title: Effects of emotion and reward motivation on neural correlates of episodic memory encoding: a PET study.
abstract: It is known that emotion and reward motivation promote long-term memory formation. It remains unclear, however, how and where emotion and reward are integrated during episodic memory encoding. In the present study, subjects were engaged in intentional encoding of photographs under four different conditions that were made by combining two factors (emotional valence, negative or neutral; and monetary reward value, high or low for subsequent successful recognition) during H2 15O positron emission tomography (PET) scanning. As for recognition performance, we found significant main effects of emotional valence (negative>neutral) and reward value (high value>low value), without an interaction between the two factors. Imaging data showed that the left amygdala was activated during the encoding conditions of negative pictures relative to neutral pictures, and the left orbitofrontal cortex was activated during the encoding conditions of high reward pictures relative to low reward pictures. In addition, conjunction analysis of these two main effects detected right hippocampal activation. Although we could not find correlations between recognition performance and activity of these three regions, we speculate that the right hippocampus may integrate the effects of emotion (processed in the amygdala) and monetary reward (processed in the orbitofrontal cortex) on episodic memory encoding.
authors.affiliation: Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan. gemune@mail.tains.tohoku.ac.jp
authors.forename: Yayoi
authors.initials: Y
authors.lastname: Shigemune
authors.forename: Nobuhito
authors.initials: N
authors.lastname: Abe
authors.forename: Maki
authors.initials: M
authors.lastname: Suzuki
authors.forename: Aya
authors.initials: A
authors.lastname: Ueno
authors.forename: Etsuro
authors.initials: E
authors.lastname: Mori
authors.forename: Manabu
authors.initials: M
authors.lastname: Tashiro
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Itoh
authors.forename: Toshikatsu
authors.initials: T
authors.lastname: Fujii
mesh_terms: D000328:Adult; D000679:Amygdala / Q000000981:diagnostic imaging / Q000502:physiology; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology*; D001931:Brain Mapping; D003903:Deuterium; D004644:Emotions; D005625:Frontal Lobe / Q000000981:diagnostic imaging / Q000502:physiology; D006624:Hippocampus / Q000000981:diagnostic imaging / Q000502:physiology; D006801:Humans; D008297:Male; D011939:Mental Recall; D009042:Motivation; D009714:Nucleus Accumbens / Q000000981:diagnostic imaging / Q000502:physiology; D049268:Positron-Emission Tomography; D012201:Reward; D013378:Substantia Nigra / Q000000981:diagnostic imaging / Q000502:physiology; D017557:Ventral Tegmental Area / Q000000981:diagnostic imaging / Q000502:physiology; D055815:Young Adult
chemical_list: D003903:Deuterium