The Brain (and how to better use it)

Potential chapter titles:

  1.  Structure – what the brain is made up of and how it performs its various functions in our body.  The various brain regions and sub sections, their locations and what functions they are mostly responsible for controlling/performing/assisting in.
  2. General Functions – brief synopsis of the brain’s role in everything we do as human beings. Broadly classified as sensory input/output and feedback functions, motor (muscle) function, and associative functioning (the way parts of the brain interconnect with other parts of the brain and body when performing complex tasks).
  3. Mind. Our Consciousness – our states of awareness and our degree of control over them. Healthy versus unhealthy states of mind.
  4. The Concept of Self. Being aware of, and identifying with, your ‘self’. Who are we and what makes us the way we are? Does our Self change? Should we have more ‘say’ in what we are, or think we are? Self delusion, personal bias, confirmation bias.
  5. Brain Psychology.
  6. Dreaming. Being unconscious. Are dreams ‘real’ – can we tell the difference between a dream state and an aware one? What is real to the brain?
  7. Meditation. How to gain more control over the way your brain works for you.
  8. Learning. What are the most effective methods of training the brain, improving our performance in various tasks/functions.
  9. Memory. Recall and recognition. How are memories created, retained, recalled? what can be done to improve memory/what things interfere with it?
  10. Sleep and the Brain. How sleep affects brain activity. What are the benefits/costs?
  11. Hypnosis. Can our brains be fooled (can they not be?) Can another person direct our consciousness without our awareness?
  12. Addiction. What is the brain’s role in addictive behaviour. Can it be self-regulated effectively?
  13. Mental health. What is mental health – what is mental unhealth? How can we best maintain a healthy mind?
  14. Emotions.
  15. Thoughts and rational thinking.
  16. Creativity and productivity. Can a well-disciplined mind produce truly original creative thoughts/ ideas?
  17. Communication – with our self; with other ‘Selves’, with other sentient beings, eg. pets, other creatures.
  18. What is ‘Real’/Reality?

Introduction

It has always amazed me that despite the fact every single human has a brain, without which we would be incapable of doing a single thing – not even breathing, we generally have such a poor understanding of it; what it is, what it looks like, how it is made up, how we ‘use’ it every second of our lives (often without even being aware of what it is doing) and particularly how each one of us might learn to use it to our greatest human advantage.

There is no manual for a human brain, we simply have trial and error as the most popular way of working out how best to use it. (Some just simply learn how to get it to do a few basic tasks to meet certain personal needs and let it wander off to do whatever it likes the rest of the time).

Our brain is possibly the most complex organism in the known Universe and is capable of almost unlimited potential in our lives. Although relatively small in size, representing around 2% of our total body mass at a little over a kilogram (2-3lb) in weight, it contains some 86 billion neuron cells (+/- 10%) and a similar number of non-neuronal cells. Each neuron may be connected to up to 10,000 other neurons, passing electro-chemical signals to each other via as many as 1,000 trillion synaptic connections, equivalent by some estimates to a computer with a 1 trillion bit per second processor!¹

It literally controls and processes everything we do, everything we are. From before we leave the womb to shortly after we die (or could be pronounced ‘brain dead’ which is a bit of a ‘fuzzy’ term capable of differing interpretation)!

Fig 1. Two diagrams representing a typical human brain – the colours were added to more clearly display areas of our brains that serve mostly one type of function.human brain fig1
Fig 2. A closer to real image of a human brain which is largely pink when living, with red blood flowing through it. Human brains we are most likely to see are generally greyish in colour having no blood and most likely have been stored in a preservative, hence ‘grey’ matter referred to when someone is using their brain.human brain fig2

 

Although the Cerebrum, which is the main part of the brain we normally can see with all the folds and valleys, is the largest part of our brain it only contains about 20% of the neuron cells, while the large majority – 80% – are contained in the smaller cerebellum region tucked in the back and underneath the cerbrum/cortex. (You can just see it sticking out in Fig 2.)

Structure

Brain structure is very complex having several ‘layers’ and components and specific regions to which certain body and mental function is attributed. Roughly 50% of the brain comprises of nerve cells called Neurons of which there are 5 main types including interneurons, pyramidal cells including Betz cells, motor neurons (upper and lower motor neurons), and cerebellar Purkinje cells. Betz cells are the largest cells (by size of cell body) in the nervous system.

Of the remaining 50% of brain cells they include:

Glial cells of which there are also 5 main types: astrocytes (including Bergmann glia), oligodendrocytes, ependymal cells (including tanycytes), radial glial cells and microglia. Astrocytes are the largest of the glial cells.

Cerebrospinal fliud acts as a cushion or buffer for the brain, providing basic mechanical and immunological protection to the brain inside the skull. CSF also serves a vital function in cerebral autoregulation of cerebral blood flow. There may be other functions it serves but little experimental documentation currently exists on these.

