Category: Abstracts

Talk to the Virtual Hands

A new paper in PlosOne has used new fancy research methods to look at whether humans are more capable of describing a word using just spoken communication, or whether the use of gesture also helps. This research is pertinent to the field of language evolution because it might help us understand if spoken language co-evolved with gesture as well as helping us understand how language is processed in the brain.

This new study builds on previous research in this area by using avatars in a virtual reality setting. Participants were either in control of the movements of their avatar, or not.

The study found that participants were much more successful in communicating concepts when the speaker was able to use their own gestures when explaining a concept using spoken language. The body language of the listener also impacted success at the task, showing the need for nonverbal feedback from the listener.

It’s worth noting that the primary purpose of this research wasn’t to find if gesture is helpful in communication (though that is certainly interesting and worthwhile) but rather whether using virtual reality is fruitful in these kinds of experiments.

The press release discusses some of the problems with using avatars:

The researchers note that there are limitations to nonverbal communication in virtual reality environments. First, they found that participants move much less in a virtual environment than they do in the “real world.” They also found that the perspective of the camera in the virtual environment affected the results.

Lead author, Dr. Trevor Dodds maintains, “this research demonstrates that virtual reality technology can help us gain a greater understanding of the role of body gestures in communication. We show that body gestures carry extra information when communicating the meaning of words. Additionally, with virtual reality technology we have learned that body gestures from both the speaker and listener contribute to the successful communication of the meaning of words.  These findings are also important for the development of virtual environments, with applications including medical training, urban planning, entertainment and telecommunication.”

The work was led by Dr. Trevor Dodds at the Max Planck Institute for Biological Cybernetics in Germany.

References
 Dodds TJ, Mohler BJ, Bu¨ lthoff HH (2011) Talk to the Virtual Hands: Self-Animated Avatars Improve Communication in Head-Mounted Display Virtual Environments. PLoS ONE 6(10): e25759. doi:10.1371/journal.pone.0025759

Neural Language Networks at Birth

I haven’t had chance to read this paper, but it throws up some interesting discussion points relating to this blog. In particular, it relates to a hypothesis I put forward last year on Domain-General Regions and Domain-Specific Networks. Here is the abstract:

The ability to learn language is a human trait. In adults and children, brain imaging studies have shown that auditory language activates a bilateral frontotemporal network with a left hemispheric dominance. It is an open question whether these activations represent the complete neural basis for language present at birth. Here we demonstrate that in 2-d-old infants, the language-related neural substrate is fully active in both hemispheres with a preponderance in the right auditory cortex. Functional and structural connectivities within this neural network, however, are immature, with strong connectivities only between the two hemispheres, contrasting with the adult pattern of prevalent intrahemispheric connectivities. Thus, although the brain responds to spoken language already at birth, thereby providing a strong biological basis to acquire language, progressive maturation of intrahemispheric functional connectivity is yet to be established with language exposure as the brain develops.

Paper Link: http://www.pnas.org/content/108/38/16056.short?rss=1

 

Confrontational scavenging as a possible source for language and cooperation

New language/cooperation paper by Bickerton and Szathmáry today. What a dream team. The best news is that it’s open access. WOO! GO OPEN ACCESS!

Here’s the abstract:

The emergence of language and the high degree of cooperation found among humans seems to require more than a straightforward enhancement of primate traits. Some triggering episode unique to human ancestors was likely necessary. Here it is argued that confrontational scavenging was such an episode. Arguments for and against an established confrontational scavenging niche are discussed, as well as the probable effects of such a niche on language and co-operation. Finally, several possible directions for future research are suggested.

Here’s a link:

http://www.biomedcentral.com/content/pdf/1471-2148-11-261.pdf

Cooperation and Conflict Colloqium papers

Papers from the “In the Light of Evolution V:  Cooperation and Conflict” edition of the Sackler Colloquium are now available in the early edition of PNAS:

http://www.pnas.org/search?tocsectionid=In+the+Light+of+Evolution+V:+Cooperation+and+Conflict+Sackler+Colloquium&sortspec=date&submit=Submit

Some papers such as “The cultural niche: Why social learning is essential for human adaptation”, “Genomic imprinting and the evolutionary psychology of human kinship” and “Evolutionary foundations of human prosocial sentiments” may be of interest to the reader of the blog.

