title: Prefrontal activity during koh-do incense discrimination.
abstract: Whenever we make reasoned decisions we must refer to relevant knowledge obtained through past experience. Our brains test multiple premises and select whichever conclusion serves as the best explanation of the current conditions. In the present study we examined the prefrontal activity of koh-do experts with near infrared spectroscopy while they reasoned about odours during an incense discrimination task. These practitioners of the Japanese incense ceremony have been trained to form and manipulate abstract images of complex olfactory stimuli represented in a multidimensional symbolic space in the mind. In koh-do experts, the right PFC showed a consistent stimulus-non-selective response during discrimination and the left PFC showed phasic stimulus-selective responses modulated by the internal subjective state of the reasoning process. These two dissociated functions appeared to cooperate with each other during reasoning. In contrast, koh-do beginners did not show the organized response pattern found in experts. The results suggest that both PFCs contribute to abductive reasoning, but do so differently through different stages of the process.
authors.affiliation: Laboratory for Symbolic Cognitive Development, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. na@brain.riken.jp
authors.forename: Naotaka
authors.initials: N
authors.lastname: Fujii
authors.forename: Dilshat
authors.initials: D
authors.lastname: Abla
authors.forename: Noriko
authors.initials: N
authors.lastname: Kudo
authors.forename: Sayaka
authors.initials: S
authors.lastname: Hihara
authors.forename: Kazuo
authors.initials: K
authors.lastname: Okanoya
authors.forename: Atsushi
authors.initials: A
authors.lastname: Iriki
mesh_terms: D000328:Adult; D000368:Aged; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000502:physiology; D003657:Decision Making / Q000502:physiology*; D004193:Discrimination Learning / Q000502:physiology*; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D006801:Humans; D007092:Imagination / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010465:Perception / Q000502:physiology; D010812:Physical Stimulation; D017397:Prefrontal Cortex / Q000033:anatomy & histology / Q000098:blood supply / Q000502:physiology*; D021641:Recognition, Psychology / Q000502:physiology; D012903:Smell / Q000502:physiology*; D019265:Spectroscopy, Near-Infrared; D013850:Thinking / Q000502:physiology*