Different kinds of embodied language: A comparison between Italian and Persian languages

Highlights

• Culture modulates the cross-talk between language and action.

• The Persians show a stronger inhibition effect in the congruent/concrete condition.

• In the Italian sample abstract sentences are processed faster than concrete ones.

• The Italians show instead of an inhibition, a tendency towards a facilitation effect.

Abstract

It is debated whether only concrete but also abstract, figurative sentences, e.g.: “She grasps the cup” vs. “She grasps the concept”, are grounded in the sensorimotor system. Importantly, studies on sentences with action verbs and motor system activation have been conducted so far only with WEIRD samples (Western cultures, in North American and European countries). The aim of our work is to investigate the relationship between language and motor responses using both concrete and abstract sentences in Italian and Persian languages. In the present study, Italian and Persian participants were asked to read the sentences on the screen. The sentences referred either literally or metaphorically to motor actions. They were accompanied by a video displaying a movement that could be congruent or incongruent with the one described in the sentence. Participants were asked to re-execute the movement observed and subsequently they had to perform the task evaluating whether the sentence made sense or not. In the Italian sample a strong effect of concreteness was present, especially in the congruent but also in the incongruent condition. In the Persian sample, instead, there was an inhibition effect of congruent trials, particularly with concrete sentences, and in the incongruent trials no difference in RTs between abstract and concrete sentences was present. Results indicate that cross-cultural differences have to be taken into account when investigating the relationship between language and action.

Introduction

Do people of different cultures comprehend action related language in a different way?

The fact that action words and sentences recruit sensorimotor information is quite an established finding. Many consolidated research lines address this issue. Here we will focus on three of them, i.e. the studies on the relationship between action verbs and involvement of effectors, the studies on the Action Sentence Compatibility (ACE) effect, and the studies on the spatial interference effect. Importantly, most studies within these research lines were conducted with Western participants. We will now briefly describe these research lines, and propose a study in which action-language integration is investigated with a cross-cultural approach.

When we process action verbs and sentences entailing action verbs, we implicitly activate the effector to which the words refer. Seminal EEG and fMRI studies have demonstrated that different areas of the brain are activated when reading verbs referring to different effectors, such as ‘kick’, ‘lick’, ‘pick’ (Hauk et al., 2004, Pulvermüller et al., 2001, Tettamanti et al., 2005), and that part of the brain is activated in a somatotopic way. Results obtained with transcranial magnetic stimulation (TMS) are contrasting. With a combined TMS and behavioral study Buccino et al. (2005) found a decrease in amplitude of MEPs recorded from hand muscles while listening to hand-action-related sentences (e.g. s/he sewed the skirt), and from foot muscles when listening to foot-related sentences (e.g. s/he kicked the ball). This finding is quite robust, even if not always replicated (Gianelli & Dalla Volta, 2015). Other TMS studies (Oliveri et al., 2004; Pulvermüller, 2005) and behavioral studies show a facilitation: for example, Scorolli and Borghi (2007) found a facilitation when reading sentences related to the foot and to the mouth and concurrently producing a response with the implied effector. Behaviorally, reading the sentence “he/she sewed the skirt” yielded longer response times with hand than with foot responses system, while the opposite was true for sentences such as “He/she kicked the ball”; interference was also found by Sato, Mengarelli, Riggio, Gallese, and Buccino (2008), but only with tasks implying deep semantic processing and not with more shallow lexical decision tasks. Overall, the most consistent pattern of results seems to show an early interference (but Gianelli and Dalla Volta (2015) and Pulvermueller (2005) found an early facilitation) in case of congruency between the effector implied by the verb and the one used to respond, and a late facilitation (but Sato et al., 2008, did not find it). In any case, all results converge in showing the action-language cross-talk. In recent work Miller, Brookie, Wales, Wallace, and Kaup (2018) performed 8 experiments in which they combined behavioral with ERPs tasks. They found a facilitation in RTs in case of congruency between the effector implied by the sentence and the one involved to respond, but the ERP (Event-related Potentials) analyses showed that ERPs differed for hand versus foot movements, but not for hand- versus foot-associated words. This invites to be cautious as it might suggest that language-related compatibility effects on RTs might emerge before action processing, hence might not be determinant for language comprehension.

