Representational precision in visual cortex reveals outcome encoding and reward modulation during action preparation

Why motor imagery is not really motoric: towards a re-conceptualization in terms of effect-based action control

Overt and imagined action seem inextricably linked. Both have similar timing, activate shared brain circuits, and motor imagery influences overt action and vice versa. Motor imagery is, therefore, often assumed to recruit the same motor processes that govern action execution, and which allow one to play through or simulate actions offline. Here, we advance a very different conceptualization. Accordingly, the links between imagery and overt action do not arise because action imagery is intrinsically motoric, but because action planning is intrinsically imaginistic and occurs in terms of the perceptual effects one want to achieve. Seen like this, the term 'motor imagery' is a misnomer of what is more appropriately portrayed as 'effect imagery'. In this article, we review the long-standing arguments for effect-based accounts of action, which are often ignored in motor imagery research. We show that such views provide a straightforward account of motor imagery. We review the evidence for imagery-execution overlaps through this new lens and argue that they indeed emerge because every action we execute is planned, initiated and controlled through an imagery-like process. We highlight findings that this new view can now explain and point out open questions.

Imitation of action-effects increases social affiliation

Imitating someone's actions influences social-affective evaluations and motor performance for the action model and the imitator alike. Both phenomena are explained by the similarity between the sensory and motor representations of the action. Importantly, however, theoretical accounts of action control hold that actions are represented in terms of their sensory effects, which encompass features of the movement but also features of an action's consequence in the outside world. This suggests that social-affective consequences of imitation should not be limited to situations in which the imitator copies the model's body movements. Rather, the present study tested whether copying the perceived action-effects of another person without imitating the eventual body movements increases the social-affective evaluation of this person. In three experiments, participants produced visual action-effects while observing videos of models who performed either the same or a different movement and produced either the same or a different action-effect. If instructions framed the action in terms of the movement, participants preferred models with similar movements (Experiment 1). However, if instructions framed the action in terms of the to-be produced action-effect in the environment, participants preferred models with similar action-effects (Experiments 2 and 3). These results extend effect-based accounts of action control like the ideomotor framework and suggest a close link between action control and affective processing in social interactions.

Neurophysiological correlates of perception-action binding in the somatosensory system

Action control requires precisely and flexibly linking sensory input and motor output. This is true for both, visuo-motor and somatosensory-motor integration. However, while perception–action integration has been extensively investigated for the visual modality, data on how somatosensory and action-related information is associated are scarce. We use the Theory of Event Coding (TEC) as a framework to investigate perception–action integration in the somatosensory-motor domain. Based on studies examining the neural mechanisms underlying stimulus–response binding in the visuo-motor domain, the current study investigates binding mechanisms in the somatosensory-motor domain using EEG signal decomposition and source localization analyses. The present study clearly demonstrates binding between somatosensory stimulus and response features. Importantly, repetition benefits but no repetition costs are evident in the somatosensory modality, which differs from findings in the visual domain. EEG signal decomposition indicates that response selection mechanisms, rather than stimulus-related processes, account for the behavioral binding effects. This modulation is associated with activation differences in the left superior parietal cortex (BA 7), an important relay of sensorimotor integration.