There’s a very interesting study in PLOS One by Curnoe and colleagues who have anlaysed human remains in South China. The specimens date back 11,000 years and the skulls are characterised by the presence of brow ridges and a lateral extension of the zygomatic arches (cheekbones) compared to modern human control groups. The specimens are further characterised by Taurodontism, that is teeth in which the pulp chamber and body of the tooth contribute to a larger proportion of the tooth in relation to the root. Taurodontism is also seen in Neanderthal specimens (e.g these specimens dating back 230,000 years were found in Pontnewydd Cave in Wales) . Taurodontism also occurs in association with pathological conditions including Amelogenesis Imperfecta.
The researchers have thus provided convincing evidence that the specimens they have grouped together are significantly different from control groups of modern humans in a number of ways. There are still other approaches that can be used to investigate this further and so the researchers are cautious about concluding that the specimens represent a new species at this stage . Nevertheless if this does prove to be a new species it adds to other species that lived in Africa, Asia and Europe in the last 30,000 years including a specimen found in Tanzania, the controversial Homo Floresiensis species of the Indonesian Island of Flores, the Neanderthals and the Siberian Denisovans.
Figure 3. Longlin 1 partial skull (each bar = 1 cm). Curnoe D et al, 2012, PLoS ONE 7(3): e31918, Creative Commons Attribution License
Figure 12. Isolated M3 – specimen MLDG 1747 (scale bar = 1 cm) exhibiting marked taurodontism, Curnoe D et al, 2012, PLoS ONE 7(3): e31918, Creative Commons Attribution License
The BMJ has a study in which the researchers report from the English Longitudinal Study of Aging. This is a large study and the researchers divided subjects into three groups according to their health literacy skills. This was measured using the ability to understand medical instructions as an example. The researchers found that the lower the health literacy, the higher was the risk of mortality in that group. The researchers noted that most of the subjects were classed as having high literacy and that the low literacy group were relatively under-represented in their study.
In a study looking at the build-up of Amyloid plaques and blood pressure, researchers used Positron Emission Tomography and Pittsburgh-B compound (which binds to Amyloid plaques) to investigate people in late middle-age. The researchers found that systolic blood pressure was significantly and positively correlated with the cerebral/cerebellar ratio of PiB distribution volume ratio (a marker of Amyloid presence) in both the Frontal and Temporal regions amongst other findings. These results may help to better characterise the relationship between blood-pressure and Alzheimer’s Disease as raised blood pressure is a risk factor for dementia.
The researchers in an Italian structural MRI study have found evidence of changes up to 10 years before the development of Alzheimer’s Disease. These changes discriminated between those who did and didn’t later develop Alzheimer’s Disease. The latter group were characterised by a significantly smaller right Medial Temporal Lobe volume at baseline
In a study at the Institute of Psychiatry, researchers investigated gene associations with mood, psychosis, agitation and behavioural dyscontrol in people with dementia. Amongst other findings, researchers found a significant association between the Dopamine Transporter gene DAT-3 and agitation.
In a small post-mortem study, there was found to be a depletion of Cholinergic neurons in the brainstem in people with Lewy Body Dementia compared to a control group and people who had been diagnosed with Alzheimer’s Disease. Acetylcholine is a neurotransmitter that is thought to play an important role in memory.
In a Japanese post-mortem study, the researchers investigated the neuropathological correlates of 18 FDG Fluorodeoxyglucose areas of hypometabolism and concluded that areas of occipital hypometabolism were associated with Lewy pathology in Lewy Body Dementia and Temporo-Parietal hypometabolism is associated with Alzheimer’s Disease pathology in Alzheimer’s Disease. While these results are not unsurprising, confirmation of this relationship is useful.
The Neuroskeptic has a write-up of a recent paper in which the researchers report that eye-blinking can interfere with the scan results in functional Magnetic Resonance Imaging studies although there is scope for modifying protocols to incorporate these findings. Bradley Voytek notes in the comments section that the influence of eye blinking has also been found in EEG studies.
There is a write-up on a series of articles in the Schizophrenia Bulletin on how smartphones can be used in the clinical setting for uses ranging from completion of questionnaires through to prompting for self-monintoring.
Discover Magazine has a piece by evolutionary neurobiologist Dr Mark Changizi on the evolutionary significance of music and language which he writes about in his new book ‘Harnessed: How Language and Music Mimicked Nature and Transformed Ape to Man’. Changizi suggests that music and language resemble naturally occurring phenomenon. Professor Robin Dunbar has also written a book on the evolution of language and music and I have made a brief video illustrating Professor Dunbar’s concepts below.
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