Research in Psychosis
The authors of a systematic review risk of conversion from Ultra-High risk state for psychosis to actual psychosis looked at 2462 papers and identified 31 which met their inclusion criteria. They concluded that 76% of the people in the high risk category did not convert to psychosis.
Research in Dementia
In one study, researchers looked at the function of a single gene SorCS1 which plays a role in Type 2 Diabetes. They looked at the effect of the gene product on the processing of Amyloid Precursor Protein. Disruptions of the processing of Amyloid Precursor Protein are implicated in the pathology of Alzheimer’s Disease. The researchers found that the the SorCS1 protein influenced where the Amyloid Precursor Protein was moved within the cell. Furthermore this location influenced how the APP was processed thus identifying a link between one risk factor for Diabetes and Alzheimer’s Disease. However both Diabetes and Alzheimer’s Disease are complex illnesses influenced by a number of factors and so further research will be needed to see how these findings fit into the broader picture. The New York Timeshas an interesting write-up of 3 studies showing the benefits of physical activity and exercise in ameliorating cognitive decline. In two of their studies sedentary behaviour was correlated with more rapid cognitive decline when compared to people who had even light levels of activity. A third study showed the benefits of resistance training in slowing cognitive decline.
There have been some interesting recommendations by the House of Commons Science and Technology Committee Report (see also coverage here). The MP’s make recommendations including training of scientists undertaking the peer review as well as increased transparency, availability of the data online and use of pre-print servers to improve the peer review process. These recommendations were made in light of controversies such as those surrounding the MMR Vaccine. Interestingly the pre-print server model was very instructive in an academic debate in neuroimaging.
The United Nations are projecting that by October 2011 the world will reach a population of 7 billion. Previously the 2010 UN estimates varied from projections of between 6.2 billion people and 15.8 billion people by 2100 depending on fertility rates. These figures also reflect changing demographics with an ageing population across the world as life expectancy increases. A paper published in the journal Science shows how education can significantly influence these projections.
Professor Sheng Ding in colloboration with Professor Stuart Lipton at the University of California San Francisco (USCF) has transformed human skin cells into neurons which will have many potential applications. The team took skin cells from a 55 year old lady and converted them to neurons using a combination of genes and microRNA.
There is a write-up of a study comparing 23,199 people who experienced traumatic brain injury and received care in hospital with 69,597 people without traumatic brain-injury who received care in hospital. The researchers found that within 3 months of the injury, the traumatic brain injury group had a 10-fold higher prevalence of stroke than the non-traumatic brain injury group with just under 1 in every 33 people being affected. This increased risk decreased with time but at 5 years was 2.3 x higher than the non-traumatic brain injury group. The researchers also found that a number of characteristics of the brain injury including fracture of the skull modified risk.
The connections betweeen groups of neurons are extremely complex with large numbers of synapses. Studying these networks has been accelerated through the development of microscopy techniques as well as software programs.
A group in Germany have used a program called KNOSSOS in conjunction with a collaborative approach between researchers to characterise a network of 100 neurons and there is a write-up here.
The BMA have brought out new guidelines on protecting vulnerable adults.
There is a short piece on a doctor who is still working at 100 here.
A new centre for neuroscience is being built at University College London.
A large studylooked at 125 baboons in the wild in Kenya. The researchers stratified them into 5 social groupings and analysed for two stress-related hormones testosterone and glucocorticoids. Essentially they found that the alpha males, those with the highest social status, were constantly exhibiting the highest levels of these two hormones. The researchers suggest that these results may be translatable to humans. However the alpha male baboons get into frequent physical altercations with other baboons which may contribute significantly to the stress hormone levels and does not translate easily into human settings.
There is an article on Austrolopithecus Sediba here. This is important archaeological work going on in South Africa to uncover some of our earliest ancestors that could be called human (i.e part of the genus homo) circa 2-million years ago. They have identified articulated skeletons, are able to gather data on some of the characteristics of the skin of these hominids and have also identified cerebral asymmetry.
