An ERP study of motor compatibility effects in action language

Syntax matters in shaping sensorimotor activation driven by nouns

Existing evidence has shown that adjectives modulate the grasp-compatibility effect elicited by object nouns. The aim of the present study was to investigate the role of syntax on the sensorimotor activation elicited by nouns in a grasp-compatibility task. We assessed two languages with different syntactic rules, Italian in Experiment 1 and English in Experiment 2. In both experiments, an adjective-noun pair was shown on the screen. The adjective was always in a pre-nominal position and denoted either a disadvantageous quality of the object graspability (e.g., sharp) or the object colour (e.g., reddish). Participants had to categorize the object nouns as natural or artifact, performing a precision or a power reach-to-grasp movement. On different trials, the grasp response was compatible or incompatible with the grip typically used to manipulate the object indicated by the noun. In Experiment 1 (Italian language) the adjective-noun order violated the syntactic order and no difference emerged between reaction times on compatible and incompatible trials (no grasp compatibility effect). In Experiment 2 (English language), the adjective-noun order followed the syntactic rule. Results showed a grasp-compatibility effect when a colour adjective was presented before a natural object noun. When a disadvantageous adjective preceded an artifact or a natural object noun, an inverted grasp-compatibility effect emerged with slower responses on compatible than incompatible trials. Taken together, these findings suggest that adjectives can shape the sensorimotor activation elicited by nouns of graspable objects only when the syntax is correct. Results are discussed with respect to embodied cognition theories.

The Semantics of Natural Objects and Tools in the Brain: A Combined Behavioral and MEG Study

Current literature supports the notion that the recognition of objects, when visually presented, is sub-served by neural structures different from those responsible for the semantic processing of their nouns. However, embodiment foresees that processing observed objects and their verbal labels should share similar neural mechanisms. In a combined behavioral and MEG study, we compared the modulation of motor responses and cortical rhythms during the processing of graspable natural objects and tools, either verbally or pictorially presented. Our findings demonstrate that conveying meaning to an observed object or processing its noun similarly modulates both motor responses and cortical rhythms; being natural graspable objects and tools differently represented in the brain, they affect in a different manner both behavioral and MEG findings, independent of presentation modality. These results provide experimental evidence that neural substrates responsible for conveying meaning to objects overlap with those where the object is represented, thus supporting an embodied view of semantic processing.

Influence of colour on object motor representation

Colour conveys specific information about the status/quality of an object; whereas its role in object recognition has been widely studied, little is known about its role in sensorimotor processes. We performed three experiments to assess whether colour influences the motor representation of graspable objects. In Experiment 1, we used a grasp compatibility task, in which participants categorized each object as natural or artifact, by performing reach-to-grasp movements. Response grasps could be compatible or incompatible with the ones normally used to manipulate the objects. Results showed faster reaction times for natural objects displayed in the correct colour compared with both opposite colour and correct colour artifact objects. In Experiment 2, to directly assess the effect of colour on object motor representation, we used an interference task in which an irrelevant object was shown while performing a pre-specified reach-to-grasp movement (i.e., verbal cues: small vs. large). Results highlighted a reversed compatibility effect when objects were shown in their correct colour, but only at the beginning of the movement (10 ms SOA). Finally, we run a third experiment using the same task as in Experiment 2. In this experiment, we compared the grasp compatibility effect driven by natural objects with the grasp compatibility effect driven by dangerous natural objects (e.g., cactus), which are objects that should not elicit a grasping program. The results of Experiment 3 confirm those of Experiment 2, highlighting also specific processes related to dangerous objects. Taken together, these results revealed that colour can be significant for the motor system, highlighting the close link between colour and shape, and also specific processes related to dangerous objects.

