Multisensory cueing facilitates naming in aphasia

Abstract

Background: Impaired naming is a ubiquitous symptom in all types of aphasia, which often adversely impacts independence, quality of life, and recovery of affected individuals. Previous research has demonstrated that naming can be facilitated by phonological and semantic cueing strategies that are largely incorporated into the treatment of anomic disturbances. Beneficial effects of cueing, whereby naming becomes faster and more accurate, are often attributed to the priming mechanisms occurring within the distributed language network.

Objective: We proposed and explored two novel cueing techniques: (1) Silent Visuomotor Cues (SVC), which provided articulatory information of target words presented in the form of silent videos, and (2) Semantic Auditory Cues (SAC), which consisted of acoustic information semantically relevant to target words (ringing for "telephone"). Grounded in neurophysiological evidence, we hypothesized that both SVC and SAC might aid communicative effectiveness possibly by triggering activity in perceptual and semantic language regions, respectively.

Methods: Ten participants with chronic non-fluent aphasia were recruited for a longitudinal clinical intervention. Participants were split into dyads (i.e., five pairs of two participants) and required to engage in a turn-based peer-to-peer language game using the Rehabilitation Gaming System for aphasia (RGSa). The objective of the RGSa sessions was to practice communicative acts, such as making a request. We administered SVCs and SACs in a pseudorandomized manner at the moment when the active player selected the object to be requested from the interlocutor. For the analysis, we compared the times from selection to the reception of the desired object between cued and non-cued trials.

Results: Naming accuracy, as measured by a standard clinical scale, significantly improved for all stimuli at each evaluation point, including the follow-up. Moreover, the results yielded beneficial effects of both SVC and SAC cues on word naming, especially at the early intervention sessions when the exposure to the target lexicon was infrequent.

Conclusions: This study supports the efficacy of the proposed cueing strategies which could be integrated into the clinic or mobile technology to aid naming even at the chronic stages of aphasia. These findings are consistent with sensorimotor accounts of language processing, suggesting a coupling between language, motor, and semantic brain regions.

Trial registration: NCT02928822 . Registered 30 May 2016.

Keywords: Aphasia; Lexical access; Multisensory cueing; Neurorehabilitation; Stroke; Word-finding.

Fig. 1

a Illustration of the Interaction Time (IT) measure, possible moves, and speech- acts. b Example of the materials. Left: stimuli undergoing SAC, right: stimuli undergoing SVC. c Fit for each participant’s averaged IT over the therapy interval for all the stimuli undergoing Silent Visuomotor (SVC, violet) and Semantic Auditory (SAC, red) cueing. Upper panels: Lines represent linear regression models for individual participants including cued and non-cued trials. Lower panels: Median ITs of all the participants including all stimuli for each therapy session

Fig. 2

a Evolution of median ITs for cued on non-cued stimuli over the therapy sessions. Lines represent nonlinear regression models for cued and non-cued visuomotor (violet) and auditory (red) cues. b Quantification of differences in ITs for SVC and SAC between cued and non-cued stimuli in the early (first 15) and late (last 15) therapy sessions