RESUMEN

In order to inform the debate whether cortical areas related to action observation provide a pragmatic or a semantic representation of goal-directed actions, we performed 2 functional magnetic resonance imaging (fMRI) experiments in humans. The first experiment, involving observation of aimless arm movements, resulted in activation of most of the components known to support action execution and action observation. Given the absence of a target/goal in this experiment and the activation of parieto-premotor cortical areas, which were associated in the past with direction, amplitude, and velocity of movement of biological effectors, our findings suggest that during action observation we could be monitoring movement kinematics. With the second, double dissociation fMRI experiment, we revealed the components of the observation-related cortical network affected by 1) actions that have the same target/goal but different reaching and grasping kinematics and 2) actions that have very similar kinematics but different targets/goals. We found that certain areas related to action observation, including the mirror neuron ones, are informed about movement kinematics and/or target identity, hence providing a pragmatic rather than a semantic representation of goal-directed actions. Overall, our findings support a process-driven simulation-like mechanism of action understanding, in agreement with the theory of motor cognition, and question motor theories of action concept processing.

Asunto(s)

Neuronas Espejo , Corteza Motora , Fenómenos Biomecánicos , Fuerza de la Mano/fisiología , Humanos , Corteza Motora/diagnóstico por imagen , Corteza Motora/fisiología , Movimiento/fisiología , Desempeño Psicomotor/fisiología

RESUMEN

We employed the 14C-deoxyglucose autoradiographic method to map the activity in the cerebellar cortex of rhesus monkeys that performed forelimb movements either in the light or in the dark and of monkeys that observed forelimb movements executed by a human experimenter. The execution of forelimb movements, both in the light and in the dark, activated the forelimb representations in the cerebellar hemispheric extensions of 1) vermian lobules IV-VI and 2) vermian lobule VIIIB, ipsilaterally to the moving forelimb. Activations in the former forelimb representation involved both a paravermal and a lateral hemispheric region. Also, Crus II posterior in the ansiform lobule (the hemispheric expansion of lobule VIIB) was activated bilaterally by execution of movements in the light but not in the dark. Action observation activated the lateral-most region of the forelimb representation in the lateral hemispheric extension of vermian lobules IV-VI, as well as the crus II posterior, bilaterally. Our results demonstrate that the cerebellar cortex, in addition to its involvement in the generation of movement, is also recruited in the perception of observed movements. Moreover, our findings suggest a modularity gradient in the primate cerebellar cortex, which progresses from unimodal (medially) to multimodal (laterally) functional areas.

RESUMEN

Motor cognition is related to the planning and generation of actions as well as to the recognition and imagination of motor acts. Recently, there is evidence that the motor system participates not only in overt actions but also in mental processes supporting covert actions. Within this framework, we have investigated the cortical areas engaged in execution, observation, and imagination of the same action, by the use of the high resolution quantitative 14C-deoxyglucose method in monkeys and by fMRI in humans, throughout the entire primate brain. Our data demonstrated that observing or imagining an action excites virtually the same sensory-motor cortical network which supports execution of that same action. In general agreement with the results of five relevant meta-analyses that we discuss extensively, our results imply mental practice, i.e. internal rehearsal of the action including movements and their sensory effects. We suggest that we actively perceive and imagine actions by selecting and running off-line restored sensory-motor memories, by mentally simulating the actions. We provide empirical evidence that mental simulation of actions underlies motor cognition, and conceptual representations are grounded in sensory-motor codes. Motor cognition may, therefore, be embodied and modal. Finally, we consider questions regarding agency attribution and the possible causal or epiphenomenal role the involved sensory-motor network could play in motor cognition.

Asunto(s)

Encéfalo/fisiología , Cognición/fisiología , Imaginación/fisiología , Percepción de Movimiento/fisiología , Animales , Humanos

