Emotion and personality

Phineas Gage

Some weeks ago I attended the last Advanced Research Seminar of the Leadership Development Research Centre (GLEAD) at ESADE. The issue presented was the Antonio Damasio’s Somatic Marker Hypotheses (SMH). The presentation started with the well known case of Phineas Gage

I was intrigued by the story so I began to read about reaching to some interesting points.

Phineas Gage is probably the most famous case of a person who has survived severe damage to the brain. On September 13, 1848, he was working on the construction of the railroad outside the town of Cavendish, Vermont. He was using a tamping iron to compact the sand that covered explosives put into the holes made on the rocks. Perhaps because the sand was forgotten he provoked an explosion that projected the instrument through his head entering on the side of his face, passing back of the left eye, and going out at the top of the head through the frontal lobe (See video).

Phineas not only survived to the accident but also from the beginning he seemed to maintain intact his intellectual capabilities and no feel pain. He recovered both mentally and physically but his personality was changed. His character became irregular, irreverent and rude, showing little respect for their fellow human beings. Also he had become impatient and stubborn, but capricious and hesitant at once.

Linking emotions, personality, and areas of the brain:

  • The mentioned Somatic Marker Hypothesis of Damasio is argued under the assumption that somatic markers provide a signal delineating which current events have had emotion-related consequences in the past. As a consequence they guide the decision making process in complex and unpredictable environments. It belongs to the field of the Affective Neuroscience, a discipline concern with the underlying neural substrates of emotion and mood. In this area, the Limbic System is one of the anatomic models more broadly supported. It was proposed by Paul McLean in 1949 and even though it has been criticized on both empirical and theoretical grounds, remains the dominant conceptualization of the “emotional brain” today. MacLean viewed the brain as a triune architecture consisting of three interacting systems. The reptilian brain, the most ancient and responsible of primitive emotions such as aggression and fear. The “old” mammalian brain which elaborates the social emotions. And the “new” mammalian brain or neocortex, which represents the interface of emotion with cognition and is the seat of top-down control over emotional responses originating within other systems (Dalgleish, Dunn, and Mobbs 2009).
  • Cases as the Phineas Gage where the ventromedial region of the frontal lobe is damaged show that even though the intellectual capabilities remain there are consequences that produce emotional inability and inappropriate social behaviour.
    There is an interdisciplinary field of research between the Affective Neuroscience and Social Psychology called Social Affective Neuroscience that seeks to understand phenomena in terms of interactions between three levels of analysis: the social level which is concerned with the motivational and social factors that influence behaviour and experience; the cognitive level, which is concerned to with the information-processing mechanisms; and the neural level, which is concerned with the brain mechanisms (Ochsner and Lieberman 2001).
  • Following the present line of arguments we have to differentiate between emotions and feelings, being the first, body states related to non rational processes generated in the subcortical structures. They would be basic mechanisms that respond to stimulus in an innate way. The feelings will relate the emotion with the object that excites it gaining consciousness of the emotion through rational processes at cortical level. Thus we have primary emotions, innate and preorganiced, that depends of the limbic system and secondary emotions which occur once we begin experiencing feelings and forming systematic connections between categories of objects and situations, on one hand, and primary emotions, on the other (Damasio 2006).
  • At this point we should distinguish between the basic emotions and those nonbasic emotions built using the first as if they were building blocks. Even though there is the assumption that there exist a small set of basic emotions, theorists disagree on how many or which they are. Nevertheless nearly everybody includes anger, happiness, sadness and fear (Ortony and Turner 1990).

Finally we see why Phineas Gage despite having recovered physically was never the same again. The damage caused prevented him basic emotions needed to evaluate daily situations and to relate with others. The personality changed forever.

 

References

Dalgleish, Tim, Barnaby D. Dunn, and Dean Mobbs. 2009. «Affective Neuroscience: Past, Present, and Future». Emotion Review 1(4): 355-368.

Damasio, Antonio. 2006. Descartes’ error : emotion, reason and the human brain. London: Vintage.

Ochsner, Kevin N., and Matthew D. Lieberman. 2001. «The emergence of social cognitive neuroscience.» American Psychologist 56(9): 717-734.

Ortony, Andrew, and Terence J. Turner. 1990. «What’s basic about basic emotions». Psychological Review 97(3): 315-331.