No evidence for embodiment: The motor system is not needed to keep action words in working memory

Increasing evidence implicates the sensorimotor systems with high-level cognition, but the extent to which these systems play a functional role remains debated. Using an elegant design, Shebani and Pulvermüller (2013) reported that carrying out a demanding rhythmic task with the hands led to selective impairment of working memory for hand-related words (e.g., clap), while carrying out the same task with the feet led to selective memory impairment for foot-related words (e.g., kick). Such a striking double dissociation is acknowledged even by critics to constitute strong evidence for an embodied account of working memory. Here, we report on an attempt at a direct replication of this important finding. We followed a sequential sampling design and stopped data collection at N=77 (more than five times the original sample size), at which point the evidence for the lack of the critical selective interference effect was very strong (BF01 = 91). This finding constitutes strong evidence against a functional contribution of the motor system to keeping action words in working memory. Our finding fits into the larger emerging picture in the field of embodied cognition that sensorimotor simulations are neither required nor automatic in high-level cognitive processes, but that they may play a role depending on the task. Importantly, we urge researchers to engage in transparent, high-powered, and fully pre-registered experiments like the present one to ensure the field advances on a solid basis.

Modality-specific attractor dynamics in dyadic entrainment

Rhythmic joint coordination is ubiquitous in daily-life human activities. In order to coordinate their actions towards shared goals, individuals need to co-regulate their timing and move together at the collective level of behavior. Remarkably, basic forms of coordinated behavior tend to emerge spontaneously as long as two individuals are exposed to each other’s rhythmic movements. The present study investigated the dynamics of spontaneous dyadic entrainment, and more specifically how they depend on the sensory modalities mediating informational coupling. By means of a novel interactive paradigm, we showed that dyadic entrainment systematically takes place during a minimalistic rhythmic task despite explicit instructions to ignore the partner. Crucially, the interaction was organized by clear dynamics in a modality-dependent fashion. Our results showed highly consistent coordination patterns in visually-mediated entrainment, whereas we observed more chaotic and more variable profiles in the auditorily-mediated counterpart. The proposed experimental paradigm yields empirical evidence for the overwhelming tendency of dyads to behave as coupled rhythmic units. In the context of our experimental design, it showed that coordination dynamics differ according to availability and nature of perceptual information. Interventions aimed at rehabilitating, teaching or training sensorimotor functions can be ultimately informed and optimized by such fundamental knowledge.

The Neural Circuitry Underlying the “Rhythm Effect” in Stuttering

Purpose Stuttering is characterized by intermittent speech disfluencies, which are dramatically reduced when speakers synchronize their speech with a steady beat. The goal of this study was to characterize the neural underpinnings of this phenomenon using functional magnetic resonance imaging. Method Data were collected from 16 adults who stutter and 17 adults who do not stutter while they read sentences aloud either in a normal, self-paced fashion or paced by the beat of a series of isochronous tones (“rhythmic”). Task activation and task-based functional connectivity analyses were carried out to compare neural responses between speaking conditions and groups after controlling for speaking rate. Results Adults who stutter produced fewer disfluent trials in the rhythmic condition than in the normal condition. Adults who stutter did not have any significant changes in activation between the rhythmic condition and the normal condition, but when groups were collapsed, participants had greater activation in the rhythmic condition in regions associated with speech sequencing, sensory feedback control, and timing perception. Adults who stutter also demonstrated increased functional connectivity among cerebellar regions during rhythmic speech as compared to normal speech and decreased connectivity between the left inferior cerebellum and the left prefrontal cortex. Conclusions Modulation of connectivity in the cerebellum and prefrontal cortex during rhythmic speech suggests that this fluency-inducing technique activates a compensatory timing system in the cerebellum and potentially modulates top-down motor control and attentional systems. These findings corroborate previous work associating the cerebellum with fluency in adults who stutter and indicate that the cerebellum may be targeted to enhance future therapeutic interventions. Supplemental Material https://doi.org/10.23641/asha.14417681

Dyadic Entrainment. An Overwhelming and Modality-Dependent Phenomenon.