An MRI study of Chimpanzees in captivity and humans showed that there was no brain atrophy in Chimpanzees in contrast with humans. However in cross-sectional studies, the researchers have to rely on comparisons between individuals rather than tracking the atrophy in individuals as in a longitudinal study. If longitudinal data confirms the hypothesis that cerebral atrophy has evolved in humans then we would know to look for corresponding gene differences between Chimpanzees and humans which account for this. In humans though the additional decades of life-expectancy mean that there are many years of environmental stress that would differentiate humans from Chimpanzees making it difficult to distinguish between the effects of genes and environment.
Professor Hawks review an interesting paper in PLOS Biology in which the authors discuss several hypotheses about the evolution of human cognition.
Much can be inferred about the neolithic or paleolithic mind from cave art and in this regards there have been interesting findings with the Britain’s oldest example of Cave Art (circa 14,000 years ago) as well as recent findings in Germany.
There has been a recent computer simulation of human cooperative behaviour the results of which have been published in PNAS. The researchers conclude based on the simulation of their model that people are inherently altruistic and that this results from adaptations to cooperative behaviour. In other words, even if our distant ancestors had started off cooperating for purely selfish reasons the very act of this cooperation over long periods of time creates an environment where altruism emerges as an adaptive trait.
A Mandrill was observed to create a pedicuring tool in this study adding another example to the extensive evidence base of non-human primates using tools.
An interesting argument over copyright has developed in the case of an Indonesia Black-Crested Macaque which took a photographer’s camera and photographed itself. The photographs were used by a magazine without asking for permission from the News Agency that employed the photographer. However since the monkey took the photograph of itself it was argued that the photographs were in the public domain. The argument however isn’t that the Macaque itself is the copyright holder.
There is a new paper on Neanderthals in the Science journal by Professor Mellars et al. The question being asked is ‘Why did the Neanderthals in Europe die out?’ and Mellar’s hypothesis is that they were outpopulated 40,000 years ago by our ancestors when the ratio of our ancestors leaving Africa to the Neanderthals in Europe was 10 to 1. Mellars asserts that our human ancestors were technologically advanced and more socially adept enabling them to increase their territory at the expense of that of the Neanderthals who were thus forced to compete with each other in ever harsher environments. To arrive at their hypothesis the researchers looked at the number of sites with Aurignacian technology which are typically considered to be human in contrast with the Neanderthal Mousterian technology. They argue that there was an increase in the number of sites at around 40,000 years ago which would be consistent with a large increase in migrating humans. We know from Paabo’s (and subsequent) research (see below) that Neanderthal DNA is in modern human populations implying ancestral interbreeding. So could this migration have resulted in interbreeding rather than a ‘hostile’ competition without interbreeding? Mellar’s response to this is that the interbreeding was 100,000 years ago not 40,000 years ago. However a microsatellite analysis suggested that the hybridisation events occurred in the Mediterranean 55,000 years ago and in East Asia 45,000 years ago. Additionally more recent specimens circa 35,000 to 33,000 years ago have been found in Europe with both Neanderthal and human features. Spanish archaeologist Jose Zilhao has argued that judging population sizes on the basis of the number and size of sites has numerous methodological problems due to confounders such as geological processes and the way in which sites were used.
In addition to the above points there is a further twist. The question that can be asked at this point is just who was migrating to Europe? – was it the human-neanderthal hybrids descendants from hybridisation 100,000 years ago? If it wasn’t then where did the Neanderthal DNA in modern human populations come from? Unless these points are answered there is in my opinion a gaping hole in the above hypothesis. The other point in this argument is about the Neanderthals being relatively unsophisticated compared to the migrating humans (or hybrids). However almost all of the organic material Neanderthals were working with has been lost over the tens of thousands of years that have passed. In those instances where it has remained archaeologists have found at least 3 significant indicators that Neanderthals were pioneers in technology and practices that would be adopted by humans 40-50,000 years later.
1. The use of pitched glue 80,000 years ago
2. Sophisticated burial rituals as demonstrated in the Shanidar findings
3. The use of body paint 50,000 years agoby combining different coloured pigments
These are just a few of the relatively relatively minor Neanderthal adaptations which challenge the central narrative of an unsophisticated archaic hominid species which was eradicated by a technologically and socially sophisticated human competitor.
