The Functional Anatomy of Empathy
The main difficulty in understanding emapthy from a neuropsychological perspective is that it is a rather wooley concept, incorporating behaviours and cognitions, metacognitions and emotions. Essentially psychologists will define empathy as the ability for animals to recognise and act accordingly to the emotional state and perspective of others. The following summary of involved brain structures is, out of necessity, unfortunately bastardised. The amygdala is the most obvious place to start. The amygdala is located deep within the medial temporal lobes. It is in close proximity to limbic structures dealing with emotional related matters. Abnormality in the amygdala has been found in a number of clinical presentations, including autism, psychopathy, bipolar disorder and other mood disorders. Functionally the amygdala is involved in emotional learning, embuing memories with emotional significance and moderating their consolidation. It is also thought that it is involved in mitigating social distance and possibly important in sexual orientation (although this is obviously a sensitively politic). Patient SM had extensive damage to the amygdala in each hemisphere. She had no motor, sensory, or cognitive deficits but when asked to identify photographs of a series of facial expressions, SM could identify every expression but one, she could not recognize fear. Similarly, when asked to draw facial expressions, SM produced accomplished pictures of each emotion, but she could not reproduce the expression of fear. When asked about her drawings, she explained that 'she did not know what an afraid face would look like.'
Functional magnetic resonance imaging (fMRI) has been incredibly useful in our understanding of empathy. Recent studies have shown that observing another person's emotional state activates parts of the neuronal network involved in processing that same state in oneself, whether it is disgust, touch, or pain. Almost by accident, researchers Preston and Frans de Waal discovered that monkey's sensory cortices would fire whilst researchers were moving experimental stimuli. So called 'mirror neurons' are neurons that fire both when the creature watches another perform an action as well as when they themselves perform it. In their paper, they argued that attended perception of the object's state automatically activates neural representations, and that this activation automatically primes or generates the associated autonomic and somatic responses, unless inhibited. This mechanism is similar to the common coding theory between perception and action.
Autism often provides a 'case in point' for empathy dysfunction. Anatomically the autistic brain undergoes a statistically significant dvelopmentally governed overgrowth of white matter, with an impeded pruning process, leading to a relative underdevelopmental of grey matter in the frontal lobes especially. Frontal lobe function is incredibly important in attending to and intellectualising the emotional and cognitive states of others. It works in tandom with the aymygdala, the orbito frontal cortex, the medial cortex, the dorsolateral frontal cortex and the frontal gyrus.
Sunday, 11 December 2011
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