 

You can read the earlier “In the light of Evolution” collections here:

In the Light of Evolution IV: The Human Condition: http://www.pnas.org/content/107/suppl.2

In the Light of Evolution III: Two Centuries of Darwin: http://www.pnas.org/content/106/suppl.1

In the Light of Evolution II: Biodiversity and Extinction: http://www.pnas.org/content/105/suppl.1

In the Light of Evolution I: Adaptation and Complex Design: http://www.pnas.org/content/vol104/suppl_1/

Laryngeal Air Sacs

So, I got a request from a friend of mine to make an abstract on the fly for a poster for Friday. I stayed up until 3am and banged this out. Tonight, I hope to write the poster justifying it into being. A lot of the work here builds on Bart de Boer’s work, with which I am pretty familiar, but much of it also started with a wonderful series of posts over on Tetrapod Zoology. Rather than describe air sacs here, I’m just going to link to that – I highly suggest the series!

Here’s the abstract I wrote up, once you’ve read that article on air sacs in primates. Any feedback would be greatly appreciated – I’ll try to make a follow-up post with the information that I gather tonight and tomorrow morning on the poster, as well.

Re-dating the loss of laryngeal air sacs in hominins

Laryngeal air sacs are a product of convergent evolution in many different species of primates, cervids, bats, and other mammals. In the case of Homo sapiens, their presence has been lost. This has been argued to have happened before Homo heidelbergensis, due to a loss of the bulla in the hyoid bone from Austrolopithecus afarensis (Martinez, 2008), at a range of 500kya to 3.3mya. (de Boer, to appear). Justifications for the loss of laryngeal air sacs include infection, the ability to modify breathing patterns and reduce need for an anti-hyperventilating device (Hewitt et al, 2002), and the selection against air sacs as they are disadvantageous for subtle, timed, and distinct sounds (de Boer, to appear). Further, it has been suggested that the loss goes against the significant correlation of air sac retention to evolutionary growth in body mass (Hewitt et al., 2002).

I argue that the loss of air sacs may have occurred more recently (less than 600kya), as the loss of the bulla in the hyoid does not exclude the possibility of airs sacs, as in cervids, where laryngeal air sacs can herniate between two muscles (Frey et al., 2007).  Further, the weight measurements of living species as a justification for the loss of air sacs despite a gain in body mass I argue to be unfounded given archaeological evidence, which suggests that the laryngeal air sacs may have been lost only after size reduction in Homo sapiens from Homo heidelbergensis.

Finally, I suggest two further justifications for loss of the laryngeal air sacs in homo sapiens. First, the linguistic niche of hunting in the environment in which early hominin hunters have been posited to exist – the savannah – would have been better suited to higher frequency, directional calls as opposed to lower frequency, multidirectional calls. The loss of air sacs would have then been directly advantageous, as lower frequencies produced by air sac vocalisations over bare ground have been shown to favour multidirectional over targeted utterances (Frey and Gebler, 2003). Secondly, the reuse of air stored in air sacs could have possibly been disadvantageous toward sustained, regular heavy breathing, as would occur in a similar hunting environment.

References:

Boer, B. de. (to appear). Air sacs and vocal fold vibration: Implications for evolution of speech.

Fitch, T. (2006). Production of Vocalizations in Mammals. Encyclopedia of Language and Linguistics. Elsevier.

Frey, R, & Gebler, A. (2003). The highly specialized vocal tract of the male Mongolian gazelle (Procapra gutturosa Pallas, 1777–Mammalia, Bovidae). Journal of anatomy, 203(5), 451-71. Retrieved June 1, 2011, from http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1571182&tool=pmcentrez&rendertype=abstract.

Frey, Roland, Gebler, Alban, Fritsch, G., Nygrén, K., & Weissengruber, G. E. (2007). Nordic rattle: the hoarse vocalization and the inflatable laryngeal air sac of reindeer (Rangifer tarandus). Journal of Anatomy, 210(2), 131-159. doi: 10.1111/j.1469-7580.2006.00684.x.

Martínez, I., Arsuaga, J. L., Quam, R., Carretero, J. M., Gracia, a, & Rodríguez, L. (2008). Human hyoid bones from the middle Pleistocene site of the Sima de los Huesos (Sierra de Atapuerca, Spain). Journal of human evolution, 54(1), 118-24. doi: 10.1016/j.jhevol.2007.07.006.

