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Decoding humor experiences from brain activity of people viewing comedy movies.

Sawahata Y, Komine K, Morita T, Hiruma N - PLoS ONE (2013)

Bottom Line: As a result, in the right dorsolateral prefrontal cortex and the right temporal area, the decoders showed significant classification accuracies even at two seconds ahead of the humor onsets.Taking into account the hemodynamic delay, our results suggest that the upcoming humor events are encoded in specific brain areas up to about five seconds before the awareness of experiencing humor.Our results provide evidence that there exists a mental state lasting for a few seconds before actual humor perception, as if a viewer is expecting the future humorous events.

View Article: PubMed Central - PubMed

Affiliation: Science and Technology Research Laboratories, NHK (Japan Broadcasting Corporation), Setagaya, Tokyo, Japan.

ABSTRACT
Humans naturally have a sense of humor. Experiencing humor not only encourages social interactions, but also produces positive physiological effects on the human body, such as lowering blood pressure. Recent neuro-imaging studies have shown evidence for distinct mental state changes at work in people experiencing humor. However, the temporal characteristics of these changes remain elusive. In this paper, we objectively measured humor-related mental states from single-trial functional magnetic resonance imaging (fMRI) data obtained while subjects viewed comedy TV programs. Measured fMRI data were labeled on the basis of the lag before or after the viewer's perception of humor (humor onset) determined by the viewer-reported humor experiences during the fMRI scans. We trained multiple binary classifiers, or decoders, to distinguish between fMRI data obtained at each lag from ones obtained during a neutral state in which subjects were not experiencing humor. As a result, in the right dorsolateral prefrontal cortex and the right temporal area, the decoders showed significant classification accuracies even at two seconds ahead of the humor onsets. Furthermore, given a time series of fMRI data obtained during movie viewing, we found that the decoders with significant performance were also able to predict the upcoming humor events on a volume-by-volume basis. Taking into account the hemodynamic delay, our results suggest that the upcoming humor events are encoded in specific brain areas up to about five seconds before the awareness of experiencing humor. Our results provide evidence that there exists a mental state lasting for a few seconds before actual humor perception, as if a viewer is expecting the future humorous events.

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Prediction of upcoming humor experiences.(A) Temporal relationship between the predicted upcoming humor and the actual humor reports. The fMRI activity patterns in the right DLPFC obtained at each time point during movie-viewing were given to the h-2-decoder (upcoming humor detector) to predict the upcoming humorous events. The blue and red rasters indicate the outcome of the upcoming humor detector and the time point of the reported humor. Prediction results for all movie stimuli are depicted from the top to bottom in each panel (the upper and lower panels are for S1 and S2, respectively). (B) Detection probability of the upcoming humor experiences across the lag to the onset of humor reports. The colored solid lines correspond to the results for the upcoming humor detector constructed for the brain areas that showed the significant decoding accuracy at t = -2 s (shown in Figure 2). Error bars correspond to s.e.m.
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pone-0081009-g003: Prediction of upcoming humor experiences.(A) Temporal relationship between the predicted upcoming humor and the actual humor reports. The fMRI activity patterns in the right DLPFC obtained at each time point during movie-viewing were given to the h-2-decoder (upcoming humor detector) to predict the upcoming humorous events. The blue and red rasters indicate the outcome of the upcoming humor detector and the time point of the reported humor. Prediction results for all movie stimuli are depicted from the top to bottom in each panel (the upper and lower panels are for S1 and S2, respectively). (B) Detection probability of the upcoming humor experiences across the lag to the onset of humor reports. The colored solid lines correspond to the results for the upcoming humor detector constructed for the brain areas that showed the significant decoding accuracy at t = -2 s (shown in Figure 2). Error bars correspond to s.e.m.

Mentions: Figure 3 illustrates the decoding outcomes of the h-2-decoder for the sequences of single volume fMRI data in each run. Figure 3A illustrates the outcomes of the h-2-decoder, denoted by upcoming humor detector, for the right DLPFC of S1 and S2. Since we chose the h-2-decoder that showed significant decoding accuracy using fMRI data obtained two seconds before the humor onset, the high detection probability of the upcoming humor at the same lag is not a surprising result. However, the results show that the positive outcomes of the h-2-decoder were found not only two seconds prior to the humor onsets but also at the subsequent time points. By sorting the predictions of upcoming humor relative to the humor onsets, we found that the h-2-decoders constructed for the bilateral DLPFC, vPFC, and temporal areas predicted the upcoming humor not only two seconds before the humor onsets but also at the same time as them (Figure 3B). A similar tendency was also observed from the h0-decoders that showed the significant accuracies in Figure 2B. Hence, the information extracted by the h-2-decoders was the same as that extracted by the h0-decoders. Therefore, it is likely that the fMRI activity elicited at two seconds before and at the same time as the humor onset represented the same information that anticipates the upcoming humor events.


