One approach to assisting linguistic expression in individuals with developmental disabilities is to physically assist them, for example by applying touch to their torso or arm, as they type characters on a keyboard or screen. There has been significant controversy over the extent to which the facilitator and not the user authors texts written with such assistance. It has been suggested that these texts are entirely the by-products of the facilitators’ unconscious and ideomotor cueing of the users’ movements towards the keyboard. Here, we use quantitative linguistic analysis techniques to investigate whether the texts produced by users with developmental disabilities exhibit their own stylistic contributions in addition to the influence of their facilitators. In Study 1, we investigate whether it is possible to identify a set of users’ stylistic fingerprints when they are all assisted by the same facilitator. In Study 2, we examine whether the users’ texts retain their individual stylistic characteristics even when the texts have been produced with the assistance of multiple facilitators. The results show that the users’ stylistic signature is detectable alongside that of their facilitator, suggesting that the texts generated by disabled users with physical assistance should be viewed as co-authored rather than wholly authored by the facilitators. The implications of these results for the users’ learning, development and quality of life are discussed.

Many techniques have attempted to provide physical support to ease the execution of a typing task by individuals with developmental disabilities (DD). These techniques have been controversial due to concerns that the support provider’s touch can influence the typed content. The most common interpretation of assisted typing as an ideomotor phenomenon has been qualified recently by studies showing that users with DD make identifiable contributions to the process. This paper suggests a neurophysiological pathway by which touch could lower the cognitive load of seated typing by people with DD. The required sensorimotor processes (stabilizing posture and planning and executing manual reaching movements) and cognitive operations (generating and transcribing linguistic material) place concurrent demands on cognitive resources, particularly executive function (EF). A range of developmental disabilities are characterized by deficits in sensorimotor and EF capacity. As light touch has been shown to facilitate postural coordination, it is proposed that a facilitator’s touch could assist the seated typist with sensorimotor and EF deficits by reducing their sensorimotor workload and thereby freeing up shared cognitive resources for the linguistic elements of the task. This is the first theoretical framework for understanding how a facilitator’s touch may assist individuals with DD to contribute linguistic content during touch-assisted typing.