Evidence for the Concreteness of Abstract Language: A Meta-Analysis of Neuroimaging Studies

The neural mechanisms subserving the processing of abstract concepts remain largely debated. Even within the embodiment theoretical framework, most authors suggest that abstract concepts are coded in a linguistic propositional format, although they do not completely deny the role of sensorimotor and emotional experiences in coding it. To our knowledge, only one recent proposal puts forward that the processing of concrete and abstract concepts relies on the same mechanisms, with the only difference being in the complexity of the underlying experiences. In this paper, we performed a meta-analysis using the Activation Likelihood Estimates (ALE) method on 33 functional neuroimaging studies that considered activations related to abstract and concrete concepts. The results suggest that (1) concrete and abstract concepts share the recruitment of the temporo-fronto-parietal circuits normally involved in the interactions with the physical world, (2) processing concrete concepts recruits fronto-parietal areas better than abstract concepts, and (3) abstract concepts recruit Broca's region more strongly than concrete ones. Based on anatomical and physiological evidence, Broca's region is not only a linguistic region mainly devoted to speech production, but it is endowed with complex motor representations of different biological effectors. Hence, we propose that the stronger recruitment of this region for abstract concepts is expression of the complex sensorimotor experiences underlying it, rather than evidence of a purely linguistic format of its processing.

Adjectives Modulate Sensorimotor Activation Driven by Nouns

We performed three experiments to investigate whether adjectives can modulate the sensorimotor activation elicited by nouns. In Experiment 1, nouns of graspable objects were used as stimuli. Participants had to decide if each noun referred to a natural or artifact, by performing either a precision or a power reach-to-grasp movement. Response grasp could be compatible or incompatible with the grasp typically used to manipulate the objects to which the nouns referred. The results revealed faster reaction times (RTs) in compatible than in incompatible trials. In Experiment 2, the nouns were combined with adjectives expressing either disadvantageous information about object graspability (e.g., sharp) or information about object color (e.g., reddish). No difference in RTs between compatible and incompatible conditions was found when disadvantageous adjectives were used. Conversely, a compatibility effect occurred when color adjectives were combined with nouns referring to natural objects. Finally, in Experiment 3 the nouns were combined with adjectives expressing tactile or shape proprieties of the objects (e.g., long or smooth). Results revealed faster RTs in compatible than in incompatible condition for both noun categories. Taken together, our findings suggest that adjectives can shape the sensorimotor activation elicited by nouns of graspable objects, highlighting that language simulation goes beyond the single-word level.

Embodiment Effect on the Comprehension of Mandarin Manual Action Language: An ERP Study

Embodiment theories argue that language comprehension involves activating specific sensory-motor systems in the brain. Previous research performed in English and other Indo-European languages suggests that, when compared to compatible sentences referring to the same actions performed sequentially (e.g. 'After cleaning the wound he unrolled the bandage'), incompatible sentences describing two manual actions performed simultaneously by an agent (e.g. 'While cleaning the wound he unrolled the bandage') were worse understood and increased the event-related potentials (ERPs) component N400. The present ERP research aims to further investigate brain response to motor compatibility in native Mandarin speakers. The Chinese experimental sentences described two manual actions either in incongruent conditions marked by the Chinese parallel structure … … ('yibian…yibian…'/'while… while…') or congruent conditions marked by the sequential structure … … ('xian…ranhou…'/'firstly… then…'). The last action clause elicited larger fronto-central N400 in the incongruent condition, which reveals that there are semantic embodiment effects on the comprehension of Mandarin manual action language.

How meaning unfolds in neural time: Embodied reactivations can precede multimodal semantic effects during language processing

