Read Online Self Comes to Mind by Antonio Damasio - Free Book Online Page B
Authors: Antonio Damasio
Ads: Link
departures from the homeostatic range and thus act as sensors for the degree of internal need. In turn, the measured departure from homeostatic range allows yet other brain devices to command corrective actions and even to promote incentive or disincentive for corrections, depending on the urgency of response. A simple record of such proceedings is the basis of the prediction of future conditions.
In brains capable of representing internal states in the form of maps, and potentially having minds and consciousness, the parameters associated with a homeostatic range correspond, at conscious levels of processing, to the experiences of pain and pleasure. Subsequently, in brains capable of language, those experiences can be assigned specific linguistic labels and called by their names— pleasure, well-being, discomfort, pain.
If you turn to a standard dictionary and look up the word value , you will find something like the following: “relative worth (monetary, material, or otherwise); merit; importance; medium of exchange; amount of something that can be exchanged for something else; the quality of a thing which renders it desirable or useful; utility; cost; price.” As you can see, biological value is the root of all those meanings.
The Success of Our Early Forerunners
What made organism-vehicles so brilliantly successful? What opened the way for complex creatures such as ours? One important ingredient for our arrival appears to be something plants do not have but that we and some other animals do: movement . Plants can have tropisms; some can turn to or away from the sun and the shadows; and some, like the carnivorous Venus flytrap, can even catch distracted insects; but no plant can uproot itself and go seek a better environment in another part of the garden. The gardener must do that for it. The tragedy of plants, though they do not know it, is that their corseted cells could never change their shape enough to become neurons. Plants have no neurons and, in the absence of neurons, never a mind.
Independent organisms without brains also developed another important ingredient: the ability to sense changes in physiological condition, inside their own perimeter and in their surround. Even bacteria respond to sunlight as well as to countless molecules; bacteria in a petri dish will respond to the drop of a toxic substance by clumping together and recoiling from the threat. Eukaryotic cells also sensed the equivalent of touch and vibration. The changes sensed either in the interior or in the surrounding environment could lead to movement from one place to another. But in order to respond to a situation in an effective manner, the brain equivalent of single cells also has to harbor a response policy , a set of extremely simple rules according to which it makes a “decision to move” when certain conditions are met.
In brief, the minimal features that such simple organisms had to have so that they could succeed and let their genes travel on to the next generation were sensing of the organism’s interior and exterior, a response policy , and movement . Brains evolved as devices that could improve the business of sensing, deciding, and moving and run it in more and more effective and differentiated manner.
Movement was eventually refined, thanks to the development of striated muscle, the kind of muscle we use today to walk and speak. As we shall see in Chapter 3 , the sensing of the organism’s interior, what we now call interoception , expanded to detect a large number of parameters (e.g., pH, temperature, presence or absence of numerous chemical molecules, tension of smooth muscle fibers). As for sensing the exterior, it came to include smell, taste, touch and vibration, hearing, and seeing, the ensemble of which we designate as exteroception .
For movement and sensing to work to the best advantage, the response policy must be something akin to an encompassing business plan outlining implicitly the conditions that
In brains capable of representing internal states in the form of maps, and potentially having minds and consciousness, the parameters associated with a homeostatic range correspond, at conscious levels of processing, to the experiences of pain and pleasure. Subsequently, in brains capable of language, those experiences can be assigned specific linguistic labels and called by their names— pleasure, well-being, discomfort, pain.
If you turn to a standard dictionary and look up the word value , you will find something like the following: “relative worth (monetary, material, or otherwise); merit; importance; medium of exchange; amount of something that can be exchanged for something else; the quality of a thing which renders it desirable or useful; utility; cost; price.” As you can see, biological value is the root of all those meanings.
The Success of Our Early Forerunners
What made organism-vehicles so brilliantly successful? What opened the way for complex creatures such as ours? One important ingredient for our arrival appears to be something plants do not have but that we and some other animals do: movement . Plants can have tropisms; some can turn to or away from the sun and the shadows; and some, like the carnivorous Venus flytrap, can even catch distracted insects; but no plant can uproot itself and go seek a better environment in another part of the garden. The gardener must do that for it. The tragedy of plants, though they do not know it, is that their corseted cells could never change their shape enough to become neurons. Plants have no neurons and, in the absence of neurons, never a mind.
Independent organisms without brains also developed another important ingredient: the ability to sense changes in physiological condition, inside their own perimeter and in their surround. Even bacteria respond to sunlight as well as to countless molecules; bacteria in a petri dish will respond to the drop of a toxic substance by clumping together and recoiling from the threat. Eukaryotic cells also sensed the equivalent of touch and vibration. The changes sensed either in the interior or in the surrounding environment could lead to movement from one place to another. But in order to respond to a situation in an effective manner, the brain equivalent of single cells also has to harbor a response policy , a set of extremely simple rules according to which it makes a “decision to move” when certain conditions are met.
In brief, the minimal features that such simple organisms had to have so that they could succeed and let their genes travel on to the next generation were sensing of the organism’s interior and exterior, a response policy , and movement . Brains evolved as devices that could improve the business of sensing, deciding, and moving and run it in more and more effective and differentiated manner.
Movement was eventually refined, thanks to the development of striated muscle, the kind of muscle we use today to walk and speak. As we shall see in Chapter 3 , the sensing of the organism’s interior, what we now call interoception , expanded to detect a large number of parameters (e.g., pH, temperature, presence or absence of numerous chemical molecules, tension of smooth muscle fibers). As for sensing the exterior, it came to include smell, taste, touch and vibration, hearing, and seeing, the ensemble of which we designate as exteroception .
For movement and sensing to work to the best advantage, the response policy must be something akin to an encompassing business plan outlining implicitly the conditions that
Similar Books
