News Round-Up: May 2011 1st Edition

  • A short small-sized trial looking at the use of Donepezil in females with Down Syndrome has shown promise in a number of outcomes although it will be interesting to see the results of larger longer-term replication studies.
  • An interesting moderately sized 5-year longitudinal study in China provides evidence that vascular risk factors increase risk of conversion from Mild Cognitive Impairment to Alzheimer’s Disease but also that treatment of these vascular risk factors decreases the risk of conversion.
  • A small study showed a significant inverse correlation between hippocampal volume and CSF p-tau levels in people with Alzheimer’s Disease

Evolutionary Psychiatry

  • An Origin for Language?: Some remarkable research hinting at the origins of language has been carried out by a UK group with the Bonobos at Twycross Zoo and has been published in PLOS One (see also a write-up of the study here).  At the time of testing the Bonobos form two groups each with their own enclosure. The 2 groups are released from their enclosures separately to forage for food.  Kiwi is favoured by the Bonobos but they also receive apples and these fruits were stored at specific locations. Bonobos communicate with a series of calls – barks, yelps, peep-yelps and peeps. The researchers recorded the calls that were made when Kiwis or Apples were found. The researchers then varied the food that was presented as well as the recorded calls that were played prior to the groups being released from the enclosures. They found that calls that were associated with Kiwis were more likely to result in Bonobos searching at the Kiwi sites. However there was a small catch in that the Bonobos were more likely to search at the Kiwi sites even without prompting. However after hearing the apple associated calls the Bonobos were more likely to visit the apple sites and so this provided evidence that the calls were likely to represent foraging signals to other group members. There was also a similar result in terms of the time spent foraging at the respective sites when the kiwi or apple associated calls were played back. The researchers suggested that in Bonobos rather than Chimpanzees the combination of different calls is turned into a sequence which has meaning. This ability to combine calls which then have new meaning expands the possibilities for communication and is a significant finding if confirmed. Our ancestors diverged from the Chimpanzee lineage some 6 to 8 million years ago. Since the Bonobo lineage diverged from the Chimpanzee lineage after this, we are related more closely to Chimpanzees than Bonobos in the evolutionary timeline. However if this ability is not present in Chimpanzees then it suggests that this ability to combine calls in humans and Bonobos would be an example of convergent evolution *(1). There was also another interesting finding. One call sequence associated with the Kiwi fruits seemed to be a very strong signal which was associated with the Bonobos searching the apple site twice as often as usual instead *(2). If the Bonobos are distinguished from Chimpanzees through the use of combination calls then this might explain other differences between Bonobos and Chimpanzees *(3) and would contribute to our understanding of the origins of language *(3)

*(1) There is an exception to this. This would not be the case if the Chimpanzee-human concestor was able to combine calls but the Chimpanzee lost this ability after their divergence from Bonobos

*(2) This seemed to me to raise the possibility of deception. There are cases of New World Monkeys specialising so that one member watches for predators while the others eat food. Sometimes this group member will raise a false alarm. When the others move away from the area, this member will then take the food. In the example above it might be possible that the Bonobo on finding the Kiwi fruit attempts to send the other Bonobos to the Apple site so it can secure more Kiwi fruits. What is even more interesting is the strength of this signal as it suggests that the motivation of the signaller before generating the signal might produce a more significant change in group behaviour (i.e it would not just be a function of the motivation of the responding group). If this were the case there may be an interesting correlation between the motivation of the signallers and the effect of the signal.

*(3)As speculation if the line of reasoning given here holds then the combination calls could be as a result of increases in working memory. However working memory capacities of Chimpanzees and Bonobos should be tested directly.

Index: An index of the site can be found here. The page contains links to all of the articles in the blog in chronological order. Twitter: You can follow ‘The Amazing World of Psychiatry’ Twitter by clicking on this link. Podcast: You can listen to this post on Odiogo by clicking on this link (there may be a small delay between publishing of the blog article and the availability of the podcast). It is available for a limited period. TAWOP Channel: You can follow the TAWOP Channel on YouTube by clicking on this link. Responses: If you have any comments, you can leave them below or alternatively e-mail justinmarley17@yahoo.co.uk. Disclaimer: The comments made here represent the opinions of the author and do not represent the profession or any body/organisation. The comments made here are not meant as a source of medical advice and those seeking medical advice are advised to consult with their own doctor. The author is not responsible for the contents of any external sites that are linked to in this blog.

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