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14
Neural topography and content of movement representations
- Journal of Cognitive Neuroscience
, 2005
"... Abstract & We have used implicit motor imagery to investigate the neural correlates of motor planning independently from actual movements. Subjects were presented with drawings of left or right hands and asked to judge the hand laterality, regardless of the stimulus rotation from its upright or ..."
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Cited by 32 (7 self)
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Abstract & We have used implicit motor imagery to investigate the neural correlates of motor planning independently from actual movements. Subjects were presented with drawings of left or right hands and asked to judge the hand laterality, regardless of the stimulus rotation from its upright orientation. We paired this task with a visual imagery control task, in which subjects were presented with typographical characters and asked to report whether they saw a canonical letter or its mirror image, regardless of its rotation. We measured neurovascular activity with fast event-related fMRI, distinguishing responses parametrically related to motor imagery from responses evoked by visual imagery and other task-related phenomena. By quantifying behavioral and neurovascular correlates of imagery on a trial-by-trial basis, we could discriminate between stimulusrelated, mental rotation-related, and response-related neural activity. We found that specific portions of the posterior parietal and precentral cortex increased their activity as a function of mental rotation only during the motor imagery task. Within these regions, the parietal cortex was visually responsive, whereas the dorsal precentral cortex was not. Response-but not rotation-related activity was found around the left central sulcus (putative primary motor cortex) during both imagery tasks. Our study provides novel evidence on the topography and content of movement representations in the human brain. During intended action, the posterior parietal cortex combines somatosensory and visuomotor information, whereas the dorsal premotor cortex generates the actual motor plan, and the primary motor cortex deals with movement execution. We discuss the relevance of these results in the context of current models of action planning. &
Multiple movement representations in the human brain: an event-related fMRI study
- J. Cogn. Neurosci
, 2002
"... & Neurovascular correlates of response preparation have been investigated in human neuroimaging studies. However, conventional neuroimaging cannot distinguish, within the same trial, between areas involved in response selection and/ or response execution and areas specifically involved in respon ..."
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Cited by 21 (5 self)
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& Neurovascular correlates of response preparation have been investigated in human neuroimaging studies. However, conventional neuroimaging cannot distinguish, within the same trial, between areas involved in response selection and/ or response execution and areas specifically involved in response preparation. The specific contribution of parietal and frontal areas to motor preparation has been explored in electrophysiological studies in monkey. However, the asso-ciative nature of sensorimotor tasks calls for the additional contributions of other cortical regions. In this article, we have investigated the functional anatomy of movement represen-tations in the context of an associative visuomotor task with instructed delays. Neural correlates of movement representa-tions have been assessed by isolating preparatory activity that
On the origin of intentions
- In
, 2007
"... Any model of motor control or sensorimotor transformations starts from an intention to trigger a cascade of neural computations, yet how intentions themselves are generated remains a mystery. Part of the difficulty in dealing with this mystery might be related to the received wisdom of studying sens ..."
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Cited by 10 (4 self)
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Any model of motor control or sensorimotor transformations starts from an intention to trigger a cascade of neural computations, yet how intentions themselves are generated remains a mystery. Part of the difficulty in dealing with this mystery might be related to the received wisdom of studying sensorimotor processes and intentions in individual agents. Here we explore the use of an alternative approach, focused on understanding how we induce intentions in other people. Under the assumption that generating intentions in a third person relies on similar mechanisms to those involved in generating first-person intentions, this alternative approach might shed light on the origin of our own intentions. Therefore, we focus on the cognitive and cerebral operations supporting the generation of communicative actions, i.e. actions designed (by a Sender) to trigger (in a Receiver) the recognition of a given communicative intention. We present empirical findings indicating that communication requires the Sender to select his behavior on the basis of a prediction of how the Receiver will interpret this behavior; and that there is spatial overlap between the neural structures supporting the generation of communicative actions and the generation of first-person intentions. These results support the hypothesis that the generation of intentions might be a particular instance of our ability to induce and attribute mental states to an agent. We suggest that motor intentions are retrodictive with respect to the neurophysiological mechanisms that generate a given action, while being predictive with respect to the potential intention attribution evoked by a given action in other agents.
