Study Overview: This study tests a special computer-based program called CBCR (Cognitive-Based Cognitive Rehabilitation) that helps improve thinking skills, known as executive functions, in three groups: people who've had a stroke, a heart stoppage (cardiac arrest), or Parkinson's Disease.

Study Details: The study will involve 307 patients who will use computers for 8 weeks, 5 days a week, for 60 minutes each day. They will take tests to check their thinking skills before, right after the 8 weeks, and three months later. They will also answer questions about their quality of life and daily activities.

• Participants need to be 18 or older, have internet access, and must have had a stroke, cardiac arrest, or Parkinson's.
• The study requires commitment for 8 weeks, with daily training sessions.
• Participants' thinking skills will be tested multiple times to see any improvements.

Eligibility: People must have a recent diagnosis of stroke, cardiac arrest, or Parkinson’s and need to meet certain health criteria to join. They must also agree to participate in the study. Some individuals, like those with certain other health issues, may not be eligible.