Uncovering the roots of unconscious memory

In In Search of Lost Time Proust describes a whole host of memories suddenly brought back to him when he dips a madeliene biscuit into a cup of lime tea. Psychologists call this process unconscious memory and researchers from the University of California Davis believe that they have found the region of the brain responsible for it. The researchers compared people with amnesia who had damage to an area of the brain called the perirhinal cortex to a group of healthy people. They gave the subjects a long list of words and asked them to think of any pleasant associations they brought to mind; later they were asked to think up words in different categories such as 'furniture.' The participants had MRI scans as they took the tests and in the healthy participants, who performed better in the tests, the perirhinal cortex showed increased activity. The study ties in with other research which shows that Alzheimer's disease often attacks the perirhinal cortex before other brain areas.

Good and bad cholesterol and memory loss

Researchers from the French National Institute for Health and Medical Research and from University College, London have found that low levels of high-density lipoproteins (HDL or 'good' cholesterol) in middle age can increase the risk of memory loss and lead to dementia in later life. At 55 years old participants with low HDL cholesterol had a 27% higher risk of memory loss compared to those with high HDL. To raise HDL and lower low-density lipoproteins (LDL or 'bad' cholesterol) the American Heart Association recommends exercising regularly, eliminating hydrogenated fats from the diet, reducing saturated fats and eating more polyunsaturates.

You can find out more about this research at

http://psychcentral.com/news/2008/07/03/cholesterol-level-can-affect-memory/2549.html

Why Americans are having less senior moments

A study of 11,000 people in the U.S. has found a significant decline in the levels of cognitive impairment between 1993 and 2002. The prevalence of cognitive impairment went down from 12.2% in 1993 to 8.7% in 2002. The researchers attributed this decline to increased rates of college education, greater personal wealth and better treatment for cardiovascular problems. In recent years research has suggested that the more education a person receives early in life the more his or her brain will be able to stay sharp later. During the time of the study the number of older people with a high-school diploma rose from 53% to 72% and the number of people with a college education rose from 11% to 17%. At the same time the use of cholesterol-lowering drugs and blood-pressure medication increased dramatically during the 1990s. This may have had the effect of reducing the incidence of vascular dementia - cognitive problems brought on by mini-strokes, strokes and decreased blood flow to and within the brain due to hardened or clogged arteries.

You can read more about this research at

http://psychcentral.com/news/2008/02/21/is-memory-loss-on-the-decline/1949.html

Stroke risk and memory loss

Although everyone loses some cognitive capacity as they age new research from the U.S. suggests that people at high risk for stroke also have the highest rate of cognitive decline. The study, of more than 17, 000 people found that those at high risk of stroke declined twice as fast as those at low risk. Those rated as having a 22% chance of having a stroke in the next ten years had double the rate of cognitive decline as those who were only thought to have a 2% chance. High blood pressure, diabetes and left ventricular hypertrophy were the three, specific, risk factors associated with memory loss.

You can find out more about this research at

http://psychcentral.com/news/2008/02/25/stroke-risk-factors-may-predict-cognitive-decline/1958.html