Comparative mammalian brain imaging: a neuroethological approach to the emergence of lexical representations
Lexical items (words) are the basic building blocks of human languages, but previous research hardly ever found items with lexical features in nonhuman vocal communicative systems, even though several species are capable of learning and discriminating arbitrary sound sequences, associating vocalizations with specific meanings, or producing human-like lexical items after extensive training. Recently, we presented the first fMRI study on how dog brain processes human words, demonstrating that dogs, similarly to humans, are capable of storing lexical representations (i.e. arbitrary associations of sound sequences to meanings) independently of paralinguistic features, such as intonation (Andics et al. 2016, Science). This research suggests that human linguistic capacity cannot be understood in isolation. A broad comparative perspective to what brain mechanisms various species have in common with humans for vocal social processing is essential for a better understanding of the contributions of biological and cultural evolution to the emergence of linguistic competence.
How and under what ontogenetic conditions do lexical representations emerge in nonhuman brains? How do mammals acquire and consolidate new meanings, and how do they fit them in their pre-existing lexico-semantic network? What are the similarities and differences of mental lexicons across different mammalian species? What are the organizing principles of learnt, vocally encoded meanings, and how do they differ across conspecific and heterospecific vocalizations, and across semantic domains (Binder 2009)? Do mammals share the representations of basic biological meanings (Ehret 2010) in vocal utterances, and can this hard-wired semantics be overruled by learnt sound-to-meaning associations? Are dogs in a better position than other mammals that had not been under a similar selective pressure to fit into the human social environment, to learn the meanings of human words?
The comparative approach
We hypothesize that the shared capacity of dogs and humans to store lexical representations is based on an ancient capacity present in the last common ancestor of the two species. We therefore expect that certain lexical processing capacities, which are shared among dogs and humans, are highly similar to those in other mammals. The domestic pig is an evolutionarily distant relative of both dogs and humans, with a domestication history that is considerably shorter than that of dogs, and that followed a very different trajectory. Nevertheless, if socialized by humans, pigs are also receptive to interspecific social cues, and can follow ostensive-referential communicative cues such as human pointing or gaze direction. With the increasing recognition of pig as a model species for biomedical research, minipig breeds with much smaller size appeared. The sociocognitive capacities and their reduced size made minipigs suitable companion animals, and the number of minipigs kept as pets have increased considerably in the last several years. When kept as pets, dogs and pigs occupy a similar ecological niche of living with humans. Extending comparative neuroscientific studies on vocal social functions to pigs could therefore shed light on the biological and cultural determinants of lexical processing, revealing how similar or variable neural representations can get in species with a highly different phylogenetic history, once the environment is stabilized, and potentially highly controlled.
Our lab is funded by a grant to the MTA-ELTE ‘Lendület’ Neuroethology of Communication Research Group in the frame of the Lendület programme of the Hungarian Academy of Sciences (LP2017-13/2017), the National Research, Development and Innovation Office (KH125527), and the Eötvös Loránd University.
Attila Andics (group leader), firstname.lastname@example.org
Gábor A, Gácsi M, Szabó D, Miklósi Á, Kubinyi E, Andics A (in press) Multilevel fMRI adaptation for spoken word processing in the awake dog brain. Scientific Reports
Pérez Fraga P, Gerencsér L, Lovas M, Újváry D, Andics A (in press) Who turns to the human? Comparing pigs’ and dogs’ behaviour in the unsolvable task paradigm. Animal Cognition. doi: 10.1007/s10071-020-01410-2
Bunford N, Hernández-Perez R, Farkas E, Cuaya L, Szabó D, Szabó Á, Gácsi M, Miklósi Á, Andics A (in press) Comparative Brain Imaging Reveals Analogous And Divergent Patterns Of Species- And Face-Sensitivity In Humans And Dogs. The Journal of Neuroscience
Boros M, Gábor A, Szabó D, Bozsik A, Gácsi M, Szalay F, Faragó T, Andics A (2020) Repetition enhancement to voice identities in the dog brain Sci Rep 10, 3989 https://doi.org/10.1038/s41598-020-60395-7 [pdf] [link]
Szabó D, Gábor A, Gácsi M, Faragó T, Kubinyi E, Miklósi Á and Andics A (2020) On the Face of It: No Differential Sensitivity to Internal Facial Features in the Dog Brain. Front. Behav. Neurosci. 14:25. doi: 10.3389/fnbeh.2020.00025 [pdf] [link]
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Gerencsér L, Pérez Fraga P, Lovas M, Újváry D, Andics A (2019) Comparing interspecific socio-communicative skills of socialized juvenile dogs and miniature pigs. Animal Cognition 22: 917, doi:10.1007/s10071-019-01284-z [pdf] [link]
Szabó D, Czeibert K, Kettinger Á, Gácsi M, Andics A, Miklósi Á, Kubinyi E (2019) Resting-state fMRI data of awake dogs (Canis familiaris) via group-level independent component analysis reveal multiple, spatially distributed resting-state networks. Scientific Reports 9: 15270. doi: 10.1038/s41598-019-51752-2 [pdf] [link]
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Gerencsér L, Bunford N, Moesta A, Miklósi Á (2018) Development and validation of the Canine Reward Responsiveness Scale –Examining individual differences in reward responsiveness of the domestic dog, Scientific Reports, 8: 4421. doi:10.1038/s41598-018-22605-1 [pdf] [link]
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