Decoding humor experiences from brain activity of people viewing comedy movies.

Sawahata Y, Komine K, Morita T, Hiruma N - PLoS ONE (2013)

Prediction of upcoming humor experiences.(A) Temporal relationship between the predicted upcoming humor and the actual humor reports. The fMRI activity patterns in the right DLPFC obtained at each time point during movie-viewing were given to the h-2-decoder (upcoming humor detector) to predict the upcoming humorous events. The blue and red rasters indicate the outcome of the upcoming humor detector and the time point of the reported humor. Prediction results for all movie stimuli are depicted from the top to bottom in each panel (the upper and lower panels are for S1 and S2, respectively). (B) Detection probability of the upcoming humor experiences across the lag to the onset of humor reports. The colored solid lines correspond to the results for the upcoming humor detector constructed for the brain areas that showed the significant decoding accuracy at t = -2 s (shown in Figure 2). Error bars correspond to s.e.m.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3852249&req=5

pone-0081009-g003: Prediction of upcoming humor experiences.(A) Temporal relationship between the predicted upcoming humor and the actual humor reports. The fMRI activity patterns in the right DLPFC obtained at each time point during movie-viewing were given to the h-2-decoder (upcoming humor detector) to predict the upcoming humorous events. The blue and red rasters indicate the outcome of the upcoming humor detector and the time point of the reported humor. Prediction results for all movie stimuli are depicted from the top to bottom in each panel (the upper and lower panels are for S1 and S2, respectively). (B) Detection probability of the upcoming humor experiences across the lag to the onset of humor reports. The colored solid lines correspond to the results for the upcoming humor detector constructed for the brain areas that showed the significant decoding accuracy at t = -2 s (shown in Figure 2). Error bars correspond to s.e.m.
Mentions: Figure 3 illustrates the decoding outcomes of the h-2-decoder for the sequences of single volume fMRI data in each run. Figure 3A illustrates the outcomes of the h-2-decoder, denoted by upcoming humor detector, for the right DLPFC of S1 and S2. Since we chose the h-2-decoder that showed significant decoding accuracy using fMRI data obtained two seconds before the humor onset, the high detection probability of the upcoming humor at the same lag is not a surprising result. However, the results show that the positive outcomes of the h-2-decoder were found not only two seconds prior to the humor onsets but also at the subsequent time points. By sorting the predictions of upcoming humor relative to the humor onsets, we found that the h-2-decoders constructed for the bilateral DLPFC, vPFC, and temporal areas predicted the upcoming humor not only two seconds before the humor onsets but also at the same time as them (Figure 3B). A similar tendency was also observed from the h0-decoders that showed the significant accuracies in Figure 2B. Hence, the information extracted by the h-2-decoders was the same as that extracted by the h0-decoders. Therefore, it is likely that the fMRI activity elicited at two seconds before and at the same time as the humor onset represented the same information that anticipates the upcoming humor events.

Bottom Line: As a result, in the right dorsolateral prefrontal cortex and the right temporal area, the decoders showed significant classification accuracies even at two seconds ahead of the humor onsets.Taking into account the hemodynamic delay, our results suggest that the upcoming humor events are encoded in specific brain areas up to about five seconds before the awareness of experiencing humor.Our results provide evidence that there exists a mental state lasting for a few seconds before actual humor perception, as if a viewer is expecting the future humorous events.

View Article: PubMed Central - PubMed

Affiliation: Science and Technology Research Laboratories, NHK (Japan Broadcasting Corporation), Setagaya, Tokyo, Japan.

ABSTRACT
Humans naturally have a sense of humor. Experiencing humor not only encourages social interactions, but also produces positive physiological effects on the human body, such as lowering blood pressure. Recent neuro-imaging studies have shown evidence for distinct mental state changes at work in people experiencing humor. However, the temporal characteristics of these changes remain elusive. In this paper, we objectively measured humor-related mental states from single-trial functional magnetic resonance imaging (fMRI) data obtained while subjects viewed comedy TV programs. Measured fMRI data were labeled on the basis of the lag before or after the viewer's perception of humor (humor onset) determined by the viewer-reported humor experiences during the fMRI scans. We trained multiple binary classifiers, or decoders, to distinguish between fMRI data obtained at each lag from ones obtained during a neutral state in which subjects were not experiencing humor. As a result, in the right dorsolateral prefrontal cortex and the right temporal area, the decoders showed significant classification accuracies even at two seconds ahead of the humor onsets. Furthermore, given a time series of fMRI data obtained during movie viewing, we found that the decoders with significant performance were also able to predict the upcoming humor events on a volume-by-volume basis. Taking into account the hemodynamic delay, our results suggest that the upcoming humor events are encoded in specific brain areas up to about five seconds before the awareness of experiencing humor. Our results provide evidence that there exists a mental state lasting for a few seconds before actual humor perception, as if a viewer is expecting the future humorous events.

Show MeSH