By Meghan Chua
Say you’re given a list of six random words. You hear them once, and after a short delay, you have to repeat as many as you can remember.
Your recall ability is based on what’s known as your working memory span. But it’s limited by constraints that vary from person to person and may be based on an individual’s experience with language.
“Understanding the nature of working memory is particularly important for understanding how humans are able to do all the varied tasks that we do,” said Steve Schwering, a psychology PhD student in the Language & Cognitive Neuroscience Lab at UW–Madison.
Schwering’s research on working memory helps to inform an innovative project, led by psychology professor Maryellen MacDonald, that was selected for a UW2020 grant. The project tests the action basis of language and language production, exploring what links exist between language production and motor production.
As it turns out, many of the constraints that influence working memory are also constraints on motor production, Schwering says. In both speaking and action, people tend to do the easiest thing first. Second, a tendency toward repetition – saying the same words and phrases often, or producing the same action the same way – is shared between the two.
These common constraints could also hint at something more.
“We’re seeing if language production planning and motor production planning are more than just parallel processes,” Schwering said. “We’re trying to see if they actually share some sort of planning mechanism.”
To do so, the team set up experiments testing whether language production is influenced by a simultaneous physical action. In the experiment, participants are asked to study and recall sentences. When they repeat the sentence, the researchers pay attention to how many times they insert the word “that” in an optional place in the sentence.
“That” serves as an easy insertion, giving the person more time to recall the sentence. Schwering said that when people are asked to tap on the keyboard at the same time as recalling the sentence, they generally use the optional “that” more often.
“It tends to suggest that people are experiencing some sort of interference or difficulty in planning an utterance when they’re engaging in this simultaneous motor task, which suggests that language and action do share some sort of processing mechanism,” he said.
In the past, Schwering says the research worlds of language and motor production have rarely intersected, despite their parallels. The UW2020 project brings together researchers from both areas to explore the possible connections, with collaborators including kinesiology professor Andrea Mason, English and linguistics professor Eric Raimy, Stanford University professor of linguistics Thomas Wasow, and Penn State University associate professor of psychology Daniel Weiss.
That collaboration is a good opportunity for researchers to understand whether the shared properties of language and action are indicative of a deep, underlying process across both, Schwering said. Such a discovery could reconceptualize the traditional language research theory that language planning and syntax are unique to humans.
Furthermore, Schwering said the research could also inform treatments for individuals with motor production difficulty and language deficits, including dyslexia.
“If we are finding shared planning mechanisms, that could help us identify treatments for action planning deficits through interventions with language, and deficits with language planning through action,” he said.
The UW2020 initiative supports innovative and groundbreaking research at the University of Wisconsin–Madison with the potential to transform a field of study. UW2020 grants are supported by the Wisconsin Alumni Research Foundation (WARF) with combined funding from the Graduate School and other sources.