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Giovanni Buccino

Publications and source records attributed to Giovanni Buccino.

13 recordsLinked to original sources
PubMed2006

The role of ventral premotor cortex in action execution and action understanding.

The human ventral premotor cortex overlaps, at least in part, with Broca's region in the dominant cerebral hemisphere, that is known to mediate the production of language and contributes to language comprehension. This region is constituted of Brodmann's areas 44 and 45 in the inferior frontal gyrus. We summarize the evidence that the motor related part of Broca's region is localized in the opercular portion of the inferior frontal cortex, mainly in area 44 of Brodmann. According to our own data, there seems to be a homology between Brodmann area 44 in humans and the monkey area F5. The non-language related motor functions of Broca's region comprise complex hand movements, associative sensorimotor learning and sensorimotor integration. Brodmann's area 44 is also a part of a specialized parieto-premotor network and interacts significantly with the neighbouring premotor areas. In the ventral premotor area F5 of monkeys, the so called mirror neurons have been found which discharge both when the animal performs a goal-directed hand action and when it observes another individual performing the same or a similar action. More recently, in the same area mirror neurons responding not only to the observation of mouth actions, but also to sounds characteristic to actions have been found. In humans, through an fMRI study, it has been shown that the observation of actions performed with the hand, the mouth and the foot leads to the activation of different sectors of Broca's area and premotor cortex, according to the effector involved in the observed action, following a somatotopic pattern which resembles the classical motor cortex homunculus. On the other hand the evidence is growing that human ventral premotor cortex, especially Brodmann's area 44, is involved in polymodal action processing. These results strongly support the existence of an execution-observation matching system (mirror neuron system). It has been proposed that this system is involved in polymodal action recognition and might represent a precursor of language processing. Experimental evidence in favour of this hypothesis both in the monkey and humans is shortly reviewed.

Animals↗
PubMed2006

Functions of the mirror neuron system: implications for neurorehabilitation.

Mirror neurons discharge during the execution of hand object-directed actions and during the observation of the same actions performed by other individuals. These neurons were first identified in the ventral premotor cortex (area F5) and later on in the inferior parietal lobule of monkey brain, thus constituting the mirror neuron system. More recently, mirror neurons for mouth object-directed actions have also been found in the monkey. Several pieces of experimental data demonstrate that a mirror neuron system devoted to hand, mouth, and foot actions is also present in humans. In the present paper we review the experimental evidence on the role of the mirror neuron system in action understanding, imitation learning of novel complex actions, and internal rehearsal (motor imagery) of actions. On the basis of features of the mirror neuron system and its role in action understanding and imitation, we discuss the possible use of action observation and imitation as an approach for systematic training in the rehabilitation of patients with motor impairment of the upper limb after stroke.

Animals↗
PubMed2005

Grasping the intentions of others with one's own mirror neuron system.

Understanding the intentions of others while watching their actions is a fundamental building block of social behavior. The neural and functional mechanisms underlying this ability are still poorly understood. To investigate these mechanisms we used functional magnetic resonance imaging. Twenty-three subjects watched three kinds of stimuli: grasping hand actions without a context, context only (scenes containing objects), and grasping hand actions performed in two different contexts. In the latter condition the context suggested the intention associated with the grasping action (either drinking or cleaning). Actions embedded in contexts, compared with the other two conditions, yielded a significant signal increase in the posterior part of the inferior frontal gyrus and the adjacent sector of the ventral premotor cortex where hand actions are represented. Thus, premotor mirror neuron areas-areas active during the execution and the observation of an action-previously thought to be involved only in action recognition are actually also involved in understanding the intentions of others. To ascribe an intention is to infer a forthcoming new goal, and this is an operation that the motor system does automatically.

Adult↗
PubMed2005

Listening to action-related sentences activates fronto-parietal motor circuits.

Observing actions made by others activates the cortical circuits responsible for the planning and execution of those same actions. This observation-execution matching system (mirror-neuron system) is thought to play an important role in the understanding of actions made by others. In an fMRI experiment, we tested whether this system also becomes active during the processing of action-related sentences. Participants listened to sentences describing actions performed with the mouth, the hand, or the leg. Abstract sentences of comparable syntactic structure were used as control stimuli. The results showed that listening to action-related sentences activates a left fronto-parieto-temporal network that includes the pars opercularis of the inferior frontal gyrus (Broca's area), those sectors of the premotor cortex where the actions described are motorically coded, as well as the inferior parietal lobule, the intraparietal sulcus, and the posterior middle temporal gyrus. These data provide the first direct evidence that listening to sentences that describe actions engages the visuomotor circuits which subserve action execution and observation.