Hewitt, G., MacLarnon, A., & Jones, K. E. (2002). The functions of laryngeal air sacs in primates: a new hypothesis. Folia primatologica international journal of primatology, 73(2-3), 70-94. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/12207055.


Sound good? I hope so! That’s all for now.

Cultural bottlenecks leads to Diversity in Birdsong

A new study has been conducted on dialect formation in birds:

Native North Island saddlebacks have developed such distinctive new songs in the past 50 years that it is not clear if birds on one island recognise what their neighbours are singing about, a Massey University study shows.

The phenomenon is an avian equivalent of the way human language develops regional accents and dialects as people migrate and settle in new locations, and provides fresh insights into how species evolve, says biology researcher Dr Kevin Parker, from the Institute of Natural Sciences at Albany.

I can’t find any published article but the press release is here.

 

Recall dependent on language?

A new study has been published in Current Biology which offers evidence to suggest that monkeys have the capacity for both recognition and recall of simple shapes.

The study showed that rhesus monkeys can recall shapes from memory. This was shown using an experiment which had the monkeys reproduce shapes on a computer touch screen. These findings suggest that the memory of humans and old world monkeys may be more similar than we previously suspected.

Recall is separate and special in comparison to recognition as it shows an ability to remember and visualise things which are not present in the moment. This is an ability which is implicated in skills such as planning and imagining. This is also thought to enhance things like navigation and social behavior. In the past it has thought that an ability to recall none present items is dependent on language. This has been suggested in the past by prominent linguists such as Charles Hockett who thought that the ability of displacement was facilitated by language and was a driving force behind its evolution.

Because of a lack of demand for recall in the lives of monkeys they will not use their recollection skills very often in the wild. In the press release, Benjamin Basile, who lead the study said:

“Maybe it’s often just easier to recognize the monkey, the food, or the landmark in front of you. What we do know is that they do seem to have the ability to recall information in the lab.”

Experiments with humans have shown that recall and recognition require different types of memory. This has been difficult to show with other primates as recall tests are difficult to devise for monkeys because they can’t draw or talk.

The experiment used five rhesus monkeys who were trained on a recall test in which they had to reproduce a simple figure on a touch screen from memory. The shapes were made up of large pixels or boxes on a screen. The monkeys were shown these shapes and then, after a delay, were presented with part of the shape in a different location. The monkeys had to replicate the rest of the shape by touching where the other pixels should be.

The monkeys remembered less in recall than in recognition tests which is the same case in humans. However, the recall performance deteriorated more slowly over time. The monkeys were also able to transfer their ability to recall shapes to novel shapes as they were shown to be able to recall shapes which weren’t used in training.

This ability has probably been present since our last common ancestor with old world monkeys some 30 million years ago and is probably not facilitated by language.

The study hypothesises that:

“Recollection and familiarity likely evolved because they solved functionally incompatible problems. For example, familiarity does not support detailed memory for context, but it is quick and resistant to distraction. Recollection is slower and more vulnerable to distraction but supports a more detailed and flexible use of memory. Familiarity might better allow rapid responses to foods and predators under distracting conditions, whereas recollection might be necessary to access knowledge of distant food locations or past social interactions for planning future behavior.”

References

Benjamin M. Basile, Robert R. Hampton. Monkeys Recall and Reproduce Simple Shapes from Memory. Current Biology, 28 April 2011

 

Bonobos Extract Meaning from Call Sequences

A new study appeared yesterday on PlosOne by Clay and Zuberbühler of St Andrews University on the communicative ability of bonobos.

Studies have been done in the past on language-trained bonobos such as Kanzi which have revealed some remarkable abilities that the species has with regards to representational and communication tasks.

These studies have focussed on trained apes which are reared in unnatural environments and extensively trained on artificial languages. This has produced some interesting results though research into bonobos’ natural communication has been thin on the ground until now.

Clay and Zuberbühler address this gap in the research with a playback study on the natural vocal communication of bonobos.

Bonobos are known to produce five distinct vocal signals when finding food, these have been demonstrated to be combined together to make longer call sequences. The study found that individual call types were poor indicators of food quality but that calls which displayed a concatenation of signals were much better indicators.

