Advanced Spatiomotor Rehabilitation for Navigation in Blindness & Visual Impairment

One of the most challenging tasks for blind and visually impaired individuals is navigation through a complex environment. The goal of the present multidisciplinary study is to increase spatial-cognition abilities in people who are blind or visually impaired through training with the previously-developed Cognitive-Kinesthetic Rehabilitation Training to improve navigation, and to investigate the resultant neuroplastic brain reorganization through multimodal brain imaging. In accordance with National Eye Institute (NEI) strategic goals, this multidisciplinary project will promote the development of well-informed new approaches to navigational rehabilitation, memory enhancement and cross-modal brain plasticity to benefit 'cutting edge' fields of mobile assistive technologies, vision restoration and memory facilitation for the aging brain.

The investigators propose a radical new multidisciplinary approach to navigation training in blindness and visual impairment. Successful navigation requires the development of an accurate and flexible mental, or cognitive, map of the navigational space and of the route trajectory required to travel from the current to the target location. The Cognitive-Kinesthetic (C-K) Rehabilitation Training that the PI has developed in the preceding period utilizes a unique form of blind memory-guided drawing to develop cognitive mapping to a high level of proficiency. Particular reliance must be placed on such mental maps (supported only by tactile and auditory inputs), and on the ability to use them effectively for spatiomotor control, when vision with its built-in spatial functionality is lost. There is, however, a fundamental gap in the practice of Orientation and Mobility (O&M), which is the lack of a specific emphasis on enhancement of these cognitive roots of spatiomotor activity, despite their known importance for navigation in the visually impaired. The investigators therefore propose a rigorous multidisciplinary approach to this issue, which lies at the intersection of the fields of spatiomotor rehabilitation, blindness assessment technologies, and brain function, each a focus of one Specific Aim. To train the spatial cognition abilities underlying successful navigation, the current proposal aims to translate the power of the C-K Rehabilitation Training to the domain of navigation. The blind and visually impaired trainees will quickly learn how to generate precise and stable cognitive maps of haptically explored raised-line images or tactile maps, and how to use the formed cognitive maps to confidently guide both drawing 'hand navigation' on a map-scale, and whole-body blind navigation on the macro-scale. Once translated to navigation, the preliminary data show that this efficient and enjoyable training will rapidly and sustainably enhance spatial cognition functions both for improved navigation performance and for enhancement of more general spatial cognitive skills. Beyond its practical advantages, the rapid and effective training protocol will also serve as an efficient tool to drive and study training-based neuroplasticity mechanisms through a comprehensive whole-brain multimodal brain imaging platform.

Since this is a regression analysis, all participants are assigned to the same Arm with blindness history and the demographics as covariates.

Training with tactile maps to improve spatial memory capability for enhanced navigational capabilities.

Change in blind map drawing speed from pre-training (Pre) to immediate post-training (Post1) timepoints

The trajectory of the drawing hand while performing memory-guided navigational tasks will be electronically recorded for assessment of from Pre to Post1 change in terms of drawing speed in cm/s. Note: The three timepoints of the study are: Pre: Immediately before the 5-day Cognitive-Kinesthetic training period Post1: Immediately after the 5-day Cognitive-Kinesthetic training period Post2: Within 3-6 months after Post1, without any training intervening between Post1 and Post2 The time frames for changes and maintenance assessment are given as ranges to allow for scheduling logistics but represent a single interval per participant for each measure.

Maintenance of change in blind map drawing speed from Post1 to extended post-training (Post2) timepoints

The trajectory of the drawing hand while performing memory-guided navigational tasks will be assessed for Post1 to Post2 change in drawing speed in cm/s.

The trajectory of the drawing hand while performing memory-guided navigational tasks will be assessed for Pre to Post1 change in navigation drawing errors in terms of number of incorrect turns.

The trajectory of the drawing hand while performing memory-guided navigational tasks will be assessed for Post1 to Post2 change in navigation drawing errors in terms of number of incorrect turns.

Change in total navigation time during blind macro-scale navigation of the shortest path from Pre to Post1 timepoints

A tactile map of the virtual layout will be explored and memorized; then, using the formed memory representation of the map, the participants will mentally plan the shortest route between two verbally-provided points on a street map, and walk along that route in the iPhone-encoded Virtual Environment within an Empty Real Space (iVEERS) system developed for this proposal. The iVEERS recorded shortest-path navigation trajectories will be assessed for Pre to Post1 change in total navigation time in s.

