Damasio


 * //Descartes’ Error// by Antonio Damasio**
 * (These people have better synopses than I.)**

“Since Descartes famously proclaimed, I think, therefore I am, science has often overlooked emotions as the source of a person's true being. Even modern neuroscience has tended, until recently, to concentrate on the cognitive aspects of brain function, disregarding emotions. This attitude began to change with the publication of //Descartes' Error// in 1995. Antonio Damasio— one of the world's leading neurologists (//The New York Times//)—challenged traditional ideas about the connection between emotions and rationality. In this wondrously engaging book, Damasio takes the reader on a journey of scientific discovery through a series of case studies, demonstrating what many of us have long suspected: emotions are not a luxury, they are essential to rational thinking and to normal social behavior.” (Publisher’s synopsis)

“In an important, gracefully written exploration of the neurochemical basis of mind, neurologist Damasio rejects the Cartesian notion of the human mind as a thinking organ more or less separate from bodily processes. Emotions and feelings, he argues, are essential to reasoning and decision-making. The human brain, he further contends, has a specialized region in the frontal lobes for making personal and social decisions, and this region works in concert with deeper brain centers that store emotional memories. To support this controversial claim, Damasio draws on his work with brain-injured patients at the University of Iowa College of Medicine, and also cites the case of Phineas Gage, a Vermont railway foreman who lost his ethical faculties after an explosion in 1848 drove a metal rod through his skull. Damasio's exciting investigation challenges the fashionable metaphor of the mind as a software program.” (Publishers Weekly)

Dolores' notes:

“Contrary to traditional scientific opinion, feelings are just as cognitive as other percepts.” P. xix

Evidence of emotion as cognitive are patients who have trouble feeling also have trouble to organize and plan, creativity, act politely naturally, and finding interest in life. “One way of describing their predicament is by saying that they never construct an appropriate theory about their persons, or their person’s social role in the perspective of past and future. And what they cannot construct for themselves, they also cannot generate for others.” P. 58

Memory is tied to emotion. For more details about the amygdale: pages 133-134.

“ [there are views]…that emotions and feelings arise in the brain’s down-under, in as subcortical as a subcortical process can be, while the stuff that those emotions and feeling qualify arises in the neo-cortex. I cannot endorse these views.” P. 159 Traditional science and general opinion is that feelings are from the base and simple parts of the brain. Damasio does not agree.

“First, it is apparent that emotion is played out under the control of both subcortical and neocortical structures. Second, and perhaps more important//, feelings are just as cognitive as any other perceptual image,// and just as dependent on cerebral-cortex processing as any other image.” P. 159

“…[feelings] come first in development and retain a primacy that subtly pervades our mental life.”p. 159

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The key to this book is the Somatic Marker Hypothesis. The brain stores "templates" of past experiences associates with pain or pleasure states. Somatic markers are essentially emotional valences that are assigned to a given situation on the basis of those templates. The prefrontal cortex directs this process. Damasio explains how this is related to decision-making, intuition, response inhibition, and motivation. ===== Executive Functions: Command our actions and integrate our attention with short and long term goals. CEO of this executive function is the frontal lobe. Patients with damage to frontal lobe have tremendous difficulty sustaining focus and blocking irrelevant stimuli. As a result, they may not pay close attention to much of anything, leading to marked decrease in concern for social appropriateness or complete disinhibition.

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Patients with ventromedial frontal lobe damage failed to evoke part of the composite memory for a class of situation—the part of the situation that describes the association between the class of situation and the somatosensory state linked to it. The factual knowledge component can still be evoked, but somatic states cannot be re-enacted, overtly or covertly, relative to those facts. ===== The turning of any card decks A and B require a high payment. Certain cards in C and D require a payment, but sums are much smaller. Player doesn’t know # of trials. Much as in life, much of the knowledge by which we live & by which we construct our adaptive future is doled out bit by bit. “Normals” begin by sampling all 4 decks in search of patterns and clues. They show an early preference for A and B, but gradually they switch to preference for C and D. They can INHIBIT for the larger reward because they intuit the smaller reward will make them come out ahead in long run. People with frontal lobe damage have an opposite pattern. After general sampling, patients systematically turned more and more from the A and B decks. Half way through they were often bankrupt and needed another loan from the examiner. Intellectually, they fully understood the task, as well as the biases of the decks. Affective element missing: Planning for future action no longer in tact. Perhaps: the images that constitute a future scenario are weak and unstable. The images would be activated but somehow not hold long enough in consciousness to play a role in the appropriate reasoning strategy. In other words, the working memory and/or attention are not functioning well as far as images about future are concerned. Somatic markers boost working memory and say: “Pay attention to me!”
 * Developed the Iowa Gambling Task to examine the Somatic Marker Hypothesis: **

