When Professor Ramachandran introduces the curious Capgras delusion, in which the sufferer believes that close family members are impostors, he highlights how emotion reaches into parts of our brain processing that we may never have imagined previously.
It is assumed that for such patients, although facial recognition is intact, a parallel system for registering the emotional meaning of the face had been damaged.
In fact, when patients are tested for the tell-tale physiological signals of emotions, such as slight changes in sweating detected by measuring skin resistance, these are found to be absent.
This emotional response would normally occur for any of us when viewing faces showing emotional expressions, or faces of those we know well. Without them there is no emotional resonance, no sense of affiliation.
In the Capgras delusion this absence of emotion is interpreted by the sufferer as evidence that this could not be someone close, despite the visual system contradicting this.
It is significant that this conflict between the emotional and visual systems is resolved in favour of emotions rather than vision: feeling, rather than seeing, is believing. It seems that without emotion the familiar face is dismissed as an impostor.
Darwin on emotions
It is widely acknowledged that much scientific progress is achieved by standing on the shoulders of the (scientific) giants that have come before us. So what did that true giant in evolutionary thinking, Charles Darwin, have to say about emotions?
In his book ‘The expression of the emotions in man and animals’ (1872), Darwin (unsurprisingly) proposed that emotions and emotional expressions had become refined through natural selection and were therefore an advantage for our ancestors.
However, he considered that emotions in (adult) humans were no longer very functional, we show expressions ‘though they may not ….. be of the least use’.
For Darwin then, human emotions were somewhat akin to other vestigial organs or parts of the body, such as the appendix in the digestive system, a non-functional evolutionary hang over from times when they did have utility. This dismissal of emotions merely continued the tradition.
Emotions as impediments
At least since Plato (375 BC), many Western thinkers have viewed emotions as impediments to rational thinking, as signs of immaturity or weakness, best set aside by upright, virtuous (and especially male) citizens. ]
With this bad press, until recently, emotions have thus been afforded low priority for study, much less important than mental functions like perception, language, thinking, and learning. Giants’ shoulders have diverted attention away from recognising what was under our very noses; emotion impacts on almost all our brain processes.
Perhaps one of the contributing factors in its previous demise is that emotion is notoriously hard to define. This could be due, in part, to its many different facets.
Emotion includes private internal feelings (conscious awareness), observable behaviours (including facial expressions and so-called ‘body language’), and physiological responses.
Interest in emotion research has increased dramatically in the last 20 years, and once again scientists seek evolutionary functions for emotion.
Emotions as a response to changing circumstances
Researchers such as Oatley and Johnson-Laird (1987) suggest that the role of emotion is to signal that some ongoing behaviour should be interrupted to take account of a conflicting goal. They argue that animals, including humans, necessarily have many different motivations and goals.
Once a particular plan of action has been started it would normally be the best option to continue it to completion. However, things change, creating new, perhaps conflicting, goals.
They suggest that it is the emotional response to the new event that interrupts on-going behaviour to take account of the current situation.
For example, giving up the goal (temporarily) of planting next summer’s food crop in favour of running to greet a returning hunting party, or to escape from an attacking lion.
Sadness during bereavement, in their framework, is not a maladaptive waste of time, but is seen as having the function of initiating readjustment of the life goals that included the lost person.
Interrupting on-going behaviour makes good sense in the context of the so-called ‘fight or flight’ reactions.
The importance of speed in reaction to imminent danger has such unambiguous evolutionary advantages that it is well developed in all vertebrates.
Complex and intricate physiological changes take place throughout the body to maximise resources available for its success.
Being startled: a rapid response
Emotion researcher, Joseph Le Doux has also identified brain pathways capable of generating such a rapid response. He describes brain circuits that provide either a ‘quick and dirty’ or a slow and (more) reasoned route.
All information is processed by the cortex where emotional responses can be mobilised, but stimulation from the senses that is either very well learned or instinctive can also pass directly to the emotional centres of the brain after the crude analysis that this route achieves.
Via this evolutionary ancient rapid route, a startle reaction can be initiated within thousandths of a second if there is a sudden frightening event.
When speed is of the essence, conscious decision-making and control are too slow to be of help. When you escape you’ll react well before being aware of the danger. The slower, cortical, brain routes allow conscious appraisal which can allow us to modify or override the initial response.
Why do we show emotions?
One function of emotions perhaps serves to direct or redirect goals, and achieve rapid responses in emergency but what advantage is there to emotional expressions? Why wear the face of fear?
The universality of emotion expressions has been much explored since Darwin himself began a pioneering cross-cultural work. Cultures have their own display rules; tears and crying might be common at a funeral in one culture, but another may find polite smiles appropriate.
However, the expressions themselves are understood world wide, functioning to communicate emotions across all language barriers. Expressions and body language communicate how we are feeling to others: an angry warning perhaps or a welcoming smile.
An enduring theme of the 2003 series of Reith Lectures is the challenge of consciousness in the brain.
The evolutionarily ancient brain structures that serve many emotional responses operate outside conscious awareness, as we saw with the ‘quick and dirty’ route of Le Doux.
Why do we need to feel emotions at all?
Let’s consider how other animals manage.
A fish can successfully flee from noxious stimulation, and is attracted towards something that is food. It shows behaviour sequences that could be called emotional but most would assume that conscious awareness or feelings of emotion are absent.
If complex sequences of emotional behaviour are possible without emotional feeling then what is the function of feelings for humans? The answer to the question ‘Why feel emotions?’ may be partly answered by understanding ‘What is the function of conscious awareness?
Peter Naish, in Consciousness and Hypnosis speculates about how consciousness allows us to imagine and pose ‘What if?’ questions, reliving past experiences, considering alternative actions and outcomes and generating options for the future.
The role of imagination
There is little purpose to imagination without the ability to make choices. Feeling emotion and imagining feeling emotion sharpen up the decision making.
Once emotional feeling is experienced in oneself, of course, the imagination can attribute it to other possible players in our life. Reflecting on possible ‘What if’ courses of action so often includes speculating on others’ possible reactions. ‘If I do this, will he like it and do that ... or if I threaten with a knife will she be frightened and run away?’
Complex social interactions and diplomacy surely depends on second guessing the emotional consequences of our actions on others. Feeling emotion may both help us to imagine, plan and remember our own actions and to include feelings of others as we plan interactions with them.
Art and emotion
Imagine an imagination without emotional feeling. You read a book, watch a film, or listen to music. It is hard, perhaps even impossible, not to feel emotions along with players in the plot or feel moved by good music.
In his fourth lecture, Ramachandran explores how the brain responds in particular ways to art and that the artist needs to tap into this style of responding to optimise effects.
Understanding how the brain responds to art exploits circuitry used in the brain to perceive the world or understand language, but the essence of the artistic response must include emotion to carry its effect.
In this Reith Lecture series, Prof Ramachandran conveys the interest and excitement that rapid strides in psychology and neuroscience are bringing.
It is intriguing to find how, as in the Capgras delusion, emotion may be fundamental to brain processes where it was previously thought to be irrelevant.
In addition, the importance of emotion in considering the big question of consciousness shows just how far we have come since our capacity for emotion was thought to be a sign of weakness and an immature, irrelevant impediment to rational and logical thinking.