Neural mechanisms for response selection: comparing selection of responses and items from working memory
- Neuroimage
, 2007
"... Recent functional imaging studies of working memory (WM) have suggested a relationship between the requirement for response selection and activity in dorsolateral prefrontal (DLPFC) and parietal regions. Although a number of WM operations are likely to occur during response selection, the current st ..."
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Cited by 6 (0 self)
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Recent functional imaging studies of working memory (WM) have suggested a relationship between the requirement for response selection and activity in dorsolateral prefrontal (DLPFC) and parietal regions. Although a number of WM operations are likely to occur during response selection, the current study was particularly interested in the contribution of this neural network to WM-based response selection when compared to the selection of an item from a list being maintained in memory, during a verbal learning task. The design manipulated stimulus–response mappings so that selecting an item from memory was not always accompanied with selecting a motor response. Functional activation during selection supported previous findings of fronto-parietal involvement, although in contrast to previous findings left, rather than right, DLPFC activity was significantly more active for selecting a memory-guided motor response, when compared to selecting an item currently maintained in memory or executing a memory-guided response. Our results contribute to the debate over the role of fronto-parietal activity during WM tasks, suggesting that this activity appears particularly related to response selection, potentially supporting the hypothesized role of prefrontal activity in biasing attention toward task-relevant material in more posterior regions. © 2006 Elsevier Inc. All rights reserved.
On the programming and reprogramming of actions.
- Cerebral Cortex,
, 2007
"... Actions are often selected in the context of ongoing movement plans. Most studies of action selection have overlooked this fact, implicitly assuming that the motor system is passive prior to presentation of instructions triggering movement selection. Other studies addressed action planning in the c ..."
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Cited by 5 (1 self)
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Actions are often selected in the context of ongoing movement plans. Most studies of action selection have overlooked this fact, implicitly assuming that the motor system is passive prior to presentation of instructions triggering movement selection. Other studies addressed action planning in the context of an already present motor plan, but focused mostly on inhibition of a prepotent response under fierce time pressure. Under these circumstances, inhibition of previous motor plans and selection of a new response become temporally intermingled. Here, we explore how the presence of earlier motor plans influences cerebral effects associated with action selection, separating in time movement programming, reprogramming, and execution. We show that portions of parietofrontal circuits, including intraparietal sulcus and left dorsal premotor cortex, are systematically involved in programming motor responses, their activity being indifferent to the presence of earlier motor plans. We identify additional regions recruited when a motor response is programmed in the context of an existing motor program. We found that several right-hemisphere regions, previously associated with response inhibition, might be better characterized as involved in response selection. Finally, we detail the specific role of a right precentral region in movement reprogramming that is involved in inhibiting not only actual responses but also motor representations.
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"... www.elsevier.com/locate/humov Evidence for a distributed hierarchy of action representation in the brain ..."
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www.elsevier.com/locate/humov Evidence for a distributed hierarchy of action representation in the brain
Neuropsychologia 47 (2009) 1670–1685 Contents lists available at ScienceDirect
"... journal homepage: www.elsevier.com/locate/neuropsychologia ..."
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unknown title
, 2004
"... www.elsevier.com/locate/neures Anterior and superior lateral occipito-temporal cortex responsible for target motion prediction during overt and covert visual pursuit ..."
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www.elsevier.com/locate/neures Anterior and superior lateral occipito-temporal cortex responsible for target motion prediction during overt and covert visual pursuit
UNCORRECTED PROOF
"... method to produce evolving functional connectivity maps during the 3 course of an fMRI experiment using wavelet-based time-varying 4 granger causality ..."
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method to produce evolving functional connectivity maps during the 3 course of an fMRI experiment using wavelet-based time-varying 4 granger causality
