Effector specific response activation during word processing
2013-01-01

Effector specific response activation during word processing Daniela K. Ahlberg (daniela.ahlberg@uni-tuebingen.de) Department of Psychology, University of Tubingen, Schleichstr. 4, 72076 Tubingen, Germany Carolin Dudschig (carolin.dudschig@uni-tuebingen.de) Department of Psychology, University of Tubingen, Schleichstr. 4, 72076 Tubingen, Germany Barbara Kaup (barbara.kaup@uni-tuebingen.de) Department of Psychology, University of Tubingen, Schleichstr. 4, 72076 Tubingen, Germany Abstract Theories of embodied cognition suggest that sensorimotor processes are involved in language comprehension processes. Recent studies suggested that sentences referring to actions that involve a typical effector (e.g. “He kicks the ball”) can systematically activate motor cortex areas that are involved in performing such actions (Hauk, Johnsrude & Pulvermuller, 2004). In behavioral studies, there is mixed evidence regarding the effects of effector-specific words on corresponding actions. In the current study, we investigated the effect of four word groups on subsequent motor responses involving the hand or the foot. The four word groups were (a) action verbs (e.g., kick, grasp) (b) nouns containing the lexeme ‘hand’ or ‘foot’ (e.g., handball, football) (c) nouns referring to objects that are typically manipulated by hand or foot (e.g., cup, shoe), and (d) as control items, nouns that have a spatial association with the upper or lower space (e.g., eagle, root) and which are known to activate locational information in paradigms where no reading is required. We found strong effector-specific compatibility effects revealing a facilitation effect in all noun-groups. Surprisingly, this effect was not present for the action-verbs. Implications of these findings will be discussed. Keywords: Embodied Cognition; Language Comprehension; Effectors Introduction Many of our daily activities involve language. We speak, we listen to people speaking, we read or we write at various occasions every day. However, in research on language processing there is still no agreement on theoretical assumptions concerning the processes and representations that are involved in language processing. For a long time, the propositional, amodal theory of language comprehension was the predominant view (Kintsch & van Dijk, 1978; Kintsch 1988; McKoon & Ratcliff, 1992). According to this view, the result of language comprehension is a meaning representation in an amodal propositional format that captures the content of the linguistic input and integrates it with the reader’s background knowledge which is also available in this format. Typically, embodied models of language understanding are viewed as the counterpart to these amodal theories of language processing (Barsalou, 1999). The main assumption of this approach is that language processing is closely connected to other cognitive systems, such as perception and action. There is a tremendous number of empirical studies providing evidence for the embodied view of language comprehension (for an overview, see Jirak, Menz, Buccino, Borghi & Binkofski, 2010). However, in many cases the individual results are somewhat inconsistent, and cannot be integrated into a coherent processing model. As a result, important theoretical questions concerning the embodied view are still unsolved, as for instance the question whether all kinds of sensorimotor activations are functionally relevant for comprehension or in contrast sometimes constitute a kind of epi-phenomenon. Before turning to these important issues, research first needs to investigate in more detail the individual phenomena, with the goal of arriving at more definite conclusions concerning the boundary conditions for the observed effects. In the present study, we aim to address the question, whether motor activation occurs in a specific manner when processing action related verbs (e.g., kick, grasp), or nouns referring to objects that are typically manipulated with the hand or the foot (e.g., brush, shoe). Evidence for an embodied view of language understanding has been reported in behavioral and neuroimaging paradigms. In the behavioral domain, observed interactions between language and visual- processing, and between language and motor processing are typically taken as strong evidence for an embodied model of language comprehension. For example, Zwaan, Stanfield and Yaxley (2002) reported that sentence processing can activate very specific visual representations. In their study, participants had to process sentences such as “The girl saw the egg in the frying pan” and subsequently respond to pictures of the target entity (egg). The pictures could either match the shape of the entity described in the sentences (e.g., a fried egg sunny side up) or mismatch the shape (e.g., an unbroken egg). Responses were faster in the matching than in the mismatching conditions, suggesting that readers had available a visual representation of an egg in the frying pan when reading the corresponding sentence. Evidence for the reactivation of motor representations during language comprehension was reported by Glenberg