I recently wrote an article about the connection between language and visual memories in which the authors of the study concluded that the strong version of embodied cognition was not supported. Another recent article about embodiment came to a very different conclusion, which I thought I’d discuss further.

This study used a different kind of methodology in which subjects were asked to remember a series of words while performing an interference task. The words belonged to one of two groups: arm-related words, like grasp, braid, nip, wash, hack, and delve; or leg-related words, such as stride, plod, skate, inch, and dance.

There were four different interference conditions: a control condition, where there was no interference activity; an articulation condition, in which subjects had to repeat a nonsense syllable; an arm interference condition, in which subjects tapped a single paradiddle (e.g. LRLLRLRRLRLLRLRR) with their hands; and a foot interference condition in which they tapped the paradiddle with their feet. After the subjects were presented with four words, there was a six-second interval in which they were asked to perform the interference task, subsequent to which they were asked to repeat the four words they were shown.

Based on a weak embodiment view, like the one I detailed in my last post on this topic, verbal memory for both categories of words should have either been affected equally by both tasks or not affected at all, depending on exactly which theory you ascribe to. However, a strong embodiment view predicts that memory for arm-related words would be more affected by arm motions, and leg words by leg motion.

Although there wasn’t a statistically significant disruption, there was a trend toward significance supporting the strong embodiment view. There was a significant interaction of word type with moving body part, providing further support to the idea that semantic memory and sensorimotor representations are closely linked in the brain and the mind.

This study does provide some compelling evidence for strong embodiment, but it also raises a lot of questions. Is it possible that there’s some other process at work here? The authors mention several times that this particular methodology has been used to draw causal conclusions in the past, and so they feel confident in doing the same, but it’s possible to draw other conclusions from this data. Another question that deserves answering is whether the choice of specific arm- and leg-related words modulates the effect. Many of the leg words, for example, actually refer to whole-body motions that are driven by leg motions.

And even if we take this study to conclusively prove that sensorimotor representations are required to for working memory, what about long-term memory? And how might they modulate attention or other cognitive actions? This is an area that is going to receive a lot of attention in the near future, and I have high hopes for some very interesting results.

References

Shebani, Z., & Pulvermüller, F. (2013). Moving the hands and feet specifically impairs working memory for arm- and leg-related action words Cortex, 49 (1), 222-231 DOI: 10.1016/j.cortex.2011.10.005

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