This is the data repository of the article published in Philosophical Transactions B (DOI:10.1098/rstb.2021-0182).
Who has not experienced that sensation of losing the power of speech by an involuntary bout of laughter? An investigation of this phenomenon affords an insight into the neuronal processes that underlie laughter. In our functional magnetic resonance imaging study participants were made to laugh by tickling in a first condition, in a second one they were requested to produce vocal utterances under the provocation of laughter by tickling. This investigation reveals increased neuronal activity in the sensorimotor cortex, the anterior cingulate gyrus, the insula, the accumbens nucleus, the hypothalamus, and the periaqueductal gray for both conditions thereby replicating the results of previous studies on ticklish laughter. However, further analysis indicates the activity in the emotion-associated regions to be lower when tickling is accompanied by voluntary vocalisation. Here, a typical pattern of activation is identified, including the primary sensory cortex, a ventral area of the anterior insula and the ventral tegmental field, comprising the ambiguus nucleus, namely, the common effector organ for voluntary and involuntary vocalisations. During the conflictual voluntary-vocalisation versus laughter experience, the laughter-triggering network appears to rely heavily on a sensory and a deep interoceptive analysis, as well as on motor effectors in the brainstem.
Treatment tickle & tickle and voluntary vocalizations: Conjunction of TiV with TiS Treatment tickle > touch & voluntary vocalisation: Conjunction of TiS>ToS with TiS>ToV Treatment: tickle and vol. voc. > touch & voluntary vocalisation: Conjunction of TiV>ToS with TiV>ToV
Anticipation main effect: Conjunction of AS (merged contrasts: comb) with AV (merged contrasts: comb)
Anticipation AS>AV: Conjunction of AS>AV touch (non-merged contrasts) with AS>AV tickle (non-merged contrasts) Anticipation AV>AS: Conjunction of AV>AS touch (non-merged contrasts) with AV>AS tickle (non-merged contrasts)