Cortical Motor Organization, Mirror Neurons, and Embodied Language: An Evolutionary Perspective

The recent conceptual achievement that the cortical motor system plays a crucial role not only in motor control but also in higher cognitive functions has given a new perspective also on the involvement of motor cortex in language perception and production. In particular, there is evidence that the matching mechanism based on mirror neurons can be involved in both pho-nological recognition and retrieval of meaning, especially for action word categories, thus suggesting a contribution of an action–perception mechanism to the automatic comprehension of semantics. Furthermore, a compari-son of the anatomo-functional properties of the frontal motor cortex among different primates and their communicative modalities indicates that the combination of the voluntary control of the gestural communication systems and of the vocal apparatus has been the critical factor in the transition from a gestural-based communication into a predominantly speech-based system. Finally, considering that the monkey and human premotor-parietal motor system, plus the prefrontal cortex, are involved in the sequential motor organization of actions and in the hierarchical combination of motor elements, we propose that elements of such motor organization have been exploited in other domains, including some aspects of the syntactic structure of language

The effect of synesthetic associations between the visual and auditory modalities on the Colavita effect

The Colavita effect refers to the phenomenon that when confronted with an audiovisual stimulus, observers report more often to have perceived the visual than the auditory component. The Colavita effect depends on low-level stimulus factors such as spatial and temporal proximity between the unimodal signals. Here, we examined whether the Colavita effect is modulated by synesthetic congruency between visual size and auditory pitch. If the Colavita effect depends on synesthetic congruency, we expect a larger Colavita effect for synesthetically congruent size/pitch (large visual stimulus/low-pitched tone; small visual stimulus/high-pitched tone) than synesthetically incongruent (large visual stimulus/high-pitched tone; small visual stimulus/low-pitched tone) combinations. Participants had to identify stimulus type (visual, auditory or audiovisual). The study replicated the Colavita effect because participants reported more often the visual than auditory component of the audiovisual stimuli. Synesthetic congruency had, however, no effect on the magnitude of the Colavita effect. EEG recordings to congruent and incongruent audiovisual pairings showed a late frontal congruency effect at 400–550 ms and an occipitoparietal effect at 690–800 ms with neural sources in the anterior cingulate and premotor cortex for the 400- to 550-ms window and premotor cortex, inferior parietal lobule and the posterior middle temporal gyrus for the 690- to 800-ms window. The electrophysiological data show that synesthetic congruency was probably detected in a processing stage subsequent to the Colavita effect. We conclude that—in a modality detection task—the Colavita effect can be modulated by low-level structural factors but not by higher-order associations between auditory and visual inputs. Keywords Synesthetic congruency Audiovisual integration Colavita effect Event-related potential

Integration of visual and auditory information by superior temporal sulcus neurons responsive to the sight of actions

& Processing of complex visual stimuli comprising facial movements, hand actions, and body movements is known to occur in the superior temporal sulcus (STS) of humans and nonhuman primates. The STS is also thought to play a role in the integration of multimodal sensory input. We investigated whether STS neurons coding the sight of actions also integrated the sound of those actions. For 23 % of neurons responsive to the sight of an action, the sound of that action significantly modulated the visual response. The sound of the action increased or decreased the visually evoked response for an equal number of neurons. In the neurons whose visual response was increased by the addition of sound (but not those neurons whose responses were decreased), the audiovisual integration was dependent upon the sound of the action matching the sight of the action. These results suggest that neurons in the STS form multisensory representations of observed actions. &amp

Development of the Mu Rhythm: Understanding Function Through Translational Research

