A study conducted by the UPV/EHU’s Lindy Lab research group involving 80 children between the ages of 3 and 9 has arrived at the conclusion that full metaphoric interpretation is achieved from the age of 6 onwards. However, the results indicate that the ability to intuit non-literal meanings begins to develop earlier. “It can be seen that at younger ages children have some grasp of figurative language, but do not master it and their ability is limited. At 6 they correctly identify its meaning, and it is later, around 10, when they seem to be able to explain metaphors,” explained Isabel Martín. The results of this research could shed light on the thesis that this PhD student is writing up on the comprehension of metaphorical language in individuals with both typical development and in those with an autism spectrum disorder; the aim is to compare what happens in both groups and thus better understand the minds of individuals with autism.

The author of the study explained that they used an innovative research method to reach these conclusions: “We initiated a new methodological trend in experimental psychology and psycholinguistics that allowed us to draw more nuanced conclusions than in existing pieces of work.” And it should be stressed that there are several studies that have analysed this issue, but their results are disparate. The UPV/EHU group has succeeded in bringing more complete information to the scientific debate by combining, for the first time ever, two different methodologies.

Firstly, they used the methodology of image selection. They set up an experiment in which each child listened to an audio in which a metaphor is stated (e.g. “Grasshoppers jump a lot; that child is a grasshopper”), while displaying four images (a jumping child, a running child, a beetle and a jumping grasshopper). Secondly, the participants had to choose the drawing that represented the message they had heard (the jumping child). “This methodology allowed us to find out that the 6-year-old participants understood figurative meanings, because it can be clearly seen at that age that they choose the appropriate representation,” said the researcher.

Infrared camera to nuance the results

However, the selection of images does not provide information on how each participant had processed the messages and to what extent he/she had considered other options. To find out these details, the UPV/EHU research team took advantage of each exercise proposed to analyse the participants’ eye movements as well.

While the participants were viewing the images, listening to the auditory stimulus and choosing the final drawing, an infrared camera measured eye movements: saccadic ones (rapid eyeball movements imperceptible to the naked eye) as well as their trajectories, and how attentively each image was viewed. Isabel Martín explained that these data enable one to find out how the participants processed what they had seen and heard: “The camera captures how their eyes move from one image to another and gives us information about what is going on inside their heads before they choose the picture they think is the right one: whether they experienced difficulties, which options they hesitated between.... Because the image they finally select is the result of a decision, which has followed a whole process.” The recording of eye movements allowed the researchers to look at the process in itself and to nuance the results obtained through the selection of images.

In fact, the combination of both methodologies made it possible to find out that, although children under 6 do not interpret metaphors clearly because they select the correct image less frequently, they do have a certain intuition for detecting figurative meanings. Through eye-tracking, the researchers detected when the participants hesitated when choosing the drawing. “Once they are absolutely sure about the meaning of the sentence, they don't think about it anymore and focus their gaze on the option they think is correct. But when in doubt, they look elsewhere. And that is what we were able to perceive in young children,” the researcher explained.

Additional information

Isabel Martín is a PhD student in the Department of Linguistics and Basque Studies. Specifically, in the Theoretical Linguistics Research Group (HiTT), of which the Lindy Lab subgroup is a part.