Conclusion

taxa recognition.

The fNIRS analyses described above are not the only ones in progress. Indeed, despite our interest on the processing of vocal recognition in several primate species, we did not differentiate in Study 6 the vocalizations expressed by baboons or chimpanzees. We recently started to assess the modulation of haemodynamic activity in the temporal cortex of our three baboons depending on the lateralization of the sounds as well as the species that expressed the vocalizations. Using GLMM, our preliminary results interestingly reveal differences in activity within the left temporal cortex between the processing of chimpanzee stereo and baboon stereo calls. These promising findings seem to emphasize the cerebral mechanisms underlying the recognition of the caller identity. However, further brain and acoustic analyses are still required.

Finally and perhaps the most challenging, future studies wanting to use fNIRS with NHP should consider the development of new protocols to investigate brain mechanisms on awake monkeys. Indeed, Study 6 was performed on three anesthetized baboons. Despite the injection of a minimum amount of propofol, we could not totally control the modulation of the haemodynamic responses induced by the anaesthesia. Furthermore, the recent appearance of wireless and portative fNIRS device on the market should make possible the development of such non-invasive paradigms to assess NHP brain functions in more ecological and ethical contexts.

In sum, Study 1 to Study 6 will hopefully contribute to improve our knowledge in neurosciences and related fields with regards to emotion processing. Yet, further investigations are still required to increase progress in research using a comparative approach.

5. Conclusion

In light of the great Hominidae history, the present thesis demonstrated the importance of an evolutionary perspective in neurosciences research. In fact, in line with Jaak Panksepp, considered as the founder of the comparative approach in affective neurosciences, our results suggest preserved brain and behavioural mechanisms in humans inherited from our common ancestor with other primates. Interestingly, we also pointed out that the

phylogenetic proximity was insufficient to explain modern human abilities to recognize affective contents in other primate vocalizations. A closer acoustic distance from the human voice to NHP vocalizations seems indeed necessary for the correct affective and species recognition by humans. Therefore, Study 1 to Study 6 revealed for the first time: i) differences between categorization and discrimination of emotions in conspecific and heterospecific vocalizations; ii) the involvement of frontal regions for the human recognition of affects in NHP calls; iii) the capacity of humans to mostly recognize all affects in all primate vocalizations; iv) acoustic similarities between human and chimpanzee calls; v) the involvement of TVA and IFG for the categorization of NHP vocalizations; and vi) the suitability of fNIRS to assess the haemodynamic activity in NHP brain.

Overall, the present thesis will hopefully promote the evolutionary approach to investigate emotional mechanisms at play in both human and non-human primates’ vocal communication.

References

Aarabi, A., Osharina, V., & Wallois, F. (2017). Effect of confounding variables on hemodynamic response function estimation using averaging and deconvolution analysis: An event-related NIRS study. NeuroImage, 155, 25–49.

https://doi.org/10.1016/j.neuroimage.2017.04.048

Aglieri, V., Chaminade, T., Takerkart, S., & Belin, P. (2018). Functional connectivity within the voice perception network and its behavioural relevance. NeuroImage, 183, 356–

365. https://doi.org/10.1016/j.neuroimage.2018.08.011

Albuquerque, N., Guo, K., Wilkinson, A., Savalli, C., Otta, E., & Mills, D. (2016). Dogs recognize dog and human emotions. Biology Letters, 12(1), 20150883.

https://doi.org/10.1098/rsbl.2015.0883

Al-Shawaf, L., & Lewis, D. M. G. (2017). Evolutionary Psychology and the Emotions. In V.

Zeigler-Hill & T. K. Shackelford (Eds.), Encyclopedia of Personality and Individual Differences (pp. 1–10). Springer International Publishing. https://doi.org/10.1007/978-3-319-28099-8_516-1

Anderson, D. J., & Adolphs, R. (2014). A Framework for Studying Emotions Across Phylogeny. Cell, 157(1), 187–200. https://doi.org/10.1016/j.cell.2014.03.003

Andics, A., Gácsi, M., Faragó, T., Kis, A., & Miklósi, Á. (2014). Voice-Sensitive Regions in the Dog and Human Brain Are Revealed by Comparative fMRI. Current Biology, 24(5), 574–578. https://doi.org/10.1016/j.cub.2014.01.058

Aoki, R., Sato, H., Katura, T., Utsugi, K., Koizumi, H., Matsuda, R., & Maki, A. (2011).