A Battle of Narratives
I will now outline the central narrative that is being proposed
Hypothesis/Narrative 1: Humans and Neanderthals were distinct. Humans were technologically and socially more sophisticated than Neanderthals. When they migrated to Europe such was their advantage that the Neanderthals were comprehensively eliminated.
There is just one small problem with the above narrative as pointed out above and that is that modern humans across the world have Neanderthal DNA. Let me just stop for one moment and look at another paper which has been recently published by Labuda and colleagues. In their paper they looked at some of the X-chromosome gene data they had gathered from people across the world and compared it to the recently and mostly translated Neanderthal Genome. What they found was that this DNA was found in people across the world from Europe to the indigenous aborigines of Australasia. Furthermore they suggest that this hybridisation is likely to have taken place in the Middle East. I have covered the landmark study by Paabo and colleagues here and this is the paradigm changing study which should fundamentally have shifted our perspective on human identity. However the narrative above which has been picked up and quickly relayed in the media suggests there is some way to go before the understanding of Neanderthals as primitive hominids that were sidelined by humans is confidently replaced by a more realistic appraisal.
In place of the above I will propose some alternative hypotheses
Hypothesis/Narrative 2: Humans emerged from Africa and mated with Neanderthals. The hybrid offspring migrated before reentering Europe to outpopulate the original Neanderthal population.
Hypothesis/Narrative 3: Humans emerged from Africa and mated with Neanderthals. The hybrid offspring migrated before reentering Europe to outpopulate the original Neanderthal population. However there was a much later hybridisation event that occurred with a small surviving population in parallel with the extinction of the main Neanderthal population and the expansion of the human/human-hybrid population.
In my opinion the third hypothesis is the most likely. However things get a lot more complicated when considering migration patterns and other hybdridisation events which are still being clarified. Genetic profiling of Cro-Magnon specimens will help to elucidate an important part of the picture. Nevertheless if the findings about outpopulation hold then it raises other interesting questions.
The Anthropocentric Distortion
Why has the Neanderthal been sidelined in the above narrative despite the groundbreaking Paabo study and recent interbreeding study that was widely reported above? In my opinion there is what I refer to as an ‘Anthropocentric Distortion’ that is so powerful that evidence to the contrary is unconsciously ignored. That is why in headlines such as ‘Neanderthals outpopulated by humans’ can run only a few weeks after ‘Evidence shows that humans and Neanderthals interbred’. In ignoring the contribution of Neanderthals to the human genome can we be accused of specism? While the reader might at first glance think this is a little far fetched I will refer to a well known example to support the argument.
When Charles Darwin published ‘The Descent of Man’ there was a marked opposition to his suggestion that humans were evolved from animals. This opposition was nowhere better exemplified than in the above caricature of Darwin which symbolises the critics’ ridicule of evolutionists and their suggestion of the relationship of humans to other primates. If there is specism in action then there are no remaining Neanderthals to lobby for the recognition of their role in our history or to admonish us for our neglect. I would argue that it is a natural tendency for people to have immense pride in their shared humanity and such is the nature of this powerful identity that it is difficult to incorporate the Neanderthal. Nevertheless the recognition of the Neanderthal in our identity is just the first stage in the development of our shared identity because at this point in time reseach findings are coming from multiple directions and telling us many important things about this identity. However it is not possible to fully understand these other findings without first of all having the wider and prolonged debate about this new understanding of our relationship with the Neanderthals and the part they have played in our history. Curiously this prolonged debate in society has been all but absent punctuated by brief discussions as research findings are published. Perhaps this wider public debate will take on shape with further research and will most likely be led by evolutionary biologists or anthropologists although there there has been a more intense debate in academia.
Never Underestimate the Intelligence of a Primate with a 400 cc Brain (or a 1400 cc Brain)
Neanderthals are commonly represented as ‘caveman’ carrying clubs and possessing rudimentary intelligence. Now I can’t be fully sure on why this is but I would hazard a guess that it runs along the following lines
Assumption 1: Humans are alive today. Neanderthals are extinct. Therefore they weren’t as smart as humans.
