COMPuter-assisted Self-training to Improve EXecutive Function

Inclusion Criteria: * A diagnose of stroke, cardiac arrest or Parkinson's disease. * Aged 18 years or older. * Impaired working memory measured with CABPad working memory test, cut off for inclusion: 5 symbols or less backwards * Computer and internet access at home. * Providing informed consent. Inclusion criteria specific for stroke * Inclusion within 6 months post-stroke * Stroke confirmed by clinical findings and imaging, both AIS and ICH is allowed. * Initial stroke severity \>/= NIHSS 3. Inclusion criteria specific for cardiac arrest • Inclusion within 6 months post ictus. Inclusion criteria specific for Parkinson's disease * Clinical diagnosis of PD. * Anti-parkinsonian medical treatment (dopaminergic or other). Exclusion Criteria: * Informed consent not provided * Other neurological or psychiatric disease which is expected to influence the patient's ability to participate in the trial according to the investigator * Not able to participate according to investigator Exclusion criteria specific for stroke * Patients with massive anosognosia for executive dysfunction or patients with no subjective feeling of executive dysfunction (Patient sustains total denial of executive symptoms over time) * Patients with severe aphasia, in which it is unclear whether the patient's performance on a neuropsychological test-battery is due to aphasia and not executive dysfunction. Exclusion criteria specific for cardiac arrest • None Exclusion criteria specific for PD • Diagnosis of PD Dementia according to the MDS PD Dementia criteria