Somatic marker hypothesis
The hypothesis of the somatic marker (also somatic marker hypothesis , English : somatic marker hypothesis , SMH for short ; from the Greek soma for body) is a theory of neurobiology about human decision-making behavior . According to the SMH, emotional experiences are embodied in people and thus influence decisions. The SMH was formulated by António Damásio . Somatic markers are located in the ventromedial prefrontal cortex (PFC).
Concept history
The origin of the hypothesis of the somatic markers is the observation of patients whose frontal lobes were caused by an accident or the like. was harmed. Those affected by such a lesion often show a fundamental change in behavior - with unchanged intelligence .
The case of Phineas Gage is famous , whose head injury in the 19th century turned a friendly fellow man into an impatient and easily irritable person. Towards the end of the 20th century, António Damásio reported in a scientific publication about a patient in whose ventromedial prefrontal cortex a tumor was discovered and then removed. The person - 35 years old, intelligent, and with a functioning social environment - developed difficulties in making decisions. Everyday situations, such as the choice of clothes or a restaurant, were dealt with with great difficulty, although each option could be described correctly. Intelligence and neurophysiological examinations continued to confirm the intelligence of the patient, who, however, could no longer dispose of the implicit meaning and so had to fall back on a more complex examination.
António Damásio deduced from this that in the injured ventromedial prefrontal cortex “somatic markers” that would otherwise be activated during decisions could no longer be accessed. These "somatic markers" arise from experiences already acquired, which physically "mark" alternatives and consequences of an action - afflicted with a positive or negative emotion.
"I propose that the ventromedial prefrontal cortex establishes a simple linkage, a memory in fact, between the disposition for a certain aspect of a situation [...] and the disposition for the type of emotion that in past experience has been associated with the situation. "
"I contend that the ventromedial prefrontal cortex creates a simple link, rather a memory, between the disposition of a particular aspect of a situation and the disposition for a type of emotion in the past that is associated with the situation ."
The evolutionary advantage of a decision with the support of or through the somatic markers is the significantly higher speed with which considerations are made on the basis of already existing experience - by means of a labor-intensive analysis , as in the case outlined above, which uses many cognitive resources (such as attention or working memory ), heterogeneous information would be available for decision-making much later.
Somatic markers
According to Damásio, a distinction must be made between emotions and feelings . Emotions represent changes in the brain or body and can be divided into primary and secondary emotions. Primary are emotions that “ can be triggered subcortically by fixed, innate stimulus situations” (these are described in the James Lange theory ). These associations can be found in the ventromedial prefrontal cortex (VMPFC).
Secondary are emotions that are based on experience and - depending on the conditioning - are related to the primary emotions.
Feelings are the perception of these changes.
How the somatic markers work
Analogous to knowledge and emotions, somatic markers can be innate or acquired.
Basically, after associations are made in the VMPFC, activities are triggered in the amygdala or ventral insula , which causes activity in the hypothalamus , in the girdle of the limbic system and in the brain stem .
Primary and Secondary Triggers
Stimuli that immediately cause pleasant or unpleasant physical states are among the primary triggers (inducers) . Examples are the positive reactions to the receipt of money or a good rating compared to the loss of goods, for example. Secondary triggers, which relate to the stimuli of the primary trigger, are distinguished from this. These ideas , thoughts or memories of such a trigger themselves produced a corresponding reaction.
"Body loop" and "As if body loop"
The effect of the somatic markers can take place in two different ways, in the "body-loop" (body loop) and in the "as-if-body-loop" (as-if body loop) .
In the body loop , changes in the physiology of the human body that have been linked to an emotion in the course of human development are processed directly into a reaction. In the as if body-loop , the physical changes are "constructed" by the brain and then trigger the reaction.
Verification
For empirical verification of the SMH, there are various methods. The Iowa Gambling Task is widely cited by Antoine Bechara , António & Hanna Damásio and Steven Anderson. In addition, the SMH was confirmed by studies with functional magnetic resonance imaging and other experimental concepts.
See also
literature
- António R. Damásio: Descartes' error - feeling, thinking and the human brain , List-Verlag , Munich 1994, ISBN 3-471-77342-8 .
Web links
- Barnaby D. Dunn, Tim Dalgleish, Andrew D. Lawrence The somatic marker hypothesis: A critical evaluation
- Ulf Hlobil: A Theoretical Critique of Antonio Damasio's Somatic Marker Hypothesis
- Emotions Create Our Preferences: The Somatic Marker Hypothesis
Remarks
- ^ According to Peter Kenning's "Consumer Neuroscience", AR Damasio, D. Tranel, H. Damasio: Individuals with sociopathic behavior caused by frontal damage fail to respond autonomically to social stimuli. (In: Behavioral brain research. Volume 41, Number 2, December 1990, pp. 81-94, PMID 2288668. ) “Manifest” distinguished from “implicit” meaning.
Individual evidence
- ↑ a b Peter Kenning : Consumer Neuroscience - a transdisciplinary textbook , Kohlhammer Verlag , Stuttgart 2014, ISBN 978-3-17-020727-1 .
- ↑ a b c Ulf Hlobil: A theoretical critique of Antonio Damasio's somatic marker hypothesis , Master's thesis , September 14, 2008.
- ^ BD Dunn, T. Dalgleish, AD Lawrence: The somatic marker hypothesis: a critical evaluation. In: Neuroscience and biobehavioral reviews. Volume 30, number 2, 2006, pp. 239-271, doi : 10.1016 / j.neubiorev.2005.07.001 , PMID 16197997 (review). Retrieved January 31, 2016.