NEUROLOGICAL BASIS FOR EMOTIONAL INTELLIGENCE

Research on the mistakes of patients with brain damage who are required to make complex social judgements has thrown light on the neurological basis for emotional intelligence. Professor Antonio Damasio at the University of Iowa has studied decision-making errors of patients who suffer bilateral lesions of the ventromedial, pre-frontal cortex (Damasio, 1994; Bechara et al., 2000). The impetus for doing so came from the clinical observation that previously well-adjusted patients who suffer bilateral lesions of the ventromedial, pre-frontal cortex show no significant deterioration in IQ, but major deterioration in planning work-related activities and relationships. Their actions lead to losses including financial losses, losses in social standing and loss of friendship.

Damasio, in light of these clinical observations, has conducted a series of experiments, in which the performance on decision-making tasks of patients with these neurological lesions is compared with that of controls who have similar IQs but no brain damage.

Thus, differences in performance may be attributed to functions subserved by the ventromedial, pre-frontal cortex.

Decision making in these experiments is evaluated using a gambling task in which participants are asked to win as much play-money as they can by selecting cards from any of four decks (A, B, C and D). If they select wincards from decks A and B they get

$100 and if they select lose-cards from these decks they lose up to $350. In contrast, if they select win-cards from decks C and D they get $50 and if they select lose-cards they only lose up to $250 per card. They are not told these rules, nor are they told that they will have 100 chances to draw cards from any of the four decks. Normal control participants find out that drawing cards from decks C and D is the best strategy because, while the gains of $50 per win-card are relatively small, the losses incurred from drawing lose-cards are not great (only $250). Participants with lesions of the ventromedial, pre-frontal cortex, in contrast, typically draw most cards from decks A and B which yield relatively large gains of $100 per win-card, but these patients fail to learn that these short-term gains are offset by the very punitive long-short-term costs of losing up to $350 for lose-cards. Thus, patients with lesions of the ventromedial, pre-frontal cortex on the gambling task show a decision-making pattern similar to that shown in their day-to-day lives. They continually make decisions that lead to short-term gains without due regard for the more significant long-term losses these entail, especially in situations where exact information about long-term losses are not explicit and must be based on gut feelings or hunches.

In these gambling task experiments, the magnitude of skin conductance responses (SCR) prior to drawing cards—an index of anticipatory physiological arousal or ‘gut feelings’—was measured. Normal participants produced more anticipatory SCRs as the experiment progressed. They also produced larger SCRs when drawing cards from the risky decks—A and B—than from the safer decks—C and D. Thus, as normal subjects

became more experienced with the four decks in the experiment, their ‘gut feelings’

informed their decision making and they avoided the risky decks A and B. In contrast, patients with lesions of the ventromedial, pre-frontal cortex did not generate anticipatory SCRs and so their decision making was not informed by ‘gut feelings’. These results show that effective decision making is guided by anticipatory emotional responses in complex situations where explicit information about risky outcomes is not available.

To determine whether these ‘gut feelings’ inform decision making only when people are fully aware of them, in one gambling task study, after every 10 card-draws, participants were asked to state their beliefs about the costs and benefits of drawing cards from each of the 4 decks. The results of this study showed that even before normal participants became consciously aware that decks A and B were riskier, they showed greater anticipatory SCRs when drawing from these decks and then greater preference for the safer decks C and D. In contrast, even when patients with lesions of the ventromedial pre-frontal cortex were fully aware that decks A and B were riskier, they showed no anticipatory SCRs and continued to show a preference for drawing from these decks.

These results show that in complex situations effective decision making is guided by anticipatory emotional responses of which the person is not conscious.

Damasio (1994) has shown that the ventromedial, pre-frontal cortex is part of a neural network involving neural projections from the sensory sense organs; the amygdala; and the somatosensory and insular cortices. In a series of studies Damasio and his team compared the responses of three groups of patients each with different brain lesions to identify the effects of: (1) bilateral lesions of the ventromedial, pre-frontal cortex; (2) bilateral lesions of the amygdala; and (3) lesions of the right somatosensory/insular cortices. He found that damage to all three centres resulted in failure to generate anticipatory SCRs and failure to learn how to make safe decisions on the gambling task.

