Global processing training to improve visuospatial memory deficits after right-brain stroke

Abstract

Visuospatial stimuli are normally perceived from the global structure to local details. A right-brain stroke often disrupts this perceptual organization, resulting in piecemeal encoding and thus poor visuospatial memory. Using a randomized controlled design, the present study examined whether promoting the global-to-local encoding improves retrieval accuracy in right-brain-damaged stroke survivors with visuospatial memory deficits. Eleven participants received a single session of the Global Processing Training (global-to-local encoding) or the Rote Repetition Training (no encoding strategy) to learn the Rey-Osterrieth Complex Figure. The result demonstrated that the Global Processing Training significantly improved visuospatial memory deficits after a right-brain stroke. On the other hand, rote practice without a step-by-step guidance limited the degree of memory improvement. The treatment effect was observed both immediately after the training procedure and 24 h post-training. Overall, the present findings are consistent with the long-standing principle in cognitive rehabilitation that an effective treatment is based on specific training aimed at improving specific neurocognitive deficits. Importantly, visuospatial memory deficits after a right-brain stroke may improve with treatments that promote global processing at encoding.

Fig. 1.

(a) ROCF, (b) drawings produced by two right-brain-damaged stroke survivors when copying the ROCF, and (c) drawings reproduced immediately from memory after the copy trial.

Fig. 2.

Study flowchart. IRB = Institutional Review Board; NOPP = Notice of Privacy Practices; HIPAA = Health Insurance Portability and Accountability Act; GDS = Geriatric Depression Scale; BIT = Behavioral Inattention Test; MMSE = Mini-Mental Status Exam; MTCF = Modified Taylor Complex Figure; ROCF = Rey–Osterrieth Complex Figure; MCGCF = Medical College of Georgia Complex Figure; IR = immediate recall; IPTR = immediate post-training recall; DR = delayed recall.

Fig. 3.

Tracing materials used in the training procedure: (a) tracing material for Global Processing Training and (b) tracing material for Rote Repetition Training.

Fig. 4.

Recognition test on ROCF: (a) subunit recognition; (b) spatial recognition; and (c) whole-figure recognition.

Fig. 5.

Accuracy scores over copy and recall trials of ROCF drawings. The error bars denote standard errors. IR = immediate recall; IPTR = immediate post-training recall; DR = delayed recall.

Fig. 6.

(a) IR accuracy scores and (b) copy organization scores at pretraining/screening (preT) and at follow-ups next day (postT1), 2 weeks (postT2), and 4 weeks post-training (postT3).