How our brains perceive us

A series of lectures are taking place for International Brain Awareness Week

A series of lectures are taking place for International Brain Awareness Week. Claire O'Connelllooks at some of the issues up for discussion

How does the brain delude us? Can friendship and mental "neurobics" help stave off Alzheimer's disease? And do our hearts rule our heads?

These are just some of the questions being asked this week in a series of public lectures hosted by Trinity College Dublin's institute of neuroscience and the Neurological Alliance of Ireland.

Bizarre twists of self-awareness will be revealed tomorrow when Prof Ian Robertson unpicks the complexities of how our brains perceive ourselves.

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"Self-awareness is one of the highest achievements of the human body," says Robertson, who is professor of psychology at Trinity College Dublin (TCD). "But if some parts of the brain stop working, it can have strange effects on self-awareness."

Extreme examples include brain injuries leading people to believe they are dead and in a dream world, or, as happened to Robertson's own father after a stroke, they think their relatives have been replaced by imposters.

Alcohol and drug use can distort our self-awareness too, notes Robertson. "It's evident when people drink alcohol they overestimate their competence, whether that be for driving, dancing or attractiveness to the opposite sex," he says.

Robertson will also look at how easily even the normal, sober brain can be duped into failing to notice changes in our environment.

"Magicians are keenly aware of the limitation of consciousness that is the norm for the human brain," he says.

Protecting our brains from the ravages of dementia will also form a central theme in this week's talks. "There's a lot being learned about how to delay the onset of Alzheimer's disease," according to Brian Lawlor, professor of old age psychiatry at TCD and St James's Hospital.

Long-recognised risk factors include old age and family history, but more recent research suggests that mental stimulation and social interactions could help stave off clinical symptoms of the disease, he says.

In particular, work with primates shows that challenging mental tasks or so-called "neurobics" can help build up connections in the brain that act as a buffer against symptoms.

"The idea is that with mental stimulation throughout life that you build up more connections, so that if Alzheimer's disease begins to develop, your brain has more reserve.

"So even with the same amount of Alzheimer pathology, you may not have the clinical dementia," says Lawlor.

Research on humans indicates that plentiful social interactions could play a similar role.

"Where you have equal amounts of Alzheimer pathology, if you have good social connections and you are not lonely you are less likely to present with the clinical symptoms of Alzheimer's disease," says Lawlor.

But he notes that social and mental stimulation are best viewed as preventative approaches.

"They are probably not that useful for people who develop the illness, they are probably more useful as potential protective agents," he says.

Meanwhile, how we treat our hearts could also affect our brains, according to RoseAnne Kenny, professor of clinical gerontology at TCD and St James's Hospital.

"Cardiovascular diseases are probably the principal risk factors for developing dementia," she says.

Conditions such as irregular heartbeat or low blood pressure could result in either clots or insufficient blood going to the brain which, in susceptible people, could contribute to the onset of dementia, according to Kenny.

"The take home message is to manage the heart and the head will follow," she says.

"If you are rigorous about your cardiovascular health risk factors - healthy diet, low cholesterol, getting blood pressure monitored, taking blackouts and falls seriously, and looking after heart irregularities - you can also reduce your risk of getting Alzheimer's."

Conversely, the head may also rule the heart, says Kenny. "There's an old expression 'he nearly died of fright'. Now there's evidence that severe stress and trauma can actually stop your heart, or that people who are under psychological stress could get blackouts."

However, the upside of unravelling the relationships between brain and heart disease is better diagnosis and prevention, she adds.

International Brain Awareness week runs from March 12th to 16th. For full details of events at TCD and around the country see the Neurological Alliance of Ireland website at www.nai.ie

For free tickets to the lectures at Trinity College Dublin, e-mail neuroscience@tcd.ie