Transcranial Direct Current Stimulation for Post Treatment Lyme Disease

Inclusion Criteria: * History of diagnosis of Lyme disease by a health care provider, meeting criteria for either definite or probable or possible LD * Willingness to provide documentation of prior LD testing and/or related medical records * Total prior antibiotic treatment for LD was at least 2 courses of antibiotic therapy * Have cognitive symptoms attributed to Lyme disease that have persisted or returned despite antibiotic therapy * Current cognitive symptoms interfere with function and/or cause distress * Have evidence of slowed processing speed on a screening measure * Participant is willing to be off of antibiotic treatment for tick-borne disease for at least 4 weeks prior to final determination of study eligibility and for the duration of the 12-week study. * Participant expresses willingness to not start new medications that might affect treatment outcome during the trial (unless medically necessary), and willingness to inform study staff regarding any changes in medication * Live in the US or Canada and comfortable speaking English * Age 18-70 * Stable and continuous access to internet service * Adequate home facilities (enough space, access to quiet and distraction free area) * Able to commit to the 12-week study period (4 weeks of training sessions and an 8-week post treatment visit) * Estimated intellectual ability \>= 85 Exclusion Criteria: \- Medical Illness: Any of the following: a. Unstable non-Lyme-related chronic medical illness over the last 12 months (e.g., cancer, acute myocardial infarction, labile hypertension) b. Any severe skin disorder or skin sensitive area near stimulation locations (e.g. forehead) Neurologic: Any of the following: * History of traumatic brain injury with persistent post-concussive symptoms * History of seizure disorder or recent (\<5 years) seizure history * History of neurosurgery to the head * Chronic headaches or migraines of moderate to severe intensity within the last month * Post stroke deficits that may interfere with assessment * Any progressive neurodegenerative disorder or other neurological disorders that may interfere with assessment at discretion of the investigator. Psychiatric: Any of the following: * History of intellectual disability, or other developmental neurological condition associated with cognitive impairment * Current primary psychiatric disorder that would interfere with ability to participate * Current alcohol or other substance use disorder * Current suicide risk as assessed by the C-SSRS (any level) * History of suicidal behavior over the last year * History of a diagnosis of a psychotic disorder, mania or bipolar disorder * Depression rating of moderate or severe at screening * Currently taking opiate-based medications, dissociative drugs (prescribed or illicit), or other medication considered likely to interfere with treatment outcome at the discretion of the investigator. The use of a stable dose of benzodiazepines, anticholinergic agents and non-narcotic pain medications is permitted. The use of an occasional dose of these medications is also permitted, but not within 48 hours of neurocognitive study assessments. * Participants whose current daily medication regimen has not been stable for a minimum of 4 weeks prior to final determination of study eligibility * Medical device implanted in the head (such as a Deep Brain Stimulator) or in the neck (such as a Vagus Nerve Stimulator), or metal implants in the head or neck * Inadequate visual or motor skills needed for regular computer use or to operate study equipment, or inability to provide informed consent * Individuals who are pregnant or breastfeeding or planning to become pregnant * Lifestyle Considerations: Participants not willing to refrain from beginning, resuming or increasing non study cognitive training or cognitive enhancing supplements/medications or other therapies that might affect treatment outcome