the brain & body in action
As humans, we have an unparalleled ability to coordinate our bodies to perform an endless number of skilled actions. What most interests me about the human brain is how a network of seemingly disparate cortical regions and subcortical nuclei gives rise to such complex and coordinated actions. Of particular interest is the remarkable plasticity of this system: how different types of physical and perceptual experience shape our capacity to learn new movements. “Mirror” neurons, discovered in the monkey ventral premotor cortex, appear to compose a cortical network that matches observation of actions with execution of those same actions (Rizzolatti et al., 1996). These specialized neurons have prompted researchers to propose that action perception and production form a bidirectional, interactive loop within the primate brain. Since the discovery of mirror neurons in monkeys, many studies have investigated similar functional regions within the human brain, providing evidence for a putative human mirror neuron system (MNS; Rizzolatti and Craighero, 2004). Action understanding thus might be explained by covert simulation of another’s movements by an observer (Grafton et al., 1996).My overarching research objective is to expand upon prior work on the MNS through exploration of cognitive strategies and experiential factors that shape neural processes linking action with perception. Through my experimental work, I have attempted to address questions of how the brain coordinates different types of experience with action execution and observation (e.g., Cross et al., 2006; 2007). In order to do so, I use a variety of perceptual, visuomotor, and learning paradigms along with an interdisciplinary approach that involves structural and functional magnetic resonance imaging (fMRI), transcranial magnetic stimulation (TMS), and psychophysics. While fMRI initially enables one to understand the potential neural networks involved in a given process, only TMS or patient work can then establish causal relations between anatomy and function. Through coordinated use of neuroimaging, neurostimulation, and behavioral measures, I am interested in exploring how language, perception, and action interact with experience to shape action cognition.
works cited
Cross ES, Hamilton AFdeC, Grafton ST (2006) Building a motor simulation de novo: Observation of dance by dancers. Neuroimage 31(3): 1257-1267.
Cross ES, Schmitt PS, Grafton ST (2007) Neural substrates of contextual interference during motor learning support a model of active preparation. Journal of Cognitive Neuroscience 19(11): 1854-1871.
Grafton ST, Arbib MA, Fadiga L, Rizzolatti G (1996) Localization of grasp representations in humans by positron emission tomography. 2. Observation compared with imagination. Exp Brain Research 112:103-111.
Rizzolatti G, Craighero L (2004) The mirror-neuron system. Annual Review of Neuroscience 27:169-192.
Rizzolatti G, Fadiga L, Gallese V, Fogassi L (1996) Premotor cortex and the recognition of motor actions. Brain Research Cognitive Brain Research 3:131-141.