Blood cells and blood vessels including a specific form of white blood cells known as Mast cells.

 

Arguably the cells of most interest in the brain are the neurons. Brain activity is made possible by the interconnections of neurons and their release of neurotransmitters in response to nerve impulses.  The whole circuitry is driven by the process of neurotransmission. Neurons can transmit and receive electrochemical signals to/from other neurons via a synapse, which allows multiple neurons to form neural pathways, neural circuits, and large elaborate network systems, in some ways comparable to computer networks. Unlike a computer however where the circuits are pre-designed and of a fixed nature, neural networks are adaptable and are able to  change continually, some being created, some reinforced and some reduced/reprogrammed.

anatomy_of_a_neuron_with_synapse
Fig 3. A typical brain neuron structure.

The brain uses both release of chemicals and electric current to allow the transfer of signals between neurons; there are chemicals that inhibit an action as well as chemicals that stimulate an action and the brain relies upon maintaining the correct balance between these activities and also getting the timing right. These chemical neurotransmitters include dopamine, serotonin, GABA, glutamate, and acetylcholine. Neuron electrical activity depends upon concentrations of surrounding chemical  ion solutions of such elements as sodium, potassium, chloride, and calcium.

That’s a ‘brief’ description of what the brain is made up of and the sort of internal activity it generally comprises. Let’s now look at the physical structure – where all the various internal structures are located, and learn a few key terms and a short coverage on what roles each one serves.

Physical Structure

Our brain is built up from 3 main groups of structures. They are the Cerebrum, the Cerebellum and the Brain Stem. The Cerebrum is the largest part of the brain, consisting of the outer cerebral cortex as well as several subcortical structures, including the hippocampus, basal ganglia, and olfactory bulb. In the human brain, the cerebrum is the uppermost region of the central nervous system.. The cerebral cortex is the outer layer of neural tissue of the cerebrum of the brain, in humans and other mammals.

brainmaps-macaque-hippocampus
Tissue slice from the brain of an adult macaque monkey. The cerebral cortex is the outer layer depicted in dark violet. Source:BrainMaps.org

It is separated into two cortices, by the longitudinal fissure that divides the cerebrum into the left and right cerebral hemispheres. The two hemispheres are joined beneath the cortex by the corpus callosum. The cerebral cortex is the largest site of neural integration in the central nervous system. It plays a key role in memory, attention, perception, awareness, thought, language, and consciousness.  The cerebral cortex is an outer layer of ‘grey’ matter, covering the core of white matter. The cortex is split into the neocortex and the much smaller allocortex. The neocortex is made up of six neuronal layers, while the allocortex has three or four. Each hemisphere is conventionally divided into four lobes² – the frontal, temporal, parietal, and occipital lobes as per Fig 1 above.

The frontal lobe is associated with executive functions including self-control, planning, reasoning, and abstract thought, while the occipital lobe is dedicated to vision. Within each lobe, cortical areas are associated with specific functions, such as the sensory, motor and association regions. Although the left and right hemispheres are broadly similar in shape and function, some functions are associated with one side, such as language in the left and visual-spatial ability in the right. The hemispheres are connected by commissural nerve tracts, the largest being the corpus callosum.500px-blausen_0102_brain_motor&sensory

The cortex directs the conscious or volitional motor functions of the body. These functions originate within the primary motor cortex and other frontal lobe motor areas where actions are planned.

As the name suggests the sensory areas of the Cortex deal with information received from our (5) senses; The senses of sight, hearing, and touch are served by the primary visual cortex, primary auditory cortex and primary somatosensory cortex respectively.

The association areas are the parts of the cerebral cortex that do not belong to the primary regions. They function to produce a meaningful perceptual experience of the world, enable us to interact effectively, and support abstract thinking and language. The parietal, temporal, and occipital lobes – all located in the posterior part of the cortex – integrate sensory information and information stored in memory. The frontal lobe or prefrontal association complex is involved in planning actions and movement, as well as abstract thought. Globally, the association areas are organized as distributed networks. Each network connects areas distributed across widely spaced regions of the cortex. Distinct networks are positioned adjacent to one another yielding a complex series of interwoven networks.

 

 

I hope that with your help and input I can start to put together a very basic (though occasionally highly detailed) Manual for the Human Brain that people can read and hopefully use to improve their understanding of what they do and why they do it and will give them choices in how to improve the parts of their lives they may be having difficulties with, which i am quite sure, for the most part, comes down to how they learned to use their brain, or what their brains were taught, via experience, to do.

 

¹ – http://www.human-memory.net/brain_neurons.html

² – Brain research is an ongoing and fluid study and new discoveries are constantly updating older ideas and pictures of the brain. Some research indicated there might be 5 or 6 lobes per hemisphere.

Advertisements