Glenberg and Kaschak (2002) were the first to demonstrate the Action Sentence Compatibility (ACE) effect: when participants process sentences referring to a movement away from or toward their body (e.g. “open/close the drawer”), responses are facilitated in case of congruency between the action implied by a sentence and a real movement, away or toward the body, performed to respond. The typical ACE task is a sentence sensibility evaluation one, in which participants are required to decide whether the sentence makes sense or not – the effects hold however with a variety of slightly different tasks, such as evaluation of words (part vs. no part), and sentence sensibility evaluations (Borghi et al., 2004, Kaup et al., 2010), and for a variety of linguistic phenomena (e.g. sentences, words, sentences describing a state, (Kaup et al., 2010). The ACE effect is not exempt from criticism: recently Papesh (2015) has questioned the strength of the ACE effect, showing though Bayesian analyses that only a minority of the published results offer strong evidence for the ACE; one of the problems pointed out by the authors is that some studies lead to a facilitation and some to an interference effect.

When visual stimuli instead of only words are presented, a reversed effect is obtained, i.e. no facilitation but an interference is reported. Estes and Barsalou (2018) found the spatial interference effect, an effect of attention on language, showing that processing words with spatial associations (e.g., “bird”, “hat”) can reduce the capability to identify an unrelated visual target (e.g., X) at the implied location (i.e., at the top of a display). Even if the reliability of the effect was criticized, Estes and Barsalou (2018) reported a meta-analysis of 37 studies indicating that the effect was reliable. They collapsed studies using single words or sentences, in which the task was to detect the visual target and the target was unrelated to the words.

Overall results from the three lines of research we have outlined reveal that the meaning of the language is intimately tied to the actions it refers to. However, the results obtained are not always coherent. There is certainly a crosstalk between language and action, but some studies report that language processing interferes with action execution while others find a facilitation (notice that similar facilitation and interference effects are also found in the action observation literature (Brass, Bekkering, & Prinz, 2001). Different explanations of these contrasting results have been advanced. The most common is based on timing (e.g. Borreggine & Kaschak, 2006; de Vega, Moreno, & Castillo, 2013), and it has been explained with a model (Chersi, Thill, Ziemke, & Borghi, 2010) that predicts interference when action and language are simultaneously processed, and facilitation in case of delayed processing. Another explanation, which is not necessarily mutually exclusive with the first, points to the ease of integration between the sentence meaning and the motor action/visual stimuli: when the integration is scarce, then interference occurs (Kaschak et al., 2005).

While numerous studies have demonstrated a tight relationship between language and motor system, only a small subset of studies have investigated whether action sentences still recruit sensorimotor information when used in an abstract sense. For example, if we hear or read the sentence “He does not grasp the concept”, do we still activate the grasping movement? The more relevant to our aims are studies that investigate grounding of figurative language, and particularly those that concern non-idiomatic, novel metaphors/abstract usage. Most results show that also figurative sentences involve areas engaged in processing concrete sentences, and thus are grounded in the sensorimotor system (e.g. Boulenger et al., 2009, Boulenger et al., 2012, Desai et al., 2011; Saygin et al., 2010, Wallentin et al., 2005). There are, however, inconsistencies: some neuroimaging studies found motor/premotor activation for literal but not for figurative sentences (Aziz-Zadeh et al., 2006, Raposo et al., 2009). Specifically, Desai, Conant, Binder, Park, and Seidenberg (2013) showed that motor activation increased at the reduction of abstractness and conventionality of sentences. At a behavioral level, Scorolli et al. (2011) investigated response times using simple sentences resulting from combinations of concrete and abstract verbs/nouns (e.g. think of/caress the dog/idea). Mixed combinations led to longer response times, especially when the concrete word preceded the abstract one: this shifting cost can be ascribed to the hypothesis that concrete and abstract words are processed in parallel systems, one more linguistic and the other more sensorimotor, in line with the hypothesis of the WAT (Words As social Tools) theory (Borghi et al., 2019, Borghi et al., 2018); this hypothesis is supported by two further fMRI and TMS studies with the same stimuli (Sakreida et al., 2013, Scorolli et al., 2012).

