Reading between the lines

Whenever we compare human and animal behaviour, one major difference that always comes up is our ability to use words to communicate with our fellow human beings. We can use words to order food in a restaurant and chat about everything and nothing over coffee with our friends, and the act of talking has become so normal to us that we don't even give much thought as to how extraordinary speech really is. And now researchers have discovered that our use of language gives away more than just the literal meaning of the words: there are hidden clues about ourselves in our words, in the frequency with which we use certain words, in the number of different words there are in our personal vocabulary and in the richness of our sentences.

In 'Vanishing Words', a recent episode of my ever favourite science-based radio programme Radiolab, Jad and Robert talk about those hidden messages. Drs Ian Lancashire, Kelvin Lim and Serguei Pakhomov are all interested in how characteristics of our personal vocabulary may be an indication of our likelihood of developing memory related diseases such as Alzheimer's. Moving from analysis of the crime novels of Agatha Christie to a comparison of how the linguistic content of teenage essays by a group of nuns relates sixty years on to their cognitive function, these researchers have found surprising associations between the richness of our language and our later susceptibility to cognitive decline.

And more messages can be found in this blog post on the British Psychological Society's Research Digest blog. Dr Paul Rozin of the University of Pennsylvania showed in a study published in Cognition and Emotion that our existential feelings about positive and negative events are reflected in our language. Analysing the frequency of positive and negative words in our language, the researchers found a large prevalence of the former type of utterance, mirroring, they claim, the preponderance of positive events that occur.  Nonetheless, while negative words are comparably scarcer, they exist in greater variety, which the authors argue again is typical of how such events occur in our everyday environment.

Perhaps this latter is not so surprising.  Even at its most gossipy or mundane, language is partly a translation of our needs and desires, and partly a reflection of our environment.  Slips-of-the-tongue have endlessly been interpreted, not just as mistakes, but as windows onto our souls (see, for instance, the furore when Gordon Brown once accidentally said that he had "saved the world" rather than just the monetary crisis). Similarly, the past fifty years have seen fierce battles over Whorfian linguistic relativism, questioning how language affects thought, perception and behaviour.

All this does give the phrase 'reading between the lines' quite a different meaning!

A simple drug for Alzheimer's disease?

Alzheimer's disease is the most common form of dementia, affecting 1 in 10 people over the age of 65 and 1 in 5 over the age of 80. This truly debilitating disease gradually reduces the patient to living in the past without the ability to make new memories, and is not only devastating for the patients and their families, but is also a heavy burden on our health system.

Researchers at the Florida Alzheimer's Disease Research Center may have found that one of the most harmless and commonplace 'drugs', caffeine, may have a positive effect on the cognitive abilities of patients who suffer from the disease. The research group studied 55 mice that were genetically modified to develop Alzheimer's disease. After the mice had developed the disease, half of the group was given 500 milligrams of caffeine – the equivalent of 5 cups of regular coffee - in their drinking water every day. The other half did not get any caffeine. The researchers showed that caffeine improved memory and thinking abilities significantly after only two months of treatment, and were able to perform as well as healthy mice of the same age. The mice that had not received treatment continued to deteriorate.

The main cause of Alzheimer's disease is the formation of tangles and plaques in the brain, causing brain cells to die and communication pathways to be disrupted and destroyed. Broadly speaking, there are two enzymes responsible for the formation of the plaques and tangles, tau and amyloid beta/β. Plaques are formed by large clumps of amyloidβ in the spaces between cells. Tangles are formed by tau. Tau, normally a building block of the transport system of a cell, starts to disintegrate this transport system as a result of a chemical change, causing damage to the cell's nutrition- and communication, eventually leading to the death of the cell.

In patients with Alzheimer’s disease, an abnormally high level of amyloidβ is found in the blood. The study published in the Journal of Alzheimer's Disease this week shows a remarkable decrease – nearly 50% – in the abnormal levels of this protein in the blood and brains of mice treated with caffeine. Thus, the improvement in memory and thinking thus seems to be related to the decrease of tangles and plaques in the brain.

Although mice, needless to say, are quite different from humans – and the development of the disease is different in both species – these results are really promising. The first very preliminary results from tests in elderly people indicate that levels of amyloidβ decrease rapidly after treatment with caffeine.

But don’t think you will be able to boost your memory by drinking coffee; when healthy mice drank 500 milligrams of coffee each day, their memory did not improve. So though we may have a wonder drug to cure one of the most debilitating diseases of our time, alas, we still haven’t found a way to become smarter.