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The Biology of Mind and Consciousness

By: , Posted on: October 31, 2014

Difficult Questions – Different Answers!

The intriguing problem of mind and consciousness has historically defied proper scientific examination, and despite scientific advancement, two big questions are left largely unanswered: What is mind? What is consciousness? We know that we are conscious when we look at a rose, or when we listen to our favorite music, or when we taste our hot pasta. We may say that we can sense all these events of the external world by using our mental faculty called mind! By this way we become conscious of the world around us! But consider this: We are conscious in the wakeful state alright – but are we conscious during sleep, or in dreams, or in deep coma? Likewise, is a baby in the womb conscious of its surroundings? If yes, when did consciousness start? If no, at what stage does it start? Many more of such questions …

Look at the problem from an evolutionary angle. We can say that our dog is conscious of a luring piece of bone in the basket. We also know that a sparrow is conscious of a worm on a leaf. Take a step further down, is a caterpillar conscious of its prey? Perhaps it is! But now, look into this: We find no difficulty in saying that a creeper plant in your garden is not conscious of a pole standing by its side – but it can ‘sense’ the pole, reach for it and wrap around it. We can also say that an entamoeba landed on a glass-slide is not conscious of the event – but it can ‘sense’ the presence of a microscopic clump of RBC and move its pseudopodia towards it. Many more such questions here as well!

What are these myriad senses and how are they sensed? How can we unify all these vague phenomena and define human consciousness/mind in definite terms? What is that which holds back our scientific progress in this field? This blog post presents a novel approach to address this issue!

Consider this: the fundamental constituent of each of the phenomena which constitutes mind or consciousness is thought – the sensations as they are presented at our receptors are transmitted to the brain where they are converted into perceptions or thoughts. These thoughts form the core of human mind and the background of consciousness. Now we can say that, an understanding of the mechanism of generation of thought sheds more light upon the concept of mind/consciousness. The discussion below also shows that the only way to correctly understand the human mind is to study its evolutionary development!

The Biology of ThoughtThe Biology of Thought proposes a new molecular mechanism by which the external world stimuli are converted into internal perceptions by the neurons, thus generating primary thoughts (described as the molecular-grid model in Chapters 4 through 8). The book also deals with scientific examination of the evolutionary development of mind and consciousness in Chapter 9 – which, at the end, culminates in a proper explanation of some difficult questions related to human psychology and intelligence – a rich dividend indeed!

This blog presents excerpts of Chapter 9.

The Four Basic Survival Functions

All life forms (including plants, animals and microorganisms) have a basic desire to live, and in order to cope with the surrounding environment, all life forms on the earth have to perform the following four basic survival functions:

  • They have to procure food
  • They have to protect themselves from predators
  • They have to grow in size
  • They have to procreate

In order to perform these survival functions all life forms need to sense their surroundings through external stimuli. They have to sense the presence of food in their surroundings in order to reach for it; sense and detect their predators to avoid danger; sense and recognize a suitable environment for them to grow and thrive; sense and identify their mates to procreate and proliferate.

The stimuli may present themselves in any form of energy – light, heat, sound, chemical, mechanical, electrical, gravitational, magnetic etc. For example, in the case of microorganisms, they employ chemotaxis to reach for their food and mechanotaxis to avoid danger – if they sense favorable environment they proliferate, if not they sporulate. In case of plants they use phototaxis to reach for light as energy source, geotaxis to grow their roots down, hydrotropism to move to the source of water, thigmotropism to move towards support etc. Animals have special faculties to move around in search of food and mate, and to avoid danger – they may employ the usual stimuli like light, sound etc; or they may engage special senses like ultraviolet detection, infrasound perception, echolocation etc.

Finally, in the case of the “versatile” human beings, they have the following recognizable senses – Special senses: vision (light energy), hearing (sound energy), smell, taste (chemical) and vestibular function (gravitational); General senses: touch, pain, pressure, vibration (mechanical energy), temperature (heat) and proprioception (? geomagnetic). However, humans have a complex interactive haptic perception of which we will not go into details now.