Research on how the brain construes meaning during language use has prompted two conflicting accounts. According to the 'grounded view', word understanding involves quick reactivations of sensorimotor (embodied) experiences evoked by the stimuli, with simultaneous or later engagement of multimodal (conceptual) systems integrating information from various sensory streams. Contrariwise, for the 'symbolic view', this capacity depends crucially on multimodal operations, with embodied systems playing epiphenomenal roles after comprehension. To test these contradictory hypotheses, the present magnetoencephalography study assessed implicit semantic access to grammatically constrained action and non-action verbs (n = 100 per category) while measuring spatiotemporally precise signals from the primary motor cortex (M1, a core region subserving bodily movements) and the anterior temporal lobe (ATL, a putative multimodal semantic hub). Convergent evidence from sensor- and source-level analyses revealed that increased modulations for action verbs occurred earlier in M1 (∼130-190 ms) than in specific ATL hubs (∼250-410 ms). Moreover, machine-learning decoding showed that trial-by-trial classification peaks emerged faster in M1 (∼100-175 ms) than in the ATL (∼345-500 ms), with over 71% accuracy in both cases. Considering their latencies, these results challenge the 'symbolic view' and its implication that sensorimotor mechanisms play only secondary roles in semantic processing. Instead, our findings support the 'grounded view', showing that early semantic effects are critically driven by embodied reactivations and that these cannot be reduced to post-comprehension epiphenomena, even when words are individually classified. Briefly, our study offers non-trivial insights to constrain fine-grained models of language and understand how meaning unfolds in neural time.

Are Sensory-Motor Relationships Encoded ad hoc or by Default?: An ERP Study

In this event-related potentials study we tested whether sensory-motor relations between concrete words are encoded by default or only under explicit ad hoc instructions. In Exp. 1, participants were explicitly asked to encode sensory-motor relations (e.g., “do the following objects fit in a pencil-cup?”), while other possible semantic relations remained implicit. In Exp. 2, using the same materials other group of participants were explicitly asked to encode semantic relations (e.g., “are the following objects related to a pencil-cup?”), and the possible sensory-motor relations remained implicit. The N400 component was sensitive to semantic relations (e.g., “desk” related to “pencil-cup”) both under implicit (Exp. 1) and explicit instructions (Exp. 2). By contrast, most sensory-motor relations (e.g., “pea” fitting in “pencil-cup”) were encoded ad hoc under explicit instructions (Exp. 1). Interestingly some sensory-motor relations were also encoded implicitly, but only when they corresponded to “functional” actions associated with high-related objects (e.g., “eraser” fitting in “pencil-cup”) and occurring at a late time window (500–650 ms; Exp. 2), suggesting that this type of sensory-motor relations were encoding by default.

Negation markers inhibit motor routines during typing of manual action verbs

We explored whether negation markers recruit inhibitory mechanisms during keyboard-based action-verb typing. In each trial, participants read two sentences: the first featured a context (There is a contract) and the second ended with a relevant verb which had to be immediately typed. Crucially, the verb could describe manual actions, non-manual actions or non-motor processes, with either affirmative (You do sign it) or negative (You don't sign it) polarity. We assessed the impact of verb type and polarity on two typing dimensions: motor programming (lapse between target onset and first keystroke) and motor execution (lapse between first and last keystroke). Negation yielded no effect on motor planning, but it selectively delayed typing execution for manual-action verbs, irrespective of the subjects' typing skills. This suggests that processing negations during comprehension of manual-action sentences recruits inhibitory mechanisms acting on same-effector movements. Our novel finding extends embodied models of language and effector-specific motor-language integration.

When syntax meets action: Brain potential evidence of overlapping between language and motor sequencing

This study aims to extend the embodied cognition approach to syntactic processing. The hypothesis is that the brain resources to plan and perform motor sequences are also involved in syntactic processing. To test this hypothesis, Event-Related brain Potentials (ERPs) were recorded while participants read sentences with embedded relative clauses, judging for their acceptability (half of the sentences contained a subject-verb morphosyntactic disagreement). The sentences, previously divided into three segments, were self-administered segment-by-segment in two different sequential manners: linear or non-linear. Linear self-administration consisted of successively pressing three buttons with three consecutive fingers in the right hand, while non-linear self-administration implied the substitution of the finger in the middle position by the right foot. Our aim was to test whether syntactic processing could be affected by the manner the sentences were self-administered. Main results revealed that the ERPs LAN component vanished whereas the P600 component increased in response to incorrect verbs, for non-linear relative to linear self-administration. The LAN and P600 components reflect early and late syntactic processing, respectively. Our results convey evidence that language syntactic processing and performing non-linguistic motor sequences may share resources in the human brain.

