News Roundup August 2011 – 2nd Edition

In another paper from the Alzheimer’s Disease Neuroimaging Initiative the researchers looked at data from 401 people with Alzheimer’s Disease and concluded that CSF ABeta42 levels were elevated in the earlier stages of the illness and that adjusted hippocampal volume and CSF Total Tau levels were altered later in the disease process.

The researchers in a 3-year longitudinal Swedish study of people with Alzheimer’s Disease taking Donepezil (n=435) concluded that the there was an average 1.6 point deterioration in ADAS-cog points every 6 months (although there was no placebo group for comparison). Furthermore the cognitive performance predicted the scores on functioning. Functioning in turn was related to the risk of admission to a residential home. Thus the researchers were able to determine the benefits of medication using a cost-analysis with admission to a care home as one of the outcome measures.

The researchers in one autopsy study analysed the results of the 1672 brain autopsies in cognitively normal adults. They found that pathology associated with a number of disease processes was present in a modest percentage of cases even though the people had been cognitively normal before death. Cerebral microinfarcts were present in 33% of cases and 6% had Braak stage V or VI for neurofibrillary tangles. Thus the findings suggest that pathology may be present in the aging brain and that this isn’t necessarily associated with cognitive impairment. Nevertheless the pathologies examined here are central to a number of disease processes which affect cognition and it will be interesting to see further research in this area which helps to better characterise the factors which influence whether the pathology does and does not impair cognition.

In an fMRI study comparing people with Frontotemporal Lobar Degeneration and Alzheimer’s Disease with a healthy control group the researchers found evidence of an association between an increase in activity in the right temporal pole in Primary Progressive Aphasia and aphasia. The researchers suggest that alterations in the connections of the temporal lobe may account for these findings.

There is a PLOS-One paper looking at predictors of conversion from Mild Cognitive Impairment to Alzheimer’s Disease which is freely available here. Using a combination of biomarkers and psychological outcome measures the researchers were able to identify MCI cases which progressed with a sensitivity of 96.43% and a specificity of 48.28%.

There is a Dutch cost-effectiveness study of Memantine in moderate to severe Alzheimer’s Disease which is freely available here.

Miscellaneous

The recent riots starting in Tottenham, London and extending to other parts of England is likely to have impacted on Mental Health Act assessments amongst the many other serious consequences. There have been a number of commentaries on the riots. In this article by Natalie Wolchover there is a discussion of crowd behaviour in terms of the Elaborated Social Identity Model. The Research Digest has links to a number of articles commenting on the riots from a psychological or neuroscience perspective.  There is also this article in Psychology Today looking at the possible role of Mirror Neurons (see here and here) and empathy. Although the application of theories to speculation about the events can be useful there is also a role for quantitative and qualitative research to test the hypotheses in the recent events (i.e the conclusions can be data driven).

Evolutionary Psychiatry

There is a replication study on Twitter looking at Dunbar’s number. Professor Robin Dunbar has hypothesised that 150 is the number of social contacts that people are able to meaningfully maintain. The researchers analysed the twitter conversations of 1.7 million people and concluded that the number of stable relationships was between 150 and 200. While there are many reasons for using Twitter which mean that there will be significant variation from these numbers in individual cases the key finding here suggests that people use Twitter socially in a similar way to other forms of social interaction.

Did monkeys gain big brains by ‘shrinking guts’? is the question asked in one paper. The researchers looked at New World Monkeys and after controlling for a number of factors concluded that there was no evidence of an inverse correlation between brain volume and decreasing volume of gastrointestinal tracts (GIT).  They used the digestibility of the diet as a proxy measure of GIT size and energy investment in digestion. Nevertheless as Professor Dunbar points out this does not necessarily generalise to humans where the relationship between diet and brain volume is debated.

The researchers in one study concluded that Orang-Utans are capable of using pantomiming to communicate with other Orang-Utans or with humans. The researchers watched 7000 hours of footage of Orang-Utans in Borneo filmed over 20 years and identified 18 examples where pantomiming was used including the clip shown below. The use of gesturing has been suggested as an important stage in the evolution of human language (see here).

A young orangutan pantomimes for help with a coconut from Science News on Vimeo.

John Hawks has been involved in genetic analysis of the Denisovan hominin which appears to have diverged from human lineage 400,000 years ago and from the Neanderthal lineage 330,000 years ago. The significance of this is that there is evidence that humans have interbred with both Neanderthals and Denisovans on the basis of recent genetic analyses in humans. However a new specimen suggests that Neanderthals and Denisovans may also have interbred producing a complex genetic history.

A look at the role of older adults in the Bronze age is covered here. The researchers looked at a 600 year period in Austria approximately 4000 years before present. They found that older adults were more likely to be buried with copper axes than younger males and as this was believed to be associated with higher social status it suggests that older adults held important positions within the community.

There is also an interesting Nature piece on human evolution here.

Debate continues over the nature of the Homo Floresiensis specimens – are they really another species or a human group with microcephaly? Perhaps the genetic analysis underway will settle the matter.

The possible role of climate change in the rise of humans is covered in this post.

Resources

Frontiers in Neuroinformatics Article on datamining in the Human Connectome Project

NIH Video and Journal of Visualised Experiments. Video and podcast material on science is indexed at this site. At the time of writing there were 7090 indexed videos.

MRI educational resource.

MR Connected Automated Pipeline – Linking structural MRI data with diffuse tensor imaging data to build connectomes.

O’Reilly Open Source Developers YouTube Channel.

The Open Connectome website.

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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