Antonio Damasio is a neuroscientist who famously argues for the importance of emotions in the brain's decision making process. Damasio and his wife Hannah used modern brain imaging techniques to locate the parts of the brain that are active when a subject reports feelings like anxiety, fear, aggression, and other emotions.

They found that the brain region activated is in the lower middle (ventromedial) part of the prefrontal cortex (VMPFC). This region has numerous neuronal connections to the limbic region of the brain in the insular cortex, particularly the amygdala and hippocampus below.. There are two amygdalae, one in each cerebral hemisphere and they may have different specializations.

When these brain regions are damaged, a person's ability to make intelligent and responsible decisions is compromised despite their continued ability to think clearly and logically about matters of fact. Damasio finds that they have lost access to emotions that should inform their reasoning and decisions.

For Damasio, René Descartes' mind model epitomizes the neglect of emotions (or passions) in his ideal of a rational mind and a rationalist philosophy. Descartes is rightly recognized as the first modern philosopher, who based philosophy on the power of reason. He was the first of three continental philosophers, along with Baruch Spinoza and Gottfried Leibniz, who are called rationalist to contrast with three British philosophers called empiricist, John Locke, George Berkeley, and David Hume, who emphasized observations and experiments as the primary source for understanding the nature of reality. [Francis Bacon is mentioned less frequently, but many consider Bacon the "father of empiricism."]

Damasio focuses in on Descartes' most famous statement, "Cogito, Ergo Sum."

Descartes is rejoic­ing with the discovery of a proposition so undeniably true that no amount of skepticism will shake it:

. . . and remarking that this truth “I think, therefore lam ’’was so certain and so assured that all the most extravagant supposi­tions brought forward by the sceptics were incapable of shaking it, I came to the conclusion that I would receive it without scruple as the first principle of the Philosophy for which I was seeking.

Here Descartes was after a logical foundation for his philosophy, and the statement was not unlike Augustine’s "Fallor ergo sum" (I am deceived therefore I am). But just a few lines below, Descartes clarifies the statement unequivocally:

From that I knew that I was a substance, the whole essence or nature of which is to think, and that for its existence there is no need of any place, nor does it depend on any material thing; so that this “me,” that is to say, the soul by which I am what I am, is entirely distinct from body, and is even more easy to know than is the latter; and even if body were not, the soul would not cease to be what it is.

This is Descartes’ error: the abyssal separation between body and mind, between the sizable, dimensioned, mechanically operated, infinitely divisible body stuff, on the one hand, and the unsizable, undimensioned, un-pushpullable, nondivisible mind stuff; the sug­gestion that reasoning, and moral judgment, and the suffering that comes from physical pain or emotional upheaval might exist sepa­rately from the body. Specifically: the separation of the most refined operations of mind from the structure and operation of a biological organism.

Descartes' Error, pp.248-250

Of course most philosophers know well that David Hume had completely reversed Descartes' priority of reason, saying that reason alone can never be a motive to any action of the will; and secondly, that it can never oppose passion in the direction of the will. For Hume, reason should be the "slave" of passion.

Damasio may not go that far, but he is correct that emotions, desires, play a major role in our free decisions, as they do in our two-stage Cogito model.

As a neuroscientist, Damasio hopes to locate the emotions in the brain, just as others hope to locate the site of our memories and our knowledge.

For several years Damasio has been developing his concept of "somatic markers," presumably stored in the prefrontal cortex.

What does the somatic marker achieve? It forces attention on the negative outcome to which a given action may lead, and functions as an automated alarm signal which says: Beware of danger ahead if you choose the option which leads to this outcome. The signal may lead you to reject, immediately, the negative course of action and thus make you choose among other alternatives. The automated signal protects you against future losses, without further ado, and then allows you to choose from among fewer alternatives. There is still room for using a cost/benefit analysis and proper deductive compe­tence, but only after the automated step drastically reduces the number of options. Somatic markers may not be sufficient for nor­mal human decision-making since a subsequent process of reason­ ing and final selection will still take place in many though not all instances. Somatic markers probably increase the accuracy and efficiency of the decision process. Their absence reduces them. This distinction is important and can easily be missed. The hypothesis does not concern the reasoning steps which follow the action of the somatic marker. In short, somatic markers are a special instance of feelings generated from secondary emotions. Those emotions and feelings have been connected, by learning, to predicted future out­ comes of certain scenarios. When a negative somatic marker is jux­taposed to a particular future outcome the combination functions as an alarm bell. When a positive somatic marker is juxtaposed instead, it becomes a beacon of incentive.

Descartes' Error, pp.173-174

Damasio says his hypothesis is grounded in principles of evolution, homeostatic self-regulation, and the brain as part of a biological organism, but he gives us little information on what markers are in neurobiological terms. He adds little to his hypothesis in his later books. In the 1999 The Feeling of What Happens he says that his patients with neurological damage in regions (like the amygdala) which regulate emotions have lost their ability to make value judgments, even though they can still reason properly about matters of fact.

This hypothesis is known as the somatic-marker hypothesis, and the patients who led me to propose it had damage to selected areas in the prefrontal region, especially in the ventral and medial sectors, and in the right parietal regions. Whether because of a stroke or head injury or a tumor which required surgical resection, damage in those regions was consistently associated with...a disturbance of the ability to decide advanta­geously in situations involving risk and conflict and a selective reduc­tion of the ability to resonate emotionally in precisely those same situations, while preserving the remainder of their emotional abilities.

The Feeling of What Happens, p.41

And in his 2010 Self Comes to Mind, Damasio's "markers" have been those "feelings" that separate the things that constitute the self from those that do not. He still gives us no specific location nor any neurobiological mechanism for a marker. Now they are just feelings that "accomplish a distinction between self and nonself."

Damasio here also claims that the "degree of emotion" in the markers indicate the "relative importance" (value?) in things...

The degree of emotion serves as a “marker” for the relative importance of the image. This is the mechanism described in the “somatic marker hypothesis.” The somatic marker does not need to be a fully formed emotion, overtly experienced as a feeling. (That is what a “gut feeling” is.) It can be a covert, emotion-related signal of which the subject is not aware, in which case we refer to it as a bias. The notion of somatic markers is applicable not just to high levels of cogni­tion but to those earlier stages of evolution. The somatic marker hypothesis offers a mechanism for how brains would execute a value-based selection of images and how that selection would translate in edited continuities of images. In other words, the principle for the selection of images was connected to life-management needs. I suspect the same principle presided over the design of primordial narrative structures, which involved the organism’s body, its status, its interac­tions, and its wanderings in the environment.

Self Comes to Mind, p.175

We can assign values not only to images, but to all past experiences, by recalling (reproducing) the emotions that accompanied past experiences. If each experience records the emotions felt during a past experience, the emotions will be reproduced when new experiences resemble some from the past. Past experiences provide context, meaning, and value to the new. These fit the description of what Damasio describes as "gut feelings" that help brains "execute a value-based transaction," namely decisions between alternative possibilities.

Donald Hebb said "neurons that fire together wire together." Our Experience Recorder and Reproducer model of the mind says that "neurons that have been wired together will fire together" when new experiences cause just some of those neurons to fire again, because of its resemblance to the past experience.

Descartes' Error: Emotion, Reason, and the Human Brain, Putnam, 1994
The Feeling of What Happens: Body and Emotion in the Making of Consciousness, 1999
Looking for Spinoza: Joy, Sorrow, and the Feeling Brain, 2003
Self Comes to Mind: Constructing the Conscious Brain, 2010
The Strange Order of Things: Life, Feeling, and the Making of Cultures, 2018. Normal | Teacher | Scholar