Right now I am aware that my mobile is just about 30% charged. The battery icon at the top right corner is staring at me. The phone will prompt me as soon as the charge goes down below 20%. If I don’t plug it in, it will shut itself down when it is fully discharged. Thankfully, the risk is limited to me not being able to use the phone. It cannot cause much harm to me or to the device. I can afford to be lazy for now. It’s an altogether different story however when something similar happens inside my body.
When I am running out of energy, my body tells me to go and get some food. Or drink. Its alerting mechanism comprises of, among other things, the feelings of hunger and thirst. I cannot ignore these prompts for long. These are bodily sensations that belong to a particular type of feelings. Some other feelings are purely mental. Being happy or feeling disgust for example. There is a whole heap of feelings that are generated by our central nervous system which prompt us to do something. Researchers in Finland have mapped our 100 core feelings by analysing how pleasant and how prominent these feelings are. A much simplified view loosely based on their work is presented here.
Right in the middle of this chart sit the feelings which help us maintain a normal body state (jargon: homeostasis). Move diagonally down left and the feelings there tell you that your body is not well. Do something about it or at the very least don’t put pressure on it. Get some rest. On the top right are feelings of being on a high. Positive Emotions. A place where you’re motivated to keep doing the good work. Reproduction being one of the good works. On the two sides of this diagonal representing bodily sensations are feelings that are more “mental” in nature. More prominent of these feelings, which are unpleasant too, tend to indicate that we are not well mentally. Some feelings here dissuade us from doing things that land us in this place. Feelings like ‘fear’ are derived from primary emotions that originate in most animals in their “deeper” brains. Diagonally opposite to this area of ‘Negative Emotions’ lie “mental” feelings that make us humans special or so we like to think. Cognition. Consciousness. Reasoning. The realm of perception, research, analysis, dreaming, art, science, language, creativity, …
These cognitive feelings originate in neocortex which is the most evolved (and evolving) part of the brain. While earlier researchers delineate this superficial area functionally from the deeper limbic system, leading neuroscientist Antonio Damasio believes that the two systems are connected. He proposed an idea that the prefrontal cortex is responsible for a signal loop that aids the deeper primary emotions area in decision making based on mental images of hypothetical scenarios of body states representing different response options to a stimulus. I wish I could introduce this tortuous hypothesis in a more lucid manner. Hopefully the text below will make it clearer.
Fundamentally, animals need drive or motivation to do things. This necessity comes with the advantage of motility that distinguishes us animals from plants. For a plant, which is rooted, energy input mechanism is driven by physics and chemistry operating at its interface with soil and with air. Animals need to be driven so that they get close to food sources and then put the food inside their body. Similarly, they need to breathe to take oxygen in and discard carbon dioxide. Animals also need to be put to sleep to give active metabolism some rest so that some important cell level activities can operate smoothly. At the right age, a higher animal must also feel the need to perform sex. All these drives are regulated via hormones inside the body. Production of appropriate hormones at appropriate time is controlled by the brain’s primitive structures. So far so good. It’s like my mobile phone producing a hormone which pops up a message warning me about the remaining charge.
The chemical based system of hormones is not enough for complex animals. In higher animals, the need for motivation goes beyond provisioning of consumables. The evolutionary forces sought out to automate monitoring and maintenance of health of the system as much as possible. What if the phone falls and hits a hard surface? What if it encounters poor connectivity? What if the touch sensitive screen is damaged? That’s when the device depends entirely on its owner for survival/functioning. Nature wants higher organisms to be self-sufficient as much as possible. They must continue to explore which amounts to taking more risks by encountering new environments. That’s why organisms have been provided with systems to assist them in this mission. And nature keeps on updating the systems. That’s what we call evolution.
If the phone were a ‘life’ object, it would feel hurt and sadness when it’s screen is scratched, find a repair shop and drive itself there to get the scratch removed. Intelligence is all about decision making. It runs on a neural network as opposed to the chemical network of hormones. Damasio’s hypothesis says that our brain not only continuously creates images of current state of our body, but it also, when faced with a decision making scenario, creates images of “as if” scenarios. These images are basically how the body will look like when each of the available options are implemented. What if I don’t do anything? What if I consult a repairer? What if I rub the screen surface with a wet cloth? Damasio calls these images of “as if” body state somatic markers. The somatic marker images assist our conscious self to choose an option which is represented by the “outcome” image of our liking. It’s almost like visualising the immediate future states of our body and then choosing the best one. That’s how we make conscious decisions. That’s how we “mind” our body as it explores new environments.
Nummenmaa, L. et al. (2018) Maps of subjective feelings. Proceedings of the National Academy of Sciences of the USA 115, 9198?9203.
Damasio, A. (1994)?Descartes’ Error: Emotion, Reason, and the Human Brain. Grosset/Putnam, New York.