RESUMEN

We used fMRI to assess the human brain areas activated for execution, observation and 1st person motor imagery of a visually guided tracing task with the index finger. Voxel-level conjunction analysis revealed several cortical areas activated in common across all three motor conditions, namely, the upper limb representation of the primary motor and somatosensory cortices, the dorsal and ventral premotor, the superior and inferior parietal cortices as well as the posterior part of the superior and middle temporal gyrus including the temporo-parietal junction (TPj) and the extrastriate body area (EBA). Functional connectivity analyses corroborated the notion that a common sensory-motor fronto-parieto-temporal cortical network is engaged for execution, observation, and imagination of the very same action. Taken together these findings are consistent with the more parsimonious account of motor cognition provided by the mental simulation theory rather than the recently revised mirror neuron view Action imagination and observation were each associated with several additional functional connections, which may serve the distinction between overt action and its covert counterparts, and the attribution of action to the correct agent. For example, the central position of the right middle and inferior frontal gyrus in functional connectivity during motor imagery may reflect the suppression of movements during mere imagination of action, and may contribute to the distinction between 'imagined' and 'real' action. Also, the central role of the right EBA in observation, assessed by functional connectivity analysis, may be related to the attribution of action to the 'external agent' as opposed to the 'self'.

Asunto(s)

Encéfalo/fisiología , Imaginación , Movimiento , Desempeño Psicomotor , Adulto , Mapeo Encefálico , Femenino , Dedos , Humanos , Imagen por Resonancia Magnética , Masculino

RESUMEN

In an attempt to shed light on the role of the prefrontal cortex in action perception, we used the quantitative 14C-deoxyglucose method to reveal the effects elicited by reaching-to-grasp in the light or in the dark and by observation of the same action executed by an external agent. We analyzed the cortical areas in the principal sulcus, the superior and inferior lateral prefrontal convexities and the orbitofrontal cortex of monkeys. We found that execution in the light and observation activated in common most of the lateral prefrontal and orbitofrontal cortical areas, with the exception of 9/46-dorsal activated exclusively for observation and 9/46-ventral, 11 and 13 activated only for execution. Execution in the dark implicated only the ventral bank of the principal sulcus and its adjacent inferior convexity along with areas 47/12-dorsal and 13, whereas execution in the light activated both banks of the principal sulcus and both superior and inferior convexities along with areas 10 and 11. Our results demonstrate that the prefrontal cortex integrates information in the service of both action generation and action perception, and are discussed in relation to its contribution in movement suppression during action observation and in attribution of action to the correct agent.

Asunto(s)

Movimiento/fisiología , Percepción/fisiología , Corteza Prefrontal/fisiología , Desempeño Psicomotor/fisiología , Animales , Mapeo Encefálico/métodos , Desoxiglucosa/metabolismo , Femenino , Macaca mulatta

RESUMEN

We used the (14)C-deoxyglucose method to reveal changes in activity, in the lateral sulcus of monkeys, elicited by reaching-to-grasp in the light or in the dark and by observation of the same action executed by an external agent. Both visually-guided execution and observation of the same action activated the secondary somatosensory cortex, the ventral somatosensory area, the somatorecipient parietal ventral area, the retroinsula and the caudo-medial area of the auditory belt. These matching activations indicate that the somesthetic consequences of movements, generated bottom-up during action execution, may also be triggered top-down during action observation to represent the predicted sensory consequences of the perceived movement. The posterior granular part of insula found to be activated only for action execution and its anterior agranular part activated only for action observation may contribute to the attribution of action to the correct agent. Also, execution in the dark implicated all components activated by execution in the light but the retroinsula. In conclusion, activation of the somatorecipient parietal areas, not only for action-execution but also for action-observation, indicates that perception of actions performed by an external agent presupposes knowledge about the action-effect relationships, and that understanding others' actions consists of running off-line previously stored sensory-motor programs.

Asunto(s)

Desempeño Psicomotor , Corteza Somatosensorial/metabolismo , Percepción Visual , Animales , Encéfalo/metabolismo , Radioisótopos de Carbono , Desoxiglucosa/administración & dosificación , Femenino , Macaca mulatta , Movimiento

RESUMEN

To determine whether the periarcuate frontal cortex spatially encodes visual and oculomotor parameters, we trained monkeys to repeatedly execute saccades of the same amplitude and direction toward visual targets and we obtained quantitative images of the distribution of metabolic activity in 2D flattened reconstructions of the arcuate sulcus (As) and prearcuate convexity. We found two topographic maps of contraversive saccades to visual targets, separated by a region representing the vertical meridian: the first region straddled the fundus of the As and occupied areas 44 and 6-ventral, whereas the second one occupied areas 8A and 45 in the anterior bank of the As and the prearcuate convexity. The representation of the vertical meridian runs along the posterior borders of areas 8A and 45 (deep in the As). In both maps, the upper part of visuo-oculomotor space is represented ventrally and laterally and the lower part dorsally and medially whereas dorsal and ventral regions are separated by the representation of the horizontal meridian.

