Applicability of Information Theory to the Quantification of Responses to Anthropogenic Noise by Southeast Alaskan Humpback Whales

Abstract:Laughter is increasingly present in biomedical literature, both in analytical neurological aspects and in applied therapeutic fields. The present paper, bridging between the analytical and the applied, explores the potential of a relevant variable of laughter's acoustic signature-entropy-in the detection of a widespread mental disorder, depression, as well as in gauging the severity of its diagnostic. In laughter, the Shannon-Wiener entropy of the distribution of sound frequencies, which is one of the key features distinguishing its acoustic signal from the utterances of spoken language, has not been a specific focus of research yet, although the studies of human language and of animal communication have pointed out that entropy is a very important factor regarding the vocal/acoustic expression of emotions. As the experimental survey of laughter in depression herein undertaken shows, it was possible to discriminate between patients and controls with an 82.1% accuracy just by using laughter's entropy and by applying the decision tree procedure. These experimental results, discussed in the light of the current research on laughter, point to the relevance of entropy in the spontaneous bona fide extroversion of mental states toward other individuals, as the signal of laughter seems to imply. This is in line with recent theoretical approaches that rely on the optimization of a neuro-informational free energy (and associated entropy) as the main "stuff" of brain processing.

Section: Discussionmentioning

confidence: 93%

The Entropy of Laughter: Discriminative Power of Laughter’s Entropy in the Diagnosis of Depression

Navarro

Moral

Cuesta-Álvaro

et al. 2016

“…Further studies along this line include the analysis of the chickadee (Parus atricapillus and P. carolinensis) [22,23], European starlings (Sturnus vulgaris) [24], Rufous-bellied thrushes (Turdus rufiventris) [25], European skylarks (Alauda arvensis L.) [26], wood thrushes (Hylocichla mustelina) and robins (Turdus migratorius) [13], bottlenose dolphins (Tursiops truncatus) [14,[27][28][29], humpback whales (Megaptera novaeangliae) [30][31][32][33] and male rock hyraxes (Procavia capensis) [34].…”

Section: Information Theory and Animal Communicationmentioning

confidence: 99%

“…These cries were investigated through the lens of information theory in several papers [30][31][32][33]. Suzuki [30] and Miksis-Olds and collaborators [31,32] analyzed the structure of humpback whale mating songs and found both that the sequences of whale cries were not stationary and could not be represented well by a first-order Markov chain model.…”

Section: Humpback Whalesmentioning

confidence: 99%

“…Suzuki [30] and Miksis-Olds and collaborators [31,32] analyzed the structure of humpback whale mating songs and found both that the sequences of whale cries were not stationary and could not be represented well by a first-order Markov chain model. Doyle and collaborators in [33] investigated the entropy and conditional entropy of humpback whale cries under the conditions of man-made noise and relative quiescence in order to establish how anthropomorphic noise may affect whale cry patterns. They found a significant effect, where whale cries seemed to have a steeper entropic slope, and are, thus, more repetitive, under high noise conditions, possibly to compensate for the more noisy channel.…”

Section: Humpback Whalesmentioning

confidence: 99%

See 1 more Smart Citation

Complexity in Animal Communication: Estimating the Size of N-Gram Structures

Smith

2014

In this paper, new techniques that allow conditional entropy to estimate the combinatorics of symbols are applied to animal communication studies to estimate the communication's repertoire size. By using the conditional entropy estimates at multiple orders, the paper estimates the total repertoire sizes for animal communication across bottlenose dolphins, humpback whales and several species of birds for an N-gram length of one to three. In addition to discussing the impact of this method on studies of animal communication complexity, the reliability of these estimates is compared to other methods through simulation. While entropy does undercount the total repertoire size due to rare N-grams, it gives a more accurate picture of the most frequently used repertoire than just repertoire size alone.

“…Slabbekoorn and Peet [15] showed that some species of birds purposely sing at a higher pitch in a city environment than they do in quiet countryside, while Doyle et al [39] found that Humpback whales increase the rate and repetitiveness of their communication calls under the influence of marine vessel noise. This strategy is a variant of simply extending the duration of each component of the call and has the advantage that it avoids complete obscuration of a part of the call by a long burst of noise.…”

Section: Noisementioning

confidence: 99%

The Variety of Information Transfer in Animal Sonic Communication: Review from a Physics Perspective

Fletcher

2009

For many anatomical and physical reasons animals of different genera use widely different communication strategies. While some are chemical or visual, the most common involve sound or vibration and these signals can carry a large amount of information over long distances. The acoustic signal varies greatly from one genus to another depending upon animal size, anatomy, physiology, and habitat, as also does the way in which information is encoded in the signal, but some general principles can be elucidated showing the possibilities and limitations for information transfer. Cases discussed range from insects through song birds to humans.