title: Neural correlates of mirth and laughter: a direct electrical cortical stimulation study.
abstract: Laughter consists of both motor and emotional aspects. The emotional component, known as mirth, is usually associated with the motor component, namely, bilateral facial movements. Previous electrical cortical stimulation (ES) studies revealed that mirth was associated with the basal temporal cortex, inferior frontal cortex, and medial frontal cortex. Functional neuroimaging implicated a role for the left inferior frontal and bilateral temporal cortices in humor processing. However, the neural origins and pathways linking mirth with facial movements are still unclear. We hereby report two cases with temporal lobe epilepsy undergoing subdural electrode implantation in whom ES of the left basal temporal cortex elicited both mirth and laughter-related facial muscle movements. In one case with normal hippocampus, high-frequency ES consistently caused contralateral facial movement, followed by bilateral facial movements with mirth. In contrast, in another case with hippocampal sclerosis (HS), ES elicited only mirth at low intensity and short duration, and eventually laughter at higher intensity and longer duration. In both cases, the basal temporal language area (BTLA) was located within or adjacent to the cortex where ES produced mirth. In conclusion, the present direct ES study demonstrated that 1) mirth had a close relationship with language function, 2) intact mesial temporal structures were actively engaged in the beginning of facial movements associated with mirth, and 3) these emotion-related facial movements had contralateral dominance.
authors.affiliation: Department of Neurosurgery, Kyoto University Graduate School of Medicine, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Yamao
authors.affiliation: Department of Epilepsy, Movement Disorders and Physiology, Kyoto University Graduate School of Medicine, Japan. Electronic address: matsumot@kuhp.kyoto-u.ac.jp.
authors.forename: Riki
authors.initials: R
authors.lastname: Matsumoto
authors.affiliation: Department of Neurosurgery, Kyoto University Graduate School of Medicine, Japan. Electronic address: kuny@kuhp.kyoto-u.ac.jp.
authors.forename: Takeharu
authors.initials: T
authors.lastname: Kunieda
authors.affiliation: Department of Neurosurgery, Kyoto University Graduate School of Medicine, Japan.
authors.forename: Sumiya
authors.initials: S
authors.lastname: Shibata
authors.affiliation: Department of Neurology, Kyoto University Graduate School of Medicine, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Shimotake
authors.affiliation: Department of Neurosurgery, Kyoto University Graduate School of Medicine, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kikuchi
authors.affiliation: Department of Neurosurgery, Nagahama City Hospital, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Satow
authors.affiliation: Department of Neurosurgery, Sapporo Medical University School of Medicine, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Mikuni
authors.affiliation: Human Brain Research Center, Kyoto University Graduate School of Medicine, Japan.
authors.forename: Hidenao
authors.initials: H
authors.lastname: Fukuyama
authors.affiliation: Department of Epilepsy, Movement Disorders and Physiology, Kyoto University Graduate School of Medicine, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Ikeda
authors.affiliation: Department of Neurosurgery, Kyoto University Graduate School of Medicine, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Miyamoto
mesh_terms: D000293:Adolescent; D004558:Electric Stimulation; D004599:Electric Stimulation Therapy / Q000379:methods*; D004576:Electromyography; D004644:Emotions / Q000502:physiology*; D004833:Epilepsy, Temporal Lobe / Q000628:therapy*; D019054:Evoked Potentials, Motor / Q000502:physiology; D005152:Facial Muscles / Q000502:physiology; D005260:Female; D005625:Frontal Lobe; D006801:Humans; D007802:Language; D007845:Laughter / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology*; D055815:Young Adult
keywords: Basal temporal language area; Electrical cortical stimulation; Laughter; Mesial temporal structure; Mirth