The Informational Patterns of Laughter

José A Bea,Pedro C Marijuán

doi:10.3390/e5020205

José A Bea, Pedro C Marijuán

Open Access

https://doi.org/10.3390/e5020205

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Abstract

Laughter is one of the most characteristic -and enigmatic- communicational traits of human individuals. Its analysis has to take into account a variety of emotional, social, cognitive, and communicational factors densely interconnected. In this article we study laughter just as an auditive signal (as a 'neutral' information carrier), and we compare its structure with the regular traits of linguistic signals. In the experimental records of human laughter that we have performed, the most noticeable trait is the disorder content of frequencies. In comparison with the sonograms of vowels, the information content of which appears as a characteristic, regular function of the first vibration modes of the dynamic system formed, for each vowel, by the vocal cords and the accompanying resonance of the vocalization apparatus, the sonograms of laughter are highly irregular. In the episodes of laughter, a highly random content in frequencies appears, reason why it cannot be considered as a genuine codification of patterned information like in linguistic signals. In order to numerically gauge the disorder content of laughter frequencies, we have performed several "entropy" measures of the spectra -trying to unambiguously identify spontaneous laughter from "faked", articulated laughter. Interestingly, Shannon's entropy (the most natural candidate) performs rather poorly.

Highlights

Following several classic authors, we may describe human laughter as the vocal output of a "confluence" produced in a variety of social, emotional, cognitive, and communicational processes that somehow contain an abrupt transition or an opposition of evaluations, and are resolved into a cancellation of effective action [1]
In a slightly different interpretation, we will consider here that laughter works as an automatic mechanism for the ad hoc minimization of a high level of neuronal excitation that circumstantially –suddenly– becomes irrelevant from the behavioral point of view as a focus of attention [2,3,4]
In the case of laughter, its genuine meaning as a ‘solved’ problem is accompanied by the regular reward –or biological pleasure– that ensues the culmination of problem solving activities at any behavioral or cognitive level

Summary

The Sonograms of Laughter

In relation with the possible orchestration of laughter out from the "old" primate emotionexpressing path [1, 10,11], we have already found in our initial analysis of laughter sonograms that there is a strong discrepancy in between the mathematical forms of laughter and language acoustic elements. In a "voluntary" or non-spontaneous laughter the sonograms detect the presence of language ordered elements, and the relative absence of entropic or "chaotic" components. This difference is very easy to detect by any subject, just listening to the respective sounds. A classical measure of disorder and uncertainty is Shannon’s entropy. Our initial proposal is to use Shannon’s entropy as a measure of the disorder of laughter. Let h be a function defined on the interval (0,1) and h( p) be interpreted as the uncertainty associated with the event X = xi , i = 1,2,K, n or the information conveyed by revealing that X has taken on the value xi in a given performance of the experiment.

The Entropy Content of Human Voice Versus Laughter

Closing Comments