Blindness, Blindness, Acquired, Blindness, Complete, Low Vision
Conditions
Keywords
blindness, plasticity, spatial memory, training, navigation
Brief summary
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.
Detailed description
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.
Interventions
BEHAVIORALCognitive-Kinesthetic Navigational Training
Training with tactile maps to improve spatial memory capability for enhanced navigational capabilities.
Sponsors
Smith-Kettlewell Eye Research Institute
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
Multiple regression analyses with life history and vision-related clinical factors as covariates
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Maintenance of change in GCC density in the cortical navigation network | 3-6 months | 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. |
| Change in blind map drawing errors from Pre to Post1 timepoints | 6-10 days | 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. |
| Maintenance of change in blind map drawing errors from Post1 to Post2 timepoints | 3-6 months | 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 | 6-10 days | 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 | 3-6 months | 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 | 6-10 days | 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 | 3-6 months | 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. |
| Change in functional MRI (fMRI) activation in the cortical navigation network | 6-10 days | 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. |
| Maintenance of change in fMRI activation in the cortical navigation network | 3-6 months | 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. |
| Change in functional MRI (fMRI) activation in the spatial working memory network | 6-10 days | 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. |
| Maintenance of change in fMRI activation in the spatial working memory network | 3-6 months | 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. |
| Change in Granger causal connectivity (GCC) density in the cortical navigation network | 6-10 days | 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. |
| Change in blind map drawing speed from pre-training (Pre) to immediate post-training (Post1) timepoints | 6-10 days | 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 | 3-6 months | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Maintenance of transfer of training to untrained spatio-cognitive abilities | 3-6 months | 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. |
| Change in Diffusion Tensor Imaging (DTI) in the cortical navigation network | 6-10 days | 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. |
| Maintenance of change in Diffusion Tensor Imaging (DTI) in the cortical navigation network | 3-6 months | 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. |
| Change in mobility self-assessment | 3-6 months | 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. |
| Transfer of training to untrained spatio-cognitive abilities | 6-10 days | 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. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Gender | Pre-training timepoint. | The covariate of gender of the participants will be measured in three categorical values (male, intermediate, female). |
| Age | Pre-training timepoint | The covariate of age of the participants will be measured in years. |
| Current level of vision | Pre-training timepoint | The covariate of current level of vision of the participants will be measured with the Bailey-Lovey eyechart in Snellen units. |
| Age of onset of current level of vision | Pre-training timepoint | The covariate of age of onset of the current level of vision across of the participant will be measured in years. |
| Duration of full vision | Pre-training timepoint | The covariate of duration of full vision of the participants will be measured in years. |
| Duration of Orientation and Mobility (O&M) training | Pre-training timepoint | The covariate of O&M training of the participants will be measured in years. |
Countries
United States
Contacts
Primary ContactLora T Likova
Backup ContactChristopher W Tyler
Outcome results
None listed