Spatial Cognitive Training (SCTVI)

Inclusion Criteria:

• Inability to perceive visual stimuli, i.e. no light perception, with stable visual loss over the past year

• The investigators anticipate that causes of blindness will be ocular, including:

  • glaucoma
  • diabetic retinopathy and macular degeneration
  • the most common causes of blindness in Veterans
  • as well as possibly late-onset Leber's optic atrophy and ocular trauma (in the absence of TBI)
• To minimize heterogeneity due to variations in age and the duration of visual loss, the investigators will restrict enrollment to Veterans and Non-Veterans over the age of 50 who lost light perception within the last 5 years, and who have completed standard O&M training.
• From a practical standpoint, this also enables the investigators to focus on participants who can potentially benefit most from the proposed intervention.

Exclusion Criteria:

• Participants will be excluded if they have any neurological condition, such as:

  • TBI
  • history of blast exposure
  • stroke
  • brain tumors
  • epilepsy, etc.

• Participants will also be excluded if MRI scanning is contra-indicated, e.g.:

  • due to an implanted device such as a pacemaker
  • or foreign bodies of ferromagnetic nature
• Cognitive screening will be performed using the Repeatable Battery for Assessment of Neuropsychological Status (RBANS, Randolph, 1998) and participants with cognitive impairment will be excluded based on a score of 1.5 SD below the mean for the Verbal Memory Index.
• The investigators will test participants' hearing using a validated screening questionnaire (Screening Version of the Hearing Handicap Inventory for the Elderly, HHIE-S, Wentry & Weinstein, 1983, Lichtenstein et al., 1988) followed by assessment of audiometric pure tone (0.5, 1.0, 2.0, 4.0 KHz) hearing thresholds in the CVNR sound booth.
• Participants with more than mild hearing loss (HHIE score >8 or audiometric thresholds >40dB) will be excluded (Wentry & Weinstein, 1983; Wilson, 2009), given that the investigators are relying on audio cues.
• The investigators will also exclude visually impaired Veterans who are dependent on a wheelchair or scooter for mobility, as they will not be able to take part in the real-world task.