Abstract
Purpose :
Recently, I developed a non-visual training method - The Cognitive-Kinesthetic (C-K) Memory Drawing Training - to enhance and study cross-modal plasticity in the visually impaired. The purpose was to assess quantitatively 1) enhancement of spatial memory, spatiomotor control, 2) transfer of the training effect to core spatial cognition, and 3) plasticity of top-down brain connectivity through this training.
Methods :
The C-K Training was run over for 5 days (2hrs/day), preceded and followed by three assessment modalities: 1) enhancement of spatial memory and precise spatiomotor control quantified by a custom, Computerized Similarity Coefficient (CSC); 2) Spatial-cognitive performance assessed through the standardized Cognitive Test for the Blind (CTB); 3) the underlying brain functions were assessed by functional Magnetic Resonance Imaging (fMRI) with a 3T Siemens Prisma, during performance of the training task and controls (tactile exploration of raised line drawings of faces and objects, tactile memory retrieval via drawing using our MR-compatible drawing tablet, and a scribble motor/memory control), and connectivity – by Granger Causalily (GC).
Results :
The CRI measures showed highly significant enhancement of detailed spatial memory and precise spatiomotor control. The CTB showed significant transfer of learning effect from the training general spatial-cognitive abilities. The fMRI & GC revealed that key memory structures causally influence the primary visual cortex (V1), which operated as a “viewing screen” for the memory-image to be externalized through the drawing recorded in the scanner.
Conclusions :
Together, the results demonstrate that, in low vision and blind patients, the novel approach of C-K training to draw-from-memory can serve as wide-range blindness rehabilitation technique, and provides a profound enhancement of (non-visual) spatial-cognitive abilities. This is the first study to demonstrate enhanced GC top-down connectivity from hippocampal memory structures to V1, implicating them as a potential source of the reorganization towards tactile representations that occurs in V1 in the blind brain.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.