Asunto(s)

Mapeo Encefálico , Movimientos Oculares/fisiología , Lóbulo Frontal/fisiología , Corteza Motora/fisiología , Campos Visuales/fisiología , Animales , Femenino , Lateralidad Funcional , Macaca mulatta

RESUMEN

The role of the superior temporal sulcus (STs) in action execution and action observation remains unsettled. In an attempt to shed more light on the matter, we used the quantitative method of (14)C-deoxyglucose to reveal changes in activity, in the cortex of STs and adjacent inferior and superior temporal convexities of monkeys, elicited by reaching-to-grasp in the light or in the dark and by observation of the same action executed by an external agent. We found that observation of reaching-to-grasp activated the components of the superior temporal polysensory area [STP; including temporo-parieto-occipital association area (TPO), PGa, and IPa], the motion complex [including medial superior temporal area (MST), fundus of superior temporal area (FST), and dorsal and ventral parts of the middle temporal area (MTd and MTv, respectively)], and area TS2. A significant part of most of these activations was associated with observation of the goal-directed action, and a smaller part with the perception of arm-motion. Execution of reaching-to-grasp in the light-activated areas TS2, STP partially and marginally, and MT compared with the fixation but not to the arm-motion control. Consequently, MT-activation is associated with the arm-motion and not with the purposeful action. Finally, reaching-to-grasp in complete darkness activated all components of the motion complex. Conclusively, lack of visibility of our own actions involves the motion complex, whereas observation of others' actions engages area STP and the motion complex. Our previous and present findings together suggest that sensory effects are interweaved with motor commands in integrated action codes, and observation of an action or its execution in complete darkness triggers the retrieval of the visual representation of the action.

Asunto(s)

Actividad Motora/fisiología , Lóbulo Temporal/fisiología , Percepción Visual/fisiología , Animales , Mapeo Encefálico , Radioisótopos de Carbono , Desoxiglucosa , Femenino , Miembro Anterior/fisiología , Objetivos , Fuerza de la Mano/fisiología , Macaca mulatta , Técnica de Sustracción

RESUMEN

Given that prerequisite of activating the mirror neuron system is the preshaping of the hand and its interaction with the object during observation of a reaching-to-grasp-an-object action, the effects of viewing the object, the reaching forelimb and the static hand may obscure the effects of observing the grasping action per se. To disentangle these effects, we employed the (14)C-deoxyglucose quantitative autoradiographic method to map the functional activity in the entire cortex of monkeys (Macaca mulatta) which observed the experimenter performing non-goal-directed (purposeless) forelimb movements towards an object that was previously presented but no longer visible. Thus, our monkeys were exposed to the view of an object, a moving arm and a static hand with extended wrist and fingers. The distribution of metabolic activity was analyzed in 20µm thick brain sections, and two dimensional maps were reconstructed in the occipital operculum, the temporal, the lateral and medial parietal, the lateral and medial frontal, the lateral prefrontal and orbitofrontal cortices, including the cortex within the lunate, superior temporal, lateral, parietoccipital, intraparietal, central, arcuate and principal sulci. Increased metabolic activity, as compared to fixation-control monkeys, was measured in the forelimb representation of the primary motor and somatosensory cortices, the premotor cortices F2 and F5, cingulate motor areas, the secondary somatosensory cortex SII, the posterior intraparietal area 5 and areas TPOc and FST, in the hemisphere contralateral to the moving arm. Moreover, bilateral activations were elicited in areas pre-SMA, 8m, SSA and the somatorecipient area VS, the retroinsula, the auditory belt area CM, motion areas MT, MST, LOP/CIP, area 31, visual areas TEO, V6, V6Av and the parafoveal and peripheral visual representations of areas V1 and V2, respectively. Few parietal, auditory and visual areas were bilaterally depressed. In brief, a surprisingly wide cortical network is recruited even by mere observation of an arm executing goalless movements, which partially overlaps with the cortical network supporting the execution and observation of goal-directed forelimb actions. Interestingly, this overlap concerns mainly lower order sensory-motor rather than higher order association prefrontal and parietal cortices. Our results demonstrate that in order to reveal the net effects specifically induced by observation of a purposeful reaching-to-grasp action, the use of an appropriate control taking into account the effects of viewing the object to be grasped, the reaching arm and the static hand is crucial.

