Gravity matters for the neural representations of action semantics

Abstract

The dynamic relationship between the neural representation of action word semantics and specific sensorimotor experience remains controversial. Here, we temporarily altered human subjects’ sensorimotor experience in a 15-day head-down tilt bed rest setting, a ground-based analog of microgravity that disproportionally affects sensorimotor experiences of the lower limbs, and examined whether such effector-dependent activity deprivation specifically affected the neural processes of comprehending verbs of lower-limb actions (e.g. to kick) relative to upper-limb ones (e.g. to pinch). Using functional magnetic resonance imaging, we compared the multivoxel neural patterns for such action words prior to and after bed rest. We found an effector-specific (lower vs. upper limb) experience modulation in subcortical sensorimotor-related and anterior temporal regions. The neural action semantic representations in other effector-specific verb semantic regions (e.g. left lateral posterior temporal cortex) and motor execution regions were robust against such experience alterations. These effector-specific, sensorimotor-experience-sensitive and experience-independent patterns of verb neural representation highlight the multidimensional and dynamic nature of semantic neural representation, and the broad influence of microgravity (hence gravity) environment on cognition.

The Influence of Long-Term Football Training on Neural Representation of Action Verb Semantics

“…Previous study found a short-term motor experience modulation altered the neural representation of action verb semantics (Xiong et al, 2023). Similarity, Kontra et al (2015) found that the increased accuracy in understanding words denoting physical concepts (e.g., angular momentum) after hands-on learning, as opposed to merely observing the consequences of wheel manipulation, is mediated by greater activation in the primary motor (M1) and somatosensory (S1) cortices.…”

“…Furthermore, our nding lls a gap in previous research, which traditionally could not directly provide strong evidence that perceptual motor experience can dynamically regulate the neural representation of verb semantics. Xiong et al (2023) demonstrated that perceptual motor experience can regulate semantic neural representations, but the researchers were unable to directly observe changes in neural representation patterns in the action execution regions before and after the intervention. Our study, by employing football players who have acquired more foot-related action experience in their long-term life, successfully identi ed the impact of foot action experience on semantic neural representation in the sensorimotor and associated cortices.…”

Long-term motor training enhances functional connectivity between semantic and motor regions in an effector-specific manner: evidence from elite female football athletes

“…Pulvermüller, 2005Pulvermüller, , 2013; Gallese & Cuccio, 2018). According to embodied theories, the semantic system can undergo plastic changes due to sensorimotor experiences (Xiong et al 2023;Beilock et al 2008). That is, short-or longterm sensorimotor experiences can alter the related semantic representations in the brain.…”

“…That is, short-or longterm sensorimotor experiences can alter the related semantic representations in the brain. For example, following a 15-day period of head-down tilt bed rest, the brain's representations for foot action verbs in subcortical motor regions and the left anterior temporal region were reduced (Xiong et al 2023). Similarly, Beilock et al demonstrated that sports motor experience enhances action-related language understanding by recruiting the left dorsal lateral premotor cortex (Beilock et al 2008).…”