Contextual Modulation of Mirror and Countermirror Sensorimotor Associations

Automatic imitation – the unintended copying of observed actions - is thought to be a behavioural product of the mirror neuron system (MNS). Evidence that the MNS develops through associative learning comes from previous research showing that automatic imitation is attenuated by counter-mirror training, in which the observation of one action is paired contingently with the execution of a different action. If the associative account of the MNS is correct, counter-mirror training should show context-specificity, because countermirror associations render action stimuli ambiguous, and ambiguity promotes contextual control. Two experiments are reported which confirm this prediction. In Experiment 1 we found less residual automatic imitation when human participants were tested in their counter-mirror training context. In Experiment 2, sensorimotor training where participants made action responses to novel abstract stimuli was insensitive to the same context manipulation, confirming that the former result was not a procedural artefact. Contextual modulation may enable the MNS to function effectively in spite of the fact that action observation often excites multiple conflicting MNS responses

Modulation of Brain Activity during Action Observation: Influence of Perspective, Transitivity and Meaningfulness

The coupling process between observed and performed actions is thought to be performed by a fronto-parietal perception-action system including regions of the inferior frontal gyrus and the inferior parietal lobule. When investigating the influence of the movements' characteristics on this process, most research on action observation has focused on only one particular variable even though the type of movements we observe can vary on several levels. By manipulating the visual perspective, transitivity and meaningfulness of observed movements in a functional magnetic resonance imaging study we aimed at investigating how the type of movements and the visual perspective can modulate brain activity during action observation in healthy individuals. Importantly, we used an active observation task where participants had to subsequently execute or imagine the observed movements. Our results show that the fronto-parietal regions of the perception action system were mostly recruited during the observation of meaningless actions while visual perspective had little influence on the activity within the perception-action system. Simultaneous investigation of several sources of modulation during active action observation is probably an approach that could lead to a greater ecological comprehension of this important sensorimotor process

Beyond sensorimotor segregation: On mirror neurons and social affordance space tracking

Mirror neuron research has come a long way since the early 1990s, and many theorists are now stressing the heterogeneity and complexity of the sensorimotor properties of fronto-parietal circuits. However, core aspects of the initial ‘ mirror mechanism ’ theory, i.e. the idea of a symmetric encapsulated mirroring function translating sensory action perceptions into motor formats, still appears to be shaping much of the debate. This article challenges the empirical plausibility of the sensorimotor segregation implicit in the original mirror metaphor. It is proposed instead that the teleological organization found in the broader fronto-parietal circuits might be inherently sensorimotor. Thus the idea of an independent ‘purely perceptual’ goal understanding process is questioned. Further, it is hypothesized that the often asymmetric, heterogeneous and contextually modulated mirror and canonical neurons support a function of multisensory mapping and tracking of the perceiving agents affordance space. Such a shift in the interpretative framework offers a different theoretical handle on how sensorimotor processes might ground various aspects of intentional action choice and social cognition. Mirror neurons would under the proposed “social affordance model” be seen as dynamic parts of larger circuits, which support tracking of currently shared and competing action possibilities. These circuits support action selection processes—but also our understanding of the options and action potentials that we and perhaps others have in the affordance space. In terms of social cognition ‘ mirror ’ circuits might thus help us understand not only the intentional actions others are actually performing—but also what they could have done, did not do and might do shortly

What We Know Currently about Mirror Neurons.

Mirror neurons were discovered over twenty years ago in the ventral premotor region F5 of the macaque monkey. Since their discovery much has been written about these neurons, both in the scientific literature and in the popular press. They have been proposed to be the neuronal substrate underlying a vast array of different functions. Indeed so much has been written about mirror neurons that last year they were referred to, rightly or wrongly, as "The most hyped concept in neuroscience". Here we try to cut through some of this hyperbole and review what is currently known (and not known) about mirror neurons

Creating the cognitive form of phonological units: The speech sound correspondence problem in infancy could be solved by mirrored vocal interactions rather than by imitation

Theories about the cognitive nature of phonological units have been constrained by the assumption that young children solve the correspondence problem for speech sounds by imitation, whether by an auditory- or gesture-based matching to target process. Imitation on the part of the child implies that he makes a comparison within one of these domains, which is presumed to be the modality of the underlying representation of speech sounds. However, there is no evidence that the correspondence problem is solved in this way. Instead we argue that the child can solve it through the mirroring behaviour of his caregivers within imitative interactions and that this mechanism is more consistent with the developmental data. The underlying representation formed by mirroring is intrinsically perceptuo-motor. It is created by the association of a vocal action performed by the child and the reformulation of this into an L1 speech token that he hears in return. Our account of how production and perception develop incorporating this mechanism explains some longstanding problems in speech and reconciles data from psychology and neuroscience

Method and evidence: Gesture and iconicity in the evolution of language

The aim of this paper is to mount a challenge to gesture-first hypotheses about the evolution of language by identifying constraints on the emergence of symbol use. Current debates focus on a range of pre-conditions for the emergence of language, including co-operation and related mentalising capacities, imitation and tool use, episodic memory, and vocal physiology, but little specifically on the ability to learn and understand symbols. It is argued here that such a focus raises new questions about the plausibility of gesture-first hypotheses, and so about the evolution of language in general. After a brief review of the methodology used in the paper, it is argued that existing uses of gesture in hominid communities may have prohibited the emergence of symbol use, rather than ‘bootstrapped’ symbolic capacities as is usually assumed, and that the vocal channel offers other advantages in both learning and using language. In this case, the vocal channel offers a more promising platform for the evolution of language than is often assumed

