term; D059906:Neuroimaging / Q000379:methods*; D017397:Prefrontal Cortex / Q000033:anatomy & histology / Q000502:physiology*; D055815:Young Adult