To summarize, all life-forms must be aware of their surroundings in order to execute their survival functions. This means that awareness is the characteristic feature of all life forms. Thus, we can say that:

Awareness is sensing the environment, and all life forms possess awareness

Evolution of Nervous System: In the case of animals (starting from coelenterates and worms to insects, reptiles, birds and mammals), they become aware of their external environment by the way of senses like touch, smell, vision, sound etc. Unlike in plants, animals receive signals from the environment, process them and store them in an organized fashion – this advanced form of awareness is possible only with the development of a specialized system called the nervous system. Thus all animals possess some sort of nervous system to perceive these sensations which enable them to move around in space more effectively and perform all the four basic functions. Thus, we can say that:

Perception is a neural form of awareness

Evolution of Consciousness: The characteristic feature of nervous system is not only to perceive but to hold these perceptions for some variable period – i.e. to form memory. Thus, all these animals are not only aware of their surroundings, but are capable of holding this awareness in memory for some time, and this memory helps them to navigate in their surroundings efficiently – even a snail needs some slight memory to move around in space. This sort of awareness stored in the nervous system as memory is consciousness. The animals now have become conscious of their surroundings (not just being aware of their surroundings like plants). A busy bee hovers over the flowers in a garden until they are empty of their nectar, and could fly to a distant garden in search of more flowers – which means that it is conscious of the next possible source; a deer is conscious of its predators in the jungle; a mother monkey is conscious of its baby monkey playing around, so on. Nervous system gave animals another leverage – the time-scale of responses to stimuli in case of plants is inexorably slow (e.g. phototaxis, geotaxis); whereas in animals nervous system made this stimulus-response phenomenon instantaneous which is essential for their survival.  Thus, we can say that:

Memory is the cornerstone of consciousness, and all animals possess consciousness

As the complexity of the nervous system increases in animals, consciousness progresses into higher levels. The lower animals (e.g. insects) have only very short memory which works only to serve their immediate survival instincts. As animals become more advanced (e.g. reptiles, birds and lower mammals) their brain’s neural connections become increasingly complex, and the consciousness progresses to provide them with a longer memory and, more importantly, in a better organized fashion. Thus, as animals ascend in their phylogeny they become more capable of organizing their memory to perform the four survival functions – an “eyeless” earthworm can only move around in space and cannot have any further memory; an insect like mosquito has a little more memory to repeat its actions over and over; a bird like parrot can do far better in memorizing the events; a mouse in a maze or a monkey in a predicament can store more details in their memory and surpass hurdles with their tricks. Thus, animals possess consciousness in improving degrees as they become more advanced.

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Evolution of Mind: The nervous system in the more advanced mammals like elephants, dogs, tigers etc is much more complex, and the consciousness is much more advanced and can store much more memory. In fact, the memory in these advanced animals takes the form of a solid long-term memory which can be used to perform certain intelligent tasks. This advanced form of consciousness is the mind. Thus, elephants are not only conscious but they have minds of their own, so is the case with your pet dog. As we can see, the simple survival function of awareness in lower life forms has transformed into a complex mind in higher animals, and reached its zenith in the human beings in the form of intelligence.

Thus, it can be concluded that human consciousness and mind are epiphenomena of awareness (and awareness is nothing but perception itself!) – and have gradually evolved from lower organisms.

Further on, in the Chapter 9 of The Biology of Thought we will demonstrate how human mind is wholly dependent on external stimuli for its existence and explores the evolution of central executive and its relationship with human intelligence, and its importance in human psychology and psychosomatic disorders.

About the Author

KG DharaniKrishnagopal Dharani is a medical doctor practicing at Adoni, a large town in South India. He has graduated in medicine from Kurnool Medical College in Andhra Pradesh, and did his general surgery from Kasturba Medical College, Manipal, South Canara. He took his post-doctoral specialization in vascular surgery at the Nizam’s Institute of Medical Sciences, Hyderabad. He is presently holding the post of Specialist Civil Surgeon in AP Medical Services, and despite having a large surgical practice, he manages to split his time between his profession and his academic pursuits in science.  The author can be contacted at

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