Publications

Abstract

We introduce a new method for measuring prediction and language-vision interactions: tracking the trajectories of hand-reaching movements in Virtual Reality (VR) environments. Spatiotemporal trajectory tracking of hand-reaching movements in VR offers an ecologically valid yet controlled medium for conducting experiments in an environment that mirrors characteristics of real-world behaviors. Importantly, it enables tracking the continuous dynamics of processing on a single-trial level. In an exploratory experiment L2 speakers heard predictive or non-predictive sentences (e.g., “The barber cuts the hair” vs. “The coach remembers the hair”). Participants’ task was to move their hands as quickly and as accurately as possible towards the object most relevant to the sentence. We measured reaction times (RTs) and hand-reaching trajectories as indicators of predictive behavior. There was a main effect of predictability: Predictable items were touched faster than unpredictable ones. Importantly, uncertainty was captured using spatiotemporal survival analysis by prolonged fluctuations in upward and downward vertical hand movements before making a final move to target or distractor. Self-correction of prediction errors was revealed by participants switching the direction of hand-reaching movements mid-trial. We conclude that the Virtual Hand Paradigm enables measuring the onset and dynamics of predictive behavior in real time in single and averaged trial data and captures (un)certainty about target objects and the self-correction of prediction error online in ‘close to real-world’ experimental settings. The new method has great potential to provide additional insights about time-course and intermediate states of processing, provisional interpretations and partial target commitments that go beyond other state-of-the-art methods.

Abstract

Dealing with text is crucial in modern societies. However, not everyone acquires sufficient literacy skills during school education. This systematic review summarizes and synthesizes research on adults with low literacy skills (ALLS) in alphabetic writing systems, includes results from behavioral and neurobiological studies, and compares these findings with those on developmental dyslexia given that this developmental disorder is one possible explanation for low literacy skills in adulthood. Twenty-seven studies focusing on the cognitive profile of ALLS met the three predefined criteria of reading level, age, and education. Results showed that ALLS performed worse than literate adults in various tasks at skill and information processing level, and exhibited structural and functional differences at the neurobiological level. The cognitive profile of ALLS was closer to that of primary school children than of literate adults. However, relative to children, ALLS’ literacy skills relied less on phonological and more on orthographic strategies. A narrative comparison of results with meta-analyses on developmental dyslexia showed large, though not complete, overlap in the cognitive profiles. The present results helps to better understand the literacy skills and reading-related cognitive functions of ALLS and may support the development of tailored interventions directed to the specific cognitive difficulties ALLS have.