The embodied typist: Bimanual actions are modulated by words' implied motility and number of evoked limbs.

The planning and execution of manual actions can be influenced by concomitant processing of manual action verbs. However, this phenomenon manifests in varied ways throughout the literature, ranging from facilitation to interference effects. Suggestively, stimuli across studies vary randomly in two potentially relevant variables: verb motility and effector quantity (i.e., the amount of movement and the number of hands implied by the word, respectively). Here we examine the role of these factors during keyboard typing, a strategic bimanual task validated in previous works. Forty-one participants read and typed high and low motility items from four categories: bimanual, unimanual, and non-manual action verbs, as well as minimally motoric verbs. Motor planning and execution were captured by first-letter lag (the lapse between word presentation and first keystroke) and whole-word lag (the lapse between the first and last keystroke). We found that verb motility modulated action planning and execution, both stages being delayed by high (relative to low) motility verbs. Effector quantity also influenced both stages, which were facilitated by bimanual verbs relative to unimanual verbs and non-manual verbs (this effect being confined to high motility items during action execution). Accordingly, motor-language coupling effects seem sensitive to words' implied motility and number of evoked limbs. These findings refine our understanding of how semantics influences bodily movement.

The negation-induced forgetting effect remains even after reducing associative interference.

Recent research has provided evidence that negation processing recruits the neural network of response inhibition (de Vega et al., 2016). Furthermore, inhibition mechanisms also play a role in human memory. In two experiments, we aimed to assess how producing a negation in a verification task may impact long-term memory. Experiment 1 used the same memory paradigm as Mayo et al. (2014), consisting of several phases: first, reading a story describing the activity of a protagonist, immediately followed by a "yes-no" verification task, then a distractive task, and finally an incidental free recall test. Consistent with the previous results, negated sentences were recalled worse than affirmed sentences. Yet, there is a possible confounding between the effect of negation itself and the associative interference of two conflicting predicates - the original and the modified one - in negative trials. To avoid this, Experiment 2 modified the paradigm by including a story describing the activities of two protagonists in such a way that the affirmed and denied verification sentences had the same content, and only differed in the attribution of a specific event to the correct or wrong protagonist. The negation-induced forgetting effect was still powerful, while controlling for potential contaminating variables. Our finding would support that the impaired long-term memory could be ascribed to reusing the inhibitory mechanism of negation.