Reconceptualizing second-person interaction

Over the last couple of decades, most neuroscientific research on social cognition has been dominated by a third-person paradigm in which participating subjects are not actively engaging with other agents but merely observe them. Recently this paradigm has been challenged by researchers who promote a second-person approach to social cognition, and emphasize the importance of dynamic, real-time interactions with others. The present article's contribution to this debate is twofold. First, we critically analyze the second-person challenge to social neuroscience, and assess the various ways in which the distinction between second- versus third-person modes of social cognition has been articulated. Second, we put forward an alternative conceptualization of this distinction—one that gives pride of place to the notion of reciprocity. We discuss the implications of our proposal for neuroscientific studies on social cognition

Applauding with Closed Hands: Neural Signature of Action-Sentence Compatibility Effects

BACKGROUND: Behavioral studies have provided evidence for an action-sentence compatibility effect (ACE) that suggests a coupling of motor mechanisms and action-sentence comprehension. When both processes are concurrent, the action sentence primes the actual movement, and simultaneously, the action affects comprehension. The aim of the present study was to investigate brain markers of bidirectional impact of language comprehension and motor processes. METHODOLOGY/PRINCIPAL FINDINGS: Participants listened to sentences describing an action that involved an open hand, a closed hand, or no manual action. Each participant was asked to press a button to indicate his/her understanding of the sentence. Each participant was assigned a hand-shape, either closed or open, which had to be used to activate the button. There were two groups (depending on the assigned hand-shape) and three categories (compatible, incompatible and neutral) defined according to the compatibility between the response and the sentence. ACEs were found in both groups. Brain markers of semantic processing exhibited an N400-like component around the Cz electrode position. This component distinguishes between compatible and incompatible, with a greater negative deflection for incompatible. Motor response elicited a motor potential (MP) and a re-afferent potential (RAP), which are both enhanced in the compatible condition. CONCLUSIONS/SIGNIFICANCE: The present findings provide the first ACE cortical measurements of semantic processing and the motor response. N400-like effects suggest that incompatibility with motor processes interferes in sentence comprehension in a semantic fashion. Modulation of motor potentials (MP and RAP) revealed a multimodal semantic facilitation of the motor response. Both results provide neural evidence of an action-sentence bidirectional relationship. Our results suggest that ACE is not an epiphenomenal post-sentence comprehension process. In contrast, motor-language integration occurring during the verb onset supports a genuine and ongoing brain motor-language interaction

Zrcadlové neurony: Mechanizmy a funkce

Mirror neurons (MN) are a group of neurons with extraordinary visuomotor character. Their activation is connected to an observation of a certain action and its execution, if the action was already in motoric repertoire of the observer. MN were firstly identified in macaque's brain, with later identification in human's brain. The most important structures where we can find the MN are Broca's area located in the inferior part of frontal gyrus (IFG), premotor cortex and superior parietal lobule (SPL). The functions of MN are various, they take part in action understanding, imitation, learning and language. According to present knowledge, they were assigned a role in social cognition - while experiencing empathy and theory of mind (ToM). Empathy can be defined as sharing of another person's emotions. ToM highlights the importance of one's ability to represent metal states of other people, knowledge, wishes and experiences. It leads towards understanding and anticipating of another person's actions. Additionally to MN, amygdala, insula and basal ganglia are also important in processes of social cognition. Impairments of social cognitive skills are in autism, schizophrenia and psychopathy. Key words: mirror neuron system, motor area, social cognition, empathy, theory of mindZrcadlové neurony (MN) jsou výjimečnou skupinou neuronů s visuomotorickými vlastnostmi. Jejich aktivace je spojena jak s pozorováním konání druhé osoby, tak i s prováděním stejného úkonu, pokud již tyto činnosti patřily do motorického repertoáru pozorovatele. MN byly poprvé identifikovány u makaků, později došlo k jejich objevu u člověka. Nejdůležitější struktury, kde můžeme nalézt zrcadlové neurony, jsou Brokova oblast, která se nachází v inferiorní části frontálního gyru (IFG), premotorický kortex a superiorní parietální lalok (SPL). MN jsou nedílnou součástí pochopení činů ostatních, imitace, učení a jazyka. Dle dnešních poznatků mají také roli v sociální kognici - při prožívání empatie a teorie mysli (ToM). Empatií lze definovat jako sdílení pocitů druhé osoby. ToM zdůrazňuje schopnost reprezentovat mentální stavy jiných osob, poznatků, přání a zkušeností. Vede k schopnosti správného pochopení a anticipování konání pozorované osoby. Kromě MN se sociálně kognitivních procesů účastní i amygdala, inzula a bazální ganglia. Poruchy sociálně kognitivních schopností jsou pozorovány v autismu, schizofrenií a psychopatií. Klíčová slova: zrcadlové neurony, motorická oblast, sociální kognice, empatie, teorie mysliDepartment of ZoologyKatedra zoologieFaculty of SciencePřírodovědecká fakult