Task related modulation of the motor system during language processing

Abstract

Recent neurophysiological and brain imaging studies have shown that the motor system is involved in language processing. However, it is an open question whether this involvement is a necessary requisite to understand language or rather a side effect of distinct cognitive processes underlying it. In order to clarify this issue we carried out three behavioral experiments, using a go-no go paradigm. Italian verbs expressing hand actions, foot actions or an abstract content served as stimuli. Participants used their right hands to respond. In Experiment 1, in which a semantics decision task with an early delivery of the go signal (during processing language material) was used, slower responses were found for hand action-related verbs than for foot action-related verbs. In Experiment 2, using the same task with either an early or a delayed delivery of the go signal (when language material had been already processed), no difference was found between responses to the two verb categories in the delayed delivery condition. In Experiment 3, in which a lexical decision task with an early delivery of the go signal was used, again no difference between the two verb categories was found. The present findings demonstrate that during language processing the modulation of the motor system crucially occurs while performing a semantics decision task, thus supporting the notion that this involvement is a necessary step to understand language rather than a side effect of upstream cognitive processes.

Are the motor features of verb meanings represented in the precentral motor cortices? Yes, but within the context of a flexible, multilevel architecture for conceptual knowledge

“…These studies, among many others (e.g., Sato et al, 2008;Mirabella et al, 2012;Aravena et al, 2012Aravena et al, , 2014, suggest that verb-induced motor activation is not a rigid, inflexible affair, but is instead sensitive to attentional and situational factors that we are only beginning to understand. It is essential to realize, however, that the mere fact that there is some variability regarding when and how the motor features of verb meanings are retrieved does not imply that those features are not really long-term components of the concepts or that they are not really subserved by the precentral motor cortices.…”

Neural Dissociations between Action Verb Understanding and Motor Imagery

“…For instance, Hauk, Johnsrude, and Pulvermuller (2004) found overlap in premotor cortex between movement of foot and fingers and during reading of foot-or hand-related action verbs (e.g., "kick", "pick"). Likewise, areas in premotor cortex activated during observation of actions done with different effectors are also activated on reading of sentences describing these actions (AzizZadeh, Wilson, Rizzolatti, & Iacoboni, 2006; see also Raposo, Moss, Stamatakis, & Tyler, 2009;Boulenger, Hauk, & Pulvermuller, 2009;Tettamanti et al, 2005; but see Postle, McMahon, Ashton, Meredith, & de Zubicaray, 2008;Sato, Mengarelli, Riggio, Gallese, & Buccino, 2008). From these and other findings, it has been concluded that understanding action language involves activating parts of premotor cortex in a somatotopic way, as is also observed during motor control (e.g., Woolsey, 1963).…”

Brain dynamics in the comprehension of action-related language. A time-frequency analysis of mu rhythms

“…One of these issues is the need to determine whether language-induced motor activations are exclusively lexical or are dependent to some extent on the semantic context. One possibility is that the activation of the motor cortex occurs automatically about 150-200 ms after the onset of action verbs, as part of their lexical processing (Pulvermüller et al, 2005;Boulenger et al, 2006;Buccino et al, 2001;Nazir et al, 2008;Sato et al, 2008). Another alternative is that the activation of the motor cortex associated with reading is a non-automatic, context-dependent process, involving lexical-semantic integration across the sentence.…”