HD-tDCS of primary and higher-order motor cortex affects action word processing

Abstract

The contribution of action-perception systems of the brain to lexical semantics remains controversial. Here, we used high-definition transcranial direct current stimulation (HD-tDCS) in healthy adults to examine the role of primary (left hand motor area; HMA) and higher-order (left anterior inferior parietal lobe; aIPL) action areas in action-related word processing (action verbs and manipulable nouns) compared to non-action-related control words (non-action verbs and non-manipulable nouns). We investigated stimulation-related effects at three levels of semantic processing: subliminal, implicit, and explicit. Broadly, we found that stimulation of HMA and aIPL resulted in relative facilitation of action-related language processing compared to non-action. HMA stimulation facilitated action verb processing in subliminal and implicit task contexts, suggesting that HMA helps represent action verbs even in semantically shallow tasks. HMA stimulation also facilitated manipulable noun comprehension in an explicit semantic task, suggesting that HMA contributes to manipulable noun comprehension when semantic demands are high. aIPL stimulation facilitated both manipulable noun and action verb processing during an implicit task. We suggest that both HMA and aIPL play a functional role in action semantics. HMA plays a general role in the semantics of actions and manipulable objects, while aIPL is important only when visuo-motor coordination is required for the action.

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

“…The IPL has been associated with the mirror neuron system, thought to be involved in understanding and imitating the actions of others (Rizzolatti & Sinigaglia, 2010). A recent study suggests that the IPL plays a critical role when visuo-motor coordination is required for action (Johari et al, 2022). As shown in Table 1 and Fig.…”

The concrete processing of Chinese action metaphors: an ERP study

“…Action-related language is currently a burgeoning area of research within the embodied semantic approach, aiming to investigate the intricate relationship between sensorimotor and semantic systems ( Vukovic et al, 2015 ; Tian et al, 2020 , 2023 ; Monaco et al, 2023 ). A series of electrophysiological studies have proved the embodiment of the processing of literal action language by showing the activation of the sensorimotor cortex during language comprehension ( Tettamanti et al, 2005 ; Aziz-Zadeh et al, 2006 ; D’Ausilio et al, 2009 ; Raposo et al, 2009 ; Kolb et al, 2010 ; Moody and Gennari, 2010 ; Fargier et al, 2012 ; Moseley and Pulvermüller, 2014 ; Gianelli and Dalla Volta, 2015 ; Vukovic et al, 2015 ; Johari et al, 2022 ). For example, the processing of literal action sentence “I grasp a knife” elicits activation in a left fronto-parieto-temporal circuit within the premotor cortex, exhibiting somatotopic organization ( Desai et al, 2011 ).…”

The Role of the Motor System in L1 and L2 Action Verb Processing for Chinese Learners of English: Evidence from Mu Rhythm Desynchronization

“…Over the past decades, a substantial amount of evidence indicating the involvement of the sensory-motor system in language processing has accumulated [5,[8][9][10][11][12][13][14]. For instance, when individuals read action words like "kick", "pick", and "lick", this process triggers the activation of brain regions associated with the preparation and execution of physical movements involving the legs, hands, and mouth [10].…”