Maintenance of change in number of total navigation time during blind navigation of the shortest path at macro-scale from Post1 to Post2 timepoints

A tactile map of the virtual layout will be explored and memorized; then, using the formed memory representation of the map, the participants will mentally plan the shortest route between two verbally-provided points on a street map, and walk along that route in the iPhone-encoded Virtual Environment within an Empty Real Space (iVEERS) system developed for this proposal. The iVEERS recorded shortest-path navigation trajectories will be assessed for Post1 to Post2 change in terms of total navigation time measured in s.

Change in total number of contact errors during blind macro-scale navigation from Pre to Post1 timepoints

A tactile map of the virtual layout will be explored and memorized; then, using the formed memory representation of the map, the participants will mentally plan the shortest route between two verbally-provided points on a street map, and walk along that route in the iPhone-encoded Virtual Environment within an Empty Real Space (iVEERS) system developed for this proposal. The iVEERS recorded shortest-path navigation trajectories will be assessed for Pre to Post1 change in terms of total number of contact errors.

Maintenance of change in total number of contact errors during blind macro-scale navigation from Post1 to Post2 timepoints

A tactile map of the virtual layout will be explored and memorized; then, using the formed memory representation of the map, the participants will mentally plan the shortest route between two verbally-provided points on a street map, and walk along that route in the iPhone-encoded Virtual Environment within an Empty Real Space (iVEERS) system developed for this proposal. The iVEERS recorded shortest-path navigation trajectories will be assessed for Post1 to Post2 change in number of contact errors.

Whole-brain fMRI will be run to measure activation in the cortical navigation network while the participant plans the shortest paths between two locations based on their memory representations of explored raised-line tactile maps. The change in average activation in the cortical navigation network will be assessed from the Pre to Post1 timepoints in z-score units.

Whole-brain fMRI will be run to measure activation in the cortical navigation network while the participant plans the shortest paths between two locations based on their memory representations of explored raised-line tactile maps. The maintenance in average activation in the cortical navigation network will be assessed from the Post1 to Post2 timepoints in z-score units.

Whole-brain fMRI will be run to measure activation in the spatial working memory network while the participant plans the shortest paths between two locations based on their memory representations of explored raised-line tactile maps. The change in average activation in the spatial working memory network will be assessed from the Pre to Post1 timepoints in z-score units.

Whole-brain fMRI will be run to measure activation in the spatial working memory network while the participant plans the shortest paths between two locations based on their memory representations of explored raised-line tactile maps. The change in average activation in the spatial working memory network will be assessed from the Post1 to Post2 timepoints in z-score units.

The changes of the GC connectivity density in the navigation network from the Pre to Post1 will be assessed in terms of the connectivity density index, defined as the ratio of the number of significant GC connections to the number of network nodes.

The changes of the GC connectivity density in the navigation network from the Post1 to Post2 will be assessed in terms of the connectivity density index, defined as the ratio of the number of significant GC connections to the number of network nodes.

The transfer of the training effect to untrained spatio-cognitive abilities will be assessed for a Pre to Post1 change in terms of the score on the Cognitive Test for the Blind (CTB) of the McCarron-Dial Comprehensive Vocational Evaluation System in its standardized IQ-style units.

The maintenance of the training effect to untrained spatio-cognitive abilities will be assessed for a Post1 to Post2 change on the Cognitive Test for the Blind (CTB) of the McCarron-Dial Comprehensive Vocational Evaluation System measured in its standardized IQ-style units.

DTI will be used to assess the change in average voxelwise Fractional Anisotropy (FA) throughout the pathways of the cortical navigation network from the Pre to Post1 timepoints in FA z-score units.

DTI will be used to assess the change in average voxelwise FA throughout the pathways of the cortical navigation network from the Post1 to Post2 timepoints in FA z-score units.

The Kuyk Mobility Function Questionnaire for blindness and profound visual impairment will be used to assess the change in effects of training on everyday mobility from the Pre to the Post2 timepoints in terms of its standardized score.

The covariate of gender of the participants will be measured in three categorical values (male, intermediate, female).

The covariate of current level of vision of the participants will be measured with the Bailey-Lovey eyechart in Snellen units.

The covariate of age of onset of the current level of vision across of the participant will be measured in years.

Inclusion Criteria: Behavioral Studies: Vision from < 20/500 to NLP (No Light Perception) Brain Imaging Studies: Vision from < 20/500 to NLP Within average gender range for height +/-1 standard deviation Within average gender range for weight +/-1 standard deviation Comfortable with MRI procedures Exclusion Criteria: Behavioral Studies: Neurological deficits Inability to normally control lower or upper extremities Inability to hear and understand instructions. Brain Imaging Studies: All standard MRI exclusion criteria, such as having any metallic objects in the body, or being too large to fit or operate comfortably in the scanner bore.

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