Mirror neurons in macaque area F5 fire when an animal performs an action, such as a mouth or limb movement, and also when the animal passively observes an identical or similar action performed by another individual. Brain-imaging studies in humans conducted over the last 20 years have repeatedly attempted to reveal analogous brain regions with mirror properties in humans, with broad and often speculative claims about their functional significance across a range of cognitive domains, from language to social cognition. Despite such concerted efforts, the likely neural substrates of these mirror regions have remained controversial, and indeed the very existence of a distinct subcategory of human neurons with mirroring properties has been questioned. Here we used activation likelihood estimation (ALE), to provide a quantitative index of the consistency of patterns of fMRI activity measured in human studies of action observation and action execution. From an initial sample of more than 300 published works, data from 125 papers met our strict inclusion and exclusion criteria. The analysis revealed 14 separate clusters in which activation has been consistently attributed to brain regions with mirror properties, encompassing 9 different Brodmann areas. These clusters were located in areas purported to show mirroring properties in the macaque, such as the inferior parietal lobule, inferior frontal gyrus and the adjacent ventral premotor cortex, but surprisingly also in regions such as the primary visual cortex, cerebellum and parts of the limbic system. Our findings suggest a core network of human brain regions that possess mirror properties associated with action observation and execution, with additional areas recruited during tasks that engage non-motor functions, such as auditory, somatosensory and affective components.

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Social cognition broadly refers to the processing of social information in the brain that underlies abilities such as the detection of others' emotions and responding appropriately to these emotions. Social cognitive skills are critical for successful communication and, consequently, mental health and wellbeing. Disturbances of social cognition are early and salient features of many neuropsychiatric, neurodevelopmental and neurodegenerative disorders, and often occur after acute brain injury. Its assessment in the clinic is, therefore, of paramount importance. Indeed, the most recent edition of the American Psychiatric Association's Diagnostic and Statistical Manual for Mental Disorders (DSM-5) introduced social cognition as one of six core components of neurocognitive function, alongside memory and executive control. Failures of social cognition most often present as poor theory of mind, reduced affective empathy, impaired social perception or abnormal social behaviour. Standard neuropsychological assessments lack the precision and sensitivity needed to adequately inform treatment of these failures. In this Review, we present appropriate methods of assessment for each of the four domains, using an example disorder to illustrate the value of these approaches. We discuss the clinical applications of testing for social cognitive function, and finally suggest a five-step algorithm for the evaluation and treatment of impairments, providing quantitative evidence to guide the selection of social cognitive measures in clinical practice.

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Seeking and selectively attending to significant extrapersonal stimuli in a dynamic environment requires the updating of an attentional priority map. Using functional magnetic resonance imaging, we investigated the role of posterior parietal cortex in such remappings of attentional priorities where the configuration, location, and significance of stimuli were systematically varied. Our data revealed a functional dissociation between 2 juxtaposed posterior parietal regions: one in the superior parietal lobule (SPL) and another in the intraparietal sulcus (IPS). SPL was preferentially activated in all conditions where a spatial displacement occurred in the location of the target, the location of the distracter, or the focus of attention (exogenous and endogenous shifts of spatial attention). Shifts of the attentional focus also activated the IPS but principally if they were guided endogenously by internal rules of relevance rather than stimulus displacement per se (endogenous attention shifts). Only the IPS region was activated by transient resetting of target significance when the stimulus configuration changed but the attentional focus remained spatially fixed (feature attention shifts). These 2 components of the large-scale frontoparietal spatial attention network therefore have common and distinctive functions. In specific, the IPS component is more closely related to the compilation of an attentional priority map, including the endogenous recalibration of attentional weights. The SPL component, on the other hand, is more closely related to the modification of spatial coordinates linked to attentional priorities (spatial shifting). Collectively, these 2 areas allow posterior parietal cortex to dynamically encode extrapersonal events according to their spatial coordinates and valence.