Last night, I read a cool paper by Bergen and colleagues on the role of embodiment in understanding language. The idea is that portions of the brain that are used for perception and motor activity also play a role in understanding language via a process referred to as “simulation”.
Variations of the Perky effect can be used to study language understanding. For example, if a person is simulating while understanding language, it may be harder for him to use that same part of the brain in a visual or motor task. This is exactly what Bergen et al. found:
In Experiment 1, participants viewed sentences whose verbs literally denoted up or down, such as “The cork rocketed,” an “UP” sentence. At the same time, they had to characterize pictures of objects that were either located at the top or bottom of a screen. When the objects were located at the top, they were slower to do so, demonstrating an interference effect that may have occurred because they were simulating an “UP” sentence. This effect was also observed for “DOWN” sentences and objects located at the bottom of the screen.
Experiment 2 was the same, except up/down nouns were used instead of verbs. The experimenters again found an interference effect in the same direction. This suggests that the specific lexical entry isn’t what causes the simulation, but instead understanding the sentence as a whole may.
In Experiment 3, sentences containing verbs that expressed metaphorical motion were used (for example, “The prices climbed.”). There was no interference effect, nor was there an effect in Experiment 3, in which abstract, non-metaphorical verbs (such as “the percentage decreased”) were used. Together, these add support to the idea that the meaning of a sentence as a whole triggers simulation, rather than individual words.
Then this morning, I read a post about a paper that counters Bergen et al.’s findings. In the fMRI study reported, participants were shown nouns, verbs, noun-like nonwords, and verb-like nonwords (their endings were what signaled whether they were noun- or verb-like). The authors found that when viewing verbs and verb-like nonwords, participants’ premotor cortices were activated more than when viewing nouns and noun-like nonwords. They took this as an indication that the observed cortical responses to action words result from ortho-phonological probabilistic cues to grammar class, as opposed to embodied motor representations.
But, what about context? We rarely come in contact with words in isolation, but instead with words embedded in the context of a sentence, and sentences in their contexts too. Since the methods in the anti-embodied language study aren’t reflective of the real-life situations in which we encounter language, are they meaningful? How can we reconcile a these two studies?