In further test—continuous monitoring of the SCRS while normal subjects and patients did the Gambling Task. In normal subjects—during the time window that precedes the selection of a card from a given deck, normal subjects begin to respond with high-amplitude skin conductance whenever they were about to make a selection from a BAD deck. As the task goes on, SCRS to bad decks continue to appear & rise in amplitude. No such anticipatory responses were seen in the patients with frontal lobe damage….But they did show normal SCRS to actual loss of money on the task. -Part of a very early automated alarm signal—perhaps triggered from ventromedial region. “The signal affects further processing of the factual knowledge connected with the situation by marking a particular option-outcome pair with a negative bias.” -Normal subjects begin producing SCRs to bad decks long before they have conscious awareness of the good or bad nature of the decks.



-When the bad outcome connected with a given response option comes into mind you experience an unpleasant gut feeling—a somatic state “marker” -What does the somatic marker do? Forces attention on the negative outcome to which a given action may lead. “automated alarm signal”—beware of the danger/outcome associated with this action. “Somatic markers are a special instance of feelings generated from secondary emotions. Those emotions and feelings have been connected, by learning, to predicted future outcomes of certain scenarios.” -Automated qualification of predictions -effective personal and social behavior requires individuals to form adequate “theories” of their own minds and of the minds of others. (Theory of Mind) -Somatic markers assist the process of sifting through detail -What is the origin of somatic markers? -Primary emotions -somatic markers are acquired by experience -survival mechanism—functionally balanced biological states—homeostasis/avoid pain/seek pleasure -Neural network for somatic markers is the prefrontal cortices—receive signals from all the sensory regions in which the images constituting our thoughts are formed, including the somatosensory cortices in which past and current body states are represented continuously -revceive signals from several bioregulatory secotrs of the brain.—this is all conveyed to prefrontal cortices and this is the reasoning and decision-making apparatus. -categorizations of situations and classifications of contingencies in our real-life experiences Directly connected to every avenue of motor and chemical response available to the brain. -Somatic markers can operate covertly (outside consciousness) -explicit imagery related to negative outcome would be generated but instead of producing a perceptible bodystate change, it would inhibit the regulatory neural circuits located in the brain core which mediate approach behaviors. -With inhibition of the tendency to act, chances of potentially negative decisions would be reduced (Motivation). -This covert mechanism is the source of intuition.

Another article that summarizes the Somatic Marker Hypothesis nicely: ** Damasio, A. (1996). The somatic marker hypothesis and the possible functions of the prefrontal cortex. **

-Compromised ability to express emotion in patients. Assumptions: * Reasoning and decision making depend on many levels of neurobiological operation. Some occur in the mind and some do not. * All mind operations depend on support processes such as attention and working memory * Reasoning and decision making depend on the availability of knowledge about situations, actions, options for action and outcomes. Such knowledge is stored in implicit/coded manner. This type of knowledge can be made explicit in a) motor responses of varying types and complexity and b) images * Knowledge can be classified: a) innate and acquired knowledge concerning bioregulatory processes and body states & actions including those which are made explicit as emotions b) knowledge about entities, facts, actions, and action-complexes and stories which are usually made explicit as images. c) knowledge about the linkages between B items and A items—reflected in individual experience d) Knowledge resulting from categorization of ABC Nature of the Marker -“Why should somatic signals be so critical to the process of reasoning and decision making?” -certain classes of situation- those that have personal/social matters are frequently linked to punishment and reward and thus to pain, pleasure, and the regulation of homeostatic states (including the part of the regulation that is expressed by emotion and feeling). -“One may also ask why a signal external to the representations over which one reasons is needed at all. The answer, as suggested above, has to do with the uncertainty of outcomes, the dimension of the logical operations required by deciding under certainty, and the advantage of constraining the decision-making space.” -Survival behavior explains the possible origin—brain has means to select good response from bad ones in terms of survival. Mechanism has been co-opted for behavioral guidance outside the realm of basic survival. The somatic markers could act to highlight in the form of an attentional mechanism certain components over others and to direct decision making. Fact memories—implicit in association cortices Body state memories—memory of the linkage between certain classes of situation and certain body states