Acoustic Stimulation↗
PubMed2004

Neural circuits underlying imitation learning of hand actions: an event-related fMRI study.

The neural bases of imitation learning are virtually unknown. In the present study, we addressed this issue using an event-related fMRI paradigm. Musically naive participants were scanned during four events: (1) observation of guitar chords played by a guitarist, (2) a pause following model observation, (3) execution of the observed chords, and (4) rest. The results showed that the basic circuit underlying imitation learning consists of the inferior parietal lobule and the posterior part of the inferior frontal gyrus plus the adjacent premotor cortex (mirror neuron circuit). This circuit, known to be involved in action understanding, starts to be active during the observation of the guitar chords. During pause, the middle frontal gyrus (area 46) plus structures involved in motor preparation (dorsal premotor cortex, superior parietal lobule, rostral mesial areas) also become active. Given the functional properties of area 46, a model of imitation learning is proposed based on interactions between this area and the mirror neuron system.

Adult↗
PubMed2004

Activation of cerebellar hemispheres in spatial memorization of saccadic eye movements: an fMRI study.

What mechanisms allow us to direct a precise saccade to a remembered target position in space? The cerebellum has been proposed to be involved not only in motor and oculomotor control, but also in perceptual and cognitive functions. We used functional MRI (Echoplanar imaging at 1.5 T) to investigate the role of the cerebellum in the control of externally triggered and internally generated saccadic eye movements of high and low memory impact, in six healthy volunteers. Memory-guided saccades to remembered locations of 3 targets (triple-step saccades) in contrast to either central fixation or to visually guided saccades activated the cerebellar hemispheres predominantly within lobuli VI-crus I. The same areas were activated when an analogous visuospatial working memory task was contrasted to the triple-step saccades. Visually guided saccades activated the posterior vermis and the triple-step saccades, contrasted to the working memory task, activated predominantly the posterior vermis and paravermal regions. Our data confirm the primary involvement of the posterior vermis for visually-triggered saccadic eye movements and present novel evidence for a role of the cerebellar hemispheres in the mnemonic and visuospatial control of memory-guided saccades.

Adult↗
PubMed2004

The mirror neuron system and action recognition.

Mirror neurons, first described in the rostral part of monkey ventral premotor cortex (area F5), discharge both when the animal performs a goal-directed hand action and when it observes another individual performing the same or a similar action. More recently, in the same area mirror neurons responding to the observation of mouth actions have been also found. In humans, through an fMRI study, it has been shown that the observation of actions performed with the hand, the mouth and the foot leads to the activation of different sectors of Broca's area and premotor cortex, according to the effector involved in the observed action, following a somatotopic pattern which resembles the classical motor cortex homunculus. These results strongly support the existence of an execution-observation matching system (mirror neuron system). It has been proposed that this system is involved in action recognition. Experimental evidence in favor of this hypothesis both in the monkey and humans are shortly reviewed.

Animals↗
PubMed2004

Motor functions of the Broca's region.

Broca's region in the dominant cerebral hemisphere is known to mediate the production of language but also contributes to comprehension. This region evolved only in humans and is constituted of Brodmann's areas 44 and 45 in the inferior frontal gyrus. There is, however, evidence that Broca's region overlaps, at least in part, with the ventral premotor cortex. We summarize the evidence that the motor related part of Broca's area is localized in the opercular portion of the inferior frontal cortex, mainly in area 44 of Brodmann. According to our own data, there seems to be a homology between Brodmann area 44 in humans and the monkey area F5. The non-language related motor functions of Broca's region comprise complex hand movements, associative sensorimotor learning and sensorimotor integration. Brodmann's area 44 is also a part of a specialized parieto-premotor network and interacts significantly with the neighboring premotor areas.

Animals↗
PubMed2003

Mirror apraxia affects the peripersonal mirror space. A combined lesion and cerebral activation study.