Asunto(s)

Encéfalo/fisiología , Miembro Anterior/fisiología , Movimiento , Percepción Visual/fisiología , Animales , Encéfalo/diagnóstico por imagen , Femenino , Macaca mulatta , Cintigrafía

RESUMEN

We have previously demonstrated that the primary motor and somatosensory cortices of monkeys are somatotopically activated for action-observation as are for action-generation, indicating that the recruitment of learned somatosensory-motor representations underlies the perception of others' actions. Here we examined the effects of seen and unseen actions on the early visual cortices, to determine whether stored visual representations are employed in addition to the somatosensory-motor ones. We used the quantitative (14)C-deoxyglucose method to map the activity throughout the cortex of the occipital operculum, lunate, and inferior occipital sulci of "rhesus monkeys" who reached to grasp a 3D object either in the light or in the dark or who observed the same action executed by another subject. In all cases, the extrastriate areas V3d and V3A displayed marked activation. We suggest that these activations reflect processing of visuospatial information useful for the reaching component of action, and 3D object-related information useful for the grasping part. We suggest that a memorized visual representation of the action supports action-recognition, as well as action-execution in complete darkness when the object and its environment are invisible. Accordingly, the internal representation that serves action-cognition is not purely somatosensory-motor but also includes a visual component.

Asunto(s)

Mapeo Encefálico , Desempeño Psicomotor/fisiología , Corteza Visual/fisiología , Animales , Autorradiografía , Oscuridad , Femenino , Fuerza de la Mano/fisiología , Macaca mulatta

RESUMEN

We have previously demonstrated that the forelimb representations of the primary motor and somatosensory cortices, as well as several premotor and parietal areas, are activated by both action-execution and action-observation, indicating that the spectator mentally simulates the observed action. Moreover, several studies demonstrated repeatedly that corticospinal excitability is modulated during action observation, providing evidence of an activation of the observer's motor system. However, evidence for the involvement of the spinal cord in action observation is controversial. The aim of the present study was to explore whether and how action-observation affects the spinal cord. To this end, we analyzed the spinal cord of eight monkeys (Macaca mulatta) trained to either execute reaching-to-grasp movements or observe the experimenter performing the same movements. Observation of grasping induced a bilateral decrease of glucose consumption in the spinal forelimb representation, whereas execution of grasping induced an increase of glucose utilization in the same area, ipsilaterally to the grasping hand. The depression of overall activity in the cervical enlargement of the spinal cord for action-observation may explain the suppression of overt movements, despite the activation of the observer's motor system.

Asunto(s)

Fuerza de la Mano/fisiología , Movimiento/fisiología , Inhibición Neural/fisiología , Estimulación Luminosa/métodos , Médula Espinal/fisiología , Animales , Femenino , Macaca mulatta , Corteza Motora/fisiología , Desempeño Psicomotor/fisiología

RESUMEN

The lateral intraparietal area (LIP) of monkeys is known to participate in the guidance of rapid eye movements (saccades), but the means it uses to specify movement variables are poorly understood. To determine whether area LIP devotes neural space to encode saccade metrics spatially, we used the quantitative [(14)C]deoxyglucose method to obtain images of the distribution of metabolic activity in the intraparietal sulcus (IPs) of rhesus monkeys trained to repeatedly execute saccades of the same amplitude and direction for the duration of the experiment. Different monkeys were trained to perform saccades of different sizes and in different directions. A clear topography of saccade metrics was found in the cytoarchitectonically identified area LIP ventral (LIPv) contralateral to the direction of the eye movements. We demonstrate that the representation of the vertical meridian runs parallel to the fundus of the IPs and that it is not orthogonal to the representation of the horizontal meridian. Instead, the latter runs through the middle of LIPv parallel to its border with area LIP dorsal (LIPd). The upper part of oculomotor space is represented rostrally and dorsally relative to the horizontal meridian toward the LIPv-LIPd border, whereas the lower part of oculomotor space is represented caudally and ventrally toward the caudal edge of the IPs. Saccade amplitude is also represented in an orderly manner.

