Investigating the functional anatomy of empathy and forgiveness

How does the brain deal with the social world?

It is only relatively recently that the search for the biological basis of social cognition has started. It is still unknown just how biological factors, from genes to brain processes, interact with environmental variables to produce individual differences in social competence and in pathology of social communication. It may seem over-ambitious to work out how connections can be made between sophisticated social behaviour and basic neurophysiological mechanisms. However, examples already exist. The neural basis of social processes such as deception and morality are now being studied by cognitive neuroscientists. In this review, we summarize recent work that has illuminated the neuro-cognitive basis of complex social interaction and communication in humans.

Social neuroscience, empathy, brain integration, and neurodevelopmental disorders

Paul MacLean has investigated integrated brain functioning through selected brain lesions in animals that disturb circuits necessary for complex behaviors, such as social displays. MacLean is unique in his comparative neurobehavioral approach that emphasizes the evolutionary origins of parenting and social behaviors and the implications of brain changes in the evolution from reptiles (social displays) to mammals (nursing, audiovocal communication, play) to man (self-awareness, intentionality, social context) that link affect and cognition. Subjectively, how "looking with feeling toward others," the basic element in empathy, evolved has been a central concern of his. Neuroimaging studies of social cognition, mother-infant communication, moral behavior, forgiveness, and trust are consistent with particular brain systems being activated in cooperative social behaviors. The identification of mirror neurons is pertinent to MacLean's model of isopraxis and studies of thalamocortical resonances may be pertinent to his neurobehavioral models. Studies of behavioral phenotypes in human neurodevelopmental disorders are consistent with MacLean's model of brain circuits being linked to complex behaviors during development. In autistic disorder, the behavioral phenotype involves disrupted social communication, deviant imaginative play, and motor stereotypies. In Lesch-Nyhan syndrome (LNS), self-injury occurs in individuals with normal sensory systems intact who require and request physical restraint to prevent self-injury; they ask for assistance from others to prevent them from harming themselves. Autism involves the lack of subjective awareness of others intentions and LNS involves a failure in self-regulation and self-control of self-injurious behavior. MacLean's models laid the groundwork for studies focused on understanding brain functioning in these conditions.

Neuroimaging studies of violence and antisocial behavior

The neurobiological basis of violence and antisocial behavior is poorly understood. Lesion studies have implicated the frontal and temporal lobes in such phenomena. Recent neuroimaging studies have provided more detailed information on the neurobiological correlates of violence and antisocial behavior. Moreover, the results of such imaging studies extend findings from prior lesion studies. These results suggest that violent and antisocial behavior is associated with disruptions in frontotemporal neural systems. This article reviews the neuroimaging literature on violence and antisocial behavior and discusses the strengths and weaknesses of the different methods that have been used in such studies. The author reviews findings from cerebral psychophysiology studies (electroencephalographic studies and evoked potentials), as well as from studies using positron emission tomography (PET), single photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI). The article concludes with a discussion of useful directions for future research. It is clear that the use of neuroimaging methods in combination offers the greatest promise for progress in the understanding of the neural basis of violence and antisocial behavior.

How (and where) does moral judgment work?

Moral psychology has long focused on reasoning, but recent evidence suggests that moral judgment is more a matter of emotion and affective intuition than deliberate reasoning. Here we discuss recent findings in psychology and cognitive neuroscience, including several studies that specifically investigate moral judgment. These findings indicate the importance of affect, although they allow that reasoning can play a restricted but significant role in moral judgment. They also point towards a preliminary account of the functional neuroanatomy of moral judgment, according to which many brain areas make important contributions to moral judgment although none is devoted specifically to it.

The neural correlates of moral sensitivity: a functional magnetic resonance imaging investigation of basic and moral emotions

Humans are endowed with a natural sense of fairness that permeates social perceptions and interactions. This moral stance is so ubiquitous that we may not notice it as a fundamental component of daily decision making and in the workings of many legal, political, and social systems. Emotion plays a pivotal role in moral experience by assigning human values to events, objects, and actions. Although the brain correlates of basic emotions have been explored, the neural organization of "moral emotions" in the human brain remains poorly understood. Using functional magnetic resonance imaging and a passive visual task, we show that both basic and moral emotions activate the amygdala, thalamus, and upper midbrain. The orbital and medial prefrontal cortex and the superior temporal sulcus are also recruited by viewing scenes evocative of moral emotions. Our results indicate that the orbital and medial sectors of the prefrontal cortex and the superior temporal sulcus region, which are critical regions for social behavior and perception, play a central role in moral appraisals. We suggest that the automatic tagging of ordinary social events with moral values may be an important mechanism for implicit social behaviors in humans.

Emotions, behaviours and mood changes in stroke

The brain mediates and integrates all cognitive activities, emotional experiences and finally behaviours. Stroke is undoubtedly a privileged disease for human behavioural studies, because of its high incidence. Recent advances in high-resolution magnetic resonance imaging techniques and functional neuroimaging allow both the precise localization of lesions and on-line visualization of the activity of cerebral areas and networks. Nevertheless, the neuropsychiatry of stroke remains uncertain in its relationship with brain dysfunction. Clinical studies on registry populations, single case studies, and functional neuroimaging data provide interesting findings, but differences in methods and great individual intervariability still prevent a complete understanding of emotional perception and behavioural responses in stroke. We adopted an anatomical-functional model as an operational framework in order to systematize the recent literature on emotional, behavioural and mood changes after stroke. The dysfunction of the areas subserving fundamental and executive functions induces behavioural and affective changes (such as depression, anxiety, apathy) that reflect the dysfunction of the whole system. Conversely, lesions in the system of instrumental functions induce signature syndromes (aphasia, anosognosia). At any delay from stroke, the diagnosis and treatment of mood and behavioural changes are a priority for clinicians and healthcare professionals to improve the quality of life of patients.