Assumption 2: Neanderthals were around for a long time but they didn’t do clever things like paint or make wheeled chariots.
Assumption 3: Neanderthals were around a long time ago. People get smarter with time.
Assumption 4: Neanderthals were very muscular. So they are a case of brawn rather than brain.
To challenge these assumptions I would propose these counterassumptions
Counterassumption 1: The assumptions above are static and not based on a modelling of how Neanderthals were operating within their environment
Counterassumption 2: Neanderthals have a brain size bigger than that of humans on average 1400 cc v 1200 cc for males (although small sample size is a draw back)
Counterassumption 3: There are plenty of examples of Neanderthal use of abstract symbolism
Counterassumption 4: Neanderthals survived for nearly half-a-million years in harsh environments. They stood the test of time and survived for longer than we ourselves have existed as a distinct species (although admittedly wasps and ants have fared much better).
Counterassumption 5: Neanderthals can be assumed to be apex predators as they have been found with the remains of 7-foot Cave Lions and numerous other carnivores.
Counterassumption 6: Living primates having less than 1/3 of Neanderthal brain volume demonstrate remarkable intelligence
Turning to counterassumption 6, let me discuss this in a little more detail. For the past 2 years I have spent time filming primates and have placed 600+ pieces of footage on YouTube so that the interested reader can draw their own inferences from the data. One of the most striking features of primates that I have made is just how important it is for them to be able to use their forelimbs to manipulate objects in the environment. This characteristic is most obvious in the Lemur (one of the earliest primates to develop) when it is compared with a cat with which it shares an otherwise similar body structure. No doubt this adaptation has led to the development of our own very specialised motor cortex which facilitates many of our defining features. The Old and New World Monkeys are agile arboreal primates moving more quickly than we do. With regards to the Greater Apes and from other footage I have seen Chimpanzees are very agile being able to move quickly up trees and along the ground. However the defining features of the Greater Apes is their ability to plan ahead and manipulate the environment in addition to their large increase in body mass and loss of tails. By the time we reach the Greater Apes these defining features may remind us very much of ourselves. However the most interesting piece of footage I have seen by far is one of a Chimpanzee in Japan by the name of Ayumu. The footage can be accessed here at the New Scientist website and shows Ayumu performing working memory tasks. What is most interesting is that Ayumu on a computerised digitial recall task outperforms college students and according to this report a human world memory champion.
The solution then is to marvel at our own abilities and shared human identity whilst recognising that other primates have remarkable intelligence. I would then further argue that Neanderthal males have on average 200 cc of additional brain volume compared to the average human adult male. In conceptualising this I would envisage that in just the same way as a Chimpanzee may not be able to comprehend a number of our abilities, were we to encounter a Neanderthal we might similarly find it difficult to comprehend some of their abilities (and they ours). Critics may argue that such findings about cranial capacity (which is a proxy measure of brain volume) result from small sample sizes and that for humans the cranial capacity has a large range of values with a small percentage of the population far exceeding the 1400 cc capacity of the average Neanderthal brain. However I would respond in turn that we are talking about the average cranial capacity. Regardless of statistical deviations the population averages suggest that we are looking at brains that are constructed in a very different way. This is further supported by evidence that Neanderthal brain development was significantly different from our own with Neanderthals reaching adult brain volume at age 9.
A Role for a Fertility Based Religion in the Second Populating of Europe?
One of the findings throughout sites associated with the Aurignacian culture and the later Gravettian culture (see image below) and beyond are the Venus figurines which appear in a number of variations. There has been much speculation about the significance of these figurines. They have been associated with a fertility religion. If such figurines symbolised the imperative for a reproductive drive to facilitate population expansion could they have played a significant role in the success of the migrating population? Correlating the number of these figurines with the estimated population size at different sites may offer one way to investigate this hypothesis.
Venus of Brassempouy (circa 25,000 years ago), Wikimedia Commons, Uploaded by Elapied, Public Domain
How Might Neanderthal Cognition Compare with Human Cognition?