The incidental discovery of mirror neurons (MN) has renewed interest in motor theories of development and has sparked considerable debate as to the existence and potential function of mirror neurons in humans. The use of invasive single-cell recordings, however, has precluded identification of single MNs in humans or developmental populations of non-human primates. Non-invasive techniques, such as the modulation of the mu rhythm in the electroencephalogram (EEG) of young infants and children, have demonstrated the existence of an action observation/execution matching system in humans. Moreover, the mu rhythm has become an effective tool for addressing questions of MN system ontogeny in other species. The aim of this project is to address two questions that have thus far remained untested. The goal of study one is to address the question of whether or not we can identify activation of the human action observation/execution system under conditions in which the participants cannot see themselves executing a grasping action. Evidence from study one further validates our EEG measures as representing activation of the putative human MN system. The goal of study two is to examine the origins of MNs in 3-day-old mother- and nursery-reared infant rhesus macaques and the extent to which differential experience may contribute to the MN system during episodes of neonatal imitation. The results of study one demonstrated activation of the putative human MN system to actions completed in the absence of visual feedback in both human adults and infants. The magnitude of mu rhythm activity in infants was significantly less than in the adults suggesting a role of experience in the formation of the putative human MN system. The results from study two further emphasized the role of early experience showing significantly greater modulation of the mu rhythm in the mother-reared compared to the nursery-reared infants to the observation of socio-affiliative facial gestures. The evidence of studies one and two are discussed within a developmental framework of ongoing behavioral development and highlight the role experience plays, not in the foundation of, but rather the elaboration of the MN system

Transitory Inhibition of the left anterior intraparietal sulcus impairs joint actions: a continuous Theta-Burst stimulation study

Although temporal coordination is a hallmark of motor interactions, joint action (JA) partners do not simply synchronize; they rather dynamically adapt to each other to achieve a joint goal. We created a novel paradigm to tease apart the processes underlying synchronization and JA and tested the causal contribution of the left anterior intraparietal sulcus (aIPS) in these behaviors. Participants had to synchronize their congruent or incongruent movements with a virtual partner in two conditions: (i) being instructed on what specific action to perform, independently from what action the partner performed (synchronization), and (ii) being instructed to adapt online to the partner's action (JA). Offline noninvasive inhibitory brain stimulation (continuous theta-burst stimulation) over the left aIPS selectively modulated interpersonal synchrony in JA by boosting synchrony during congruent interactions and impairing it during incongruent ones, while leaving performance in the synchronization condition unaffected. These results suggest that the left aIPS plays a causal role in supporting online adaptation to a partner's action goal, whereas it is not necessarily engaged in social situations where the goal of the partner is irrelevant. This indicates that, during JAs, the integration of one's own and the partner's action goal is supported by aIPS

Spectators’ aesthetic experience of sound and movement in dance performance:a transdisciplinary investigation

We utilize qualitative audience research and functional brain imaging (fMRI) to examine the aesthetic experience of watching dance both with and without music. This transdisciplinary approach was motivated by the recognition that the aesthetic experience of dance revealed through conscious interpretation could have neural correlates in brain activity. When audiences were engaged in watching dance accompanied by music, the fMRI data revealed evidence of greater intersubject correlation in a left anterior region of the superior temporal gyrus known to be involved in complex audio processing. Moreover, the qualitative data revealed how spectators derived pleasure from finding convergences between 2 complex stimuli (dance and music). Without music, greater intersubject correlation was found bilaterally in a posterior region of the superior temporal gyrus, showing that bodily sounds such as breath provide a more salient auditory signal than music in primary auditory regions. Watching dance without music also resulted in increased intersubject correlation among spectators in the parietal and occipitotemporal cortices, suggesting a greater influence of the body than when interpreting the dance stimuli with music. Similarly, the audience research found evidence of corporeally focused experience, but suggests that while embodied responses were common across spectators, they were accompanied by different evaluative judgments

Action execution, action perception and 'mirror' neurones

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Enriched learning : Behavior, brain, and computation

Open Access via the Elsevier Agreement Funder: German Research Foundation: KR 3735/3-1,MA 9552/1-1 Acknowledgments We thank Agnieszka Konopka, Antje Proske, Joost Rommers, and Anna Zamm for providing useful comments on an earlier version of the manuscript; Mingyuan Chu for feedback on Figure 1; and Stefan Kiebel for feedback on Box 3. This work was supported by the German Research Foundation (grants KR 3735/3-1, KR 3735/3-2, and MA 9552/1-1).Peer reviewedPublisher PD