27 July 2009

Reptiles and relationships?!

My daughter told me a story this morning about her friend’s brother and his pet python. Evidently his mother insisted he get rid of the python as it kept turning on him and biting his chest. The snake breeder who had sold it to him said that he wasn’t handling it enough and therefore hadn’t had time to build up a relationship.

As humans, we share the brain of snakes and lizards, but have evolved to a higher state, capable of cognitive thought, choices and decisions. In the 1960s, neurologist Paul MacLean proposed that our skull holds not one brain, but three, each representing a distinct phase of evolutionary development. He called his theory the "triune brain."  MacLean says that three brains operate like "three interconnected biological computers, each with its own special intelligence, its own subjectivity, its own sense of time and space and its own memory. He refers to these three brains as the neocortex or neo-mammalian brain, the limbic or mammalian system, and the reptilian brain, the brainstem and cerebellum. Each of the three brains is connected by nerves to the other two, but each seems to operate as its own brain system with distinct capacities.  Innermost in our brain is the reptilian brain, its oldest and most primitive part. The reptilian brain appears to be largely unchanged by evolution and we share it with all other animals which have a backbone. This reptilian brain controls body functions required for sustaining life such as breathing and body temperature. At this level of evolution, behaviour relating to survival of the species, such as sexual behaviour and catching prey is instinctive and responses are automatic. Territory is acquired by force and defended. Might is right. The python is wired to survive and will attack if threatened or seeking prey. In the wild, reptiles are independent immediately from birth fully adapted to their environment from the offset.  I am not a snake breeder, but from a brain perspective, I am pretty sure the python wasn’t sulking as there was no effort at a relationship. I am also convinced that a tank in the corner of a boy’s bedroom in west London isn’t the most natural environment. I am however very interested in human survival instincts and use of our reptilian brain so would appreciate any thoughts.

26 July 2009

Forgetfulness

It often happens, I boil the kettle, make a cup of tea and then forget to drink it. However, I am not alone, according to research carried out by The National-Lottery, every day exactly the same thing happens to around 15 million of us while a similar number of us will forget where they put their car keys. Apparently, the average Briton forgets three such things each and every day, with the most worrying (according to the research) being to buy a lottery ticket!

Obviously the purpose of the research was to promote the National Lottery, but it raises an interesting question: Since our brains are so amazing at remembering vast amounts of information, why do we forget simple things?

Some scientists believe that the answer lies in the differences between your short-term working memory and your long-term memory. It is known that the two are different and that your short-term memory is somewhat transient. This is why some brain-damaged patients can suffer from a condition where they are unable to create any new memories. In these cases their memory will be intact up to the time when the brain injury took place, but they will have no memories from that time onwards.

Another theory is that our memory works on associations. For example, if you show people pictures of a part of an object, such as the end of a settee, they generally have no difficulty in identifying what the object is. Scientists have discovered that we remember the details of literally thousands of objects when shown part pictures in this way because our memory works on associations – by being shown a bit of an object, our brain instantly recalls all the rest of the information necessary to reconstruct the whole object. However, although the brain contains detailed representations of lots of different events and objects, our memory performs much less well when we attempt to remember things spontaneously. The reason is that it doesn’t have the associations to work from. If you want to remember where you put your keys, you therefore need to be consciously aware of them when you put them down – easier said than done!

This brings me on to the last reason why we might forget small things – it is because we were not really aware of them in the first place. Some months ago I lost our home telephone. I tried paging it and I searched high and low, all to no avail, and I ended up having to buy a new one. Some months later I found it – in the garage! I must have been in the middle of something with the phone in my hand when I needed my hand for something else. My brain helpfully would have known that I could not hold two things at once so it subconsciously instructed my hand to put it down.

Because our brains can only consciously process around seven pieces of information at any one time, they have become brilliant at dealing with everything else subconsciously. For example, most of us will have had the experience of not being able to remember the journey home from work even though we managed to drive perfectly safely.

The reason we forget trivial things therefore is because our brains prioritise. I forget to drink my tea because I am concentrating on something else, I lost the phone because I was trying to do too many things at once and I forget the journey home from work because I know the route so well that I don’t have to think about it.

Brilliant things brains!

What are the things you forget?

19 July 2009

Optimists see more

People often assume that when we see things it is a bit like an image from the eyes being projected onto the brain. In reality, the process is nowhere near as simple as this.

What actually happens is that the information from the eyes is directed to a form of processing centre in the brain where it is added to information from our other senses and memories of our past experiences. Once all this information has been assembled our brain jumps to a conclusion as to what it is we are looking at.

It therefore stands to reason that factors such as our mood, tiredness or health might affect our ability to process all this information. In fact, this is the conclusion of researchers at the University of Toronto who have found that our mood can affect our sight.

Their findings, which were published in the Journal of Neuroscience, were that people in a positive mood saw while those who were more down in the dumps suffered from tunnel vision. While being cheerful is generally seen as a good thing, Taylor Schmitz, one of the researchers, commented; “this can lead to distractions on critical tasks that require narrow focus, such as operating dangerous machinery or airport screening of baggage.”

The conclusion therefore seems to be that if you need to do something that requires you to focus your vision in a concentrated way; rose tinted spectacles can be dangerous!

14 July 2009

Eat curry to prevent Alzheimer’s

Research at the University of North Carolina has discovered that curcumin, from which the spice Turmeric is made, can act as an agent to bloc the development of Alzheimer’s.

One of the conditions associated with Alzheimer’s is a build up of amyloid protein plaques in the brain. It is thought that this interrupts the transmission of electrical signals between brain cells, resulting in the symptoms of dementia. Scientists have found that brain plaques in mice have been shown to dissolve when the mice were given high doses of curcumin and that in younger mice the spice appears to prevent the plaques from forming in the first place. The research is supported by evidence from India where, according to Dr Susanne Sorensen of the Alzheimer's Society, "communities that regularly eat curcumin have a surprisingly low incidence of Alzheimer's”. However, to have any impact, you would need to eat a curry meal two to three times a week, making it difficult to fit in all the other things we are supposed to eat as part of a healthy diet. Luckily they are working an a “curry pill” as an alternative. Click here to see related comments from the Alzheimer's Society.
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06 July 2009

Envy thy neighbour - it's good for you!

Darwin taught us that we are the way we are as a result of natural selection. But scientists have often puzzled over why our brains have become so highly developed as our mental capability is vastly in excess of anything that would be necessary to keep us at the top of the food chain.

However, according to a report in the journal “Human Nature” the reason the human brain has tripled in size over the past two million years is because we became envious of our neighbours.
In other words, once we no longer needed to compete with other animals we started competing with each other. Scientists at the University of Missouri came to this conclusion as they have uncovered evidence to suggest that the brains of our ancestors who lived in larger communities grew faster than the brains of those living in smaller communities.

Their conclusion is that competing against other people is the biggest factor in the brain’s development.

So there you have it, science has established that one of the Deadly Sins delivers beneficial effects – just six more to go!
 
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