The science behind PRISM
The
brain is vital to our existence. It controls our voluntary
movements, and it regulates involuntary activities such as breathing and
heartbeat. The brain stores our memories, enables us to feel emotions,
and gives us our personalities. In short, the brain dictates the behaviours
that allow us to survive and makes us who we are. All our experiences,
thoughts, actions and emotions constantly change the make up of our brain.
PRISM looks at the structure and function of the brain, and especially
at the differences between the brain’s hemispheres, not only in terms
of attention and flexibility, but in attitudes to the world. Fundamentally, PRISM is
about our attention to the world – how we see and respond to our environment,
including the people in it. More accurately, it is about our perception,
or representation, of our environment. Our attention can either be broad
or narrow.
The right hemisphere is responsible for broad attention, the left hemisphere
for narrowly focused attention. Although the brain is split into hemispheres,
it is a single, integrated, highly dynamic system. Events anywhere in
the brain are connected to, and potentially have consequences for, other
brain areas
As you read the words on this page, you are using thousands of the 100 billion
nerve cells that make up your brain. The electrical firings and chemical
messages running between these cells, called neurons, are what produce
our thoughts, feelings and interactions with the world around us.
To learn
more about the brain click here >>
To
view the brain’s key structures click here >>
In order to understand our behaviour it is necessary to consider the makeup
of the brain. For decades scientists maintained that once the brain’s
physical connections were completed during childhood, the brain had become
hardwired and remained like that for life. Now, thanks to the latest
imaging technologies and brilliant clinical research, we now have proof
that development is a continuous, unending process. The key to individuality,
however, is not to be found in the overall organisation of the brain, but
rather in the fine tuning of the underlying networks. In particular,
it is about the balance between our natural, instinctive reactions and
our considered responses to everyday situations.
The PRISM Model of Human behaviour is a metaphor for how the
brain’s functional architecture and neural networks interact with
brain chemicals such as glutamate, dopamine, noradrenaline, serotonin,
testosterone and oestrogen to create behaviour. Modern neuroscience rests
on the assumption that our thoughts, feelings, perceptions, and behaviours
emerge from electrical and chemical communication between brain cells.
PRISM is intended to be a sort of beginner’s guide to neuroscience.
The neuroscientific language about the brain is extremely complex. PRISM attempts,
therefore, to simplify that language so that is can be more easily understood.
As a result, it contains many oversimplifications. For example, when we
say “the
left hemisphere is responsible for this”, or the right hemisphere is
responsible for that”, it must be understood that in any one human brain
at any one time both hemispheres will be actively involved. No single
part of the brain does solely one thing and no part of the brain acts alone.
All our thoughts, emotions and actions are the results of many parts of
the brain acting together.
The adult brain weighs about 3 pounds (1.4 kg) and contains about one trillion
brain cells, 100 billion of them neurons. This is a gigantic number of cells.
Neurons have both short and long fibres that contact the bodies of other neurons,
and there are about one million billion connections between cells in the brain.
100 billion cells is such a large number, it is hard to imagine. One million
is 1,000 times 1,000, the population of a very large town, for example. One
billion is 1,000 times one million. The number of connections in the human
brain is much bigger than the whole earth's population, which is about 6 billion.
Most of who we are is the result of the interaction of our genes and our
experiences. In some cases the genes are more important, while in others
the environment is more crucial. Genes set boundaries for human behaviour,
but within these boundaries there is immense room for variation.
The brain is split down the middle from front to back into two blocks known
as hemispheres. The left hemisphere controls the right side of the body
and the right hemisphere controls the left side of the body.
Each hemisphere can be divided into four individuals chunks, known as lobes.
The lobes are called ‘frontal (front), ‘temporal’ (side),
parietal (top), and occipital (back).
The right hemisphere (Green and Blue on the PRISM model) is predominantly
hard-wired for empathy and novelty. The left hemisphere (Gold and Red on the PRISM model)
is predominantly hard-wired for systemizing and routine.
Empathizing is the drive to identify another person’s emotions and
thoughts, and to respond to them with appropriate emotion. For example,
the right hemisphere helps us pick up on nonverbal cues in speech and gesture
as well as in facial expressions.
Systemizing is the drive to analyse, explore and construct a system. Systemizing
intuitively figures out how things work, or extracts the underlying rules
that govern the behaviour of a system.
The right hemisphere is interested in others as individuals. Self-awareness,
empathy and identification with others are largely dependent upon the right
hemisphere. The left hemisphere is not impressed by empathy. Its
concern is with maximising gain for itself and its driving value is practical
usefulness.
The left hemisphere is competitive and its concern, its prime motivation,
is power. The right hemisphere is particularly well equipped to deal
with passions, sense of humour, metaphoric and symbolic understanding,
and all imaginative and intuitive processes.
Neorochemically the hemispheres differ in their sensitivity to hormones (the
right hemisphere is more sensitive to testosterone) and they depend on different
neurotransmitters (the left is more reliant on dopamine and the right hemisphere
on noradrenaline).
While a lot of attention has been focused in the press on the interaction
between the right and left hemispheres, it is also important to focus on
the interaction between the front and the back of the brain. The back
of the brain (Red and Blue on the PRISM model) is the sensory
or input half, which receives input from the outside world and sorts, processes,
and stores all of our sensory representations. This area is, however,
not simply a site for processing sensory information. It is also the region
of cortex for associative processes, where information from the various
senses is ‘bound together’ for higher order processing.
To
view the brain’s key structures click here >>
In the front of the brain, the cortex is devoted to the processing of motor
programs or output – we use this area to react to the input data from
our senses. It is here we plan, create strategies, and create our responses
to the world, and it is this area that has been adapted for use in abstract
thinking and planning. The frontal lobes perform the most advanced and
complex functions in all of the brain, the so-called executive functions.
They are linked to intentionality, purposefulness, and complex decision making.
Motivation, drive, foresight, and clear vision of one's goals are central
to success in any walk of life. The frontal lobes play a critical role in
dealing with novelty. A novel task activates predominantly the right prefrontal
cortex. As
the task becomes familiar, the overall level of activation drops and shifts
from the right to the left prefrontal regions.
Underneath the cortex lies the limbic system which is involved in the generation
of emotions. The limbic system is made up of several pieces including the
hippocampus (memory), the amygdala (emotion, including fear) and the hypothalamus
(the body’s thermostat), Also, in moments of emergency the limbic system
commandeers the rest of the brain to protect us from harm.
Other items such as the anterior cingulate gyrus directs our inner response
to others and keeps us willing and interested in being with them. The orbitofrontal
cortex is the error catcher and with its partners, the anterior cingulate
and the ventromedial cortex of the frontal lobe, is crucial for empathy and
evaluation of the genuineness of the words and intentions and comments of
others.
The human brain remains the most complex item in the know universe. It
has been described as follows by Professor Robert Ornstein:
“The brain regulates all bodily functions; it controls our most primitive
behaviour – eating, sleeping, keeping warm; it is responsible for our
most sophisticated activities – the creation of civilisation, of music,
art and language. Our hopes, thoughts, emotions and personality are all lodged
somewhere in there. After thousands of scientists have studied it for
centuries, the only word to describe it remains: ‘amazing’.”