title: Neural substrates associated with evaluative processing during co-activation of positivity and negativity: a PET investigation.
abstract: Affective symmetries, such as the positivity offset and negativity bias, have been postulated to be attributable to distinct activation functions of the positive and negative affect systems. We investigated the neural substrates that are engaged when the positive and negative affect systems undergo parallel and integrative processing. Eleven subjects were scanned using H(2)(15)O PET during choosing the subjective feeling produced by a stimulation pair of pictures or words. Four different conditions were designed for contrast: pure positivity, pure negativity, positivity offset, and negativity bias. The dorsolateral prefrontal activation was associated with positivity offset and negativity bias condition, whereas the ventromedial prefrontal activation, together with limbic and subcortical activations, was associated with pure positivity and pure negativity condition. The results indicated that positivity offset and negativity bias are not merely due to asymmetric activations of the positive and negative systems, but integrative processing of higher neocortical levels is involved.
authors.affiliation: Institute of Behavioral Science in Medicine, Severance Mental Health Hospital, Yonsei University College of Medicine, 696-6 Tanbul-dong Gwangju-si, Gyeonggi-do 464-100, Republic of Korea.
authors.forename: Young Chul
authors.initials: YC
authors.lastname: Jung
authors.forename: Suk Kyoon
authors.initials: SK
authors.lastname: An
authors.forename: Jeong Ho
authors.initials: JH
authors.lastname: Seok
authors.forename: Jae Seung
authors.initials: JS
authors.lastname: Kim
authors.forename: Seung Jun
authors.initials: SJ
authors.lastname: Oh
authors.forename: Dae Hyuk
authors.initials: DH
authors.lastname: Moon
authors.forename: Jae-Jin
authors.initials: JJ
authors.lastname: Kim
mesh_terms: D000328:Adult; D000339:Affect / Q000502:physiology*; D001143:Arousal / Q000502:physiology; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology; D001931:Brain Mapping; D004292:Dominance, Cerebral / Q000502:physiology*; D004644:Emotions / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009415:Nerve Net / Q000000981:diagnostic imaging / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology*; D049268:Positron-Emission Tomography; D017397:Prefrontal Cortex / Q000000981:diagnostic imaging / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D011932:Reading; D012016:Reference Values; D012660:Semantics