EXPRESS: Your action does matter to me: examining the role of the co-actor’s action-effects in resolving the self-other discrimination problem

Sharing a task with another person can introduce the need to discriminate representations that refer to our own action from that of the other person’s. The current understanding is that information about the stimulus event drives the self-other discrimination process, as it promotes (via the reactivation of feature codes) the representation that encodes the corresponding action. However, this mechanistic explanation relies on experimental situations in which stimulus event information (e.g., spatial location) is always, and directly available. Thus, it remains unclear whether, and how we could successfully discriminate between self- and other-related action representations in the absence of such information. The present study addressed this unanswered question using a novel joint Simon task-based paradigm. We report the results of three experiments in which we manipulated the availability of stimulus event information into the contralateral space. Our findings demonstrate that participants are able to compensate for the absence of stimulus event information by relying on temporal features of their co-actor’s action-effects (Experiment 1). Even more surprising was that participants continued to monitor the temporal features of their co-actor’s actions even when given a verbal signal by their co-actor (Experiments 2a), or full access to the common workspace (Experiment 2b). Our results are strong evidence that the representation of actions is not purely stimulus driven. They suggest that the temporal dimension of the other person’s actions is able to drive the self-other discrimination process, in the same way as other perceptual dimensions and feature codes that are shared with the stimulus event.

Are treatment effects consistent with hypothesized mechanisms of action proposed for postoperative delirium interventions? Reanalysis of systematic reviews

Aim: Postoperative delirium (POD) is associated with increased morbidity and is poorly understood. The aim of this review was to identify putative mechanisms through re-analysis of randomized trials on treatment or prevention of POD. Materials & methods: A systematic review was performed to identify systematic reviews of treatments for POD. Constituent randomized controlled trials were identified, and interventions were grouped according to hypothesized mechanisms of action. Effects were meta-analyzed by hypothesized mechanism and timing of intervention. Results: A total of 116 randomized controlled trials described 47 individual interventions for POD, with nine mechanisms identified. The largest effects were observed for postoperative inflammation reduction, and preoperative reinforcement of sleep–wake cycle. Conclusion: This approach identifies treatments focused on mechanisms of action that may be front runners for future trials and interventions.

Sound-Action Symbolism

Recent evidence has shown linkages between actions and segmental elements of speech. For instance, close-front vowels are sound symbolically associated with the precision grip, and front vowels are associated with forward-directed limb movements. The current review article presents a variety of such sound-action effects and proposes that they compose a category of sound symbolism that is based on grounding a conceptual knowledge of a referent in articulatory and manual action representations. In addition, the article proposes that even some widely known sound symbolism phenomena such as the sound-magnitude symbolism can be partially based on similar sensorimotor grounding. It is also discussed that meaning of suprasegmental speech elements in many instances is similarly grounded in body actions. Sound symbolism, prosody, and body gestures might originate from the same embodied mechanisms that enable a vivid and iconic expression of a meaning of a referent to the recipient.