Processing abstract language modulates motor system activity

Abstract

Embodiment theory proposes that neural systems for perception and action are also engaged during language comprehension. Previous neuroimaging and neurophysiological studies have only been able to demonstrate modulation of action systems during comprehension of concrete language. We provide neurophysiological evidence for modulation of motor system activity during the comprehension of both concrete and abstract language. In Experiment 1, when the described direction of object transfer or information transfer (e.g., away from the reader to another) matched the literal direction of a hand movement used to make a response, speed of responding was faster than when the two directions mismatched (an action–sentence compatibility effect). In Experiment 2, we used single-pulse transcranial magnetic stimulation to study changes in the corticospinal motor pathways to hand muscles while reading the same sentences. Relative to sentences that do not describe transfer, there is greater modulation of activity in the hand muscles when reading sentences describing transfer of both concrete objects and abstract information. These findings are discussed in relation to the human mirror neuron system.

Keywords:

• Language
• Embodiment
• Abstraction
• Mirror neurons
• TMS

Acknowledgments

This work was supported by National Science Foundation (NSF) Grant BCS-0315434 to Arthur Glenberg, as well as by the University of Wisconsin, the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, and the Department of Neuroscience, University of Parma, Parma, Italy. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the funding agencies.

Notes

¹ It is worth underlining that in Italian the sentence “Andrea ti porta la pizza”, referred to as toward transfer (see Table 1), may be expressed also as “Andrea porta la pizza a te” where the personal pronoun is postponed to the object. Although this last construction is more parallel to the sentence “Tu porti la pizza ad Andrea” used as away transfer, we preferred the first one because it is more common in colloquial Italian.

² Separate analyses were conducted on the concrete and abstract sentences (although with reduced power). For the concrete sentences, the ACE interaction was not significant, F(1, 19) = 1.54, MSE = 3,253. However, there was an ACE interaction in the error rates, F(1, 19) = 4.14, MSE = 0.002 (4% errors when sentence direction mismatched response direction and 2% error when they matched). For the abstract sentences, the ACE interaction approached significance, F(1, 19) = 2.45, MSE = 4,853, p = .13, and there was no interaction in the analysis of error rates, F < 1.

³ Based on the Laudanna, Thornton, Brown, Burani, and Marconi (1995) database, the mean frequencies for the verbs are 124 and 27 for the sensible concrete transfer sentences and sensible abstract transfer sentences, respectively. The difference between the means should be treated with some caution, however, because it is greatly affected by the very high frequency of the Italian verb “dare” (“to give”).

⁴ We thank Rolf Zwaan for suggesting this account.

⁵ Separate analyses were conducted on the concrete and abstract sentences (although with reduced power). For the concrete sentences, the effect of sentence type approached significance, F(1, 8) = 3.90, MSE = 0.09, p = .08. For the abstract sentences, the effect of sentence type approached significance, F(1, 8) = 3.84, MSE = 0.05, p = .09.