Rhythmic joint coordination is ubiquitous in daily-life human activities. In order to coordinate their actions towards shared goals, individuals need to co-regulate their timing and move together at the collective level of behavior. Remarkably, basic forms of coordinated behavior tend to emerge spontaneously as long as two individuals are exposed to each other’s rhythmic movements. The present study investigated the dynamics of spontaneous dyadic entrainment, and more specifically how they depend on the sensory modalities mediating informational coupling. By means of a novel interactive paradigm, we showed that dyadic entrainment systematically takes place during a minimalistic rhythmic task despite explicit instructions to ignore the partner. Crucially, the interaction was organized by clear dynamics in a modality-dependent fashion. Our results showed highly consistent coordination patterns in visually-mediated entrainment, whereas we observed more chaotic and more variable profiles in the auditorily-mediated counterpart. The proposed experimental paradigm yields empirical evidence for the overwhelming tendency of dyads to behave as coupled rhythmic units. In the context of our experimental design, it showed that coordination dynamics differ according to availability and nature of perceptual information. Interventions aimed at rehabilitating, teaching or training sensorimotor functions can be ultimately informed and optimized by such fundamental knowledge.

The neural circuitry underlying the “rhythm effect” in stuttering

PurposeStuttering is characterized by intermittent speech disfluencies which are dramatically reduced when speakers synchronize their speech with a steady beat. The goal of this study was to characterize the neural underpinnings of this phenomenon using functional magnetic resonance imaging.MethodData were collected from 17 adults who stutter and 17 adults who do not stutter while they read sentences aloud either in a normal, self-paced fashion or paced by the beat of a series of isochronous tones (“rhythmic”). Task activation and task-based functional connectivity analyses were carried out to compare neural responses between speaking conditions and groups.ResultsAdults who stutter produced fewer disfluent trials in the rhythmic condition than in the normal condition. While adults who do not stutter had greater activation in the rhythmic condition compared to the normal condition in regions associated with speech planning, auditory feedback control, and timing perception, adults who stutter did not have any significant changes. However, adults who stutter demonstrated increased functional connectivity between bilateral inferior cerebellum and bilateral orbitofrontal cortex as well as increased connectivity among cerebellar regions during rhythmic speech as compared to normal speech.ConclusionModulation of connectivity in the cerebellum and prefrontal cortex during rhythmic speech suggests that this fluency-inducing technique activates a compensatory timing system in the cerebellum and potentially modulates top-down motor control and attentional systems. These findings corroborate previous work associating the cerebellum with fluency in adults who stutter and indicate that the cerebellum may be targeted to enhance future therapeutic interventions.

Rhythm in translation, with two accounts of Leconte de Lisle’s ‘Midi’

This article explores the translation of poetic rhythm: not the rhythm of the source text, but the rhythm of the translational act itself. This re-conception of translation’s rhythmic task is enabled by a translation designed for the polyglot, rather than for the monoglot, reader. In this new understanding of translational process, rhythm not only embodies the perceptual and cognitive experience of the translating subject, it also makes more intimate the relationship between language and voice, the linguistic and the paralinguistic. Furthermore, it has as much to do with the space of translation, its distribution on the page, as with its changing temporal modes. The translator, then, does not translate the rhythm of a text so much as a text’s capacity for rhythm, and that capacity includes both espousing the perspective of a translating ‘I’ and releasing what is not linguistically manifest in the source text. These propositions are tested in two translations of Leconte de Lisle’s ‘Midi’.

Does the motor system functionally contribute to keeping words in working memory? A pre-registered replication of Shebani and Pulvermüller (2013, Cortex)

Increasing evidence implicates the sensorimotor systems with high-level cognition, but the extent to which these systems play a functional role remains debated. Using an elegant design, Shebani and Pulvermüller (2013) reported that carrying out a demanding rhythmic task with the hands led to selective impairment of working memory for hand-related words (e.g., clap), while carrying out the same task with the feet led to selective memory impairment for foot-related words (e.g., kick). This striking double dissociation constitutes strong evidence for an embodied account of working memory, a system that has received scarce attention in the embodiment literature. However, the original study was likely underpowered and used suboptimal statistical analyses, raising questions about the robustness of the results. In fact, our Bayesian reanalysis with a more appropriate model yields inconclusive evidence for the effect (BF10 = 1.7). To re-examine this seminal finding, we here attempt an appropriately powered, fully pre-registered replication of the original study, following a sequential design with a maximal participant sample size over seven times that of the original (108 vs. 15). We will analyse the results with Bayesian generalized mixed models and use Bayes factors to quantify the evidence in support of the effect predicted by theories of embodied cognition.