Relationship of negative mood with prefrontal cortex activity during working memory tasks: An optical topography study. Neuroscience Research, 70(2), 189–196.

https://doi.org/10.1016/j.neures.2011.02.011

Aqil, M., Hong, K.-S., Jeong, M.-Y., & Ge, S. S. (2012). Detection of event-related hemodynamic response to neuroactivation by dynamic modeling of brain activity.

NeuroImage, 63(1), 553–568. https://doi.org/10.1016/j.neuroimage.2012.07.006

Arnal, L. H., Flinker, A., Kleinschmidt, A., Giraud, A.-L., & Poeppel, D. (2015). Human Screams Occupy a Privileged Niche in the Communication Soundscape. Current Biology : CB, 25(15), 2051–2056. https://doi.org/10.1016/j.cub.2015.06.043

Arnellos, A., & Keijzer, F. (2019). Bodily Complexity: Integrated Multicellular Organizations for Contraction-Based Motility. Frontiers in Physiology, 10.

https://doi.org/10.3389/fphys.2019.01268

Arnold, M. B. (1960). Emotion and personality. Columbia University Press.

Arnsten, A. F. T. (2009). Stress signalling pathways that impair prefrontal cortex structure and function. Nature Reviews. Neuroscience, 10(6), 410–422.

https://doi.org/10.1038/nrn2648

Ashburner, J. (2007). A fast diffeomorphic image registration algorithm. NeuroImage, 38(1), 95–113. https://doi.org/10.1016/j.neuroimage.2007.07.007

Bach, D., Grandjean, D., Sander, D., Herdener, M., Strik, W., & Seifritz, E. (2008). The effect of appraisal level on processing of emotional prosody in meaningless speech.

NeuroImage, 42, 919–927. https://doi.org/10.1016/j.neuroimage.2008.05.034

Balardin, J. B., Zimeo Morais, G. A., Furucho, R. A., Trambaiolli, L., Vanzella, P., Biazoli, C.,

& Sato, J. R. (2017). Imaging Brain Function with Functional Near-Infrared Spectroscopy in Unconstrained Environments. Frontiers in Human Neuroscience, 11.

https://doi.org/10.3389/fnhum.2017.00258

Balconi, M., Grippa, E., & Vanutelli, M. E. (2015). What hemodynamic (fNIRS), electrophysiological (EEG) and autonomic integrated measures can tell us about emotional processing. Brain and Cognition, 95, 67–76.

https://doi.org/10.1016/j.bandc.2015.02.001

Balconi, M., & Vanutelli, M. E. (2016). Hemodynamic (fNIRS) and EEG (N200) correlates of emotional inter-species interactions modulated by visual and auditory stimulation.

Scientific Reports, 6, 23083. https://doi.org/10.1038/srep23083

Banse, R., & Scherer, K. R. (1996). Acoustic Profiles in Vocal Emotion Expression. 23.

Baraud, I., Buytet, B., Bec, P., & Blois-Heulin, C. (2009). Social laterality and ‘transversality’

in two species of mangabeys: Influence of rank and implication for hemispheric specialization. Behavioural Brain Research, 198(2), 449–458.

https://doi.org/10.1016/j.bbr.2008.11.032

Barbas, H. (2000). Connections underlying the synthesis of cognition, memory, and emotion in primate prefrontal cortices. Brain Research Bulletin, 52(5), 319–330.

https://doi.org/10.1016/s0361-9230(99)00245-2

Barbas, Helen, Zikopoulos, B., & Timbie, C. (2011). Sensory Pathways and Emotional Context for Action in Primate Prefrontal Cortex. Biological Psychiatry, 69(12), 1133–

1139. https://doi.org/10.1016/j.biopsych.2010.08.008

Barch, D. M., & Yarkoni, T. (2013). Introduction to the special issue on reliability and replication in cognitive and affective neuroscience research. Cognitive, Affective, &

Behavioral Neuroscience, 13(4), 687–689. https://doi.org/10.3758/s13415-013-0201-7 Belin, P., Zatorre, R. J., Lafaille, P., Ahad, P., & Pike, B. (2000). Voice-selective areas in

human auditory cortex. Nature, 403(6767), 309–312. https://doi.org/10.1038/35002078 Belin, P. (2006). Voice processing in human and non-human primates. Philosophical

Transactions of the Royal Society B: Biological Sciences, 361(1476), 2091–2107.

https://doi.org/10.1098/rstb.2006.1933

Belin, P, Fecteau, S., Charest, I., Nicastro, N., Hauser, M. D., & Armony, J. L. (2008). Human