A touch with words: Dynamic synergies between manual actions and language

Manual actions are a hallmark of humanness. Their underlying neural circuitry gives rise to species-specific skills and interacts with language processes. In particular, multiple studies show that hand-related expressions - verbal units evoking manual activity - variously affect concurrent manual actions, yielding apparently controversial results (interference, facilitation, or null effects) in varied time windows. Through a systematic review of 108 experiments, we show that such effects are driven by several factors, such as the level of verbal processing, action complexity, and the time-lag between linguistic and motor processes. We reconcile key empirical patterns by introducing the Hand-Action-Network Dynamic Language Embodiment (HANDLE) model, an integrative framework based on neural coupling dynamics and predictive-coding principles. To conclude, we assess HANDLE against the backdrop of other action-cognition theories, illustrate its potential applications to understand high-level deficits in motor disorders, and discuss key challenges for further development. In sum, our work aligns with the 'pragmatic turn', moving away from passive and static representationalist perspectives to a more dynamic, enactive, and embodied conceptualization of cognitive processes.

Readers of narratives take the protagonist's geographical perspective. Evidence from an event-related potential study

This ERP study explores how the reader's brain is sensitive to the protagonist's perspective in the fictitious environment of narratives. Participants initially received narratives describing a protagonist living in a given geographical place. Later on they were given short paragraphs describing another character as "coming" or "going" to a place either close to or distant from the protagonist. Paragraphs referring to distant places elicited larger negative waves than those with places close to the protagonist. Moreover, narratives with the verb to come incoherent with the protagonist's perspective (e.g., "she came to the distant place") elicited larger negative-going waves in the 320-400ms time window than coherent paragraphs (e.g., "she came to the close place"). These results indicate that readers of narratives were able to take the protagonist's geographical perspective, showing discourse-level coherence effects when they read motion sentences with the marked deictic verb to come.

The linguistic context effects on the processing of body-object interaction words: An ERP study on second language learners

Embodied theories of cognition argue that the processing of both concrete and abstract concepts requires the activation of sensorimotor systems. The present study examined the time course for embedding a sensorimotor context in order to elicit sensitivity to the sensorimotor consequences of understanding body-object interaction (BOI) words. In the study, Event-Related Potentials (ERPs) were recorded while subjects performed a sentence acceptability task. Target BOI words were preceded by rich or poor sensorimotor sentential contexts. The behavioural results replicated previous findings in that high BOI words received a response faster than low BOI words. In addition to this, however, there was a context effect in the sensorimotor region as well as a BOI effect in the parietal region (involved in object representation). The results indicate that the sentential sensorimotor context contributes to the subsequent BOI processing and that action-and perception-related language leads to the activation of the same brain areas, which is consistent with the embodiment theory.

Spatial configuration of vertically related word pairs modulates the N400 component

This study examined the effect of spatial iconicity on the N400 component. Spatial iconicity is defined as the spatial arrangement of words on a screen relative to the spatial arrangement of their referents (e.g. attic-basement). In two experiments, electroencephalograms were recorded in 32 participants while performing a semantic relatedness judgment task on pairs of words that were either related or unrelated. All of the related word pairs were parts of objects that shared a vertical spatial relationship. In Experiment 1, the words of each pair were presented simultaneously on top of one another. Results showed that related word pairs presented in a spatial arrangement that mismatched the spatial relationship of their referents were associated with increased error rates as well as larger N400 components known to index semantic/conceptual processing cost. These findings thus suggest that the words automatically activated visuospatial simulations of their referents and that semantic/conceptual processing difficulty arose when the vertical arrangement of the word pairs was inconsistent with those simulations. In line with this interpretation, these effects were not present in Experiment 2 when the words of each pair were presented in succession in the middle of the screen. Overall, these results provide evidence that perceptual simulations contribute to some of the underlying processes of the N400 component (see video abstract, Supplemental digital content 1, http://links.lww.com/WNR/A304).