Asunto(s)

Mapeo Encefálico , Lateralidad Funcional/fisiología , Lóbulo Parietal/fisiología , Movimientos Sacádicos/fisiología , Animales , Isótopos de Carbono/metabolismo , Desoxiglucosa/metabolismo , Femenino , Macaca mulatta , Lóbulo Parietal/diagnóstico por imagen , Estimulación Luminosa/métodos , Cintigrafía , Campos Visuales/fisiología , Percepción Visual/fisiología

RESUMEN

We used the (14)C-deoxyglucose method to map the functional activity in the cortex of the lateral and medial parietal convexity, the intraparietal and the parietoccipital sulci of monkeys which either reached and grasped a 3D-object or observed the same reaching-to-grasp movements executed by a human. Execution of reaching-to-grasp induced activations in the superior parietal areas SI-forelimb/convexity, PE, PE caudal (PEc); in the intraparietal areas PE intraparietal (PEip), medial intraparietal (MIP), 5 intraparietal posterior, ventral intraparietal (VIP), anterior intraparietal (AIP), lateral intraparietal dorsal; in the inferior parietal areas PF, PFG, PG; in the parietoccipital areas V6, V6A-dorsal; in the medial cortical areas PGm/7m and retrosplenial cortex. Observation of reaching-to-grasp activated areas SI-forelimb/convexity, PE lateral, PEc, PEip, MIP, VIP, AIP, PF, V6, PGm/7m, 31, and retrosplenial cortex. The common activations were stronger for execution than for observation and the interhemispheric differences were smaller for observation than for execution, contributing to the attribution of action to the correct agent. The extensive overlap of parietal networks activated for action execution and observation supports the "mental simulation theory" which assigns the role of understanding others' actions to the entire distributed neural network responsible for the execution of actions, and not the concept of "mirroring" which reflects the function of a certain class of cells in a couple of cortical areas.

Asunto(s)

Fuerza de la Mano/fisiología , Conducta Imitativa/fisiología , Imagen por Resonancia Magnética/métodos , Lóbulo Parietal/fisiología , Desempeño Psicomotor/fisiología , Animales , Femenino , Humanos , Macaca mulatta , Estimulación Luminosa/métodos

RESUMEN

We used the quantitative 14C-deoxyglucose method to map the activity pattern throughout the frontal cortex of rhesus monkeys, which either grasped a three-dimensional object or observed the same grasping movements executed by a human. We found that virtually the same frontal cortical networks were recruited for the generation and the perception of action, including the primary motor cortex (MI/F1), premotor cortical areas (F2, F5, and F6), the primary (SI) and supplementary (SSA) somatosensory cortex, medial cortical areas (8m and 9m), and the anterior cingulate. The overlapping networks for action execution and action observation support the notion that mental simulation of action could underlie the perception of others' actions. We suggest that the premotor and the somatotopic MI/F1 activations induced by action observation reflect motor grasp of the observed action, whereas the somatotopic SI and the SSA activations reflect recruitment of learned sensory-motor associations enabling perceptual understanding of the anticipated somatosensory feedback. We also found that the premotor activations were stronger for action observation, in contrast to the primary somatosensory-motor ones, which were stronger for action execution, and that activations induced by observation were bilateral, whereas those induced by execution were contralateral to the moving forelimb. We suggest that these differences in intensity and lateralization of activations between the executive and the perceptual networks help attribute the action to the correct agent, i.e., to the "self" during action execution and to the "other" during action observation. Accordingly, the "sense of agency" could be articulated within the core components of the circuitry supporting action execution/observation.

Asunto(s)

Lóbulo Frontal/fisiología , Fuerza de la Mano/fisiología , Imaginación/fisiología , Conducta Imitativa/fisiología , Red Nerviosa/fisiología , Desempeño Psicomotor/fisiología , Animales , Aprendizaje por Asociación/fisiología , Autorradiografía/métodos , Mapeo Encefálico/métodos , Radioisótopos de Carbono , Circulación Cerebrovascular/fisiología , Desoxiglucosa/metabolismo , Retroalimentación/fisiología , Femenino , Dedos/inervación , Dedos/fisiología , Lóbulo Frontal/anatomía & histología , Glucosa/metabolismo , Giro del Cíngulo/anatomía & histología , Giro del Cíngulo/fisiología , Macaca mulatta , Corteza Motora/anatomía & histología , Corteza Motora/fisiología , Movimiento/fisiología , Red Nerviosa/anatomía & histología , Corteza Somatosensorial/anatomía & histología , Corteza Somatosensorial/fisiología

