Inclusion Criteria:  Ages 22 to 65 Any gender Diagnosis of PTSD, established according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V) 1 to 20 years since index trauma Ability to give signed, informed consent Normal or corrected-to-normal vision Normal or corrected to normal hearing Subject is able to adhere to the study schedule  Exclusion Criteria:  Have completed two or more full courses of trauma-focused therapy in the past (i.e., EMDR, Prolong Exposure Therapy, etc.), eligibility will be deemed upon the clinical judgment of the investigator. Lifetime diagnosis for schizophrenia, schizoaffective disorder, schizophreniform disorder, Bipolar I disorder, or delusional disorder Any mood disorder and anxiety disorder according to DSM-5 (in addition to those described in Exclusion 2) that is the primary focus of treatment in the last 6 months prior to screening, as per the clinical judgment of the investigator Lifetime diagnosis of autism, mental retardation at the discretion of the investigator. Diagnosis of moderate or severe substance use disorder within the last 3 months of screening visit (as defined in DSM-5-substance use disorder) or at screening visit Any prescribed Benzodiazepine which cannot be ceased for the duration of the study (with a washout period of at least 2 weeks prior to the first Prism training session) or which cannot be replaced with short-acting benzodiazepines that are taken only for sleeping during the night Any psychotropic medication other than a stable dose of selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitor (SNRIs) Any change in or initiation of- SSRIs or SNRIs antidepressants within the past 4 weeks. At the time of recruitment, subjects must have no intention of changing their medication or psychotherapy during the study duration Any suicidal behavior in the past 1 year (i.e. actual attempt, interrupted attempt, aborted attempt, or preparatory acts or behavior) prior to screening and during the screening period Recent initiation (within the past 3 months) of cognitive-behavioral therapy or any evidence-based PTSD psychotherapy (Cognitive Processing Therapy [CPT], Prolonged Exposure [PE], Eye Movement Desensitization and Reprocessing [EMDR]); continuation of established maintenance supportive therapy will be permitted Any history of brain surgery, of penetrating, neurovascular, infectious, or other major brain injury, of epilepsy, or of other major neurological abnormality (including a history of traumatic brain injury [TBI] with loss of consciousness for more than 24 hours or posttraumatic amnesia for more than 7 days) Any unstable medical condition, as per the clinical judgement of the investigator In process of establishing/changing governmental/institutional compensation payments for PTSD symptoms Enrollment in another clinical study at screening or within 2 months prior to screening, or intended enrollment within the duration of this study Women who are pregnant, nursing, or who plan to become pregnant while in the trial