Mirror neurons: from origin to function.
This article argues that mirror neurons originate in sensorimotor associative learning and therefore a new approach is needed to investigate their functions. Mirror neurons were discovered about 20 years ago in the monkey brain, and there is now evidence that they are also present in the human brain. The intriguing feature of many mirror neurons is that they fire not only when the animal is performing an action, such as grasping an object using a power grip, but also when the animal passively observes a similar action performed by another agent. It is widely believed that mirror neurons are a genetic adaptation for action understanding; that they were designed by evolution to fulfill a specific socio-cognitive function. In contrast, we argue that mirror neurons are forged by domain-general processes of associative learning in the course of individual development, and, although they may have psychological functions, they do not necessarily have a specific evolutionary purpose or adaptive function. The evidence supporting this view shows that (1) mirror neurons do not consistently encode action "goals"; (2) the contingency- and context-sensitive nature of associative learning explains the full range of mirror neuron properties; (3) human infants receive enough sensorimotor experience to support associative learning of mirror neurons ("wealth of the stimulus"); and (4) mirror neurons can be changed in radical ways by sensorimotor training. The associative account implies that reliable information about the function of mirror neurons can be obtained only by research based on developmental history, system-level theory, and careful experimentation.
Department of Psychology, City University London, London EC1R 0JD, United Kingdom. richard.cook.1@city.ac.uk http://www.city.ac.uk/people/academics/richard-cook.
Richard
R
Cook
MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London SE5 8AF, United Kingdom. geoff.bird@kcl.ac.uk https://sites.google.com/site/geoffbirdlab/ http://www.iop.kcl.ac.uk/staff/profile/default.aspx?go=13152.
Geoffrey
G
Bird
Department of Psychology, University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom. c.catmur@surrey.ac.uk http://www.surrey.ac.uk/psychology/people/dr_caroline_catmur/ http://sites.google.com/site/carolinecatmur/
Caroline
C
Catmur
Department of Psychological Sciences, Birkbeck College, University of London, London WC1E 7HX, United Kingdom. c.press@bbk.ac.uk http://www.bbk.ac.uk/psychology/actionlab/ http://www.bbk.ac.uk/psychology/our-staff/academic/dr-clare-press.
Clare
C
Press
All Souls College, University of Oxford, Oxford, OX1 4AL, and Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, United Kingdom. cecilia.heyes@all-souls.ox.ac.uk http://www.all-souls.ox.ac.uk/users/heyesc/
Cecilia
C
Heyes
D000818:Animals; D001245:Association Learning / Q000502:physiology; D005075:Biological Evolution; D001921:Brain / Q000502:physiology*; D006801:Humans; D007858:Learning / Q000502:physiology*; D059167:Mirror Neurons / Q000502:physiology*; D012919:Social Behavior; D012938:Social Perception