Mirror apraxia is a condition in which patients with lesions of the posterior parietal cortex have deficits in reaching to objects presented through a mirror. The aim of the present study was to investigate possible mechanisms underlying this disorder. First, we addressed the question of whether mirror apraxia is exhibited to the same extent in peripersonal and in body space. Four patients with lesions of the posterior parietal lobe on either side and with marked mirror apraxia were required to reach for objects that were presented to them through a mirror and located either in body space (i.e. on the body surface) or in peripersonal space (i.e. in the reaching distance). Whereas reaching for objects located in body space was flawless in all patients, the performance deteriorated when the same objects were transferred to the peripersonal space. Although the objects were located only a few centimetres above the body surface, the patients reached towards the virtual object in the mirror. Based on these results we suggest that mirror apraxia may originate from a dissociation between the representations of body schema and peripersonal space and that objects located on the body surface become integrated into the body schema. In the second part of the study, using positron emission tomography study (PET), we studied the cerebral activation pattern during reaching to objects presented through a mirror in the peripersonal space in healthy subjects. The results show that increased neural activity in the anterior part of the intraparietal sulcus and in the dorsal premotor cortex was bound to the transformation of the target position from the mirror space to the real space. In contrast, the activity related to object localization in the mirror occurred at the parieto-occipital junction. Both mirror and arm transformation involved the medial posterior part of the superior parietal lobule, putatively area V6a. The results demonstrate that acting through a mirror is processed in a number of cortical areas of the dorsal stream.

Aged↗
PubMed2003

A fronto-parietal circuit for tactile object discrimination: an event-related fMRI study.

Previous studies of somatosensory object discrimination have been focused on the primary and secondary sensorimotor cortices. However, we expected the prefrontal cortex to also become involved in sequential tactile discrimination on the basis of its role in working memory and stimulus discrimination as established in other domains. To investigate the contributions of the different cerebral structures to tactile discrimination of sequentially presented objects, we obtained event-related functional magnetic resonance images from seven healthy volunteers. Our results show that right hand object exploration involved left sensorimotor cortices, bilateral premotor, parietal and temporal cortex, putamen, thalamus, and cerebellum. Tactile exploration of parallelepipeds for subsequent object discrimination activated further areas in the dorsal and ventral portions of the premotor cortex, as well as parietal, midtemporal, and occipital areas of both cerebral hemispheres. Discriminating a parallelepiped from the preceding one involved a bilateral prefrontal-anterior cingulate-superior temporal-posterior parietal circuit. While the prefrontal cortex was active with right hemisphere dominance during discrimination, there was left hemispheric prefrontal activation during the delay period between object presentations. Delay related activity was further seen in the anterior intraparietal area and the fusiform gyrus. The results reveal a prominent role of the human prefrontal cortex for somatosensory object discrimination in correspondence with recent models on stimulus discrimination and working memory.

Adult↗
PubMed2002

Speech listening specifically modulates the excitability of tongue muscles: a TMS study.

The precise neural mechanisms underlying speech perception are still to a large extent unknown. The most accepted view is that speech perception depends on auditory-cognitive mechanisms specifically devoted to the analysis of speech sounds. An alternative view is that, crucial for speech perception, it is the activation of the articulatory (motor) gestures that generate these sounds. The listener understands the speaker when his/her articulatory gestures are activated (motor theory of speech perception). Here, by using transcranial magnetic stimulation (TMS), we demonstrate that, during speech listening, there is an increase of motor-evoked potentials recorded from the listeners' tongue muscles when the presented words strongly involve, when pronounced, tongue movements. Although these data do not prove the motor theory of speech perception, they demonstrate for the first time that word listening produces a phoneme specific activation of speech motor centres.

Acoustic Stimulation↗
PubMedDate not supplied

Neural circuits involved in the recognition of actions performed by nonconspecifics: an FMRI study.

Functional magnetic resonance imaging was used to assess the cortical areas active during the observation of mouth actions performed by humans and by individuals belonging to other species (monkey and dog). Two types of actions were presented: biting and oral communicative actions (speech reading, lip-smacking, barking). As a control, static images of the same actions were shown. Observation of biting, regardless of the species of the individual performing the action, determined two activation foci (one rostral and one caudal) in the inferior parietal lobule and an activation of the pars opercularis of the inferior frontal gyrus and the adjacent ventral premotor cortex. The left rostral parietal focus (possibly BA 40) and the left premotor focus were very similar in all three conditions, while the right side foci were stronger during the observation of actions made by conspecifics. The observation of speech reading activated the left pars opercularis of the inferior frontal gyrus, the observation of lip-smacking activated a small focus in the pars opercularis bilaterally, and the observation of barking did not produce any activation in the frontal lobe. Observation of all types of mouth actions induced activation of extrastriate occipital areas. These results suggest that actions made by other individuals may be recognized through different mechanisms. Actions belonging to the motor repertoire of the observer (e.g., biting and speech reading) are mapped on the observer's motor system. Actions that do not belong to this repertoire (e.g., barking) are essentially recognized based on their visual properties. We propose that when the motor representation of the observed action is activated, the observer gains knowledge of the observed action in a "personal" perspective, while this perspective is lacking when there is no motor activation.

Adult↗