Abstract: |
Background: Gesture is often used as a modality to promote recovery of communication in aphasia, both as a compensation device and as a facilitator of language recovery. To date, there has been no systematic analysis of the quantitative effects of gesture training for aphasia in light of the quality of the research methods undertaken. Aims: The aim of the current project was to systematically evaluate the scientific evidence for the effects of symbolic and nonsymbolic gestural training in post-stroke aphasia. Specifically, we aimed to evaluate the effects of gesture treatment for measures of verbal and nonverbal communication. Methods & Procedures: A systematic search of the literature was conducted between August and September 2012, on relevant electronic databases utilising 16 search terms. Study characteristics were summarised. The methodological quality of the studies was independently rated by the first two authors, using the PEDro and SCED scales for group and single-case experimental designs (SCEDs), respectively. Effect sizes were calculated where none was provided by the original manuscript. Results: This initial search yielded 177 citations, of which 23 met the inclusion and exclusion criteria: 4 group designs and 19 SCEDs. Of the 134 individuals who participated in these studies, the majority had nonfluent moderate?severe chronic aphasia. Methodological rigour was weak in the group studies, but 11 of the 19 SCEDs achieved high-quality scores of 8 or higher out of 10. Gesture training alone had nonsignificant effects on verbal production. Combined gesture + verbal training showed positive effects for verbal production of nouns and verbs for over 50% of participants, with a mixed pattern of generalisation to untrained words and contexts. Gesture + verbal training paradigms had limited advantage over those with verbal training alone. Significant gains in gesture production were reported for trained gestures only following gesture training protocols. Few studies have examined generalisation to discourse. The effects of training with nonsymbolic gestures were less conclusive. Conclusions: Comparative effect sizes support a benefit of combined gesture + verbal treatment for noun and verb production for some individuals with aphasia. Whether that benefit surpasses the results of verbal treatment alone is not well established. Symbolic gestures can be acquired by individuals with aphasia, although their communicative effectiveness requires further study. Overall, gestural training in aphasia, while generating some positive outcomes, is relatively understudied. There is a need for large-scale investigation taking into account the considerable participant variability. |