RESUMEN

Although the role of the motion complex [cortical areas middle temporal (V5/MT), medial superior temporal (MST), and fundus of the superior temporal (FST)] in visual motion and smooth-pursuit eye movements is well understood, little is known about its involvement in rapid eye movements (saccades). To address this issue, we used the quantitative 14C-deoxyglucose method to obtain functional maps of the cerebral cortex lying in the superior temporal sulcus of rhesus monkeys executing saccades to visual targets and saccades to memorized targets in complete darkness. Fixational effects were observed in MT-foveal, FST, the anterior part of V4-transitional (V4t), and temporal-occipital areas. Saccades to memorized targets activated areas V5/MT, MST, and V4t, which were also activated for saccades to visual targets. Regions activated in the light and in the dark overlapped extensively. In addition, saccades to visual targets activated areas FST and the intermediate part of the polysensory temporal-parietal-occipital area. Cortical activity related to visually guided saccades could be explained, at least in part, by visual motion. Because only oculomotor signals can account for the equally robust activations induced by memory saccades in complete darkness, we suggest that areas V5/MT, MST, and V4t receive and/or process saccade-related oculomotor information.

Asunto(s)

Mapeo Encefálico/métodos , Movimientos Sacádicos/fisiología , Lóbulo Temporal/fisiología , Animales , Femenino , Glucosa/farmacocinética , Macaca mulatta , Memoria/fisiología , Lóbulo Temporal/citología

RESUMEN

Engagement of the primary motor cortex (MI) during the observation of actions has been debated for a long time. In the present study, we used the quantitative 14C-deoxyglucose method in monkeys that either grasped 3-D objects or observed the same movements executed by humans. We found that the forelimb regions of the MI and the primary somatosensory (SI) cortex were significantly activated in both cases. Our study resolves a debate in the literature, providing strong evidence for use of MI representations during the observation of actions. It demonstrates that the observation of an action is represented in the primary motor and somatosensory cortices as is its execution. It indicates that in terms of neural correlates, recognizing a motor behavior is like executing the same behavior, requiring the involvement of a distributed system encompassing not only the premotor but also the primary motor cortex. We suggest that movements and their proprioceptive components are stored as motor and somatosensory representations in motor and somatosensory cortices, respectively, and that these representations are recalled during observation of an action.

Asunto(s)

Autorradiografía , Glucemia/metabolismo , Procesamiento de Imagen Asistido por Computador , Imaginación/fisiología , Corteza Motora/fisiología , Reconocimiento Visual de Modelos/fisiología , Desempeño Psicomotor/fisiología , Corteza Somatosensorial/fisiología , Animales , Mapeo Encefálico , Percepción de Profundidad/fisiología , Dominancia Cerebral/fisiología , Electromiografía , Femenino , Lateralidad Funcional/fisiología , Macaca mulatta , Corteza Motora/anatomía & histología , Práctica Psicológica , Reclutamiento Neurofisiológico/fisiología , Procesamiento de Señales Asistido por Computador , Corteza Somatosensorial/anatomía & histología

RESUMEN

Goal-directed reaching requires a precise neural representation of the arm position and the target location. Parietal and frontal cortical areas rely on visual, somatosensory, and motor signals to guide the reaching arm to the desired position in space. To dissociate the regions processing these signals, we applied the quantitative [(14)C]-deoxyglucose method on monkeys reaching either in the light or in the dark. Nonvisual (somatosensory and memory-related) guidance of the arm, during reaching in the dark, induced activation of discrete regions in the parietal, premotor, and motor cortices. These included the dorsal part of the medial bank of the intraparietal sulcus, the ventral premotor area F4, the dorsal premotor area F2 below the superior precentral dimple, and the primary somatosensory and motor cortices. Additional parietal and premotor regions comprising the ventral intraparietal cortex, ventral premotor area F5, and the ventral part of dorsal premotor area F2 were activated by visual guidance of the arm during reaching in the light. This study provides evidence that different regions of the parieto-premotor circuit process the visual, somatosensory, and motor-memory-related signals which guide the moving arm.

Asunto(s)

Encéfalo/fisiología , Imagen por Resonancia Magnética , Desempeño Psicomotor/fisiología , Animales , Antimetabolitos , Mapeo Encefálico , Oscuridad , Desoxiglucosa , Femenino , Lóbulo Frontal/fisiología , Lateralidad Funcional/fisiología , Macaca mulatta , Memoria/fisiología , Lóbulo Parietal/fisiología , Radiofármacos