The aim of our work is to investigate the relationship between language and motor responses using both concrete and abstract sentences in two different languages, Italian and Persian. To the best of our knowledge, studies on the relationship between sentences with action verbs have been conducted so far only with WEIRD (Henrich et al., 2010a, Henrich et al., 2010b) participants, i.e. participants of Western cultures, in North American and European countries. The only exception we are aware of is a study by Dennison and Bergen (2010) that showed that social and cultural practices influence the way people represent action language. They focus on a social practice common in Korean culture, in which people tend to use both hands to give objects to people of higher social status. The authors manipulated the status of the recipient of the presented sentences, using sentences such as “You are now giving a letter to (your) professor / to (your) younger sibling”. The acquired cultural practice is reflected in the ACE effect found: consistently with the acquired behavior, when presented with sentences referring to transfer of an object to high status recipients Korean participants were slower in bimanual responses, while unimanual responses were slower with sentences referring to low status recipients.

Even if this study shows the tight relation language-action in an Eastern culture, it does not compare Eastern and Western cultures using the same task. This is instead what we did in the present work.

Here, we used sentences that referred either literally or metaphorically to motor actions, with no directional information. They were accompanied by a video displaying a movement that could be congruent or incongruent with the one described in the sentence. Participants were asked to reproduce the movement observed in the video, then they had to perform the task evaluating whether the sentence made sense or not. We wanted to render the task as much implicit as possible, hence we opted for asking participants to perform a sentence sensibility judgment rather than requiring participants to evaluate the congruency between the action and the sentence. Since the displayed actions could involve the hands, we asked participants to respond by pressing a pedal when the sentence made sense and to refrain from responding when it did not: it was thus a go-nogo paradigm. Response times and accuracy were recorded. The reason why we decided to show participants a video and ask them to perform the observed movement is that we intended to boost motor activation, in order to verify its relationship with language processing.

To investigate whether the relationship between language and movement was the same across the two different languages/cultures, we submitted the same task to Italian and Iranian participants. Notice that these two cultures are likely not extreme in their Western/Eastern characteristics: for example, Italian culture is less individualistic than US culture (Henrich, Heine, & Norenzayan, 2010b), Iranian culture likely differs from East-Asian cultures on a variety of dimensions. Evidence has shown that belonging to a Western or an Eastern culture influences a variety of cognitive processes, starting from perception to decisional processes (review in Henrich et al., 2010b): Asian people tend to perceive the environment in a more holistic way, Western cultures are generally more analytic (Nisbett & Masuda, 2003); sense of agency differs as well - Western people tend to perceive events as the outcome of a choice more often than Eastern people (Savani, Markus, & Conner, 2008). Similarly to other Asian cultures, Iran can be considered as a collectivist culture (Hofstede, 1980), as testified by the presence of extended families, by the important role played by the ingroup, by the strong sense of national belonging, and also by some linguistic habits such as the frequent use of the pronoun “we” instead of “I”. Because of the strong differences between typical WEIRD cultures and Iranian culture, we intended to test whether the compatibility effect, found in WEIRD cultures, extended also to an Iranian sample.

Hypotheses. Based on the reviewed literature, we advanced the following hypotheses:

First, we predicted that there would be a difference between congruent and incongruent trials, likely leading to a facilitation of congruent over incongruent trials since the timer started after the sentence was presented.

Second, we predicted that action sentences would elicit faster responses compared to abstract ones, in line with the previously discussed results on figurative sentences and on the well-established concreteness effect, showing that concrete words/sentences are processed faster and recalled better than concrete ones (Paivio, 1990).

Third, and more crucially, we advanced the (directional) hypothesis that the congruency action-video with the sentence would be perceived as stronger in the case of concrete sentences, leading to a greater difference in response times between concrete congruent and incongruent trials than between abstract congruent and incongruent trials. As to the cultural and linguistic difference, we advanced two hypotheses, hypothesis four and five. Fourth, we intended to investigate whether the congruency effect we expected to replicate in the Italian sample would be extended or not to a different culture. Finally, we intended to investigate whether using a different language has a different effect with responses to concrete and abstract sentences. We expected the difference between the two languages to be more marked with abstract than with concrete sentences, in line with the idea that linguistic experience is more influential on abstract than on concrete sentences processing (Borghi et al., 2018, Borghi et al., 2019).