Bilateral lesions of the amygdala and lesions of the right somatosensory/insular cortices led to errors in judging the intensity of emotions conveyed by facial expression. Only patients with bilateral lesions of the amygdala failed to develop a conditioned emotional response (SCRs) when a blue screen (UCS) was presented alone after repeated pairing with a startling sound (UCS). Only patients with lesions of the right somatosensory/

insular cortices failed to re-experience emotions when thinking about memories of happy, sad, frightening or anger-provoking situations.

From these results it may tentatively be concluded that decision-making impairment arising from damage to the amygdala may be due to an impaired ability for developing conditioned emotional responses which inform us about the emotional significance of stimuli. Decision-making impairment arising from damage to the right somatosensory/insular cortices may arise from failure to remember emotions associated with particular events. Decision-making impairment arising from damage to ventromedial, pre-frontal cortex may be due to failure to inhibit responses that the person knows they should inhibit. Thus they have difficulty with higher-order conditioning where the contingency is remote and/or symbolic.

It seems that emotional intelligence requires the efficient functioning of the neural network involving the amygdala, the right somatosensory/insular cortices and the ventromedial, pre-frontal cortex.

Formative experiences and trauma may compromise the efficiency with which this neural network operates. Joseph LeDoux (1996) has produced evidence that the amygdala

can operate independently of the pre-frontal cortex, and memories of the emotional significance of events stored in the amygdala can guide decision making without involvement of the pre-frontal cortex. Rats in whom the auditory cortex was ablated learned to fear a tone (CS) that was previously paired with an electric shock (UCS).

LeDoux (1996) argues that while factual memory is subserved by the hippocampus, memory of the emotional significance of events is subserved by the amygdala. The hippocampus allows us to remember where the university exam hall is, but the amygdala permits us to remember how anxiety-provoking exams can be. In emergency situations or under stress, our perception and reactions are governed not by the hippocampus but by the amygdala.

From an evolutionary viewpoint, the lower sections of the human brain, in the brainstem, are structurally like that of phylogenetically earlier species such as reptiles;

the next layer of the brain—the limbic system—is like that of early mammals; the next layer—the thin mammalian cortex—is like the brain of higher mammals; and the highest layer of the brain—the huge neocortex—is uniquely human. The amygdala is part of the limbic system and when we react to emergency situations or cues that remind us of previous emotionally intense events we are reacting like early mammals. The ventromedial pre-frontal cortex is part of the uniquely human part of the brain. It is this structure that allows us to deal in a measured way with emotional situations.

There are pros and cons to the fact that in emergencies or when reminded of past intense emotional experiences our rational brain is bypassed and we react like evolutionarily more primitive mammals. On the positive side, subtle signals in new situations remind the amygdala of past emergencies that involved similar signals and trigger intense emotional memories and rapid reactions without involving the pre-frontal cortex or consciousness in this, thus protecting us from harm. For example, the flicker of sunlight on the windscreen of a car on the very edge of the visual field can trigger a person to quickly step backwards onto the pavement to avoid being hit by a car without having to first weigh up the costs and benefits of doing so. On the negative side, some of the memories stored in the amygdala may trigger intense rapid emotional reactions that are completely inappropriate. For example, a young father told me that the first time he smelled his wife’s breast milk he felt an inexplicably intense rage. He was unable to trace the memory of this but later found out from his older sibling that his breast feeding as a child had stopped abruptly due to his mother’s illness and he subsequently had difficulty taking to a bottle or to being bottle-fed with expressed breast milk. The young husband’s intense experience of rage made no sense in terms of his very positive relationship with his wife and his devotion to his child. However, his amygdala had encoded a memory of the smell of breast milk being associated with his mother’s disappearance, replacement of her breast with a bottle that smelled like her breast milk, and with an intense experience of rage. This emotional memory, because of its great emotional significance, was triggered without the involvement of the pre-frontal cortex. People with high levels of emotional intelligence are probably aware of the possibility of these types of reactions and can predict them in themselves and others, avoid them, or modify them. In psychotherapy people learn to recognise and modify these types of reactions. However, direct research on the neurological correlates of people with high and low levels of emotional intelligence has not yet been done so that this hypothesis awaits testing.