Spatial Cognitive Training

The investigators will recruit 40 blind participants, randomized by the investigators' CVNR
statistician into two groups. One group will undergo the experimental intervention (spatial
cognitive training) and the other will undergo a control intervention involving letter-number
matching. The participants will include women and minorities in proportion to the
demographics of the Veteran population attending the Atlanta VA.

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.