Summary: When people with language disorders such as aphasia speak, their communication partners are more likely to pay attention to the speaker’s hand movements and gestures. Gestures, researchers say, may help supplement understanding of what is being verbally communicated.
Source: University of Zurich
When words fail, gestures can help to get the message across—especially for people who have a language disorder.
An international research team has now shown that listeners attend the gestures of people with aphasia more often and for much longer than previously thought. This has implications for the use of gestures in speech therapy.
People who suffer from an acquired language disorder due to a brain injury—for example after a stroke, traumatic brain injury or brain tumor—often have difficulties communicating with others.
Previous research on aphasia indicates that these patients often try to express their needs using hand gestures. It was previously assumed that conversation partners pay relatively little attention to such non-verbal forms of communication—but this assumption was based on research involving participants without language disorders.
Communicating with gestures
A new study from the University of Zurich, carried out together with researchers from the Netherlands and Japan, looked at whether gestures receive more attention if the verbal communication is impeded by aphasia.
The researchers showed healthy volunteers video clips in which people with and without speech disorders described an accident and a shopping experience. As the participants watched the video clips, their eye movements were recorded.
Focus of attention shifts
“Our results show that when people have very severe speaking difficulties and produce less informative speech, their conversation partner is more likely to pay attention to their hand movements and to look longer at their gestures,” says Basil Preisig of the Department of Comparative Language Science at UZH.
In people who have no limitations in verbal production, hand gestures are granted less attention. Thus, it seems that listeners shift their attention when the speaker has a speech impediment and focus more on the speaker’s nonverbal information provided through gestures.
“For people with aphasia, it may be worth using gestures more in order to be better understood by the other person,” says Preisig.
Using gestures as a specific tool in therapy
Published in Neuropsychologia, the present study not only illustrates the importance of gestures in communication, but also reinforces their relevance in speech rehabilitation.
“Individuals with aphasia should be encouraged in therapy to use all available forms of communication. This includes increased use of gestures. In addition, their family and friends need to learn about hand gestures to improve communication,” Preisig believes.
About this language and communication research news
Gesture in the eye of the beholder: An eye-tracking study on factors determining the attention for gestures produced by people with aphasia
Co-speech hand gestures are an ubiquitous form of nonverbal communication, which can express additional information that is not present in speech.
Hand gestures may become more relevant when verbal production is impaired, as in speakers with post-stroke aphasia. In fact, speakers with aphasia produce more gestures than non-brain damaged speakers.
Furthermore, there is evidence to suggest that speakers with aphasia produce gestures that convey information essential to understand their communication. In the present study, we addressed the question whether these gestures catch the attention of their addressees.
Healthy volunteers (observers) watched short video clips while their eye movements were recorded. These video clips featured speakers with aphasia and non-brain damaged speakers describing two different scenarios (buying a sweater or having witnessed an accident).
Our results show that hand gestures produced by speakers with aphasia are on average attended to longer than gestures produced by non-brain damaged speakers. This effect was significant even when we controlled for the longer duration of the gestural movements in speakers with aphasia.
Further, the amount of information in speech was also correlated with gesture attention. That is gestures produced by speakers with less informative speech were attended to more frequently. In conclusion, our findings suggest that listeners reallocate their attention and focus more strongly on non-verbal information from co-speech gestures if speech comprehension becomes challenging due to the speaker’s verbal production deficits.
These findings support a communicative function of co-speech gestures and advocate for instructing people with aphasia to communicate things in the form of gestures that cannot be expressed verbally because interlocutors take notice of these gestures.