1,721,105 research outputs found
Mirrors in the brain : How our minds share actions and emotions
No full textPresents a fascinating account of one of the defining scientific discoveries of the past 50 years, from the man who made the breakthrough
Explains in a clear and accessible style how mirror neurons enable us to share experiences of emotions, movements, and feelings
Emotions and actions are powerfully contagious; when we see someone laugh, cry, show disgust, or experience pain, in some sense, we share that emotion. When we see someone in distress, we share that distress. When we see a great actor, musician or sportsperson perform at the peak of their abilities, it can feel like we are experiencing just something of what they are experiencing. Yet only recently, with the discover of mirror neurons, has it become clear just how this powerful sharing of experience is realised within the human brain. This book provides, for the first time, a systematic overview of mirror neurons, written by the man who first discovered them.
In the early 1990''s Giacomo Rizzolatti and his co-workers at the University of Parma discovered that some neurons had a surprising property. They responded not only when a subject performed a given action, but also when the subject oberved someone else performing that same action. These results had a deep impact on cognitive neuroscience, leading the neuroscientist VS Ramachandran to predict that ''mirror neurons would do for psychology what DNA did for biology''. The unexpected properties of these neurons have not only attracted the attention of neuroscientists. Many sociologists, anthropologists, and even artists have been fascinated by mirror neurons. The director and playwright Peter Brook stated that mirror neurons throw new light on the mysterious link that is created each time actors take the stage and face their audience - the sight of a great actor performing activates in the brain of the observer the very same areas that are active in the performer - including both their actions and their emotions
The organization of the cortical motor system: new concepts.
No full textA series of recent anatomical and functional data has radically changed our view on the organization of the motor cortex in primates. In the present article we present this view and discuss its fundamental principles. The basic principles are the following: (a) the motor cortex, defined as the agranular frontal cortex, is formed by a mosaic of separate areas, each of which contains an independent body movement representation, (b) each motor area plays a specific role in motor control, based on the specificity of its cortical afferents and descending projections, (c) in analogy to the motor cortex, the posterior parietal cortex is formed by a multiplicity of areas, each of which is involved in the analysis of particular aspects of sensory information. There are no such things as multipurpose areas for space or body schema and (d) the parieto-frontal connections form a series of segregated anatomical circuits devoted to specific sensorimotor transformations. These circuits transform sensory information into action. They represent the basic functional units of the motor system. Although these conclusions mostly derive from monkey experiments, anatomical and brain-imaging evidence suggest that the organization of human motor cortex is based on the same principles. Possible homologies between the motor cortices of humans and non-human primates are discussed
Attributing a meaning to hand movements: an fMRI study
No full textIncreasing attention is being paid to functional activations related to body movement inner representations, during either observation or imagery (1,2). So far, however, few studies have dealt with the presence or absence of a meaning in the observed and/or imagined movements (3).MethodsThirteen healthy right-handed volunteers (5 males, 8 females; age 20-31) took part in the study. At the beginning of each trial, a short video was presented, showing different kinds of intransitive hand movements: pantomimes, or symbolic gestures, or nonsense movements. The subjects had either to imagine to perform the same movement they had just seen in the previous video (imagery task); or to observe another movement, different from the previous one (observation task). Four runs, twenty trials each, were carried out for each subject. Functional imaging was performed on a 1.5 Signa GE MR scanner, acquiring 18 contiguous axial slices (TR: 2000 ms; voxel size: 3.75x3.75x6 mm). Data analysis was carried out using the SPM99 package (Wellcome Department of Imaging Neuroscience, London, UK). Multi-subject analyses were performed using a random effect model. In particular, in order to identify patterns of activation related to the attribution of a meaning to movements, we performed a conjunction analysis of the contrasts “pantomimes vs. nonsense” and “symbolic vs. nonsense”, for observation and imagery separately.ResultsDuring the observation of meaningful actions, as compared with meaningless movements, mainly left hemisphere activations (Fig. 1A) were found in the frontal and temporal cortex: namely, in precentral gyrus (BA 6), inferior frontal gyrus (IFG, BA45) and middle frontal gyrus (BA10), and in superior temporal gyrus (BA22); in addition, activity increased in the right middle temporal gyrus and in medial occipital areas bilaterally. During imagery of meaningful vs. meaningless movements, regions of increased signal were in the left IFG (BA45) (Fig 1B), in the right parietal operculum/posterior insula, and in lateral occipital/posterior temporal cortex in both hemispheres.ConclusionsA common region functionally activated during both imagery and observation of meaningful vs. meaningless movements is the left IFG. Actually, a smaller signal increase was present in IFG also for meaningless movements (data not shown). The IFG had been found active in a previous study when observing meaningful upper limb movements with the intention to either recognize or to imitate them (3). The IFG is part of the so-called mirror system, devoted to action understanding and imitation (1). Our results support the hypothesis that the left IFG is specifically involved in attributing a meaning to upper limb movements, during both passive (observation) and active (imagery) inner representations. 1) G. Rizzolatti and L. Craighero Annu.Rev.Neurosci. 2004.2) M. Jeannerod Neuroimage. 14:S103-S109, 2001.3) J. Decety et al. Brain 120:1763-1777, 1997
Click-evoked responses in cats with tenotomized middle ear muscles during sleep and waking
No full text- …