The study looked into whether receivers could extract meaning about the quality of food encountered by the caller by integrating across different call sequences.

They started by training four captive bonobos to find two types of foods in two different locations, those which are more preferred such as kiwis and those which are less preferred such as apples. The apes were recorded when finding these different food types and these recordings were used in the playback experiments. When the bonobos discovered their preferred food they emitted higher pitched long barks and short “peeps” and when they discovered the less-preferred food they made lower pitch “peep-yelps” and yelps. Sequences of the four calls which used different compositions were played back to bonobos who were familiar with those apes who had originally made the calls. All sequences contained the same number of calls. In response to these playbacks the study found that the apes devoted significantly more effort and time searching the space which was known to contain the food type indicated by the call sequence (shown in the graph below).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The bonobos were shown to attend not just to individual calls but to the entire sequences before they made inferences about the food encountered by a caller.

These results provide the first empirical evidence that bonobos are able to extract information about external events by attending to natural vocal sequences made by other bonobos. This study really highlights the importance of call combinations in their natural communication system.

References
Clay Z, Zuberbühler K, 2011 Bonobos Extract Meaning from Call Sequences. PLoS ONE 6(4): e18786. doi:10.1371/journal.pone.0018786

Neanderthal-human Hybrids

Paul Mason and Robert Short have an article out called Neanderthal-human hybrids (I wonder what that’s about?). Here is the abstract:

Evidence from studies of nuclear and mitochondrial DNA extracted from Neanderthal fossils and humans points to fascinating hypotheses concerning the types of interbreeding that occurred between these two species. Humans and Neanderthals share a small percentage of nuclear DNA. However, humans and Neanderthals do not possess the same mito­chondrial DNA. In mammals, mitochondrial DNA is exclusively maternally inherited. Taking into account an understanding of interspecific hybridity, the available data leads to the hypothesis that only male Neanderthals were able to mate with female humans. If Haldane’s Law applied to the progeny of Neanderthals and humans, then female hybrids would survive, but male hybrids would be absent, rare, or sterile. Interbreeding between male Neanderthals and female humans, as the only possible scenario, accounts for the presence of Neanderthal nuclear DNA, the scarcity of Neanderthal Y-linked genes, and the lack of mitochondrial DNA in modern human populations.

Paul Mason previously wrote about the topic over at Neuroanthroplogy, so I really don’t have much more to say on the topic, other than that I’ll get around to reading it over the next couple of days. I’m curious to see if the usual suspects in the genetics (Razib Khan), anthropological (Dienekes) and evolutionary (John Hawks) communities offer some food for thought on the topic.

For me, I’m actually more interested in Mason’s recent work on degeneracy… But that’s for a later post 😉

The Parental Antagonism Theory of Language Evolution

Human Biology are publishing a special issue on “Integrating genetic and Cultural Evolutionary Approaches to Language” this month! Abstracts for all of the papers can be found here.

William Brown‘s paper has been published on his blog ahead of the boat today. The Abstract is below and there is a link to the paper at the bottom.

Language—as with most communication systems—likely evolved by means of natural selection. Accounts for the natural selection of language can usually be divided into two scenarios, either of which used in isolation of the other are insufficient to explain the phenomena: (1) there are group benefits from communicating, and (2) there are individual benefits from being a better communicator. In contrast, this paper argues that language emerged during a coevolutionary struggle between parental genomes via genomic imprinting, which is differential gene expression depending on parental origin of the genetic element. It is hypothesized that relatedness asymmetries differentially selected for patrigene-caused language phenotypes (e.g., signals of need) to extract resources from mother early in child development and matrigene-caused language phenotypes (e.g.,  socially transmitted norms) to influence degree of cooperativeness  among kin later in development. Unlike previous theories for language evolution, parental antagonism theory generates testable predictions at the proximate (e.g., neurocognitive areas important for social transmission and language capacities), ontogenetic (e.g., the function of language at different points of development), ultimate (e.g., inclusive fitness), and phylogenetic levels (e.g., the spread of maternally derived brain components in mammals, particularly in the hominin lineage), thus making human capacities for culture more tractable than previously thought.

Brown, W.M. (2011). The parental antagonism theory of language evolution: Preliminary evidence for the proposal. Human Biology, 83 (2)