Patterns of finger-tracking in Italian early readers with Autism Spectrum Disorder

Background: Of late, the synergistic interaction of eye and hand movements in the exploration of a visual scene displayed on a computer touchscreen was shown to provide a congruent signature of the "attention maps" of subjects with autism spectrum disorders (ASD). A familiar context where this visual and tactile interaction is exploited is when children use the finger of their dominant hand to point the letters of written words as they are reading, particularly at early stages of their literacy development. In the present work, a dedicated app running on a common tablet is used to capture and analyse the finger-tracking behaviour of children with ASD while they are reading few episodes of a connected text on the tablet touchscreen. The reader's voice is also recorded through the tablet built-in microphone. The sliding movements of the finger across the tablet touchscreen are discretized into a series of densely distributed "touch events", which are then mapped onto the text lines in much the same way eye fixations are projected onto a sequence of words using an eye-tracker. Reading texts are linguistically annotated, to control for levels of reading difficulty, and finger-tracking times are associated with linguistic glosses.Objectives: Investigate patterns of finger-tracking as a potential non biological marker for identification of children with ASD .Methods: A preliminary analysis is offered of evidence of the finger-tracking behaviour of 20 Italian children with high functioning ASD, aged 7-11 years, while they are engaged in reading. A grade-matched control group of children with typical development was included. Patterns of finger-tracking are assessed in connection with three complementary aspects of reading behaviour: (1) word recognition, (2) pace of reading of multi-word intonation units, and (3) text comprehension, controlled by asking children a few multiple-choice questions on text content after each reading session.Results: Considerable variation in levels of reading ability was observed in the ASD sample, with a few children showing clear evidence of impaired reading comprehension. However, fluent readers with ASD exhibit the same correlation between accurate decoding (assessed by measuring per-word reading speed) and high levels of reading comprehension found in controls. Likewise, decoding rates were found to significantly increase with increasing grade levels, following the typical developmental pattern observed in controls. On a less local level of linguistic analysis, the reading pace of ASD readers fails to be modulated according to major syntactic structures, punctuation marks and direct speech turns, an effect concomitant with a flat prosodic intonation of oral reading.Conclusions: Preliminary findings confirm the heterogeneous nature of reading skills in children with ASD, showing that the use of a tablet screen as a tactile interface for visual perception analysis can offer a robust experimental protocol for large-scale, multimodal collection of naturalistic data for extensive assessment of readers with ASD.