This is obviously very difficult to answer and indeed there may be no obvious cognitive skills unique to Neanderthals. In an environment and eras which changed between warm and very cold extremes it is perhaps difficult to make generalisations about the environment to which they were adapted to particularly as their range extended from the Middle East and throughout Eurasia. There is the possibility that modern humans possessing certain combinations of Neanderthal genes in relation to neural development may manifest some peculiarities of Neanderthal cognition. However it must be emphasised that this is unlikely as although there a relatively small number of gene differences between humans and Neanderthals it is likely the combination of these differences which leads to the peculiarities of Neanderthal intelligence. Thus having one or two of these genes may not in itself be of much significance. From the skull casts which I have reviewed in the videos below the most obvious differences in skull shape occur in the occipital region. Whilst some may comment on the superficially underdeveloped frontal region in the skull, the endocasts have revealed that the frontal region is probably roughly equivalent in volume to our own frontal cortical region but sits further back.
Turning to the occipital region this is very much expanded particularly during the late Pleistocene. There is one interesting hypothesis by Professor Robin Dunbar and colleagues which was recently published in this paper (covered here). The researchers having studied skulls from human populations living at different latitudes and conclude that living in colder darker environments at higher latitudes is associated with an increase in the size of the eyes as well as the corresponding visual cortex. Presumably this is an adaptation to increase the effectiveness of light capture and processing in conditions with low ambient lighting. Certainly these results fit well with findings in Neanderthal skulls although some researchers have suggested Neanderthal-Human skull differences may result from random genetic drift. Additionally their range was broad and included lower latitude regions. The possible remains that Dunbar’s findings resulted not from environmental adaptations but from differential incorporation of Neanderthal genes into the human gene pool. There remains the possibility as a result that the Occipital Cortex expansion plays another role. The Occipital Cortex has connections with both the Parietal and Temporal Lobes and this expansion may produce differences in visual memory and perceptual skills compared to modern humans although this is speculation.
Analysis of Neanderthal DNA suggests they possessed the same FOXP2 gene variant as humans which is very suggestive of them having the capabilities of similar language abilities (although language will also be a function of culture). When comparing genome differences between humans and Neanderthals gene candidates have been identified which have associations with Autism, ADHD and Schizophrenia.
Appendix 1 – Neanderthal Interbreeding Study in the Media
Calgary Herald article: Canada.com article: CBC article: Daily India.com article: Daily News and Analysis article: Discover Magazine article: Edmonton Journal article: Fox News article: Global News article: Independent online article: International Business Times article: Montreal Gazette article: National Post article: Ottawa Citizen article: The Province article: Reason Online article: Reginal Leader Herald article: Science Daily article: Science 2.0 article: Scientist article: Star Phoenix article: Time article: Times and Transcript article: Truth Dive article: Windsor Star article: Wired News article: World Science article: WTSP article:
Appendix 2 – Neanderthals Outpopulated Paper – Media Response
Ars Technica article: Arts Daily article: Bioscholar Network article: Bloomberg article: Calgary Herald article: Canada article: China Daily article: Climb the Net article: Daily Mail article: Dayton Daily News article: Discovery News article: Edmonton article: Eureka article: Express article: Guardian article: International Business Times article: Irish Weather Online: Live Science: Los Angeles article: Mirror article: Montreal Gazette article: Mother Nature Network article: MSNBC article: New Scientist article: News Tonight article: Newser article: Newstrack India article: Online Journal article: Ottawa Citizen article: R&D magazine article: RedOrbit article: Regina Leader article: Sacramento Bee article: Star Phoenix article: Telegraph article: The Australian article: The Province article: Third Age article: Times of India article: Today Online article: UPI.com article: USA Today article: Victoria Times article: Windsor Star article: Wired News article: Vancouver Sun article:
Appendix 3 – Neanderthal Articles on this Site
Were Neanderthals Smarter Than Us? Were Neanderthals Smarter Than Us? Update 27th August 2008 Were Neanderthals Smarter Than Us? Update 26th August 2008 What are the Implications of the Sequencing of the Neandertal Genome
Appendix 4 – Annual News Roundups
News Roundup 2008 News Roundup 2009 News Roundup 2010 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 email@example.com. 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.